Day :
- Advance Nanomaterials and Nanoparticles | Nanotechnology in Energy and Environment | Materials Science and Nanotechnology | Nano Electronics and Microsystems | Nanotechnology in Waste water treatment
Location: Salon VII
Chair
Nikolaus Stolterfoht
Helmholtz-Zentrum Berlin, Germany
Co-Chair
Jerzy Zajac
University of Montpellier, France
Session Introduction
Mike S Scurrell
University of South Africa, South Africa
Title: The importance of nanoarchitecture in advanced high performance heterogeneous catalysts
Time : 13:45-14:15
Biography:
Mike Scurrell is Research Professor in the Department of Civil and Chemical Engineering at the University of South Africa and Emeritus Professor of Chemistry at the University of the Witwatersrand, Johannesburg, South Africa. His research interests concern heterogeneous catalysis and nanomaterials, especially for energy conversion and environmental processes and he is also involved in novel nanomaterials synthesis involving microwave radiation and non-thermal plasma treatment.
Abstract:
Our current lifestyle in the developed countries would not be possible if we did not have access to high performance heterogeneous catalysts. These materials lie at the heart of our industrial processes for oil, petrochemicals, polymers, pharmaceuticals, energy conversion and environmental protection and ever-increasing demands are being placed on catalysts for the future. Very high performance heterogeneous catalysts will almost always demand that considerable attention is paid to the detailed nanoarchitecture of the solids. This point will be illustrated by several examples, including thermostable gold catalysts for environmental protection, based on the use of nanoflower-structured support decorated with nano-sized metal particles. These materials have greatly improved thermal stabilities against conventional materials and this could see new applications in several areas, especially environmental protection. Catalysts for the decomposition of methane in low carbon footprint conversion of natural gas to electricity can also be improved by incorporation of suitable nanomaterials such as medium and wide-pore zeolites. A further example is provided by photocatalysts for biomass conversion to syngas and hydrogen, where at the nano level the inhibition of charge pair recombination is required for high reaction rates. The devices and procedures available for manipulation of nanoarchitecture include microwave radiation treatment and the use of non-thermal plasmas. The extent to which these approaches can be used in improving solid catalysts will also be discussed.
Jens Martin
National University of Singapore, Singapore
Title: Robust resistive memory devices based on solution processable metal co-ordinated azo-aromatics
Time : 14:15-14:45
Biography:
Jens Martin has obtained his PhD from the University of Tübingen, Germany. He has then worked almost 3 years in the R&D Department of Omicron Nanotechnology, Germany. He has also worked at the Weizmann Institute, first as Postdoctorate then as Research Associate. Further, he had worked for 3 years at Harvard University as a Research Associate and Teaching Fellow. Later, he became Lecturer at the Graphene Center at the University of Exeter, UK, before joining the NUS Graphene Center as an Associate Professor. His research interests include low dimensional electronic systems, electronic interactions, scanning probe microscopy and most recently electronic conduction through molecular thin films
Abstract:
Resistive memory devices can be broadly defined as electrical switches that retain a state of internal resistance based on the history of applied voltage. Such devices hold several performance characteristics that can potentially exceed conventional integrated circuit technology and are projected as the building blocks in next generation of computing architectures. Organic resistive memories suffer from insufficient consistency, stability, endurance and lack of understanding of the operating device mechanisms. These difficulties need to be overcome to furnish a good candidate for commercial applications. Here we describe a reproducible, stable and endurable resistive memory device with a spin-coated active layer of transition metal complex contacted with electrodes, prepared by standard methods. Insight into the in operando molecular properties of the device is obtained via in situ Raman-spectroscopy in conjunction with UV-VIS spectroscopy and spectro-electrochemistry allowing us to determine the molecular structure at each conductance state and thus the mechanism of switching. Density functional theory (DFT) calculations support our experimental findings and provide further insights into the switching mechanism of the devices at the molecular level. This insight provides opportunities for ligand engineering and we demonstrate rewritable resistive memory devices with multistate memory functionality.
D C Saxena
Sant Longowal Institute of Engineering & Technology, India
Title: Development of organic and inorganic nanoparticles and their subsequent application in nanocomposites for food and non-food packaging systems
Time : 14:45-15:15
Biography:
D C Saxena is dedicated to the continuing development and practice of creative teaching, innovative research and high impact public service programs that have improved food safety, food quality and processing. He has been a Visiting Faculty of Asian Institute of Technology, Bangkok, Thailand. His areas of interest for research includes utilization of starches for food and non-food applications from non-conventional sources, traditional product technology, dough rheology, grain quality assessment, design and fabrication of food processing equipment and has about 90 publications in reputed journals.
