Scientific Program

Conference Series Ltd invites all the participants across the globe to attend 7th Annual Congress on Materials Research and Technology Berlin, Germany (Golden Tulip Berlin Hotel Hamburg).

Day 1 :

Keynote Forum

Jim De Yoreo

University of Washington, USA

Keynote: Investigating materials formation with liquid-phase TEM

Time : 08:25-08:50

Materials Research 2017 International Conference Keynote Speaker Jim De Yoreo photo
Biography:

Jim De Yoreo is a Chief Scientist for Materials Science at Pacific Northwest National Laboratory (PNNL) and Affiliate Professor of Materials Science and Engineering at University of Washington. He completed his PhD in Physics at Cornell University in 1985. Following Post-doctoral work at Princeton University, he became a Staff Member at Lawrence Livermore National Laboratory, where he held numerous positions. He joined Lawrence Berkeley National Laboratory in 2007, serving as Interim Director of the Molecular Foundry before moving to PNNL in 2012. His research focuses on “Interactions, assembly and crystallization in inorganic, bio-molecular and bio-mineral systems”. He has authored over 220 publications and is a recipient of the MRS David Turnbull Lectureship.

Abstract:

Nucleation is the seminal process in the formation of ordered structures ranging from simple inorganic crystals to macromolecular matrices. Observations over the past 15 years have revealed a rich set of hierarchical pathways involving higher-order species ranging from multi-ion clusters to dense liquid droplets, as well as transient crystalline or amorphous phases. These non-classical pathways are diverse, in contrast to those of classical models that consider only addition of monomeric chemical species. Despite their complexity, a holistic framework for understanding particle-based pathways both during the nucleation and growth phases that extends classical concepts emerges when the coupled effects of complexity in free energy landscapes and the impact of dynamical factors governing particle formation and interaction are considered. Here, I describe that framework and use of a series of in situ TEM studies on inorganic and macromolecular systems to illustrate the evolution in nucleation and growth processes as these complexities and dynamical factors come into play. The introduction of either size-dependent phase stability associated with the high surface-to-volume ratios of nanoparticles, or high driving force coupled with the existence of metastable polymorphs leads to true two-step pathways characterized by the initial appearance of bulk precursor phases. Creation of micro-states, which represent local minima in free energy stabilized by configurational factors can also lead to hierarchical pathways, but the intermediates are transient states not present in the bulk phase diagram. In either of these cases, reduction in molecular mobility, either through reduced temperature or introduction of ion-binding macromolecules, can freeze non-equilibrium states into place for dynamical reasons. However, even when energy landscapes are smooth, high driving force creates dynamic factors that lead to hierarchical pathways through post-nucleation interaction and assembly of nanoparticles. Many of these processes can occur concurrently or sequentially in a single system.

Keynote Forum

Gerd Kaupp

University of Oldenburg, Germany

Keynote: ISO-standards 14577 violate the first energy law: Can we further live with that?

Time : 08:50-09:15

Materials Research 2017 International Conference Keynote Speaker Gerd Kaupp photo
Biography:

Gerd Kaupp studied Chemistry at University of Würzburg, Germany and completed his Post-doctoral studies at Albert Ludwigs University of Freiburg, where he appointed as an Associate Professor. He was appointed as Full Professor at University of Oldenburg in 1982. He guided a successful research group with various projects and cooperation with numerous industries and worldwide academic research groups. He served as Guest Professor for three international universities. He is now a retired member at University of Oldenburg. He has expertise in “Chemical kinetics, laser photochemistry, waste-free benign syntheses and productions, solid-state chemistry, reactive milling, mechanochemistry, atomic force microscopy AFM, scanning near-field optical microscopy SNOM, nano-scratching, nano-indentation, standardization in nano-mechanics and bionics”.

Abstract:

The precise mathematical deduction from 2013 of the indentation work contribution that is lost for the penetration reveals that all the standards under ISO-14577 violate the first energy law. This concerns the definition of ISO-hardness and reduced modulus and also deduced further mechanical parameters. And also the recently published physical foundation of the experimentally validated (since 2003 by the author) exponent 3/2 on the depth h for pyramidal indentations, creates dilemma for industry and security agencies, while ISO still dictates exponent two in relation to the applied normal force FN, as in Sneddon-citing textbooks. They have to obey ISO standards with legal character, even though physics tells differently. Even  NIST (US member of ISO) published six new mechanical parameters in a tutorial that continues distributing false physics using exponent two and energy-law violation. We must thus urgently try to change that situation, because falsely calculated mechanical properties severely harm all public in daily life, in medicine (implants), and techniques. Material's compatibilities (including solders) and mechanical stress are ubiquitous, to name a few. Material's failures have been claimed as fatigue of materials, rather than calculations against physics and violating the energy-law. Errors are also with finite element simulations always resulting with exponent two, not noticing phase transitions with their onset and energy, nor surface effects. These are only recognized when applying exponent 3/2, but not by polynomial curve fittings, or best exponent iterations. Almost all mechanical parameters require re-deduction on the basis of the correct exponent. ISO-hardness H and ISO-modulus Er are triply flawed: Violating energy law, false exponent and often unconscious characterization after phase transitions. All materials require genuine and reliable physical characterization! Thus, physical H, Er and other parameters (adhesion energy, etc.) must be deduced. This will be addressed upon, and unexpected applications will be presented.

Keynote Forum

Xiang Zhang

University of Cambridge, UK

Keynote: New concept of bioresorbable polymer-based ceramic hybrids for cardiovascular stent applications

Time : 09:15-09:40

Materials Research 2017 International Conference Keynote Speaker Xiang Zhang photo
Biography:

Xiang Zhang is a Royal Society Industry Fellow at University of Cambridge. He has over 34 years combined academia (17 years) and industrial (17 years) experience in Advanced Materials Science and Technology. He is an expert in Polymer and Polymeric Hybrid Materials Science and Technology. He is Head of Lucideon Cambridge School of Advanced Materials. He is an author of three books: “Inorganic Biomaterials; Inorganic Controlled Release Technology and Science” and; “Principes of Biodegradable” and “Bioresorbable Medical Polymers - Materials and Properties”. He completed his PhD and Post-doctoral research at Cranfield University where he studied “Materials physics, nano/micro-mechanics and nano/micro-fracture mechanics of polymeric hybrid (organic and inorganic) materials”.

Abstract:

This presentation will introduce new theories and industry practice for design and development of polymer-based ceramic hybrids. The evolution from pure polymer-based medical devices to polymer-based ceramic hybrids is to meet unmet market needs for better clinical performance over existing systems. There are many factors that can affect medical implant performance and, historically, most of them have been well studied, such as bioactivities and biocompatibility. In this presentation, new concept will be mainly addressing issue surround biomechanics, bio-fracture mechanics and bio-functionality for design and development of new hybrid biomaterials for implant applications. It will report the principles on formulations for two types of the new systems. One family is of biodegradable and bioresorbable hybrids and 2nd is of non-biodegradable hybrids. It will be followed by design and development of medical devices in view of industry practice with clinical performance considerations of medical devices. The main topics covered in the presentation include: New concepts and synthetic pathway of polymer-based ceramic hybrids; nano/micro mechanics and nano/micro fracture mechanics; industry practice – two case studies will be used to demonstrate on how to design and develop polymer-based ceramic hybrid biomaterials and relevant processing technology for the applications of medical implants. Cardiovascular stent, as an example is traditionally made of metal such as bare metal stents (BMS) or with drug coatings, i.e. drug eluting stents (DES). There are, however, clinical complications associated with these technologies, such as, early stage restenosis, very late thrombosis and risk associated with revision surgery. In light of these challenges research focus has turned to the development of bioresorbable vascular scaffold (BVS) technologies. We have developed new bioresorbable polymer-based ceramic stent that has been reinforced resorbable therapeutic cardiovascular stent to address the known limitations of cardiovascular technologies. We have developed a bioresorbable stent with intrinsic toughness for handling and deployment via balloon angioplasty, radial strength, controlled drug-release technology to suppress restenosis and surface functionalization to promote endothelialization to reduce risk of thrombosis. We present the novel synthetic polymer-ceramic composites developed as candidate stent-core materials, both their preparation and the characterization of their mechanical behavior, in vitro degradation will be presented.

