21^st World Congress on Materials Science and Engineering June 22-23, 2020 Rome, Italy

Biography:

Abdeen Mustafa Omer (BSc, MSc, PhD) is an Associate Researcher at Energy Research Institute (ERI). He obtained both his PhD degree in the Built Environment and Master of Philosophy degree in Renewable Energy Technologies from the University of Nottingham. He is qualified Mechanical Engineer with a proven track record within the water industry and renewable energy technologies. He has been graduated from University of El Menoufia, Egypt, BSc in Mechanical Engineering. His previous experience involved being a member of the research team at the National Council for Research/Energy Research Institute in Sudan and working director of research and development for National Water Equipment Manufacturing Co. Ltd., Sudan. He has been listed in the book WHO’S WHO in the World 2005, 2006, 2007 and 2010. He has published over 300 papers in peer-reviewed journals, 200 review articles, 7 books and 150 chapters in books

Abstract:

Globally, buildings are responsible for approximately 40% of the total world annual energy consumption. Most of this energy is for the provision of lighting, heating, cooling, and air conditioning. Increasing awareness of the environmental impact of CO₂, NO_x and CFCs emissions triggered a renewed interest in environmentally friendly cooling, and heating technologies. Under the 1997 Montreal Protocol, governments agreed to phase out chemicals used as refrigerants that have the potential to destroy stratospheric ozone. It was therefore considered desirable to reduce energy consumption and decrease the rate of depletion of world energy reserves and pollution of the environment. This article discusses a comprehensive review of energy sources, environment and sustainable development. This includes all the renewable energy technologies, energy efficiency systems, energy conservation scenarios, energy savings and other mitigation measures necessary to reduce climate change.

There is strong scientific evidence that the average temperature of the earth’s surface is rising. This was a result of the increased concentration of carbon dioxide and other GHGs in the atmosphere as released by burning fossil fuels. This global warming will eventually lead to substantial changes in the world’s climate, which will, in turn, have a major impact on human life and the built environment. Therefore, effort has to be made to reduce fossil energy use and to promote green energies, particularly in the building sector. Energy use reductions can be achieved by minimising the energy demand, by rational energy use, by recovering heat and the use of more green energies. Low energy design of urban environment and buildings in densely populated areas requires consideration of wide range of factors, including urban setting, transport planning, energy system design and architectural and engineering details. The focus of the world’s attention on environmental issues in recent years has stimulated response in many countries, which have led to a closer examination of energy conservation strategies for conventional fossil fuels. One way of reducing building energy consumption is to design buildings, which are more economical in their use of energy for heating, lighting, cooling, ventilation and hot water supply. The study was a step towards achieving this goal.

Biography:

Cuong Manh Vu has completed his PhD at the age of 28 years from Hanoi University of Science and Technology (Vietnam). He is the lecturer at Le Qui Don Technical University. He has published more than 30 ISI papers relating to polymer science in peer reviewed journal.

Abstract:

The combined effects of phosphorous-jointed epoxidized soybean oil (DOPO-J-ESO) and rice husk-based silica (RH-SiO2) on the flammability and mechanical properties of epoxy resin were examined in detail. The chemical structures of the ESO, DOPO-J-ESO, RH-SiO₂ were confirmed using Fourier transform infrared spectroscopy and proton nuclear magnetic resonance. Many characteristics of the obtained composite materials were examined, such as the tensile properties, impact strength, flexural strength, critical stress intensity factor (KIC), dynamic mechanical analysis, and flammability. The incorporation of both 10 phr DOPO-J-ESO and 20 phr RH-SiO2 into the epoxy resin yielded the optimum values of the flexural strength, tensile strength, impact strength, and KIC, with increases of 87.78%, 67.23%, 109.34%, and 111.32%, respectively, compared with pristine samples. The limiting oxygen index increased from 23.1% to 29.3%, the peak heat-release rate decreased by up to 37.2%, and the sample satisfied the UL94 V-0 rating.

