Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

University of Wollongong

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1261 - 1290 of 4868

Full-Text Articles in Physical Sciences and Mathematics

Microstructural Origin For The Piezoelectricity Evolution In (K0.5na0.5)Nbo3-Based Lead-Free Ceramics, Hanzheng Guo, Shujun Zhang, Scott P. Beckman, Xiaoli Tan Jan 2013

Microstructural Origin For The Piezoelectricity Evolution In (K0.5na0.5)Nbo3-Based Lead-Free Ceramics, Hanzheng Guo, Shujun Zhang, Scott P. Beckman, Xiaoli Tan

Australian Institute for Innovative Materials - Papers

Chemically modified (K0.5Na0.5)NbO3 compositions with finely tuned polymorphic phase boundaries (PPBs) have shown excellent piezoelectric properties. The evolution of the domain morphology and crystal structure under applied electric fields of a model material, 0.948(K0.5Na0.5)NbO3-0.052LiSbO3, was directly visualized using in situ transmission electron microscopy. The in situ observations correlate extremely well with measurements of the electromechanical response on bulk samples. It is found that the origin of the excellent piezoelectric performance in this lead-free composition is due to a tilted monoclinic phase that emerges from the PPB when poling fields greater than 14 kV/cm are applied. 2013 AIP Publishing LLC.

Go to article

Synthesis, Structural Analysis, And Thermal Decomposition Studies Of [(Nh3)2bh2]B3h8, Zhenguo Huang, Hima K. Lingam, Xuenian Chen, Spencer Porter, Aijun Du, Patrick M. Woodard, Sheldon Shore, Ji-Cheng Zhao Jan 2013

Synthesis, Structural Analysis, And Thermal Decomposition Studies Of [(Nh3)2bh2]B3h8, Zhenguo Huang, Hima K. Lingam, Xuenian Chen, Spencer Porter, Aijun Du, Patrick M. Woodard, Sheldon Shore, Ji-Cheng Zhao

Australian Institute for Innovative Materials - Papers

Boron–nitrogen containing compounds with high hydrogen contents as represented by ammonia borane (NH3BH3) have recently attracted intense interest for potential hydrogen storage applications. One such compound is [(NH3)2BH2]B3H8 with a capacity of 18.2 wt% H. Two safe and efficient synthetic routes to [(NH3)2BH2]B3H8 have been developed for the first time since it was discovered 50 years ago. The new synthetic routes avoid a dangerous starting chemical, tetraborane (B4H10), and afford a high yield. Single crystal X-ray diffraction analysis reveals N–Hd+…Hd2–B dihydrogen interactions in the [(NH3)2BH2]B3H8?18- crown-6 adduct. Extended strong dihydrogen bonds were observed in pure [(NH3)2BH2]B3H8 through crystal structure solution …

Go to article

Nitrogen Removal From Natural Gas Using Solid Boron: A First-Principles Computational Study, Qiao Sun, Meng Wang, Zhen Li, Ping Li, Weihua Wang, Xiaojun Tan, Aijun Du Jan 2013

Nitrogen Removal From Natural Gas Using Solid Boron: A First-Principles Computational Study, Qiao Sun, Meng Wang, Zhen Li, Ping Li, Weihua Wang, Xiaojun Tan, Aijun Du

Australian Institute for Innovative Materials - Papers

Selective separation of nitrogen (N2) from methane (CH4) is highly significant in natural gas purification, and it is very challenging to achieve this because of their nearly identical size (the molecular diameters of N2 and CH4 are 3.64 Å and 3.80 Å, respectively). Here we theoretically study the adsorption of N2 and CH4 on B12 cluster and solid boron surfaces a-B12 and c-B28. Our results show that these electron-deficiency boron materials have higher selectivity in adsorbing and capturing N2 than CH4, which provides very useful information for experimentally exploiting boron materials for natural gas purification.