Keynote Forum

Hyoyoung Lee

Sungkyunkwan University, South Korea

Keynote: Graphene flake and graphene quantum dot-receptor sensor for detecting nerve agents

Time : 09:40-10:05

Materials Research 2017 International Conference Keynote Speaker Hyoyoung Lee photo
Biography:

Hyoyoung Lee completed his PhD in Department of Chemistry at University of Mississippi, USA in 1997. He held Post-doctoral Associate position at North Carolina State University, USA, for two years. He worked at Electronics and Telecommunications Research Institute from 2000 to 2009 as Team Leader. He moved to Sungkyunkwan University and has served as a Full Professor at Department of Chemistry, lecturing organic chemistry. He served as a Director of National Creative Research Initiatives, Center of Smart Molecular Memory from 2006 to February, 2015. Currently, he is serving as an Associate Director of Centre for Integrated Nanostructure Physics, Institute of Basic Science from November 2015. His current research area includes “Organic semiconducting materials and devices including molecular/organic memory, OLED, OTFT, sensors, energy harvesting and storage, graphene oxide, reduced graphene oxide, and 2D transition metal chalcogenide”. He has written more than 120 journal articles with top-tier journals.

Abstract:

A novel gas sensor consisting of porous, non-stacked reduced graphene oxide (NSrGO)-heaxfluorohydoroxypropanyl benzene (HFHPB) nanosheets was successfully fabricated, allowing the detection of dimethyl methyl phosphonate (DMMP), similar to sarin toxic gas. The HFHPB group was chemically grafted to the NSrGO via a diazotization reaction to produce NSrGO-HFHPB. The NSrGO-HFHPB 3D film has a mesoporous structure with a large pore volume and high surface area that can sensitively detect DMMP and concurrently selectively signal the DMMP through the chemically-attached HFHPB. The DMMP uptake of the mesoporous NSrGO-HFHPB was 240.03 Hz, 12 times greater than that of rGO-HFHPB (20.14 Hz). In addition, the response rate of NSrGO-HFHPB was faster than that of rGO-HFHPB, an approximately 3 times more rapid recovery due to the mesoporous structure of the NSrGO-HFHPB. In addition we like to present a band gap tuning of environmental-friendly graphene quantum dot (GQD) for a photoluminescence (PL) sensor. With the help of the electron withdrawing HFHPB group, the energy band gap of the HFHPB-GQD was widened and its PL decay life time decreased. As designed, after addition of dimethyl methylphosphonate (DMMP), the PL intensity of HFHPB-GQD sensor sharply increased up to approximately 200% through a hydrogen bond with DMMP. The fast response and short recovery time was proven by quartz crystal microbalance (QCM) analysis. This HFHPB-GQD sensor shows highly sensitivity to DMMP in comparison with GQD sensor without HFHPB and graphene. In addition, the HFHPB-GQD sensor showed high selectivity only to the phosphonate functional group among many other analytes and also stable enough for real device applications. Thus, the tuning of the band gap of the photo-luminescent GQDs may open up new promising strategies for the molecular detection of target substrates.

Break: Coffee Break 10:05-10:20 @ Sylt Foyer
  • Materials Science and Engineering | Materials in Industry
Location: Sylt 3

Session Introduction

Nekane Guarrotxena

Spanish National Research Council, Spain

Title: Smart functional nanoscale-hybrid materials: Surface modification and applications

Time : 10:20-10:40

Biography:

Nekane Guarrotxena completed her PhD at University of Complutense, Madrid-Spain and Post-doctoral research at Ecole Nationale Superieure d´Arts et Metiers (ENSAM), Paris-France and University of Science II, Montpellier-France. She was a Vice-Director at Institute of Polymer Science and Technology (ICTP-CSIC) from 2001 to 2005 and; Visiting Professor at University of California, Santa Barbara-USA and University of California, Irvine-USA from 2008 to 2011. Currently, she is a Research Scientist at ICTP-CSIC (Spain); an Editorial Board Member of some Materials Science and Chemistry journals and; an External Expertise Consultant on I+D+I management policy for national and international agencies. Her research interest focuses on “The synthesis and assembly of hybrid nanomaterials, nanoplasmonics, and their uses in nano-biotechnology applications (bio-imaging, drug delivery, therapy and bio-sensing)”.

Abstract:

The unique feature to respond to small changes in its environment, usually reversibly, has made the stimuli-responsive polymers very promising in the generation of smart materials for medical and engineering applications. Very interesting and appealing seems to be their combination with inorganic nanoparticles to yield nano hybrids which combine the interesting and intriguing properties of the individual components, modify them, or exhibit novel properties. Within this presentation, we want to highlight some of our recent progress in their successful integration via multidentate grafting to conjugation which accomplishes the highly desirable features, such as hydrodynamic size compression, amphiphilic, pH- and thermo-responsiveness, and enhanced optical properties for future biological and technological applications of our functional nano hybrids.

Petr Vasina

Masaryk University, Czech Republic

Title: Ductile behavior of hard MoBC and WBC nano laminated coatings

Time : 10:40-11:00

Biography:

Petr Vasina completed his PhD in 2005 at Université Paris-Sud in discipline Waves and Matter and at Masaryk University in discipline Plasma Physics. He works at Masaryk University, Brno, Czech Republic. He is a Senior Researcher; a Group Leader at CEPLANT Research Center; Associate Professor and; Deputy Director of Department of Physical Electronics, Faculty of Sciences. His primary research areas are “Study of elementary processes in discharges, diagnostics and modeling of reactive plasmas, study and development of deposition processes and their application for thin film deposition, high power impulse magnetron sputtering and deposition of nanostructured composite materials”. He has published more than 40 peer-reviewed papers and he is a Co-inventor of a patent.

Abstract:

State-of-art ceramic materials nowadays used as protective coatings such as TiN, TiAlN, c-BN, etc., generally exhibit high hardness and high stiffness. These positive features are often accompanied by negative brittle deformation behavior. To overcome this limitation, a new generation of materials with high hardness and moderate ductility is desired. Recently, there has been an increased interest in boron and carbon based nanolaminates such as Mo2BC. According to the ab-initio models, these materials were predicted to exhibit unusual combination of high stiffness and moderate ductility. The coatings were deposited either by DCMS at extremely high substrate temperature of 900°C or at moderate temperature of 380°C employing HiPIMS. In our research, co-sputtering of Mo (W), C and B4C targets to finely tune the coating composition of Mo2BC and W2BC was used. Mid-frequency pulsed DC plasma excitation was employed to enhance the ion flux on the substrate by factor of three compared to DCMS case which promoted the crystallization of Mo2BC. Coatings with the same XRD patterns as those deposited by HiPIMS at the same substrate temperature were prepared. The moderate deposition conditions resulted in growth of partially crystalline Mo2BC coatings with nano composite structure where small Mo2BC crystallites of approx. 10 nm sizes were embedded in an amorphous matrix. These coatings showed high hardness of 31.6±0.8 GPa and extremely high fracture toughness– it was even impossible to form a crack in these coatings at extremely high indentation load with cube corner indenter where both the coatings and the underlying hard-metal substrate were severely plastically deformed. Only a shear/slip plane defects typical for ductile materials were detected. This required ductile behavior of hard coating observed for partially crystallite Mo2BC with nano composite structure.