Biography:

Daolun Chen is a Professor of Ryerson University, Toronto, Canada. He completed his BSc and MSc at Northeastern University (China), PhD at Chinese Academy of Sciences, and Dr.rer.nat. at University of Vienna. Dr. Chen has published 398 peer-reviewed journal (316) and conference (82) papers, plus 190+ non-refereed conference papers/research reports. He is a recipient of numerous prestigious awards, including Premier’s Research Excellence Award, Canadian Metal Physics Award, G.H. Duggan Medal, MetSoc Award for Research Excellence, MetSoc Distinguished Materials Scientist Award. Dr. Chen is an elected Fellow of Canadian Academy of Engineering (FCAE), and an Editorial Board Member of 28 journals.

Abstract:

Vehicle lightweighting is today recognized as one of the predominant approaches to improve fuel efficiency and reduce anthropogenic climate-changing, environment-damaging, costly and human death-causing emissions, since every 10% reduction in weight would lead to about 6~8% increase in fuel efficiency. This, along with materials designed for improved fatigue, creep, impact or corrosion resistance, has been identified as one of six areas critical to solving national and global grand challenges. Magnesium alloy, as an ultra-lightweight metallic structural material, has been increasingly used in the transportation industry to reduce the weight of vehicles. However, the hexagonal close-packed crystal structure of magnesium alloys limits the availability of slip systems and results in strong mechanical anisotropy and tension-compression yield asymmetry due to the presence of twinning and the related development of deformation texture. For the vehicle components subjected to dynamic cyclic loading, such asymmetry could exert an unfavorable influence on the material performance and compromise the structural integrity, safety, and durability of highly loaded structural components. This problem could be overcome through weakening the basal texture via the addition of rare-earth (RE) elements. In this talk a few examples on the deformation behavior of extruded magnesium alloys containing both high and low RE contents will be presented in comparison with RE-free extruded magnesium alloys. Furthermore, twinning and twin growth during uniaxial compression along the extrusion direction and de-twinning along the transverse direction will be discussed as well.

Biography:

Dinfa L. Domtau has completed his PhD at the age of 37 years from University of Nairobi, Kenya. He also visited the Institute of Energy and Climate Change Research, Julich, Germany for six months for his PhD research. He is a Lecturer at the Department of Physics, University of Jos, Jos, Nigeria. He has published more than 14 papers in reputed journals.

Abstract:

Light harvesting efficiency in dye sensitized solar cell is currently enhanced by the employment of an additional TiO₂ scattering layer hence increasing the overall film thickness. This has limitations on effective charge transport especially in dense electrolyte media due to the increased film thickness. The additional film layer further reduces light intensity on the adsorbed dye hence decreasing photocurrent generation. Therefore, there is still the challenge of light scattering optimization versus charge transport and photocurrent generation. In addition, though TiO₂ is a relatively cheap material, the addition of TiO₂ layer raises the production cost of the dye sensitized solar cell effectively and rendering it not cost effective. In this study, carbon black was employed to create artificial pores in TiO₂ thin films to enhance light harvesting and hence photocurrent generation. TiO2 films deposited by screen printing method had 0, 1.0, 1.5, 2.0 and 3.0 wt% carbon black. On annealing of the films at 500oC in air for 30 minutes, carbon black decomposed leaving behind voids. Transmittance, reflectance and absorbance spectra of the films determined by a UV-Vis-NIR show that transmittance decreased as the carbon black concentration increased. On the other hand, both reflectance and absorbance increased with increase in carbon black concentration. Micrograph images obtained from both Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) show that the pore size of the films increased as the carbon black concentration increased. Furthermore, the XRD results of these films show that the TiO2 are anatase and without any carbon contamination. Conductivity of the films determined using a four point probe was found to decrease with increase in pore size due to decrease in electrical contacts among the TiO₂ molecules. The values 384.61, 352.11, 103.41, 52.41 and 35.29 Siemen’s cm-1 were determined for 0, 1.0, 1.5, 2.0 and 3.0, respectively. Current-Voltage (I-V) characteristics of the cell fabricated with different pore sizes were determined using a solar cell simulator at 100 mW/cm2 illumination. The results show that photocurrent generated by these cells increased from 6.1 mA/cm2 to a maximum value of 9.9 mA/cm² as the wt % carbon black increased from 0 wt% to 1.5 wt %, respectively. Beyond 1.5 wt%, photocurrent begun to drop until it got to its minimum value of 4.7 mA/cm² at 3.0 wt%. The overall efficiencies for 0, 1.0, 1.5, 2.0 and 3.0 wt% were found to be 2.3, 2.6, 4.3, 2.4 and 1.4 %, respectively. The result shows an improvement in the photovoltaic performance of DSSC as a result of the artificial voids created. However, beyond the optimum concentration of 1.5 wt%, the cell performance begun to decline. This approach greatly enhanced the current density of the cells and consequently the overall conversion efficiency significantly.

