Scientific Program

Conference Series Ltd invites all the participants across the globe to attend 8th International Conference and Exhibition on Materials Science and Engineering Osaka, Japan.

Day 1 :

  • Materials in Research

Session Introduction

Jana Zarubova

Institute of Physiology of the Czech Academy of Sciences, Czech Republic.

Title: Dynamic decellularization and recellularization of vascular grafts
Speaker
Biography:

Jana Zarubova gained her Ph.D. in Biochemistry from the Charles University in Prague. Her research focuses mainly on the design and biological evaluation of materials for vascular and bone tissue engineering. Jana Zarubova participates in the development of bioreactors for dynamic cell culture. She has long-term experience with mesenchymal stem cell culture, differentiation and their co-culture with different cell types. Jana Zarubova is also interested in the extracellular matrix and its influence on cell behavior.

Abstract:

Cardiovascular diseases are one of the leading causes of death worldwide [1]. A common treatment option to replace the diseased blood vessels is vascular grafting using patient’s own blood vessels. The availability of such grafts is however limited by the patient’s age or pathology. Artificial alternatives to the autologous grafts are currently made of relatively inert non-degradable materials such as expanded polytetrafluoroethylene and polyethylene terephthalate [2]. These polymers have been successfully used for the replacements of blood vessels with a high blood flow and an internal diameter larger than 6 mm. However, smaller-diameter grafts show very poor long-term patency, largely due to the thrombogenicity of the artificial surface under low flow conditions and intimal hyperplasia [3, 4]. Recently, decellularized tissues have emerged as promising scaffolds for constructing replacements of various tissues and organs. In this study, decellularization of porcine vessels in a perfusion dynamic system was examined and compared with the manual decellularization procedure. The composition of extracellular matrix proteins [5], structure and mechanical properties of decellularized vessels were tested and compared with native blood vessels. Decellularized scaffolds were then seeded with endothelial cells and adipose-derived stem cells and cultured in a bioreactor with defined shear stress in order to simulate physiological conditions in the body.  It was shown that dynamic decellularization dramatically shortens the time needed for decellularization. It also enables standardization of the decellularization process resulting in a consistent scaffold material. Cultivation of recellularized vessels under dynamic conditions induces anti-thrombogenic phenotype in endothelial cells and improves cell adhesion and ingrowth into the scaffold. 

Speaker
Biography:

Dr. Xiaowang Zhou completed his PhD from Clemson University, South Carolina, USA. He has been principal member of technical staff, Mechanics of Materials Department, Sandia National Laboratories since 2012. He has published more than 100 papers in reputed journals and has been serving as an editorial board member of Journal of Materials Science Research.

Abstract:

This work uses molecular dynamics simulations to study surface and interface properties of PdHx that are relevant to hydrogen storage applications. In particular, surface energies, interfacial energies, surface diffusivities, and surface segregations are all determined as a function of composition and temperature. During the course of the calculations, we demonstrated robust molecular dynamics methods that can result in highly converged finite temperature properties. Challenging examples include accurate calculations of hydrogen surface diffusivities that account for all possible atomic jump mechanisms, and constructions of surface segregation composition profiles that have negligible statistical errors. Our robust calculations reveal that the Arrhenius plots of hydrogen surface diffusion is ideally linear at low compositions, and becomes nonlinear at high compositions. The fundamental cause for this behaviour has been identified. This nonlinear surface diffusion behaviour is also in good agreement with available experimental data for bulk diffusion. The implication of our calculated properties on hydrogen storage application is discussed.

 

Speaker
Biography:

Ms. Yi Wen Phuan received her B.Eng (Hons 1A) in Chemical Engineering from Monash University Malaysia in 2013. She continued her postgraduate studies in 2013 under the supervision of Assoc. Prof. Dr. Meng Nan Chong and Assoc. Prof. Dr. Eng Seng Chan. Her research focuses on the electrochemical synthesis and modification of nanostructured hematite (α-Fe2O3) as an efficient semiconductor photoanode material for application in photoelectrochemical (PEC) water splitting.