Biography:

Kislon Voïtchovsky is currently an Associate Professor (Senior Lecturer) at Durham University, UK. His research focuses on “Molecular-level phenomena occurring at solid/liquid interfaces”. He is particularly interested in mesoscale effects (1-10 nm) that occur at the boundary between atomistic and continuum descriptions of the liquid. Such effects tend to occur in systems where the solid is structurally and chemically  heterogeneous on the nanoscale and can give rise to unforeseeable phenomena, often induced by molecular group effects. He is an expert in Atomic Force Microscopy in Liquid and developed an experimental approach to map the local behavior of interfacial liquids with sub-nanometer precision.

Abstract:

At the interface with solids, liquid tend to behave differently than in bulk. The interaction of the liquid molecules with the surface of the solid and their loss of configurational entropy often results in this interfacial liquid being more ordered and less mobile than its bulk counterpart, with dramatic consequences for the behavior of dissolved molecules and ions. The nanoscale organization and dynamics of interfacial liquids is key to countless processes from lubrication to protein function, heterogeneous catalysis, crystal growth and self-assembly. Experimentally little is known about the behavior of the interfacial liquid at the molecular level, partly for lack of technique able to gather in-situ local information, including over inhomogeneous interfaces. Atomic force microscopy (AFM) can in principle overcome this difficulty and provides sub-nanometer maps of the solvation landscape and the local solid-liquid affinity. Because the measurement is dynamical, more information can be derived about the nanoscale flow of the liquid parallel to the solid. Here, I present studies investigating the unusual dynamics of ions and small molecules at the interface with minerals in solution using a combination of high-resolution AFM and molecular dynamics simulations. I show that hydration water can drive the  selfassembly of counter-ions, control adsorption of molecules such as stearate and nitrate, and dominate the surface restructuring of the solid. Tracking the dynamics of single atomic sites in solution shows remarkably slow changes ranging in the millisecond time-scale. Interfacial self-assembly of the liquid itself can also be achieved, for example, when using homogenous solutions comprising two pure liquids such as water and alcohol. The resulting solid-like nanostructures are remarkably stable and comprise both types of molecules. These structures can be exploited for controlled self-assembly and the development of functional interfaces.

Biography:

Emad Mowafy has expertise in Solvent Extraction Technology. He designed, developed and evaluated many novels organic and inorganic ion exchanger advanced materials for selective recovery and separation of economic and strategic elements from their aqueous waste solutions. Most of these new designed extractants can be utilized in different industrial fields. These new designed reagents have many advantages (speed kinetic, high stability, selectivity and solubility in organic diluents) compared with most commercial ligands.

Abstract:

Recovery and separation of palladium from their aqueous waste solutions is one of the most important subject from economic and environment viewpoints. In fact, palladium is a very rare metal in the Earth's crust, the worldwide reserves being localized in very few countries. Therefore, the amount of palladium that can be recovered from the so-called secondary resources, that is, recycling of catalytic converters and electronic scrap, is very important. For this purpose, many ligands have been developed and used during the last decades. These ligands have many limitations (e.g. slow kinetic, poor solubility and instability in acidic medium etc. To overcome the situation, it becomes imperative to look for other classes of extractants. Within this context, the present study focusing on using N,N,N',N'-tetra-substituted dithiodiglycolamide derivatives as a novel and promising solvent extraction reagents to mainly perform the separation of Pd from other PGMs and from some commonly associated elements contained in concentrated hydrochloric acid. Liquid–liquid batch extraction studies were investigated to understand the influence of various parameters on the extraction behavior of palladium. They showed great extractability and selectivity for palladium than the other investigated metal ions, which showed negligible extraction values. On the other hand, the novel ligands could be a potential candidate for separation and recovery of palladium from spent catalyst dissolver (SSCD) solution.

Biography:

Abstract:

Depending on the material structure and the indentation device capabilities, it’s often not possible to measure the true coating parameters without any underlying material effect. SIO developed a model and a dedicated software package called Oliver & Pharr for Coatings which allows the determination of true generic material parameters for a coating by knowing the parameters of the substrate and all underlying layers. To apply this approach to a complex multilayer stack of different materials, one needs to stop the production process after every added layer. Then the indentation measurements are performed to determine the material parameters for the top coating. This analysis is repeated for every layer in a possibly very complex coating structure. This approach has severe drawbacks: Firstly, it’s not always possible to coat the complete structure layer by layer and perform the measurements after a layer is added. Secondly, it's possible that during the coating process the parameters of the underlying layer are changed, because of some interface effects. Because the calotte grinding tests are widely used to determine the layer thicknesses, SIO thought about using the possibility to directly access the deeper parts of a complex layer stack by applying a combination of calotte grinding and subsequent indentation testing. We created a new module which analyzes a series of indentation measurements which were performed from the inside to the outside of the calotte test crater. So, it’s possible to perform tests on the substrate and all layers. It was built into the software package FilmDoctor® which subsequently analyzes such a measurement series starting with the substrate measurements. All evaluated values are used for the next iteration step of the new analysis method. At the end the material parameters for all layers are determined without the need of stopping or changing the production process.

Biography:

Lei Zhang is an Associate Professor of Physics at Winston Salem State University. He completed his PhD in Applied Physics and has expertise in Optics and Materials. His research interest includes “Electro-optical properties of crystalline materials, fiber-optics devices, micro-hardness of crystals, carbon nanofibers, polymer micelles and thin films”. He was working on a National Science Foundation (NSF) sponsored MRSEC program to develop and optimize IZO thin films in room temperature. The result shows that the electrical conductivity and optical transparency in IZO thin film deposited by radio frequency magnetron sputtering are similar to these of ITO.

Abstract:

Transparent Conducting Oxide (TCO) thin films of In2O3, SnO2, ZnO, and their mixtures have been extensively used in optoelectronic applications such as transparent electrodes in solar photovoltaic devices. In this project, I deposited amorphous Indium–Zinc Oxide (IZO) thin films by radio frequency (RF) magnetron sputtering from a In2O3–10 wt.% ZnO sintered ceramic target to optimize the RF power, argon gas flowing rate, and the thickness of film to reach the maximum conductivity and transparency in visible spectrum. The results indicated optimized conductivity and transparency of IZO thin film is very closer to ITO’s conductivity and transparency, and is even better when the film was deposited with one special tilted angle.

Biography:

Vijaya Kumar has his expertise in “Microgravity materials science and conducting experiments using space environment”. His research area includes “Solidification, crystal growth, measurement of thermo-physical properties and conducting experiments using space environment”. He worked at Japan Aerospace Exploration Agency (JAXA), Japan and NASA, Tufts University, USA. He has built the container less levitation facility for controlling the atmosphere and also to create a microgravity environment on earth. Using these facilities, he has developed new metastable materials, multiferroic composites, metastable phase diagrams, high refractive index glass and so on.