Biography:

Born in Havana, Cuba in 1962, graduated in Physics in 1985, working for the Microelectronics Industry, as head of final control investigations degradation production of electronic components, working for the Electronics Industry, department of reliability, characterization work performed Luma-Chroma plate worker Research   Institute of Metrology, work Challenges of Metrology in Cuba in the era of nanotechnology. Work published in the ISO TC 229, ISO TC229 / IEC 113, required for conformity assessment of research and nano-scale productions Tool page. Master of Science. Currently my research is directed towards an analysis of the chains of traceability that are needed in the industrial revolution that we are experiencing the Convergences of technologies, which is approaching the Quantum revolution with the objective of the evaluation of conformity, of a sustainable way, with a minimum of environmental impact and with social responsibility.

Abstract:

The convergence of nanotechnologies generates synergies among different technologies to say, nanotechnologies, neurotechnology, computers and biotechnology, these technologies must converge) itchier regulations, the application of medical devices in nanotechnologies should lead us to a link between the technical committee TC 210 and ISO technical committee 229 link that does not exist in our work in this moment In this do an analysis of the management of risk from an optical NC-ISO 14971 ). Studying the global trend in this respect as imported for manufacturers medical Devices worldwide. The convergences of technologies is a consequence of atomic precision, where the boundary between the biotic and abiotic mute blur the interaction. The interaction between nanotechnologies, biotechnology and informatics and communications (NBI) generates a synergy of unusual consequences of all is known that the industry of semiconductor)s is the one of greater precision that is atomic, the new medical devices that will be applied in the teranocis will dose Physical principles that will be governed under the laws of quantum mechanicsbut there are two problems that have not been solved even though they are one the non-existence of quantum biology and the transition from quantum to classical mechanics. On the other hand, the redefinition of the international system of units based on the universal constants that will be implemented by 2019 has a deficiency that is the second that redefirms implies redefinition of the meter the chain of traceability proposed for nanometrology presents a serious difficulty when putting the microcopy of atomic force wing of effect  tunnel situation that is changing the verification of the Wiedemann-Franz law at atomic level yields a result where the phononic component is taken into account, a result that launches STM to the cusp of the chain of traceability above inclusive of interferometry.

Biography:

He Zhang is a second year PhD candidate in the major of Chemical engineering at University of New South wales. His research maily focous on desgining 2D nanomaterilas towards efficient drug delivery system.

Abstract:

Two-dimensional (2D) layered double hydroxide (LDH) nanoparticles have been widely studied for biomedical applications due to its tremendously biocompatible properties at the nanoscale.  Exfoliating LDH nanoparticles into ultrathin nanosheets is an efficient way to maximize the utility of each single layer, which possess the higher specific surface area. However, current exfoliation methods of LDH nanoparticles are either time-consuming or lack of biocompatibility (bottom-up method), which remains a bottleneck for biomedical applications of LDH nanosheets. Herein, we developed a novel and rapid method to synthesis ultrathin LDH nanosheet with a thickness of around 3nm via bottom up method. In this work, the modified Poly (ethylene glycol) (PEG) is not only successfully applied as layer inhibitor to urge the formation of LDH nanosheet, but also acted as a surfactant to improve its biocompability, making this ultrathin LDH nanosheet an excellent candidature for drug delivery system. Comparted with pristine LDH nanoparticles, this nanosheets show a good colloid stability among different artificial biological solutions. It is also featured with superb drug loading capacity and loading efficiency of universal anticancer drug doxorubicin (DOX). This nanosheet loaded DOX also exhibit a pH-controlled DOX releasing manner, indicating a good tumour selectivity. Additionally, both in vivo and in vitro results reveal the excellent anticancer activity and superior biocompatibility of the DOX loaded nanosheet. overall, this work provides a potential strategy of modifying functional LDH nanosheet for its bioapplication in drug delivery system.

Biography:

Ifra Mirza is a research scholar at Indian Institute of Technology, Delhi. She has expertise in particle’s fabrication via electrohydrodynamic jetting technique (modification of electrospinning) and surface modification.

Abstract:

The performance of particles is highly influenced by particle size, shape, surface chemistry, elasticity and permeability1. Electrohydrodynamic jetting technique has proven to be a versatile technique to fabricate particles with different shapes and sizes. In this work, we have fabricated topologically anisotropic cup shaped made from polylactide (PLA)/ poly[methylmethacrylate-co-2-(2-bromopropionyloxy) ethyl methacrylate]  (75/25) of ~6 μm size using electrojetting technique. Solution and processing parameters were changed to understand the mechanism of cup shape formation and to control particle’s shape from cups to discoids. Surface initiated atom transfer radical polymerization (ATRP) of stimuli responsive DMAEMA (2-dimethylamino ethyl methacrylate) was subsequently carried out for 1 h onto the surface of cup shaped particles to observe pH responsiveness of the modified anisotropic particles. An interesting change in the morphology of cup shaped particles was observed which changed to elongated cup and showed significant swelling under acidic pH (swelling ratio:~1.6), also enhanced dye adsorption at specific pH was observed by optical microscope and confocal laser scanning microscope implying that DMAEMA polymerization happened onto the surface of the composite microparticles. The Raman microscopy and FTIR spectra obtained from the particles after polymerization further confirmed the immobilization of pH responsive poly(DMAEMA) brushes onto the cup shaped particles which may potentially function as triggered/targeted drug delivery vehicles. Moreover, the brush modified cup shaped particles were found to be two times more efficient in adsorbing dye compared to disc shaped one indicating a clear advantage of using cup shaped particles over other shapes for immobilizing/adsorbing charged species e.g. sensitive biomolecules.

Biography:

Iyad is an Emerging Technologies professional who obtained his PhD from the University of Cambridge. He has worked in the field of Organic Electronics where he has published his studies in high ranking journals and is a patent holder. Iyad has most recently worked in the commercialisation of organic technologies into emerging consumer electronics.

Abstract:

Organic semiconductors have had a vibrant history and have enabled the highest quality display technologies that we use today. Their low-cost manufactring paradigms which are compatible with Industry 4.0, as well as introducing flexible form factors into the electronics world has put them at the forefront of contenders to enable emerging applications, wearable and biomedical technologies and the wider Internet-of-Things (IoT). This talk will introduce organic semiconductors, their merits and their history. A highlight of the current state-of-the-art,  current markets and  appications will also be visited, as well as a look beyond the horizon onto what they will be bringing in the future.

Biography:

Junjian Fu is with the College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China.