Abstract:
In order to improve performance properties of packaging systems, nanotechnology has come up with its contribution by providing different types of nanoparticles to be used as fillers in polymer matrices. Nano-sized organic and inorganic particles have attracted much attention owing to their unique properties that vary from their bulk materials, thus facilitating their use in packaging industry, food industry and pharmaceutical industry. Recent studies reported that these nanoparticles incorporated in various polymer matrices result in packaging material with improved mechanical properties, thermal properties and improved barrier properties for the food packaging systems. As per studies, variety of inorganic nanoparticles viz. titanium dioxide, zinc oxide, magnesium oxide, gold and silver and organic nanoparticles such as starch and chitosan are available for reinforcing physical and barrier properties selectively for the food systems. Different methods are used for preparation of organic and inorganic nanoparticles. For starch nanoparticles, acid hydrolysis, reactive extrusion, gamma irradiation, ultrasonication, high power homogenization and nanoprecipitation are used for their preparation. Inorganic nanoparticles are prepared by sol gel method, mechano-chemical processing and physical vapor synthesis etc., depending upon the type of inorganic nanoparticle. Organic nanoparticles have an upper edge in terms of biodegradability over the inorganic nanoparticles, so they result in bio-nanocomposites when blended with a biodegradable polymer whereas the inorganic nanoparticles are extensively used as antimicrobial agents in the food packaging systems. The following paper summarizes the information available till date relating to organic and inorganic nanoparticles and contribution to packaging systems as a part of nanocomposites. This paper provides an overview of aspects related to organic and inorganic nanoparticles, including methods of preparation, reinforcing and other specific properties, characterization and application and prospects. Future researches need the area of organic and inorganic nanoparticles related to packaging technology are outlined.
Zhaoxin Geng
Chinese Academy of Sciences, China
Title: THz modulators based 2D nanosheet materials
Time : 15:15-15:45
Biography:
Zhaoxin Geng has completed his PhD degree from Institute of Electronics, Chinese Academy of Sciences. Presently, he is an Associate Professor of School of Information Engineering, Minzu University of China. Meanwhile, he is a Visiting Associate Researcher in MEMS Research Center, Institute of Microelectronics, Peking University. Presently, he works in Institute of Semiconductors, Chinese Academy of Sciences as a Postdoctoral Fellow. His current research focuses on the micro/nanofluidic, biosensor and applications of nanoplasmonic and localized surface Plasmon resonance.
Abstract:
Terahertz (THz) modulator plays an important role in THz communication system. There are different modulators which have been developed to meet different application. Especially, THz modulator based on metamaterials need complex fabrication processes and high cost, therefore, the simpler and cheaper devices are in greatly demand for THz communication in near future. Two-dimension (2D) materials, such as graphene, MoS2, WS2 and other beyond graphene materials, were introduced to modulator to balance between modulation characters and cost. Therefore, different THz modulators based on different 2D materials were developed and compare the difference among them. The results illustrate that graphene and MoS2 did not present ideal results due to their relatively narrow band gap. WS2, as another kind of 2D materials, which has wider band gap and some merits such as better chemical and thermal stability, could be used for photoelectric devices in THz regime. An all-optical pumped THz modulator based on WS2-silicon, MoS2-silicon and graphene-silicon heterostructure were demonstrated. The p-type WS2 was formed by an annealing treatment in air and the silicon substrate was slightly n-type doped with a high-resistivity. Both the modulator and bare silicon (as reference) were measured by THz time-domain spectroscope (THz-TDS) system. The results compared with bare silicon, THz transmissivity of the modulator significantly reduced when the power of pumping laser increased. A relative low normalized transmission of this device was around 5% with a radiation light power of 4 W, while the bare silicon was 45.6% under the same condition. The working mechanism of the modulator lies in that carriers transfer between the silicon and WS2 when the pump light illuminates the chip. We compared the difference between results of the bare silicon, the WS2-Si sample before annealed and after annealed and found that the WS2-Si sample could separate electrons and holes more effectively. THz transmissivity decreased when conductivity of the modulator increased due to separation of electrons and holes. Meanwhile, the MoS2-based device even exhibited much higher modulation efficiency compared with the graphene-based device. The mechanism of the convincing modulation enhancement originated from MoS2 annealed as a p-doping, which is different from that of graphene-based modulator. Therefore, under a guidance of the working mechanism, THz modulators with higher modulation depth could be developed based WS2-silicon heterostructure through changing the annealing time, layers of WS2, bias voltage, pumping light power and so on. The unique optical modulating properties of the device based on 2D materials exhibit tremendous promise for applications in terahertz communication based graphene device, we also developed other optoelectronic devices such as frequency tripler, thermo-optic modulator and mixer.
Kalyan Mandal
S N Bose National Centre for Basic Sciences, India
Title: Transition metal oxide nanostructures and their novel properties
Time : 16:00-16:30
Biography:
Kalyan Mandal is a Senior Professor in S. N. Bose National Centre for Basic Sciences, Kolkata, India, mainly works on magnetism and magnetic materials including magnetic nanomaterials. He has received his PhD degree from the Indian Institute of Technology Kharagpur, India and performed his Postdoctoral Research in Queen’s University, Canada and Institute de Magnetismo Aplicado, Madrid, Spain. He has received Humboldt Fellowship from Germany and worked in IFW-Dresden and other universities/institutes in Germany as a Humboldt Fellow. He has received UK-India Education and Research Initiative Award to work in Durham University, UK. He has also worked in Osaka University, Japan as a Visiting Professor and received Materials Research Society of India Award in 2016.