Abstract:

Recently, research on bulk glass and glass-ceramics has attracted the attention due to their low cost optical materials of the future. Alumina based ceramics have wide significant applications because of their refractory nature, high hardness, high strength, transparency in the infra-red region and resistant to chemical attack. Conventionally, rare earth perovskites were prepared by melting process or by sintering techniques because of their refractory nature and recently prepared through several low temperature solution routes. Conventionally, it is difficult to vitrify them without using the network forming agents. In this study, Aero-Dynamic Levitator (ADL) was used to undercool the melt well below the melting temperature. The formation of bulk spherical glass and crystalline RAlO3 (R=rare-earths) phases has been investigated due to their unique features in terms of the solidification process, glass structure and optical properties. RAlO3 sample was levitated by an ADL and completely melted by a CO2 laser and then cooled by turning off the CO2 laser and solidified. Among the rare earth aluminum perovskites, La, Nd and Sm aluminum perovskites solidified as glass and Eu to Lu aluminum perovskites solidified as crystalline phases. The NdAlO3 glass phase showed a high refractive index of ~1.89, suggesting that container less levitation is an elegant technique for fabrication of new glass and crystalline ceramics from an undercooled melt.

Biography:

Thendralarasu Udhayakumar is a Research Engineer in the field of Materials Science and Metallurgy; he is currently employed at Corporate Technology Centre, R & D division of Tube Investments of India Ltd. His key areas of research interest include “Material selection, heat treatment of HF welded tubes and cold drawn tubes, process optimization for typical tubular components and material characterization”. He is currently working in the development of wear resistant grades for the agricultural industry.

Abstract:

Micro alloyed HSLA steels continue to evolve and grow in application, particularly in automotive industry. Welded tubular components made of micro alloyed HSLA steel grades are highly emerging and manufacturing them is quite challenging. Generally micro alloyed grades exhibit higher strength & formability owing to the presence of fine recrystallized ferritic grains due to thermo mechanical treatment. This study deals with the material characterization and process optimization works involved in the development of electric resistance high frequency welded micro alloyed HSLA steel tubes for twist beam application with enhanced torsional performance. Difficulties in the high frequency (HF) welding of the HSLA tubes have also been discussed. Weld bond width, HAZ width and bond angle are the significant factors that directly influences the weld quality and strength. The effect of key welding parameters like heat input, welding temperature, squeeze roll pressure, vee-angle, vee-length and impeder diameter on the above mentioned significant factors was analyzed. Samples processed with different welding parameters were subjected to critical forming operation and it was seen that narrow bond, minimum HAZ width with pronounced hour glass pattern and optimum bond angle resulted in superior bond strength & formability. Microstructural characterization was done using light optical microscopy and scanning electron microscopy. Residual stress is very critical since the tubes will undergo torsional fatigue during application. Residual stress was determined using X-ray diffractometer and tube slitting method. Higher tensile residual stress of magnitude 200 MPa was observed in the weld region. Since such high magnitude of tensile residual stress is detrimental to torsional fatigue life, stress relieving of the tubes was carried out. Stress relieving was done at different subcritical temperatures 600°C, 650°C & 700°C with different soaking time. Without significant drop in the tensile properties, compressive residual stress of magnitude 129 MPa was observed at a particular stress relieving cycle. This would eventually lead to improvement in fatigue life. Thus, high frequency welded micro alloyed HSLA steel tubes with enhanced torsional fatigue performance were successfully developed.

Break: Lunch Break 13:00-13:30 @ Restaurant Rienacker
Biography:

Thendralarasu Udhayakumar is a Research Engineer in the field of Materials Science and Metallurgy; he is currently employed at Corporate Technology Centre, R & D division of Tube Investments of India Ltd. His key areas of research interest include “Material selection, heat treatment of HF welded tubes and cold drawn tubes, process optimization for typical tubular components and material characterization”. He is currently working in the development of wear resistant grades for the agricultural industry.

Abstract:

Micro alloyed HSLA steels continue to evolve and grow in application, particularly in automotive industry. Welded tubular components made of micro alloyed HSLA steel grades are highly emerging and manufacturing them is quite challenging. Generally micro alloyed grades exhibit higher strength & formability owing to the presence of fine recrystallized ferritic grains due to thermo mechanical treatment. This study deals with the material characterization and process optimization works involved in the development of electric resistance high frequency welded micro alloyed HSLA steel tubes for twist beam application with enhanced torsional performance. Difficulties in the high frequency (HF) welding of the HSLA tubes have also been discussed. Weld bond width, HAZ width and bond angle are the significant factors that directly influences the weld quality and strength. The effect of key welding parameters like heat input, welding temperature, squeeze roll pressure, vee-angle, vee-length and impeder diameter on the above mentioned significant factors was analyzed. Samples processed with different welding parameters were subjected to critical forming operation and it was seen that narrow bond, minimum HAZ width with pronounced hour glass pattern and optimum bond angle resulted in superior bond strength & formability. Microstructural characterization was done using light optical microscopy and scanning electron microscopy. Residual stress is very critical since the tubes will undergo torsional fatigue during application. Residual stress was determined using X-ray diffractometer and tube slitting method. Higher tensile residual stress of magnitude 200 MPa was observed in the weld region. Since such high magnitude of tensile residual stress is detrimental to torsional fatigue life, stress relieving of the tubes was carried out. Stress relieving was done at different subcritical temperatures 600°C, 650°C & 700°C with different soaking time. Without significant drop in the tensile properties, compressive residual stress of magnitude 129 MPa was observed at a particular stress relieving cycle. This would eventually lead to improvement in fatigue life. Thus, high frequency welded micro alloyed HSLA steel tubes with enhanced torsional fatigue performance were successfully developed.

Robert Beckenlechner

University of Stuttgart, Germany

Title: Graphite based minimum quantity dry lubrication at drilling CFRP

Time : 13:50-14:05

Biography:

Robert Beckenlechner has studied Mechanical Engineering at University of Aalen. He has been working as a Research Fellow in Department for Lightweight Construction Technologies in cooperation with Institute for Machine Tools at University of Stuttgart since 2014. He is investigating new cooling and lubricating technologies for the machining of lightweight materials, especially for fiber reinforced plastics.

Abstract:

The machining of carbon fiber reinforced plastic (CFRP) causes high tool wear and thus induced costs. One approach is to use liquid cooling lubricants e.g., Minimum Quantity Lubrication (MQL), as known from metal cutting. Due to the unlimited types of CFRP and cooling lubricants, chemical interactions between them cannot be excluded. The humidity of cooling lubricants can also affect the mechanical properties of the CRFP, like a softening of the matrix. An additional consequene can be a reduced fiber-matrixadhesion which results in lower fracture toughness. Therefore, this article presents a new MQL technology, which is completely dry. For this purpose, a prototypical fluidization device was constructed. It boosts minimal amounts of graphite powder by using compressed air to the cutting zone between the tool and work piece. Graphite was selected as dry lubricant because of three reasons: First, graphite can be used as a dry lubricant; second, the contamination by graphite powder is not relevant as the dust and chips from the cutting process are extracted by exhaustion anywhere and; third, chemical interactions between the carbon fibers and graphite are not to be expected. By spraying tests with internally cooled drills, it was shown that the current fluidization device is already able to deliver graphite mass flows less than 3 g/h reliably. First drilling tests with internal MQDL-supply have shown a significant reduction in tool wear, compared with cooling by pure compressed air. Finally, a H2O-enrichment device was constructed to extend the fluidization prototype. The aim is to include foreign molecules in the lattice structure of the graphite by using H2O-molecules. As described in literature, the sliding characteristics of graphite are improved by these additional molecules. The H2O-enrichment device is able to achieve almost a 90% relative humidity of the compressed air that is used to transport the graphite.

Biography:

Chinmayananda Gouda completed his BS and MS in Organic Chemistry at Berhampur University in 2008 and in 2012, respectively. In 2013, he joined Laboratory of Prof. Hong-Cheu Lin at National Chaio Tung University, Taiwan, to pursue his PhD in Materials science and Engineering. His current research interests are focused on “Synthesis and assembly of crown-ether cycle, molecular recognition and linear supra molecular polymer based on host-guest chemistry.