Abstract:

Magnesium alloys, as a new type of biodegradable medical metal material, have a promising application in the field of interventional medical devices. In this work, Mg-4Zn-0.2Mn-xCa (0.05~1wt.%) were designed to study the effect of Ca element on the mechanical and corrosion properties of the alloy. And the alloy with 0.2wt.% Ca element has the best comprehensive properties. The micro-tubes for vascular stent application of Mg-4Zn-0.2Mn-0.2Ca alloy with 3.6 mm in outer diameter and 0.4 mm in thickness were prepared by hot extrusion-drawing composite process. The microstructure evolution and mechanical properties of tubes showed that the crystal slip, twins and recrystallization occurred during the plastic deformation, and the work hardening was significant. This drawn tube exhibited a tensile strength of 427.3 MPa, yield strength of 383.4 MPa, and elongation of 5.2%. After annealing at 300℃ for 30 min, the microstructure became uniform and the elongation increased to 18.0%. In vitro degradation of tubes were investigated by means of immersion testing in Hank’s simulated solution. The results showed that the corrosion resistance of tubes can be improved by annealing treatment. The long-term immersion tests revealed that the corrosion process of the micro-tubes was relatively uniform. The corrosion rate after immersion for 180 days was 0.3094 mm/y, before complete biodegradable when soaked for 202 days. The results showed that the Mg-4Zn-0.2Mn-0.2Ca alloy exhibited great potential to be used as biodegradable stents.

Biography:

Linyue Jia is with the College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China.

Abstract:

Due to the great potential for weight reduction in aerospace and automotive industries, magnesium-rare earth (Mg-RE) based alloys with outstanding mechanical performance have been widely investigated for decades. However, magnesium alloys are still restricted in engineering applications because of their lower strength and ductility, hence, there are large spaces and challenges in achieving high-performance Mg alloys. This work reports a Mg-Gd-Er-Zn-Zr alloy with ultrahigh strength and good ductility developed via hot extrusion, pre-deformation and two-stage aging. The extruded alloy comprises fine dynamically recrystallized (DRXed) grains and coarse worked grains with large aspect ratio. Pre-deformation has little effect on the microstructure and macro-texture, and serves primarily to introduce a large number of dislocations, resulting in strain hardening and higher precipitation strengthening during subsequent aging due to more nucleation sites. As a result, the alloy exhibits a yield strength (YS) of 506 MPa, an ultimate tensile strength (UTS) of 549 MPa and an elongation (EL) of 8.2% at room temperature, showing superior strength-ductility balance than the other wrought Mg-RE alloys previously reported. The current study proposes a combination of pre-deformation and two-stage aging to further improve the mechanical properties of wrought Mg alloys for engineering application.

Biography:

Osman Adiguzel graduated from Department of Physics, Ankara University, Turkey in 1974 and received PhD- degree from Dicle University, Diyarbakir-Turkey. He has studied at Surrey University, Guildford, UK, as a post doctoral research scientist in 1986-1987, and studied on shape memory alloys. He worked as research assistant, 1975-80, at Dicle University and shifted to Firat University, Elazig, Turkey in 1980. He became professor in 1996, and he has already been working as professor. He published over 60 papers in international and national journals; He joined over 100 conferences and symposia in international and national level as participant, invited speaker or keynote speaker with contributions of oral or poster.

Abstract:

Shape memory alloys take place in a class of functional materials by exhibiting a peculiar property called shape memory effect. This property is characterized by the recoverability of two certain shapes of material at different conditions, and shape reversibility between critical low and high temperatures, which are martensite finish and austenite finish temperatures. Shape memory effect is based on two diffusionless phase transformations, thermal and stress induced martensitic transformations. Thermal induced martensitic transformation occurs on cooling along with lattice twinning with cooperative movements of atoms in atomic scale, with which ordered parent phase structures turn into twinned martensite structures. This transformation occurs as martensite variants with lattice invariant shears which occur in <110> -type directions on the {110}-type planes of austenite matrix, and twinned martensite structures turn into the detwinned martensite structures by means of stress induced martensitic transformation by stressing material in the martensitic condition. Martensitic transformations have diffusionless character and movements of atoms are confined to inter atomic distances. 

Copper based alloys exhibit this property in metastable β-phase region, which has bcc-based structures. Lattice invariant shears are not uniform in these alloys, and the ordered parent phase structures martensitically undergo the non-conventional complex layered structures on cooling. The long-period layered structures can be described by different unit cells as 3R, 9R or 18R, depending on the stacking sequences on the close-packed planes of the ordered lattice. The unit cell and periodicity is completed through 18 layers in direction z, in case of 18R martensite, and unit cells are not periodic in short range in direction z.