Abstract:
Iron and other transition metal oxides nanostructures receive considerable attention due to their extensive technological applications in high density magnetic storage media, high frequency devices, magnetically assisted drug delivery, cell isolation, MRI contrast agents, immobilization of proteins and enzymes, biosensors and so on. We observed many novel and enhanced properties in those oxides depending on their shapes and sizes. They can be functionalized with suitable ligands to get biocompatible and water-soluble nanostructures with interesting multifunctional properties. For example, intrinsic multicolor fluorescence in MnFe2O4 nanoparticles (NPs)/hollow spheres (NHSs) from blue, cyan, and green to red is observed upon functionalization with a small organic ligand such as Na-tartrate because of ligand-to-metal charge transfer from tartrate ligand to lowest unoccupied energy level of Mn2+/3+or Fe3+ of the NPs and Jahn-Teller distorted d-d transitions centered over Mn3+ ions in the Nanostructures. CoFe2O4 nanoparticles functionalized with surfactants having π-acceptor/π-donor head group along with different chain-length show much higher coercivity compared to bare particles due to NP-ligand interaction which modifies the splitting of d-orbital energy levels as well as spin motion of surface Co+2 ions. Many of the above oxide nanostructures show excellent photocatalytic activities and potential for various biomedical applications depending on their shape, size and surface functionalizations.
Mika Naumanen
VTT Technical Research Centre of Finland, Finland
Title: Action roadmaps paving the way towards electric mobility and circular economy
Time : 16:30-16:50
Biography:
Mika Naumanen is a Senior Scientist in the Innovation and Knowledge Economy group of VTT. He has run VTT’s “business from technology” program and managed a portfolio of business development projects in the fields of industrial systems management, services and built environment, ICT and electronics. He is a Visiting Scholar in Statistics Finland.
Abstract:
We present action roadmaps paving the way towards electric mobility and circular economy. We do this within the CASI-F (common framework for assessment and management of sustainable innovation) framework, where we first analyze critical issues that influence the uptake of electric mobility and new storage media for electric power. The main lesson from the analysis of the positive and negative effects that the identified critical issues have on the mapped innovations is that the actions to manage such an extensive set of barriers, drivers, opportunities and threats might need to be implemented by multiple actors with different managerial roles and responsibilities. Due to government’s ability to change legal and administrative structures and procedures, one important role for government and the public sector is related to changing and/or adapting such infrastructures in a way that would support the implementation, scaling, diffusion and institutionalization of electric mobility innovations. Not only monetary resources are of importance, but also the positive acknowledgement and general support, e.g., through awareness raising activities and campaigns, is a task in which the public sector can assist the development, up-scaling and institutionalization processes. An important task for civil society is related to campaigning and awareness raising activities. Thoughtful marketing and an effective issue communication could help in stipulating behavioral changes within people, a task that reoccurs at all three levels for civil society, as well as it could enhance further community engagement. Similar to government and civil society, also businesses have reoccurring tasks and responsibilities. Such responsibilities are mostly concerned with the provision of various kinds of resources, both tangible and intangible. The sharing of knowledge regarding appropriate business models and strategies, their development and implementation, is of great interest. Additionally, businesses are encouraged to engage in networks and to cooperate and collaborate with partners and other relevant stakeholders in order to enhance future battery technologies’ and their recycling potential. Research and education are supporting social innovation by fundamental but practical relevant research, including evaluation of programs and initiatives and the development of tools and methods for (up) scaling electric mobility innovations. This also comprises of giving access to research results and tools for the public (social innovators) and an own engagement in up-scaling processes.
Roaa Sait
Emerging Technologies Research Centre, UK
Title: Synthesis and characterization of TiN NWs towards neural electrode application
Time : 16:50-17:10
Biography:
Roaa Sait is currently a PhD student at De Montfort University in the UK. She has been active in the area of material science and nanotechnology. Recently she has published a paper on synthesis and characterization of sputtered TiN as a nucleation layer. Her current research involves the study of neural electrode interface materials for improving recording and stimulation of neurons in the brain. She focuses on controlling the properties titanium nitride nanostructures.
Abstract:
In neurophysiological measurements, a neural electrode interface material plays a critical role in eliciting action potentials without damaging the tissue of interest. However, the need to minimize electrode dimensions and reduce invasiveness and the activation of glial cells has rendered the choice of a suitable interface material. Platinum, iridium oxide and gold are currently the most utilized microelectrode material due to their apposite electrical and mechanical properties, however their performance becomes limited when electrode dimensions are reduced; as the total surface area decreases, limitations are placed on the successful transfer of charge or charge injection into the tissue for stimulation. Research on nanostructured surfaces has shown a great potential for improving the electrochemical and mechanical properties. Thin films of titanium nitride (TiN) have been implemented in neural electrode applications previously due to its useful properties e.g., TiN has a higher charge injection (2.2-3.5 mC/cm2) as compared to that of Pt (0.02-0.15 mC/cm2). Moreover TiN nanowires (NWs) have not been synthesized previously towards for neural interface application, which is the aim of the work described here. The synthesis involves the low temperature and cost effective hydrothermal growth of Titanium Oxide NWs (TiO2-NWs) grown, for the first time, from a TiN sputtered layer optimized elsewhere. The growth is followed by a novel nitridation process. The effects of the hydrothermal growth parameters (e.g. seeding layer thickness, time and temperature) on the properties of the TiO2 nanowires were investigated using Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Cyclic voltammetry (CV) for morphological, structural and electrochemical studies respectively. Aspect ratio as well as crystalline structure, electrical resistivity and capacitance will be presented and distilled here. The ease and convenience to tune the nanowires properties bring this approach great potential for building an optimum neural electrode interface material.