Abstract:

We report the construction of novel host H1 and guest G1 consisting TPE and BODIPY linked together with the dibenzo- 24-crown-8 macro cycle and secondary ammonium salt respectively for the host guest interactions. As a proof of concept recognition of secondary ammoniums by 24-crown-8 macro cycle resulted a linear supramolecular polymer (pseudorotaxanes) in situ where the main chain was composed of TPE and BODIPY as a donor-acceptor pair. Occurrence of intra molecular FRET from TPE to BODIPY and related prominent changes into absorption bands determined the stoichiometric ratio as the primary evidence of polymerization which were then further confirmed by 1H-NMR and other spectroscopic techniques. Moreover, interaction of host macro cycle with K+ ion destructed the supramolecular polymer formation, which was a property of the reporter groups. Interestingly, cation characteristics of triazoles into guests under acidic conditions were also capable of destructing the conjugates of host and guest of polymer, especially due to electrostatic repulsion. Overall, cleavage of supramolecular assembly via interaction of K+ ion and cationic triazoles may push the limit of polymer towards exploring the critical mechanism involving such events in biology or other applications.

  • Nanomaterials | Biomaterials and Healthcare
Location: Sylt 3

Session Introduction

Nikolay Ledentsov

VI Systems GmbH, Germany

Title: Recent progress in epitaxial quantum dots for lasers and light emitting diodes

Time : 14:20-14:40

Biography:

Nikolay Ledentsov completed his Graduation at Electrical Engineering Institute in Leningrad (LETI) in 1982. He completed his Cand Sci and DSci Degrees in Physics and Mathematics at Ioffe Institute, Russia in 1987 and 1994, respectively. He has been a Professor at LETI since 1994, at Ioffe Institute since 2005 and at TU Berlin (1998-2007). His main interests are in the field of “Physics and technology of semiconductor nanostructures and the related devices”. He has Co-authored 800 papers and 30 patent families. He is a member of Russian Academy of Sciences, senior member of IEEE and Fellow of Institute of Physics. He received Young Scientist Award of International Symposium on Compound Semiconductors for pioneering contributions to the field of quantum dots and quantum dot lasers.

Abstract:

Epitaxial quantum dots (QDs) resulted in multiple breakthroughs in physics of zero-dimensional structures and allowed advancements of optoelectronic devices. Most importantly, these tiny structures provided unique opportunities to modify and extend all basic principles of heterostructure lasers and light emitting diodes and extend their applications. The breakthrough occurred when techniques for self-organized growth allowed the fabrication of dense arrays of coherent islands, uniform in shape and size and simultaneously free from undesirable defects. The work on the development of the technology for such QDs contributed enormously to the progress in material science. First ever lasing at low and at room temperatures was achieved in self-organized QDs in 1993 (photo pumped, at equivalent current densities of 4 kA/cm2). At that time, the term quantum dots were not yet fully established and the 3D quantized structures were referred to as quantum clusters. Injection lasing was realized soon after. Since that time, a lot of progress has been made extending the wavelengths, performance and application ranges of QD lasers. Control over the processes during QD formation and application of post-QD-deposition defect reduction techniques were the keys in industrial device fabrication and also led to success in InGaN LEDs and InGaN lasers. Such techniques, protected by patents, are being broadly applied by industries now. Further progress in QDs allows developing of further novel approaches for QD fabrication and continuous improvement in the performance of QD-related devices.

Yuri Lvov

Louisiana Tech University, USA

Title: Functional metal-ceramic nanocomposites based on tubule clay

Time : 14:40-15:00

Biography:

Yuri Lvov is a Professor and eminent Endowed Chair of Micro-Nanosystems at Louisiana Tech University. He is an expert in “Nanocomposites, drug nanocapsules, clay nanotubes for controlled release of chemicals”. He has 14 US patents, edited four books, published 240 papers with citations 17,000.

Abstract:

Halloysite is aluminosilicate tubular clay with diameter of 50 nm, inner lumen of 15 nm and length of 600-900 nm. Halloysite tubes are formed by rolling of aluminosilicate sheets. It is a natural biocompatible nanomaterial available in thousands of tons at low price which makes it a good candidate for nano architectural composites. Halloysite nanotubes are a promising meso-porous media for catalytic nanoparticles which may be seeded on the tube surface or synthesized exclusively in the tube lumen, providing enhanced catalysis, especially at high temperatures. Core-shell materials based on abundantly available halloysite clay nanotubes with efficient loading with heavy metal ions through Schiff-base binding were developed. This allowed for synthesis of Ru, Rh, Co or Ag nanoparticles at selected positions in the tubes either on the outside surface or inside lumens and in the multilayer wall voids. The two-step in situ synthesize of Ru and Ag nanoparticles inside halloysite nanotubes allowed for ca. 90% intercalated tubule product with metal particles’ diameter of 3-5 nm. These metal-ceramic nano composites have high surface area providing a good support for catalysis and can be also used for adsorption of metal ions from water. The ease of manufacturing of this novel, green, scalable products proves its capability to respond to the demands of increasing catalytic efficiency along with keeping our environment safe.

Haruhisa Kato

National Institute of Advanced Industral Science and Technology, Japan

Title: Characterization of nanosuspension using pulsed field gradient nuclear magnetic resonance

Time : 15:00-15:20

Biography:

Haruhisa Kato has his expertise in “Characterization of polymer and nanomaterials”. He has been investigating novel characterization instrument and method. Various nanomaterial standards (certified reference materials) are also produced by his laboratory and he is also concerned with the international standardization work in ISO/TC24, TC229 and TC256.

Abstract:

There have been numerous reports on nano sized materials and investigations of the relationship between their size and physical properties. In general, commercial nanomaterials are provided as dry powder. The sizes of the primary nanoparticles are determined using the Brunauer, Emmett and Teller method or a microscopic technique. However, nanomaterials are easily aggregated in liquid phase when one want to disperse them to make novel functional application, since the high ionic nature of the solution and the electrostatic/Van der Waals interaction between nanomaterials result in secondary particles. In such a sense, the accurate characterization of the nano suspension is necessary to understand the real properties of nanomaterials in liquid phase, not only characterization of primary particles by gas-phase characterization method such as electron microscope. This study therefore concerns with characterization of the nano suspension using Pulsed Field Gradient Nuclear Magnetic Resonance (PFG-NMR) techniques. PFG-NMR spectroscopy has not been commonly employed to determine the size of nanomaterials because of the very low local reorientation mobility of hard sphere type molecules such as gold sphere. The short T2 relaxation time also makes it difficult to determine the size of hard-core materials and large molecules. However, the PFG-NMR requires no special handling or preparation of the sample. In addition, the individual self-diffusion coefficients in a multi-component system can be obtained by simultaneously monitoring NMR signals at different chemical shifts. In this study, we therefore used this PFG-NMR technique and developed the quantitative evaluation of the size of materials in nano suspension and also determine the number of bound dispersant on nanomaterials to recognize the real structure of nanomaterials in liquid phase. Since the dispersant is one of the key to disperse nanomaterials stably in liquid phase our characterization on both nanomaterials and dispersant in nano suspension by PFG-NMR should be significant in nano technological field.