Go to article

Cation Exchange At Semiconducting Oxide Surfaces: Origin Of Light-Induced Performance Increases In Porphyrin Dye-Sensitized Solar Cells, Matthew J. Griffith, Kenji Sunahara, Akihiro Furube, Attila J. Mozer, David L. Officer, Pawel Wagner, Gordon G. Wallace, Shogo Mori Jan 2013

Cation Exchange At Semiconducting Oxide Surfaces: Origin Of Light-Induced Performance Increases In Porphyrin Dye-Sensitized Solar Cells, Matthew J. Griffith, Kenji Sunahara, Akihiro Furube, Attila J. Mozer, David L. Officer, Pawel Wagner, Gordon G. Wallace, Shogo Mori

Australian Institute for Innovative Materials - Papers

The origin of simultaneous improvements in the short-circuit current density (Jsc) and open-circuit voltage (Voc) of porphyrin dye-sensitized TiO2 solar cells following white light illumination was studied by systematic variation of several different device parameters. Reduction of the dye surface loading resulted in greater relative performance enhancements, suggesting open space at the TiO2 surface expedites the process. Variation of the electrolyte composition and subsequent analysis of the conduction band potential shifts suggested that a light-induced replacement of surface-adsorbed lithium (Li+) ions with dimethylpropylimidazolium (DMPIm+) ions was responsible for an increased electron lifetime by decreasing the recombination with the redox mediator. …

Go to article

Quantifying Fibronectin Adhesion With Nanoscale Spatial Resolution On Glycosaminoglycan Doped Polypyrrole Using Atomic Force Microscopy, Amy Gelmi, Michael J. Higgins, Gordon G. Wallace Jan 2013

Quantifying Fibronectin Adhesion With Nanoscale Spatial Resolution On Glycosaminoglycan Doped Polypyrrole Using Atomic Force Microscopy, Amy Gelmi, Michael J. Higgins, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

The interaction of ECM proteins is critical in determining the performance of materials used in biomedical applications such as tissue regeneration, implantable bionics and biosensing. Methods: To improve our understanding of ECM protein–conducting polymer interactions, we have used Atomic Force Microscopy (AFM) to elucidate the interactions of fibronectin (FN) on polypyrrole (PPy) doped with different glycosaminoglycans. Results: We were able to classify four main types of FN interactions, including those related to 1) non-specific adhesion, 2) protein unfolding and subsequent unbinding from the surface, 3) desorption and 4) interactions with no adhesion. FN adhesion on PPy/hyaluronic acid showed a significantly …

Go to article

Aging Effect Evolution During Ferroelectric-Ferroelectric Phase Transition: A Mechanism Study, Zuyong Feng, Zhenxiang Cheng, Dongqi Shi, S X. Dou Jan 2013

Aging Effect Evolution During Ferroelectric-Ferroelectric Phase Transition: A Mechanism Study, Zuyong Feng, Zhenxiang Cheng, Dongqi Shi, S X. Dou

Australian Institute for Innovative Materials - Papers

Aging can significantly modify the dielectric, piezoelectric, and ferroelectric performance of ferroelectrics. However, little attention has been paid to the aging effect during ferroelectric-ferroelectric phase transitions that is essentially correlated with real applications. In this letter, the authors report the aging effect evolution between two ferroelectric phases in an acceptor-doped piezoceramics. The results show that aging-induced double hysteresis loops were exhibited in different ferroelectric phases, but disappeared during ferroelectric-ferroelectric phase transitions, suggesting the mechanism that the intrinsic restoring force for the reversible switching of domains caused by the alignment of defect dipoles was weakened due to ferroelectric dipole reorientation.

Go to article

In-Situ Observation Of Nanomechanical Behavior Arising From Critical-Temperature-Induced Phase Transformation In Ba(Zr0.2ti 0.8)O3-0.5(Ba0.7ca0.3)Tio 3 Thin Film, Z M. Wang, Zh L. Cai, K Zhao, X L. Guo, J Chen, W Sun, Zh X. Cheng, H Kimura, B Li, G L. Yuan, J Yin, Zh G. Liu Jan 2013

In-Situ Observation Of Nanomechanical Behavior Arising From Critical-Temperature-Induced Phase Transformation In Ba(Zr0.2ti 0.8)O3-0.5(Ba0.7ca0.3)Tio 3 Thin Film, Z M. Wang, Zh L. Cai, K Zhao, X L. Guo, J Chen, W Sun, Zh X. Cheng, H Kimura, B Li, G L. Yuan, J Yin, Zh G. Liu