Silvia Villa
University of Genoa, Italy
Title: Biocompatible multifunctional magnetic nanoparticles for possible applications in nanomedicine
Time : 17:10-17:30
Biography:
Silvia Villa has received her Bachelor’s and Master’s degrees in Chemical Sciences from University of Genoa, Italy. Later, she began a Fellowship on the synthesis of iron oxides NPs as MRI contrast agents at the Italian Institute of Technology, Pisa, Italy. She is currently pursuing PhD at the University of Genoa, Italy, working on magnetic nanoparticles for environmental and biomedical applications. During her PhD, she had the opportunity to work on magnetic ferrites for hyperthermia studies at Norwegian University of Science and Technology, Trondheim, Norway.
Abstract:
Multifunctional nanoprobes combining magnetic nanoparticles (MNPs) with organic dyes have attracted great interest due to their promising applications in biomedical field. Among the wide selection of different nanoprobes, superparamagnetic iron oxide nanoparticles (SPIONs), loaded with different functionalities, provide promising application in the drug delivery therapy. In cancer treatment, a possible drug delivery approach is the well-known prodrug monotherapy (PMT), in which the drug is released by enzymes naturally overexpressed in tumor tissues. A recognized enzyme suitable for this method is plasmin, a serine protease. A combination of the two approaches can enhance the cancer treatment because, under the influence of an external magnetic field, it is possible to orient the magnetic nanoparticles to the tumor site and concentrate the drug in the ill tissue. In this perspective, our project aimed at optimizing this approach, planning a superparamagnetic probe based on iron oxide NPs and conjugating a fluorescent tag through a tripeptide linker. This peculiar system has been designed to be cleaved by plasmin with the resulting release of the fluorescent tag. Therefore, this original system could find applications either in the imaging diagnostic or in the drug delivery fields. Herein, we present the synthesis and the characterization of the two components (SPIONs and the tripeptide linked to a fluorescent tag) and the study of their conjugation. Furthermore, we present the preliminary results of the enzymatic cleavage, as proof of concept of our project.
- Materials Science and Nanotechnology | Applications of Nanotechnology | Nanomedicine | Molecular Nanotechnology | Nano Chemistry | Nano Bio Materials
Location: Salon VII
Chair
M Vlcek
University of Pardubice, Czech Republic
Co-Chair
Mike S Scurrell
University of South Africa, South Africa
Session Introduction
Basma El Zein
University of Business and Technology, KSA
Title: Nanomaterials for 3rd generation sensitized solar cells
Time : 13:45-14:15
Biography:
Basma El Zein is the Dean of Scientific Research at UBT. She has nearly 18 years of experience in academic and research institutions. She was a Research Scientist at King Abdullah University of Science and Technology (KAUST) and an Associate Researcher at IEMN, Lille, France. She is a Senior Member of IEEE, Member of ACS, MRS, SPIE and ECS. She has been selected as winner of Albert Nelson Life Achievement Award by Marquis Who’s Who, 2017 and Solar Pioneer by MESIA, 2015. Her research interests include working on nanostructures for third generation eco-green solar cells, energy harvesting and energy storage. She is exploring new materials perovskite to be used as light absorber for solid state sensitized solar cells. She is a Reviewer in many international, peer-reviewed journals, the chair or co-chair and on the committee of different international conferences, has published many international journals and had one patent.
Abstract:
Nano-materials are considered as building block for many optoelectronic devices. They differ from bulk counterpart in the size, characteristic and offer new opportunities to be employed in various applications. Zero dimensional (0D) and one dimensional (1D) nanostructures have attracted lots of attention in solar energy harvesting, conversion and storage, owing to their unique physical and chemical properties. Nano-materials offer many advantages in energy conversion specifically in solar cells. These solar cells, depends on the physical interaction between nanomaterials or chemical reaction at the surface or interface of the nanomaterials. In this presentation, we will discuss the zero and one dimensional nanostructures and the role they play in increasing the conversion efficiency of solar cells, taking in consideration the materials to be used to meet the main objective of developing an eco-green solar cell with high conversion efficiency.
Ali Trabolsi
New York University Abu Dhabi, UAE
Title: Calix[n]arene based multi-functional porous materials for environmental applications
Time : 14:45-15:15
Biography:
Ali Trabolsi has received his BSc degree in Chemistry from the Lebanese University in Beirut. He has received his Master’s degree in Analytical Chemistry and also completed his PhD. Later he joined KAUST in Saudi Arabia as a Research Scientist in the Membrane Center. Presently, he is an Assistant Professor at New York University Abu Dhabi.