Break: Coffee Break 15:20-15:35 @ Sylt Foyer

Nekane Guarrotxena

Spanish National Research Council, Spain

Title: Engineering optical Raman active nanoassemblies for nanosensor purposes

Time : 15:35-15:55

Biography:

Nekane Guarrotxena completed her PhD at University of Complutense, Madrid-Spain and Post-doctoral research at Ecole Nationale Superieure d´Arts et Metiers (ENSAM), Paris-France and University of Science II, Montpellier-France. She was a Vice-Director at Institute of Polymer Science and Technology (ICTP-CSIC) from 2001 to 2005 and; Visiting Professor at University of California, Santa Barbara-USA and University of California, Irvine-USA from 2008 to 2011. Currently, she is a Research Scientist at ICTP-CSIC (Spain); an Editorial Board Member of some Materials Science and Chemistry journals and; External Expertise Consultant on I+D+I management policy for national and international agencies. Her research interest focuses on “The synthesis and assembly of hybrid nanomaterials, nanoplasmonics, and their uses in nano-biotechnology applications (bio-imaging, drug delivery, therapy and bio-sensing)”.

Abstract:

An important number of applications reports the use of noble metal nanoparticles (NPs) as optical tags in single-molecule assays, as local orientation- or sensitive biochemical- nanosensor and enhance Raman scattering of surface-bound molecules (SERS). Assembly of several NPs has also been used to develop scalable fabrication of new nano devices, just by playing with a controlled coupling chemistry. This condition requires positioning the reporting molecule within special sites in nanostructured metal surfaces where the enhancement is greatest. However, this rational clustering of two NPs (dimers or SERS hot-spots application) by solutions methods has been a notable challenge, since the current nanofabrication strategies are still far from ideal nano assembly–dissociation/ aggregation controls during performance or application. This communication reports a post synthetic purification approach which has overcome this difficulty yielding highly desirable optical Raman active nanoassemblies for nano sensors.

Biography:

Jörg Barner is an Application Scientist at JPK Instruments AG, Berlin, Germany. His international experience includes various programs, contributions and participation in different countries for diverse fields of study. His research interests as a Scientist reflect in his wide range of publications in various national and international journals.

Abstract:

Besides structural and physico-chemical composition, the topography, roughness, adhesiveness and mechanical properties of biomaterials are relevant parameters which strongly affect cell differentiation and tissue formation, and are thus crucial for assessing biocompatibility in the human body. We have developed a multipurpose AFM device which allows comprehensive characterization of these properties and interactions on the nanoscale under physiological conditions and in combination with advanced optical microscopy. Our unique quantitative imaging (QI™) mode determines several sample properties, like topography and the Young’s modulus, with one measurement. With the CellHesion® technique, the adhesion of a single cell to any substrate can be measured and validated. The NanoWizard® ULTRA Speed technique enables fast AFM imaging of dynamic processes with approx. 1 frame per second. Using QI™, we have characterized the topography and mechanical properties of challenging samples like living cells and tissue sections. The adhesion of single fibroblast cells to various surface modifications could be quantified and their suitability as cochlear implant coatings could be assessed. Fast AFM imaging revealed collagen type I fibrillogenesis and the formation of the 67 nm D-banding in situ with high spatio-temporal resolution. Here, we are presenting an enhanced AFM, making this technique a valuable tool for biomedical research.

Mark Schvartzman

Ben-Gurion University of the Negev, Israel

Title: Soft thermal nanoimprint lithography

Time : 16:15-16:35

Biography:

Mark Schvartzman received his PhD in Columbia University, NY, and did hos postdoc training in Weizmann Institute, Rehovot , Israel, Since 2014 he is an Assistant Professor in the Department of Materials Engineering and in the Isle Katz Institute for Nanoscale Science & Technology that is part of the Ben-Gurion University of the Negev, Israel. He has over 10 years of research experience on nanoimprint lithography and nanostructured materials. Over the years, he has publications in various prestigious international journals including Science and PNAS, and presented my work at various national and international conferences. Since joining academia, he won research grants close to 1 Million USD over a short span of just 2 years. He is a reviewer for the Journal of Vacuum Science and Technology since 2008 and affiliated with the Israel Vacuum Society since 2009.

Abstract:

Nanoimprint lithography (NIL) can be performed using two types of resists. In the UV nanoimprint, a liquid UV curable resist film is embossed at the room temperature, and hardened by UV-crosslinking. Such resists can be imprinted either by rigid or soft (elastomeric molds). In thermal nanoimprint, a film of thermoplastic resist is embossed when heated above its glass transition temperature. This type of nanoimprint is not compatible with soft molds, whose relief features would deform while pressed against the highly viscous molten polymer. This limitation precludes many application of thermal NIL, such as ultra-high resolution nanopatterning of curved surfaces. In this work, we introduce a novel concept of hybrid Soft-Substrate-Rigid-Feature (SSRF) nano imprint mold, which is based on soft substrate with rigid relief features. The SSRF mold was fabricated by electron-beam lithography of Hydrogen Silsesquioxane (HSQ) on a sacrificial substrate, followed by transferring the obtained HSQ features to elastomeric PDMS substrate. Anti-adhesive coating, which is usually used for hard Si based molds, was successfully applied on SSRF mold, and was shown to be essential for robust demolding after the imprint. SSRF molds were used to imprint thin films of Polymethyl Benzacrylate – a thermal resist with the glass transition temperature around 60 oC. This is, for the best of our knowledge, the first time that a thermal NIL was done with soft elastomeric molds. Furthermore, to demonstrate the uniqueness of our approach, we thermally imprinted PBMA films applied on lenses. In summary, we demonstrate here a novel concept of facile and robust mold for thermal nanoimprint lithography, which will pave a way to the broad variety of applications impossible up today.

Yongmei Zheng

Beihang University, China

Title: Bioinspired gradient surfaces with controlling of dynamic wettability

Time : 16:35-16:55

Biography:

Yongmei Zheng is a Professor at School of Chemistry and Environment, Beihang University. Her research interests are focused on “Bioinspired surfaces with gradient micro- and nanostructures to control dynamic wettability and develop the surfaces with characteristics of water repellency, anti-icing, anti-frosting or fogharvesting, tiny droplet transport, water collection, fog-harvesting and so on”. She has published more than 90 SCI papers in Nature, Adv. Mater., Angew. Chem. Int. Ed., ACS Nano and Adv. Funct. Mater., etc., with 12 cover stories and a book “Bioinspired wettability surfaces: Development in micro- and nanostructures” by Pan Standard Publishing, USA. Her work was highlighted as Scientist on News of Royal Society of Chemistry, Chemistry World in 2014. She is a senior member of Chinese Composite Materials Society (CSCM), member of Chinese Chemistry Society (CCS), American Chemistry Society (ACS), International Society of Bionic Engineering (ISBE) and International Association of Advanced Materials (IAAM). She wins an ISBE outstanding contribution award in 2016 by ISBE and an IAAM Medal in 2016 by IAAM, in Sweden.

Abstract:

Biological surfaces create the enigmatical reality to be contributed to learning of human beings. They run cooperate between of endlessly arranged various-style gradient micro- and nanostructures (MN) that greatly provide with excellent functions via natural evolvement. Such biological surfaces with multi-gradient micro- and nanostructures display unique wetting functions in nature for water collection and water repellency, which have inspired researchers to design originality of materials for promising future. In nature, a combination of multiple gradients in a periodic spindle-knot structure take on surface of spider silk after wetrebuilding process in mist. This structure drives tiny water droplets directionally toward the spindle-knots for highly efficient water collection. Inspired by the roles of gradient MNs in the water collecting ability of spider silk, a series of functional fibers with unique wettability has been designed by various improved techniques such as dip-coating, fluid-coating, tilt-angle coating, electro-spun and self-assembly, to combine the Rayleigh instability theory. The geometrically-engineered thin fibers display a strong water capturing ability than previously thought. The bead-on-string hetero-structured fibers are capable of intelligently responding to environmental changes in humidity. Also a long-range gradient-step spindle-knotted fiber can be driven droplet directionally in a long range. An electro-spun fiber at micro-level can be fabricated by the self-assembly wet-rebuilt process, thus the fiber displays strong hangingdroplet ability. The temperature or photo or roughness-responsive fibers can achieve a controlling on droplet driving in directions, which contribute to water collection in efficiency. Besides inspired by gradient effects on butterfly wing and lotus leaves, the surfaces with ratchet MN, flexible lotus-like MN are fabricated successfully by improved methods, which demonstrate that the gradient MN effect rises up distinctly anti-icing, ice-phobic and de-ice abilities. These multifunctional materials can be designed and fabricated for promising applications such as water-collecting, anti-icing, anti-frosting or anti-fogging properties for practical applications in aerospace, industry and so on.