In the present contribution, x-ray diffraction and transmission electron microscopy studies were carried out on two copper based CuZnAl and CuAlMn alloys. X-ray diffraction profiles and electron diffraction patterns reveal that both alloys exhibit super lattice reflections inherited from parent phase due to the displacive character of martensitic transformation. X-ray diffractograms taken in a long time interval show that diffraction angles and intensities of diffraction peaks change with the aging time at room temperature. This result reveals a new transformation in diffusive manner.

Biography:

Pavol Kovač has completed his PhD in 1988 at Faculty of Electrical Engineering of the    Slovak Technical University in Bratislava. He is the head of the Department of Superconductors in the Institute of Electrical Enginnering of Slovak Academy of Sciences and the number of editorial board of. He has published more than 300 papers in reputed journals and has been serving as an editorial board member of the Journal of Superconductor Science and Technology.

Abstract:

Functional superconductors are usually composite wires consisting of superconducting filaments inside a severall metallic sheaths playing the role of inter-diffusion protection (diffusion barrier) and also the role of electrical and mechanical stabilization. Up to now, MgB₂ phase is the lightest existing superconducting compound with specific mass of only 2.5 gcm^-3. The combination of MgB₂ filaments with Ti-barriers and Al-stabilization outer sheath would provide a composite wire with the minimal mass. But, pure Al is too soft to be used for the outer sheath of composite wires subjected to apparent cold deformation by drawing or rolling. Therefore, micro-structure and properties Al+Al₂O₃ material produced by powder metallurgy was carefuly tested and then successfully utilized for composite MgB2/Ti/Al+Al₂O₃ wire. Mechanical and electrical properies of such wire were examined at low temperatures and used also for the superconducting coil made by wind and react process with utilization of self-insulated 15 µm Al2O3 layer created on the wire surface by the anodic oxidation. Very thin and high temperature resistant Al₂O₃ layer offers high space factor which maximize the current density and winding efficiency. High electrical performance and also tolerance to axial stress have been obtained for MgB2/Ti/Al+Al₂O₃ wires at low temperatures. Such lightweight MgB₂ composite conductors can be especially interesting for future high power density aircraft engines and also for some of space applications (e.g. active magnetic shielding), where the total mass of system is important issue.

Biography:

Weiye Zhang received his B.S.Degree in Qufu Normal University in 2008.He is currently pursuing her Master’s Degree at the College of Materials Science and Techlogy,Beijing Forestry University under the supervision of Prof.Hongwu Guo and Lecturer Yi Liu.His research has focused on wood-based advanced energy storage materials and devices.

Abstract:

Hydrothermal or electrochemical deposition method has been employed to fabricate porous wood carbon (PWC)/pseudocapacitance hybrid materials for use as a free-standing supercapacitor electrode. However, its cycle stability is rather poor, and its specific capacitance needs to be further improved because of the existence of pseudocapacitor material. In this paper, PWC was directly used as conductive matrix by the pyrolysis of nature balsa wood, and then manganese oxide (MnO₂) and graphene quantum dots (GQDs) were deposited to fabricate PWC/MnO₂/GQDs electrode by hydrothermal method. Compared with the PWC/MnO₂ electrode, unique needle-like nanostructures formed by adding GQDs have resulted in better electrochemical performance for supercapacitor electrode including high areal specific capacitance (2712 mF/cm⁻² at the current density of 1.0 mA/cm⁻²), good cycling stability, and excellent rate capability (95.3 % retention after 2000 cycles). This work indicate that GQDs decorated composites will promote the development of high performance energy storage device.