Abstract:
Owing to the increasing level of attention focused on the preservation of the environment, there is a growing need for novel multi-functional materials that can meet the increasing demands from society on water resources and pollution remediation. Porous organic polymers composed of light elements that possess high specific surface areas, large pore volume and multiple functionalities are good candidate to fulfill the requirements. In particular, porous covalent organic polymers (COPs) are a promising class because of their ultrahigh hydrothermal stabilities and high yielding synthetic polymer chemistry. Calix[n]arenes (n=4, 6, 8) have long been recognized as versatile supramolecular scaffolds, however, many previous studies report the syntheses and properties of monomeric calixarenes, fewer describe their incorporation into polymers and in most of these, the macrocycles serve only as side-chain pendants. Very recently, we reported the successful synthesis of a first-in-class calixarene-based porous covalent polymer and tested its adsorption ability toward oil and organic solvents. Building on this exciting finding, we synthesized library of porous materials having different calix[n]arene homologs (n=4, 6, 8) as their backbone (BET surface area ranged from 500 to 1000 m2 g-1). In addition, these materials found to be super hydrophobic and therefore, we successfully implemented these materials for multiple applications including oil spill recovery, toxic dyes and micropollutants removal, iodine vapor enrichment and selective gas adsorption and separation. The high efficiency and ease of implementation of the polymer demonstrate the advantages of incorporating the calixarene moiety within a functional material and bode well for the development of calixarene-based materials for environmental applications.
Haythem Suliman Basheer
University of Bahri, Sudan
Title: ZnO synthesis using wet chemical growth with various nanostructures
Time : 15:15-15:45
Biography:
Haythem Suliman Basheer has obtained his MSc in Nanoscience and Nanotechnology. He has been teaching at University of Bahri, Faculty of Applied and Industrial Sciences and his research interest is in nanotechnology especially in clean renewable energy (solar cell) to improve its efficiency and water treatment and purification and desalination.
Abstract:
In this work, zinc oxide nanostructures (NSs) are formed by aqueous chemical growth using equal molar quantities of zinc acetate dehydrate and Hexamethylenetetramines (HMTA) (C6H12N4, 99.5%) at low temperature on Aluminum substrate. The surface morphology of the ZnO (NSs) was characterized using Scanning Electron Microscope (SEM) which showed the change in shape. Pictures of ZnO nanobelts, nanotubes and nanoroses were achieved with the average dimensions ranging between 100 to 300 nm. EDX analysis was used to confirm ZnO purity and UV visible absorption spectrum of ZnO was determined and maximum absorption wavelength was located at 410.67 nm. The calculated band gab was found to be 3.04 eV. XRD was used to confirm the crystallinity of ZnO (NSs).
Dongmyung Oh
National University of Singapore, Singapore
Title: Competition for Grb2 recruitment between EphA2 and EGFR during ligand activation
Time : 16:00-16:30
Biography:
Dongmyung Oh has expertise in single molecule biophysics in live cell imaging. In a recent study of receptor tyrosine singling, he found that the rebinding mechanism by which a cytosolic signaling molecules bind/unbind and rebind to receptor.
Abstract:
Activation of EphA2 and EGFR receptor tyrosine kinases (RTKs) is initiated immediately after binding of their respective ligands, recruiting a variety of downstream signaling proteins and ultimately triggering a diverse range of biological outcomes. Although EphA2 and EGFR respond to distinct ligands (ephrinA1 and EGF, respectively) and trigger distinct responses, they also share key proximal signaling molecules. One such molecule is Grb2, which is an adaptor protein recruited to phosphorylated tyrosine residues and responsible for the recruitment of the Ras activator, SOS. How such receptor triggered signaling activities retain the identity of the triggering receptor and how (or if) different receptors may synergize or compete remains largely unknown. Here, we monitor Grb2 recruitment to ligand-activated receptors in a live cell system in which EphA2 and EGFR are spatially segregated, thus allowing unambiguous distinction of which receptor signaling complex each Grb2 molecule is binding. Results reveal a competitive effect by which, one receptor type can influence the signaling activity of the other remotely. Detailed analysis of Grb2 membrane recruitment kinetics reveals distinct differences between Grb2 recruitment to activated EphA2 clusters and clusters of activated EGFR. Consequences of this type of molecular competition for adaptor proteins in the overall context of signal transduction will be discussed.
Bhaskar Das
University of Nebraska, USA
Title: Unusual ferromagnetism at nanoscale due to surface-spin-reorientation
Time : 16:00-16:30
Biography:
Bhaskar Das is a post-doctoral scientist at the Ames Laboratory of United States Department of Energy (US-DOE). He did his Ph.D. at the Nebraska Center for Materials and Nanoscience of University of Nebraska-Lincoln, Department of Physics and Astronomy. His area of research involves physics of magnetism, nanoscience, materials physics and spintronics. Currently he is working at the US-DOE lab in the project related to magnetism for renewable energy and device technologies.