Abstract:

In this study, a novel ternary hematite (α-Fe2O3)-based nanostructured photoanode with excellent photoelectrochemical (PEC) performance consisting of 2D-electrochemical reduced graphene oxide (eRGO) and nickel oxide (NiO) was successfully developed through electrodeposition method. The surface morphology and structural properties of the nanostructured photoanode were characterised by using field emission-scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HRTEM). Results showed that the flexible eRGO sheets provide intimate and coherent interfaces between α-Fe2O3, NiO and eRGO, promoting charge transfer over their interfaces and thus, lowering the photogenerated electron-hole pairs recombination rate. X-ray diffraction (XRD) patterns, Raman spectra and X-ray photoelectron (XPS) spectra validated that both eRGO and NiO were successfully electrodeposited onto the ternary eRGO/NiO/α-Fe2O3 nanostructured photoanode. As evidenced from the ultraviolet-visible (UV-vis) diffuse reflectance spectra, the incorporation of eRGO and NiO has endowed α-Fe2O3 nanostructured photoanode with a wider spectral absorption range where the light absorption intensities in the visible light and near infared regions are improved. Electrochemical impedance spectroscopy (EIS) further confirmed that the ternary eRGO/NiO/α-Fe2O3 nanostructured photoanode possesses the lowest charge transfer resistance, indicating that the combined effects of eRGO and NiO could improve the electron mobility by impeding the recombination process of photogenerated charge carriers and resulting in superior PEC performance. This is because eRGO sheets act as surface passivation layer and electron transporting bridge that increase the electron transfer at the semiconductor/liquid junction. Whereas, NiO serves as hole acceptor that effectively hinders the recombination of photogenerated electron-hole pairs and accelerate the interfacial charge transfer. The solar hydrogen evolution rate of the ternary eRGO/NiO/α-Fe2O3 nanostructured photoanode was about 3-fold higher than the bare hematite. It is expected that the fundamental understanding gained through this study is helpful for the rational design and construction of highly efficient ternary nanostructured photoanodes for application in solar hydrogen energy conversion through PEC process.

Speaker
Biography:

Mr. Chot Chun Yuan graduated with a Bachelor of Engineering in Chemical Engineering with Honours from UCSI University in 2015. He joined Monash University Malaysia in the same year for postgraduate studies under the supervision of Assoc. Prof. Dr. Meng Nan Chong, Prof. Dr. Ai Kah Soh, and Assoc. Prof. Dr. Khang Wei Tan. His research focuses on the development of molybdenum trioxide-based photoanodes with charge storage capacity for PEC water splitting under illuminated and non-illuminated conditions. 

Abstract:

Photoelectrochemical (PEC) technology is one of the most promising methods that converts solar irradiation into storable chemical energy in the form of hydrogen (H2) via water splitting reaction. To date, the PEC technology has been studied extensively in terms of the synthesis of photoelectrodes such as synthesis approaches, structural modifications, and improvement of photoresponses. However, the PEC technology is still limited by one of the most challenging bottlenecks where all PEC cells can only be operated under well-illuminated condition. Generally, light source is the most crucial element in a PEC cell as it initiates the photoreactions and producing photogenerated charge carriers. When the light source used is withdrawn (i.e. non-illuminated condition), all the photoreactions will be terminated instantaneously. Therefore, there is a growing significance in enabling the operation of PEC technology under non-illuminated condition via the rational design of photoelectrodes for efficient solar energy conversion and storage. Recently, molybdenum trioxide (MoO3) has attracted numerous research attention due to its unique layered crystalline structure that leads to charge storage capacity in PEC technology application. Within the MoO3 structure, a portion of the charges could be stored in the layered crystalline structure via intercalation (MoO3 + xNa+ + xe- à NaxMoO3) during the well-illuminated condition. Whilst the stored charges will be released from the molybdenum bronze (NaxMoO3) and continuously flow to the counter electrode via de-intercalation (NaxMoO3 à MoO3 + xe- + xNa+) during non-illuminated condition. Thus, the main aim of this work was to synthesize thin films of MoO3 via the aerosol-assisted chemical vapour deposition (AA-CVD) method for application as photoanode used in PEC water splitting. This was followed by a systematic optimisation of the ultrasonication time on the precursor colloidal suspension, and annealing temperature on the eventual crystalline MoO3 structure formed. FE-SEM images showed that the MoO3 thin films that are synthesized from the AA-CVD method exhibited a 3D plate-like crystalline structure. Further electrochemical characterisations measured that the AA-CVD synthesized MoO3 thin films possessed a high charge storage capacity of 1.22 mC/cm2 and a low charge transfer resistance of 87.6 Ω at the optimum ultrasonication time of 25 min and annealing temperature of 550o