Australian Institute for Innovative Materials - Papers

In this Letter, we use the nanoindentation technique and vary the testing temperature to above and below critical values to study the nanomechanical features of a strong Pb-free piezoelectric Ba(Zr0.2Ti 0.8)O3-0.5(Ba0.7Ca0.3)TiO 3 (BZT-0.5BCT) thin film across its piezoelectric-optimal morphotropic phase boundary. The mechanisms responsible for the Young's modulus and hardness evolution are then discussed. An X-ray diffraction method that can detect the d(110) variation associated with the change in the inclination angle ψ of the (110) plane was developed to quantify the residual stress in the BZT-0.5BCT films.

Go to article

Extrusion Printing Of Ionic-Covalent Entanglement Hydrogels With High Toughness, Shannon Bakarich, Marc In Het Panhuis, Stephen T. Beirne, Gordon G. Wallace, Geoffrey Maxwell Spinks Jan 2013

Extrusion Printing Of Ionic-Covalent Entanglement Hydrogels With High Toughness, Shannon Bakarich, Marc In Het Panhuis, Stephen T. Beirne, Gordon G. Wallace, Geoffrey Maxwell Spinks

Australian Institute for Innovative Materials - Papers

Three-dimensional (3D) printing of hydrogels has recently been investigated for use in tissue engineering applications. One major limitation in the use of synthetic hydrogels is their poor mechanical robustness but the development of ‘tough hydrogels’ in conjunction with additive fabrication techniques will accelerate the advancement of many technologies including soft robotics, bionic implants, sensors and controlled release systems. This article demonstrates that ionic–covalent entanglement (ICE) gels can be fabricated through a modified extrusion printing process that facilitates in situ photopolymerisation. The rheological properties of alginate–acrylamide hydrogel precursor solutions were characterised to develop formulations suitable for extrusion printing. A range of …

Go to article

Flexible Cellulose Based Polypyrrole-Multiwalled Carbon Nanotube Films For Bio-Compatible Zinc Batteries Activated By Simulated Body Fluids, Sha Li, Zai Ping Guo, Cai Yun Wang, Gordon G. Wallace, Hua-Kun Liu Jan 2013

Flexible Cellulose Based Polypyrrole-Multiwalled Carbon Nanotube Films For Bio-Compatible Zinc Batteries Activated By Simulated Body Fluids, Sha Li, Zai Ping Guo, Cai Yun Wang, Gordon G. Wallace, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

This work aims to develop biocompatible non-toxic materials for implantable bio-electronic cells. Polypyrrole (PPy)–carbon nanotube (CNT) composites with varied ratios of PPy to CNTs were chemically synthesized and used as cathodes with the support of cellulose paper. Zinc foil was used as the anode material due to its non-toxicity and moderate dissolution rate in aqueous solutions. Simulated body fluids (SBFs) with various protein concentrations were applied as electrolytes in this battery system. The PPy–CNT|Zn cell is capable of being discharged up to 24.5 hours at a current density of 60 μA cm−2 in a protein free SBF. The batteries …

Go to article

An Overview - Functional Nanomaterials For Lithium Rechargeable Batteries, Supercapacitors, Hydrogen Storage, And Fuel Cells, Hua-Kun Liu Jan 2013

An Overview - Functional Nanomaterials For Lithium Rechargeable Batteries, Supercapacitors, Hydrogen Storage, And Fuel Cells, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

There is tremendous worldwide interest in functional nanostructured materials, which are the advanced nanotechnology materials with internal or external dimensions on the order of nanometers. Their extremely small dimensions make these materials unique and promising for clean energy applications such as lithium ion batteries, supercapacitors, hydrogen storage, fuel cells, and other applications. This paper will highlight the development of new approaches to study the relationships between the structure and the physical, chemical, and electrochemical properties of functional nanostructured materials. The Energy Materials Research Programme at the Institute for Superconducting and Electronic Materials, the University of Wollongong, has been focused on …

Go to article

Additive Bio Fabrication: Impact, Opportunities And Challenges, Gordon G. Wallace, Stephen Beirne Jan 2013