Abstract:
Mn-based silicides are attractive from the viewpoints of fundamental science and potential applications in spintronics, owing to their exotic spin textures and unique crystal structures. However, bulk alloys show only weak low-temperature magnetic ordering and this inhibits their practical room-temperature applications. Our recent report shows that magnetic nanoclusters exhibit entirely different magnetic properties from the corresponding bulk alloys due to nanoscale effects. In this study, we report the synthesis of novel Mn5Si3 nanoclusters using a gas-aggregation type cluster-deposition method and show unusual ferromagnetism experimentally and by first-principle DFT calculations, in a sharp contrast to antiferromagnetic behavior shown by bulk alloys below 100 K. TEM studies show that Mn5Si3 nanoclusters are monodispersed with an average size d » 8.7 nm and an rms standard deviation σ/d»0.1. The nanoclusters are also single crystalline and form the D88-type hexagonal structure as shown by HRTEM (Figure-1a) and FFT (Figure-1b) images, respectively. The nanoclusters show appreciable coercivities (Hc=900 Oe at 3 K and 450 Oe at 300 K) and high saturation magnetic polarization (Js=12.5 kG at 3 K and 10.5 kG at 300 K) [Figure-1(c)] with a high Curie temperature (Tc≈590 K) [Figure-1(d)]. The fitting of magnetization curve at high-field region (35-70 kOe) using the law-of-approach to saturation method yields an appreciable magneto crystalline anisotropy constant K1≈12 Mergs/cm3. Thus, easy-axes of the nanoclusters were successfully aligned using an external magnetic field prior to deposition, which results in improved Hc (1700 Oe at 3 K and 600 Oe at 300 K). The nanocluster magnetic properties are mainly due to the large surface spin-polarization (m=3.3 µB/Mn) that subsequently spin-polarizes the nanocluster-core (m=0.9 µB/Mn), as revealed by the DFT simulations.
Peng-Sheng Wei
National Sun Yat-Sen University, Taiwan
Title: The effects of wave characteristics on energy generation during additive manufacturing
Time : 16:30-16:50
Biography:
Peng-Sheng Wei has received his PhD in Mechanical Engineering Department from University of California, Davis. He has been a Professor in the Department of Mechanical and Electro-Mechanical Engineering of National Sun Yat-sen University, Taiwan. He has contributed in advancing the understanding of and to the applications of electron and laser beam, plasma and resistance welding through theoretical analyses coupled with verification experiments. He has published more than 80 SCI journal papers. He has been the Xi-Wan Chair Professor of NSYSU and Invited Distinguished Professor in the Beijing University of Technology, China.
Abstract:
A systematical investigation of energy generation responsible for heating and melting during selective laser melting or selective laser sintering in additive manufacturing with a pulsed laser is studied. A surface Plasmon on a rough or grating metal surface can be excited by an incident laser beam in a TM mode. The surface plasma wave is an electromagnetic wave that propagates at the boundary between two media, leading to a concentrated and distributed energy generation on the surface. In this study, energy generated is composed of resistive, dielectric and magnetic losses. Distributions of different modes of energy generated for different frequencies and widths of laser beam irradiating on particles on a surface are presented. Heating and melting during additive manufacturing are, therefore, revealed. Figure-1 shows high energy generation or divergence of Poynting vector occurs near the peak and surface of particles on a surface for different radii of incident electromagnetic wave. Electrical field propagates in radial directions while energy generation decreases, provided that the radius of incident electromagnetic wave decreases.
Martin Caldarola
Leiden University, Netherlands
Title: Single-molecule fluorescence enhancement by gold nanorods: An application to electrochemistry
Time : 16:50-17:10
Biography:
Martin Caldarola is a Postdoctoral Researcher at the Single-Molecule Optics group, Leiden University, Netherlands. He holds a PhD in Physics from the University of Buenos Aires and his expertise is in the field of nanophotonics. His research interest is focused on light-matter interactions, specifically the interaction between single-molecules and nanostructures, including fluorescence enhancement and nonlinear effects in the nanoscale.
Abstract:
Electrochemical (EC) reactions are of crucial importance in diverse fields of nanoscience. Methylene Blue (MB) is well-known redox indicator that can be used as nanoscale probe of the electrochemical environment. With this aim we studied the fluorescence redox-induced blinking of single MB molecules: this molecule is fluorescent in the oxidized state and non-fluorescent in the reduced state. Due to the low fluorescence yield of this molecule Single Molecule (SM) optical sensitivity was achieved employing the high fluorescence enhancement factors provided by individual gold nanorods for weak red fluorophores. Our experimental approach combined single-molecule sensitive confocal setup with an electrochemical cell which allowed the fluorescence readout for an externally-controlled oxidation state of the MB molecule. We work with immobilized MB molecules on a glass surface and we observe the molecules that are enhanced near the tip of the nanorod. We could study the same MB molecule at different electrochemical potentials and we observed that the fluorescence blinking responds to the EC potential change. We performed this type of measurement for several single molecules and from the Nernst Equation we extracted the mid-point potential value, the potential where the molecule spends half of the time in the reduced (dark) state and half of the time in the oxidized state (fluorescent). We found a small dispersion for this value of about 21 mV in a mean value of 78 mV. In conclusion, we accessed the electrochemical properties of methylene blue at single-molecule level using an optical method based on fluorescence enhancement by individual gold nanorods.
- Young Research Forum
Location: Salon VII
Session Introduction
Mika Naumanen
VTT Technical Research Centre of Finland, Finland
Title: Action roadmaps paving the way towards electric mobility and circular economy
Time : 16:30-16:50
Biography:
Mika Naumanen is a Senior Scientist in the Innovation and Knowledge Economy group of VTT. He has run VTT’s “business from technology” program and managed a portfolio of business development projects in the fields of industrial systems management, services and built environment, ICT and electronics. He is a Visiting Scholar in Statistics Finland.