Speaker
Biography:

Mr. Yaw Chong Siang graduated with a Bachelor of Engineering in the discipline of Chemical Engineering with Honours from Monash University Malaysia in 2014. He returned to Monash University Malaysia the following year for postgraduate studies under the supervision of Assoc. Prof. Dr. Meng Nan Chong and Prof. Dr. Ai Kah Soh. His research focuses on the synthesis of BiVO4-based heterojunction-tandem photoelectrodes for solar hydrogen energy conversion from PEC water splitting.

Abstract:

Hydrogen (H2) has featured prominently as a potential alternative and renewable energy source. To date, one of the most feasible production routes of solar H2 generation is through the photoelectrochemical (PEC) water splitting. In this regard, bismuth vanadate (BiVO4) is a promising semiconductor photoelectrode material that can be used for PEC water splitting. This is owing to its low-cost, relatively narrow bandgap of 2.4 eV and favourable positioning of valance band edge that provides sufficient overpotential for water oxidation. To date, however, the practical photocurrent yield of BiVO4 photoelectrode reported in the literature is far lower than its full potential due to poor photogenerated carriers separation and high bulk and surface recombination rates. The emergence of heterojunction photoelectrode design is considered to be able to address these setbacks, while providing an internal electric field for improving the photogenerated charge carriers transfer in a PEC cell setup. Thus, the main aim of this study was to fabricate a heterojunction V2O5/BiVO4 photoanode due to the fact that V2O5 is the most stable form of vanadium oxide, and has received intense interest due to its inherently good electrochemical and photochemical properties. The resultant heterojunction V2O5/BiVO4 photoanode structure was characterised by using field emission-scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV-visible spectroscopy, and a number of PEC measurements and analysis. Through this study, it was found that the photocurrent density of a bare BiVO4 photoanode increased from 0.07 to 0.40 mA/cm2 (at 1V vs. Ag/AgCl) after the formation of a heterojunction photoanode structure with an underneath V2O5 layer. This is almost a 6-fold improvement in terms of photocurrent density, and this study has demonstrated the presence and role of V2O5 in the heterojunction structure that extends the light absorption range as well as improving the electrons mobility and effective separation of photogenerated charge carriers. 

Speaker
Biography:

My current position is a Scientist and Researcher at Department of Applied Radiation and Isotopes Faculty of Science, Kasetsart University. I have 4 years experience in radiation detection and nuclear instrument operation i.e. Gamma spectrometer, Liquid scintillation counter and Imaging plate system. Also, I have experiences in the design and development of radiation instrument such as development of data storage system for multichannel analyzer by using SD card. I am also responsible for the academic services in radionuclide measurement in foods imported from Japan.

Abstract:

Graphene aerogels (GAs) is one of the most promising nano materials leading to several potential applications to capture and sequestration of radionuclides, in this work, the synthesis graphene oxide (GO) was fabricated based on the modified Hummer’s method. Graphene oxide gel (GO gel) prepared by centrifuged graphene solution at 5000 rpm for 20 min then it washed by DI water. In case of graphene aerogel, the dry graphene oxide gel by Freeze Drying (at -10 °C for 300 min). For absorption part we mixed GO gel 0.5 g and GAs 0.5 g with Sodium iodide solution concentration 3.40% (w/v) at room temperature for 24 hours. It was revealed that the type of graphene has impacts to the adsorption iodine particles in water. The results of scanning electron microscopy (SEM) showed iodine particles on the surface of GO aerogel more than GO gel. Moreover the results of EDX show percentage of Iodine element inside The GO aerogel have 14.97% it better than the GO gel have 4.82 % of iodine element on the surface.