Biography:

WU Yongling gained her B.Eng and M.Phil in Mechanical Engineering from Tsinghua University in 1985 and 1988 respectively, and Ph.D in nanomaterials synthesis and coating from Nanyang Technological University of Singapore in 2009. Prior to joining Shandong University of Technology (SDUT), she was a Senior Scientist in the Agency for Science, Technology and Research (A-STAR) of Singapore leading a research team in Surface Technology. Her research field include chemical synthesis of nano-materials for bio-imaging and functional coatings (Quantum Dots, photochromic, IR absorption, antimicrobial, UV shielding etc.); sol-gel chemistry and technology, chemical formulation of coating materials for multi-functional coatings,  hydrophobic hard coating, anti-reflective coating, coloured decorative coatings for plastics and metals, non-stick, low friction, scratch resistant and abrasion resistant coatings, antimicrobial and bio-compatible coatings.

Abstract:

Silver ion and silver nanoparticles are well known for their ability to kill bacteria effectively[1]. However, the side effect of high dose silver on humans especially children has been a major concern when designing antimicrobial coatings for daily life environment.  ZnO quantum dots have been studied intensively by doping with different levels of elements, which emit the constituents of white light covering violet, blue, green, yellow, and red [2], making it very attractive for the application as luminescent material and bio-markers [3]. ZnO nanorod arrays were used to fabricate LED light and highly sensitive chemical sensors for O₂ and NO₂ [4] and hydrazine (N₂H₄) [5] respectively. The most important property of ZnO is its antimicrobial property and photocatalytic activity under UV-light [6] owning to the disruption of cell membrane during the nanoparticles interaction with the bacterial [7]. In this paper, we report a study into the effect of size, shape and metal ions doping of ZnO nanoparticles on the bacterial killing efficacy. We use a solution synthesis method varying the way of adding precursors, the doping element type and amount, the surface capping agents, and the processing parameters. We obtained several shapes (spherical, hexagonal prism, nanorod, flower-like etc.) in different sizes ranging from 30nm to 100nm. We analyzed the morphological structures of the particles, measured the antibacterial properties using JIS Z2801 method, and finally confirmed that the combined effect of size, doping, shape and surface morphology contributed to the antibacterial property of ZnO nanoparticles. Our research suggests that only 0.05-0.2% of silver doping into ZnO could effectively reduce the size of ZnO nanoparticles with Ag ions preferentially located on surface of particles making high efficacy of antibacterial property

Biography:

Ziyi Guo is a PhD candidate at the school of Chemical Engineering and Graduate School of Biomedical Engineering in University of New South Wales (Australia), supported by the Australian Government Research Training Program Scholarship. She obtained her BSc degree in Materials Science and Engineering in Central South University (China) in 2017. Her research interests focused on smart responsive nano-bio-hybrid materials.

Abstract:

Artificial and micro/nano biohybrids have emerged as an exciting branch of research at the interface of materials engineering and biological science. People have found vast potential for applications ranging from nanomedicine to environmental remediation. Among the biohybrids, self-propelled artificial micromotors have been extensively investigated in the last few years, showing promise for controlled drug delivery, sensors, environmental remediation, and micromanipulation. As we advance toward real-world applications, steering of the motors to a specific destination and with speed regulation will be required.

Here, we report for the first time the design of a novel submarine-like micromotor that is capable of regulating its buoyancy force to achieve reversible, corporative directional vertical motion in centimeter-scale. Guided by density functional theory (DFT) calculations, we synthesized a composite metal-organic framework (MOF)-based micromotor system containing a bioactive enzyme as the engine for gas bubble generation and a pH-responsive, hydrophilic/hydrophobic phase-shifting polymer as the gear to tune the micromotor buoyancy force through modulated interaction with the produced gas bubbles. Importantly, anti-cancer drug-loaded micromotors showed directional cytotoxicity to the three-dimensional cell cultures, depending on the pH of the cellular environment. We found that such facile and versatile method for exploring novel driving forces for motion manipulation could be further applied to colloidal science and electrochemistry, showing potential as smart cargo transport microsystems that could accomplish more challenging tasks by exploiting the complex biological environment.