Abstract:
We present action roadmaps paving the way towards electric mobility and circular economy. We do this within the CASI-F (common framework for assessment and management of sustainable innovation) framework, where we first analyze critical issues that influence the uptake of electric mobility and new storage media for electric power. The main lesson from the analysis of the positive and negative effects that the identified critical issues have on the mapped innovations is that the actions to manage such an extensive set of barriers, drivers, opportunities and threats might need to be implemented by multiple actors with different managerial roles and responsibilities. Due to government’s ability to change legal and administrative structures and procedures, one important role for government and the public sector is related to changing and/or adapting such infrastructures in a way that would support the implementation, scaling, diffusion and institutionalization of electric mobility innovations. Not only monetary resources are of importance, but also the positive acknowledgement and general support, e.g., through awareness raising activities and campaigns, is a task in which the public sector can assist the development, up-scaling and institutionalization processes. An important task for civil society is related to campaigning and awareness raising activities. Thoughtful marketing and an effective issue communication could help in stipulating behavioral changes within people, a task that reoccurs at all three levels for civil society, as well as it could enhance further community engagement. Similar to government and civil society, also businesses have reoccurring tasks and responsibilities. Such responsibilities are mostly concerned with the provision of various kinds of resources, both tangible and intangible. The sharing of knowledge regarding appropriate business models and strategies, their development and implementation, is of great interest. Additionally, businesses are encouraged to engage in networks and to cooperate and collaborate with partners and other relevant stakeholders in order to enhance future battery technologies’ and their recycling potential. Research and education are supporting social innovation by fundamental but practical relevant research, including evaluation of programs and initiatives and the development of tools and methods for (up) scaling electric mobility innovations. This also comprises of giving access to research results and tools for the public (social innovators) and an own engagement in up-scaling processes.
Roaa Sait
Emerging Technologies Research Centre, UK
Title: Synthesis and characterization of TiN NWs towards neural electrode application
Time : 16:50-17:10
Biography:
Roaa Sait is currently a PhD student at De Montfort University in the UK. She has been active in the area of material science and nanotechnology. Recently she has published a paper on synthesis and characterization of sputtered TiN as a nucleation layer. Her current research involves the study of neural electrode interface materials for improving recording and stimulation of neurons in the brain. She focuses on controlling the properties titanium nitride nanostructures.
Abstract:
In neurophysiological measurements, a neural electrode interface material plays a critical role in eliciting action potentials without damaging the tissue of interest. However, the need to minimize electrode dimensions and reduce invasiveness and the activation of glial cells has rendered the choice of a suitable interface material. Platinum, iridium oxide and gold are currently the most utilized microelectrode material due to their apposite electrical and mechanical properties, however their performance becomes limited when electrode dimensions are reduced; as the total surface area decreases, limitations are placed on the successful transfer of charge or charge injection into the tissue for stimulation. Research on nanostructured surfaces has shown a great potential for improving the electrochemical and mechanical properties. Thin films of titanium nitride (TiN) have been implemented in neural electrode applications previously due to its useful properties e.g., TiN has a higher charge injection (2.2-3.5 mC/cm2) as compared to that of Pt (0.02-0.15 mC/cm2). Moreover TiN nanowires (NWs) have not been synthesized previously towards for neural interface application, which is the aim of the work described here. The synthesis involves the low temperature and cost effective hydrothermal growth of Titanium Oxide NWs (TiO2-NWs) grown, for the first time, from a TiN sputtered layer optimized elsewhere. The growth is followed by a novel nitridation process. The effects of the hydrothermal growth parameters (e.g. seeding layer thickness, time and temperature) on the properties of the TiO2 nanowires were investigated using Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Cyclic voltammetry (CV) for morphological, structural and electrochemical studies respectively. Aspect ratio as well as crystalline structure, electrical resistivity and capacitance will be presented and distilled here. The ease and convenience to tune the nanowires properties bring this approach great potential for building an optimum neural electrode interface material.
Silvia Villa
University of Genoa, Italy
Title: Biocompatible multifunctional magnetic nanoparticles for possible applications in nanomedicine
Time : 17:10-17:30
Biography:
Silvia Villa has received her Bachelor’s and Master’s degrees in Chemical Sciences from University of Genoa, Italy. Later, she began a Fellowship on the synthesis of iron oxides NPs as MRI contrast agents at the Italian Institute of Technology, Pisa, Italy. She is currently pursuing PhD at the University of Genoa, Italy, working on magnetic nanoparticles for environmental and biomedical applications. During her PhD, she had the opportunity to work on magnetic ferrites for hyperthermia studies at Norwegian University of Science and Technology, Trondheim, Norway.