Additive Bio Fabrication: Impact, Opportunities And Challenges, Gordon G. Wallace, Stephen Beirne

Australian Institute for Innovative Materials - Papers

In recent years we have outrun our ability to fabricate structures from the amazing materials that we can now create. While this can be said of many areas of materials research it is particularly so in the area of biomaterials. Here, we are often confronted with delicate compositions with nano- to microscopic features that will not survive the traditional (hammer and chisel) approach to fabrication. There is good reason why nature “grows” complex, highly functional structures. Such structures with functionality determined by the spatial distribution of composition with nanodimensional resolution can not be chiselled from a slab of …

Go to article

Spin Switching And Magnetization Reversal In Single-Crystal Ndfeo3, S J. Yuan, W Ren, F Hong, Y B. Wang, J C. Zhang, L Bellaiche, S X. Cao, G Cao Jan 2013

Spin Switching And Magnetization Reversal In Single-Crystal Ndfeo3, S J. Yuan, W Ren, F Hong, Y B. Wang, J C. Zhang, L Bellaiche, S X. Cao, G Cao

Australian Institute for Innovative Materials - Papers

We report an experimental and computational study of single-crystal NdFeO3, which features two inequivalent magnetic sublattices, namely, Fe and Nd sublattices that are coupled in an antiparallel fashion. This paper reveals that a strong interaction between 3d and 4f electrons of the two sublattices along with a spin-lattice coupling drives an extremely interesting magnetic state that is highly sensitive to the orientation and history of weak magnetic field. The following phenomena are particularly remarkable: (1) sharply contrasting magnetization M(T) along the a and c axes; (2) a first-order spin switching along the a axis below 29 K when the system …

Go to article

Conducting Polymer Coated Neural Recording Electrodes, Alexander R. Harris, Simon Morgan, Jun Chen, Robert M. Kapsa, Gordon G. Wallace, Antonio Paolini Jan 2013

Conducting Polymer Coated Neural Recording Electrodes, Alexander R. Harris, Simon Morgan, Jun Chen, Robert M. Kapsa, Gordon G. Wallace, Antonio Paolini

Australian Institute for Innovative Materials - Papers

Neural recording electrodes suffer from poor signal to noise ratio, charge density, biostability and biocompatibility. This paper investigates the ability of conducting polymer coated electrodes to record acute neural response in a systematic manner, allowing in depth comparison of electrochemical and electrophysiological response. Approach. Polypyrrole (Ppy) and poly-3,4-ethylenedioxythiophene (PEDOT) doped with sulphate (SO4) or para-toluene sulfonate (pTS) were used to coat iridium neural recording electrodes. Detailed electrochemical and electrophysiological investigations were undertaken to compare the effect of these materials on acute in vivo recording. Main results. A range of charge density and impedance responses were seen with each respectively doped …

Go to article

Passive Dorsiflexion Stiffness Is Poorly Correlated With Passive Dorsiflexion Range Of Motion, J W. Whitting, J R. Steele, D E. Mcghee, B J. Munro Jan 2013

Passive Dorsiflexion Stiffness Is Poorly Correlated With Passive Dorsiflexion Range Of Motion, J W. Whitting, J R. Steele, D E. Mcghee, B J. Munro

Australian Institute for Innovative Materials - Papers

The purpose of this study was to determine the relationships among passive measures of weight-bearing dorsiflexionrange of motion, non-weight-bearing dorsiflexionrange of motion and dorsiflexionstiffness, thereby establishing whether they assess similar mechanical characteristics, as each measure has been implicated in injury risk during landings.