Rita Haj Ahmad

De Montfort University, UK

Title: EHDA technology utilizing different bio-structure

Time : 16:55-17:15

Biography:

Rita Haj Ahmad has completed her PhD at University of Sunderland and currently pursuing Post-doctoral studies at School of Pharmacy, De-Montfort University under the supervision of Professor Zeeshan Ahmad. Her research interest is focused on “Utilizing various nanotechnologies for the delivery of proteins, peptides, antibacterial and anticancer agents”. She has published more than 11 peer-reviewed papers in internationally recognized journals.

Abstract:

The growing trend within the nanotechnology remit has led to the emergence of novel approaches and techniques for advanced pharmaceutical formulations. Electrohydrodynamic atomization (EHDA) is a single step and multipurpose technology for the fabrication of products suitable for biomedical and other healthcare applications include in drug delivery, tissue engineering, wound dressing development, targeted drug delivery and sustained drug delivery. The principal underlying EHDA is based on applying an electrical force to drive atomization of liquids in to formulated micro- and nano- structures. Various morphologies can be achieved using a range of EHDA systems including particles (through electro spraying) and fibers (through electro spinning). Processing parameters (flow rate and applied voltage) and crucial liquid physical properties (density, electric conductivity, viscosity and surface tension) impact on structure topography, morphology and size. The process is able to incorporate various biological and other materials of significance (e.g. proteins, living cells, spore and DNA) with synthetic and existing materials (such as polymers, ceramics and metals). More specifically, EHDA systems have significantly enhanced; encapsulation ability, stability, dissolution and bioavailability of existing active pharmaceutical ingredients (API) which maybe either hydrophilic or hydrophobic. In addition, the nature of these chemicals can be afforded into the amorphous state making them more suitable for permeation and bioavailability. This presentation will focus on the fundamental process, examples of structures that can be engineered and various administration routes that can be addressed. It will also discuss the key technological advances in the field and will provide an insight into the EHDA network which is currently working towards the appreciation of these technologies in the drug delivery remit.

Biography:

S Ananda has more than 30 years of teaching and research experience. Presently, he is a Chairman and Professor in Department of Chemistry, University of Mysore, India. He has published 150 research articles in reputed international journals in the area of Chemical Kinetics, Bio-physical Chemistry and Nano Chemistry. At present, he is working on “Synthesis of nano materials by solvothermal, hydrothermal, electrochemical and biological, sol-gel method”. These materials are applicable in the field of Photocatalysis, Electrical, Optical and Biological studies. His group is actively involved in the synthesis of nanocomposites of doped zinc oxide, doped zinc sulfide and polymers nano composites. He has reviewed many international research papers. He worked as a Research Associate at Tokyo Institute of Technology, Japan. He has visited several countries like USA, China, France, Japan and Singapore for paper presentation in conferences. He is Principle Investigator and Co-investigator for many projects sponsored by UGC, DST-PURSE, UPE, CPEPA and IOE. He has guided 16 PhD candidates and four MPhil candidates.

Abstract:

A facile technique for electrochemical synthesis of multi-functional metal oxide and metal sulfide nanocomposites like In2O3/ ZnO, In2O3/SnO/ZnO, ZrS2/ZnS, CdO/ZnS and bio-synthesis of MnO2 is achieved. Under ambient conditions, these methods are capable of producing nanorods, nanoflakes and flower-like particles in a size range about 05-30 nm with a wide band gap of 3.15-5.8 eV. Characterization techniques like SEM-EDS, TEM, ICPMs, XRD, PALS, zeta potential reveals the hierarchical structure and functionality of these materials. The enhancing influence of these nanomaterials as photo-catalyst for the degradation of textile industrial effluents and decomposition of KMnO4 for oxygen evolution as source of energy has been studied. Anti-bacterial activity is tested against bioluminescent bacteria via MIC which shows 50% efficiency at mere 250 μg of nanoparticle. A linear correlation is achieved for photo-degradation and inactivation of bacteria as both are ROS dependent phenomena. The nanomaterials synthesized are doped into different polymers to prepare polymeric films like PVA-CoO/ZnO, POE- CdO/ZnS¬. Conductivity studies of these polymeric films using conductometer, photo-voltaic property is done at different % of doping which shows a steep increase in the conductivity upon doping. These nanoparticles can be potentially applied to the rapid, green and low-cost degradation of industrial printing and dyeing wastewater.

Ming Yau Chern

National Taiwan University, Taiwan

Title: Synthesis and characterization of single-crystal bismuth telluride nanowires

Time : 17:35-17:55

Biography:

Ming Y Chern has his expertise in “The synthesis and characterization of thin films and nanomaterials”. His current research interests include “ZnO and Bi2Te3 nanowires with focus on potential applications in optoelectronics and spintronics”.

Abstract:

Topological insulators have high values in both theoretical and application aspects. In this work, we synthesize and study the nanowires of topological insulator bismuth telluride (Bi2Te3). The nanowires are grown on glass substrates by thermal evaporation of bulk Bi2Te3 at elevated temperature in an argon flow two-zone furnace, where the substrate temperature can be adjusted independently. The growth temperature has a strong influence on the growth direction of the nanowires. Currently, the known growth direction of the Bi2Te3 nanowires is rhombohedral indexing, less is known about other growth directions. We are able to grow nanowires of Bi2Te3 in different directions by tuning the substrate temperature. Other growth factors such as the flow rate of the argon gas, the background pressure, and the vapor pressure of Bi2Te3 are discussed. We examine the nanowires with XRD, SEM and TEM. We also measure the transport properties of single nanowires. The properties and anisotropy of these nanowires are discussed.

Biography:

Lina Fernanda Mojica Sánchez: Colombian Environmental Engineer specialized in project formulation and evaluation. Researcher Professor at the Center for Environmental Research at CIAM-UNIMETA which promotes the approach and execution of proposals for sustainable development.