Abstract:
Multifunctional nanoprobes combining magnetic nanoparticles (MNPs) with organic dyes have attracted great interest due to their promising applications in biomedical field. Among the wide selection of different nanoprobes, superparamagnetic iron oxide nanoparticles (SPIONs), loaded with different functionalities, provide promising application in the drug delivery therapy. In cancer treatment, a possible drug delivery approach is the well-known prodrug monotherapy (PMT), in which the drug is released by enzymes naturally overexpressed in tumor tissues. A recognized enzyme suitable for this method is plasmin, a serine protease. A combination of the two approaches can enhance the cancer treatment because, under the influence of an external magnetic field, it is possible to orient the magnetic nanoparticles to the tumor site and concentrate the drug in the ill tissue. In this perspective, our project aimed at optimizing this approach, planning a superparamagnetic probe based on iron oxide NPs and conjugating a fluorescent tag through a tripeptide linker. This peculiar system has been designed to be cleaved by plasmin with the resulting release of the fluorescent tag. Therefore, this original system could find applications either in the imaging diagnostic or in the drug delivery fields. Herein, we present the synthesis and the characterization of the two components (SPIONs and the tripeptide linked to a fluorescent tag) and the study of their conjugation. Furthermore, we present the preliminary results of the enzymatic cleavage, as proof of concept of our project.
- Poster presentation
Location: Salon VII
Session Introduction
T Cele
University of South Africa, South Africa
Title: PGM nanoparticles and hybrid nanocomposites by gamma radiolysis/EISA
Time : 17:10-17:30
Biography:
Takalani Cele has received her MSc in Physical Science from University of the Western Cape, South Africa. She is currently pursuing PhD in Nanotechnology at University of South Africa. Her research interest is PGMs nanoparticles by radiolysis, jointly supported by iThemba Laboratory for Accelerator Based Science in South Africa and Université du Maine, Le Mans, France. She is also working on other projects in the Department of Trade and Industry in Innovation and Technology unit.
Abstract:
The multi-functional Platinum Group Metals (PGMs) pure and hybrid nanostructures are based on a biomimicking approach. Marine organisms like diatoms and radiolaria provide material scientists with many examples microstructures are formed by biomineralization a templated self-assembly process in which pre-organized organic surfaces regulate the nucleation, growth, morphology and orientation of inorganic crystals. Recently, various synthetic pathways that mimic aspects of biomineralization have been explored to produce patterned ceramic materials, among which the so-called EISA and EISA templating processes. This research project focuses on the development of pure and hybrid advanced 1-, 2- and/or 3-dimensional PGMs nanocomposites for multi-functional technological applications by a versatile novel hybrid nanotechnology-nuclear process: Radiolysis and Evaporation Induced Self Assembly (EISA). Pt solution of different concentration was prepared from K2PtCl4. The effect of irradiation on Pt4+ solutions with different concentrations irradiated at a certain dose was shown. The big black particles that are fairly agglomerated were spotted when the concentration is above 5×10-3 M. The UV-Vis spectrum of Pt of different concentrations shows a strong absorption peak at the wavelength 261 nm after irradiation, which indicates the presence of platinum nanoparticles. Furthermore, XRD and HRTEM images also confirmed the presence of the nanoparticles produced by radiolysis.
Mamta Bhardwaj
Sant Longowal Institute of Engineering & Technology, India
Title: Synthesis of starch nanoparticles by acid hydrolysis alone and coupled with other technique and their subsequent characterization and utilization
Time : 17:30-17:50
Biography:
Mamta Bhardwaj has obtained her Bachelor’s degree in Biotechnology, Masters in Food Engineering & Technology and is presently a Doctoral student and an INSPIRE Fellow at Sant Longowal Institute of Engineering & Technology, India. Her current research interests include starch and its nanoparticles and rheology of food materials, particularly the dynamic mechanical analysis.
Abstract:
Starch is one of the most abundant biopolymer extracted from plants in the form of micro-granules. Due to fascinating properties of being non-toxic, non-irritant, low-cost, ease of modification and versatile use, etc., makes starch a promising candidate to prepare nanoparticles. Starch nanoparticles already attract great interest because of their wide application in food, cosmetics, medicines as well as various composites. Various botanical sources are available for extraction of starch nanoparticles facilitating nanoparticles with a range of amylose content, shape, viscosity in suspension and thermal resistance. Starch nanoparticles can be synthesized by both physical and chemical methods. In the present study, starch nanoparticles were synthesized from two varieties of Pearl millet (HHB67 and ProAgro 9444) by acid hydrolysis and acid hydrolysis coupled with ultrasonication. Acid hydrolysis at 3.2 M H2SO4 and 40 oC for 5 days resulted in starch nanoparticles in the range of 40-60 nm whereas acid hydrolysis for 2 days coupled with ultrasonication resulted in 20-30 nm particle size. Among the two varieties HHB67 gave nanoparticles with smaller size than ProAgro 9444 due to more amylopectin content viz., 85% amylopectin in HHB67 and 79% in ProAgro 9444. Morphological and crystalline structure was analyzed by scanning electron microscopy and XRD respectively. The results revealed that nanoparticles possess A-type granular structure as obtained for the crystalline structure of original starch varieties. Besides the nanometric size, methods and varieties showed significant difference in solubility, hygroscopicity and paste clarity. Dynamic mechanical analysis was studied to obtain temperature and amplitude sweep data. Nanoparticles obtained by acid hydrolysis and acid hydrolysis coupled with ultrasonication can be used in bio-nanocomposites.