Abstract:

Statement to the problem: Searching for new inputs for bio-construction that adapt to the socio-economic reality of regional development, within the framework of sustainable development and land use, we have encountered the paradox of reviewing ancestral materials for innovative processes, and It is thus as of comparative way between arecaceae and bambusas we have visualized the wide use of the palms in all the Colombian tropic, like raw material of diverse nature; Such as utensils, tools, constructive elements among others, but also drawing our attention in a worrisome way that unlike bambusas, arecaceaeas do not have norms that allow legal or sustainable exploitation, but only points to rules that restrict exploitation For conservation purposes but that in the long run, they will not avoid the demand and the smuggling chains that specifically affect some species. We will study the Iriartea deltoidea of common name CHONTA and the Socratea exorrhiza commonly recognized in the region of Orinoquia and Colombian Amazonia as CHUAPO. These varieties are extremely resistant and have been used ancestrally by the natives to carry out their constructions, and we will investigate them. Methodology & Theoretical Orientation: We will be based on the type of project research with a mixed approach. The design of this will be developed through the following activities: Secondary information processing, fieldwork, diagnosis, laboratory tests, interviews, surveys, sampling, case study and analysis of primary information; formulation of hypotheses and first stage of integrated biosystems, technical proposals and recommendations. Findings: Currently, these woods are characterized by contemporary constructors as a "very hard material, which wears and damages cutting tools" contrary to what happens with the Guadua angustifolia Kunth; Easy to work, abundant in tropical regions of the world but prone to deterioration processes, so with this background we will compare the resistance of the chonta and the chuapo with physical and mechanical tests in a specialized laboratory. Conclusions & Significance: the performance of this research is to formulate an integrated biosystems for the total exploitation of the biomass of these two species. Generating indicated tools to propose norms that support use and management of chuapo and chonta, in a sustainable way, as well as the inclusion in the resistant earthquake norm, allowing to create a formally established productive chain and to be recognized as "sustainable materials" for bioconstruction.

Biography:

Ludwig Erik Aguilar has his expertise in “Creating and modifying medical devices to enhance their effectiveness”. He works primarily on stimuli responsive polymers and their application for controlled drug delivery on vascular and non-vascular stents and other medical implants with the use of electro spinning and other fabrication methods. He also has experience in creating and utilizing other polymeric materials and exploits their intrinsic properties to be used as a biomaterial and for drug delivery systems.

Abstract:

Gastrointestinal malignancies have been a tremendous problem in the medical field and cover a wide variety of parts of the system, (i.e., esophagus, duodenum, intestines and rectum). Usually these malignancies are treated with palliation with the use of nonvascular nitinol stents. However, stenting is not a perfect solution for the problem. While it can enhance the quality of life of the patient, in time the device will encounter problems such as reocclusion due to the rapid growth of the tumor. Therefore, a functional cover made up of core-shell nanofibers with a unique combination of thermo responsive polymeric shell and stretchable polymeric core for non-vascular nitinol stents that uses an alternating magnetic field (AMF) to induce heat in the stent for hyperthermia therapy and simultaneously release 5-fluorouracil and/or paclitaxel was designed. Varied ratios of NIPAAm to HMAAm monomer resulted in different LCST properties was utilized for an on-demand drug release. Biocompatibility test using NIH-3T3 fibroblast cells indicates that the composite with drug content are biocompatible and the in vitro cancer cytotoxicity test using ESO26 and OE21 cancer cells proved that the material shows cancer cytotoxic properties via combination of dual drug and hyperthermia therapy. With this functional material, we propose a tailorable and on-demand drug release with more control that can be employed for a combination drug therapy/single drug therapy combined with hyperthermia therapy for cancer cytotoxicity effect.

Amrita Rath

Indian Institute of Technology Madras, India

Title: Reversible and irreversible self-folding behavior of water responsive poly (vinyl alcohol) films

Time : 18:30-18:45

Biography:

Amrita Rath is currently pursuing her integrated Master’s and PhD in Department of Applied Mechanics, Indian Institute of Technology Madras, India. She has completed her Bachelor’s in Mechanical Engineering from ITER, Bhubaneswar, Odisha in the year 2012. Her research interests include designing of smart biopolymers that would find interesting futuristic and novel applications in the field of bio-engineering, sensors, water purification etc. This needs development of various methodologies for fabrication of the bio-films of desired mechanical strength and rigidity by understanding its mechanical behavior. This is performed experimentally by applying nano-mechanical characterization. The mechanical performance of the bio-polymers can be engineered better by getting an insight into the molecular mechanics. This is investigated by modelling the dynamics of polymer system at molecular length scale. Currently, she is working on “Designing of controlled self-folding bio-polymer”.

Abstract:

Self-folding of biopolymers arising from mechanical instabilities has a vast scope for investigation in futuristic smart engineering applications. Motivated by enormous examples available in nature in the form of pine cone responding to humidity, mimosa pudica plant folding responding to touch, the biopolymers can be engineered to respond in a smart way. The response of the biopolymers can be in the form of water, temperature, light etc. Poly (vinyl alcohol) (PVA) is a biodegradable and biocompatible polymer with hydroxyl reactive group. It responds to water by performing reversible folding behavior. The self-folding phenomena is characterized by the folding time and rate of folding. It will be interesting to design these films in a certain three dimensional geometries and permanently retaining the shape undergone during folding. Reversible/permanent folding is based on the molecular interaction of the reactive groups between biopolymer and solvent molecules. The chains in a PVA matrix are relaxed due to the mobility of water molecules, leading to reversible folding. However, the chain relaxation can be restricted by the presence of different biomolecules in the matrix, where the competitive interaction between the reactive sites can lead to a permanent folding. This competitive interactions are explored using molecular dynamics simulations. Moreover, control over the folding in terms of total time and rate is possible to achieve by correct choice of a solution. In this work, we are reporting the possibility of obtaining permanent folding shape of pristine PVA films by designing one such biopolymer solution. Experimentally, it is observed that permanent shape of PVA films depends on the physical property of that particular solution. Furthermore, by changing these properties, a control over the time and rate of folding is achieved. In this work, we will discuss in detail the reversible and permanent folding characteristics of pristine PVA films in terms of folding time and rate. The results will include the effect of the thickness on the folding behavior. Also, the molecular mechanisms observed from MD simulations will be used to address the experimental observations.

Biography:

Ankan Dutta Chowdhury completed his BS in 2006 at Calcutta University, Kolkata, India and MS in Chemistry at G.G.U., Bilaspur, India. He is currently continuing his research as a Post-doctoral Scientist at ECCL, NCTU, Taiwan on “Bio-sensing, drug delivery and capacitative study using synthesized nanomaterials”. He completed his PhD in Chemical Sciences at Saha Institute of Nuclear Physics, India. His research interests lie in the area of “Biosensor and different nano materials applications”.

Abstract:

Fluorescence imaging using doxorubicin (DOX) has been used to image free and encapsulated drug uptake into cells, since intercalation of Dox with DNA leads to a characteristic change. However, suitable nano-conjugates which can able to deliver Dox in a much targeted manner with high specificity in cancer cell are still in extensive search. In this study, we report an anticancer drug delivery system based on doxorubicin-conjugated Fe3O4-GQD based nanoparticles which can act as pH mediated as well as magnetic targeted drug delivery nanocarrier. The as-synthesized nanoparticles consist of uniform spherical size with an average diameter of 35 nm. The drug delivery system demonstrates the ability to release DOX by desorption of drug molecule from GQD surface in mildly acidic environments, mimicking the cancerous cell environment. By functionalizing the surface of the GQD with the iron oxide nanoparticle, the drug releasing phenomenon can be controlled and targeted by the external magnetic effect. The quenching of GQD by DOX due to resonance energy transfer mechanism is applied as optical probe to confirm the DOX conjunction and monitor the release of DOX. The DOX-conjugated nanocarrier exhibits an obvious cytotoxic effect on HELA cancer cells via MTT assay. In addition, the less cytotoxicity of the drug nanocarrier in normal endothelium cell also strongly support the specificity towards the cancer cell which is the most successful aspect of this delivery system. Meanwhile, the successful delivery on magnetic environment of DOX-conjugated nanoparticles was demonstrated through in house made dialysis bag chamber and fluorescence microscopy. Such drug delivery system, which combines pH-triggered and external magnet controlled drug release, has excellent potential applications in cancer therapy and smart imaging. We demonstrate here that, this new class of nanocarrier can fulfill the required specificity and sensitivity as next generation cancer imaging, therapy and sensing system in vitro.