Go to article

Spinel Linixmn2-Xo4 As Cathode Material For Aqueous Rechargeable Lithium Batteries, F X. Wang, S Y. Xiao, Y Shi, L L. Liu, Y S. Zhu, Y P. Wu, J. Z. Wang, R Holze Jan 2013

Spinel Linixmn2-Xo4 As Cathode Material For Aqueous Rechargeable Lithium Batteries, F X. Wang, S Y. Xiao, Y Shi, L L. Liu, Y S. Zhu, Y P. Wu, J. Z. Wang, R Holze

Australian Institute for Innovative Materials - Papers

Ni-doped spinel LiNixMn2-xO4 (x = 0, 0.05, 0.10) samples were prepared by a sol-gel method. Structure and morphology of the samples were characterized by X-ray diffraction, scanning electron microscopy, Brunnauer-Emmet-Teller method and inductively coupled plasma atomic absorption spectrometry. The electrochemical behavior as a cathode material (positive mass) for aqueous rechargeable lithium batteries (ARLBs) was investigated by cyclic voltammetry, electrochemical impedance spectroscopy, capacity measurements and cycling tests. The results show that the LiNi 0.1Mn1.9O4 electrode presents the best rate and cycling performance but low reversible capacity. In contrast, the LiNi 0.05Mn1.95O4 electrode shows a higher reversible capacity and relatively good cycling …

Go to article

Controlled Delivery For Neuro-Bionic Devices, Zhilian Yue, Simon E. Moulton, Mark Cook, Stephen O'Leary, Gordon G. Wallace Jan 2013

Controlled Delivery For Neuro-Bionic Devices, Zhilian Yue, Simon E. Moulton, Mark Cook, Stephen O'Leary, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Implantable electrodes interface with the human body for a range of therapeutic as well as diagnostic applications. Here we provide an overview of controlled delivery strategies used in neuro-bionics. Controlled delivery of bioactive molecules has been used to minimise reactive cellular and tissue responses and/or promote nerve preservation and neurite outgrowth toward the implanted electrode. These effects are integral to establishing a chronically stable and effective electrode-neural communication. Drug-eluting bioactive coatings, organic conductive polymers, or integrated microfabricated drug delivery channels are strategies commonly used.

Go to article

Magnetism And The Magnetocaloric Effect In Prmn1. 6fe0. 4ge2, W D. Hutchison, Jianli Wang, S J. Campbell Jan 2013

Magnetism And The Magnetocaloric Effect In Prmn1. 6fe0. 4ge2, W D. Hutchison, Jianli Wang, S J. Campbell

Australian Institute for Innovative Materials - Papers

The magnetic and magnetocaloric properties of PrMn1.6Fe0.4Ge2around the ferromagnetic transitions T C inter ~ 230 K and T C Pr ~ 30 K have been investigated by magnetisation, 57Fe Mössbauer spectroscopy and electron paramagnetic resonance (EPR) measurements over the temperature range 5–300 K. The broad peaks in magnetic entropy around TC inter (intralayer antiferromagnetism of the Mn sublattice to canted ferromagnetism) and TC Pr (onset of ferromagnetic order of Pr sublattice in addition to ferromagnetically ordered Mn sublattice) are typical of second order transitions with maximum entropy values of -ΔS M ~ 2.0 J/kg K and -ΔS M ~ 2.2 …

Go to article

Driving Magnetostructural Transitions In Layered Intermetallic Compounds, Jianli Wang, L Caron, S J. Campbell, S J. Kennedy, M Hofmann, Z X Cheng, M Md Din, A J. Studer, E Bruck, S X. Dou Jan 2013

Driving Magnetostructural Transitions In Layered Intermetallic Compounds, Jianli Wang, L Caron, S J. Campbell, S J. Kennedy, M Hofmann, Z X Cheng, M Md Din, A J. Studer, E Bruck, S X. Dou

Australian Institute for Innovative Materials - Papers

We report the dramatic effect of applied pressure and magnetic field on the layered intermetallic compound Pr0.5Y0.5Mn 2Ge2. In the absence of pressure or magnetic field this compound displays interplanar ferromagnetism at room temperature and undergoes an isostructural first order magnetic transition (FOMT) to an antiferromagnetic state below 158 K, followed by another FOMT at 50 K due to the reemergence of ferromagnetism as praseodymium orders (TCPr). The application of a magnetic field drives these two transitions towards each other, whereas the application of pressure drives them apart. Pressure also produces a giant magnetocaloric effect such that a threefold increase …

Go to article

High Strain Stretchable Solid Electrolytes, Sureyya Saricilar, Dennis Antiohos, Kewei Shu, Philip G. Whitten, Klaudia Wagner, Caiyun Wang, Gordon G. Wallace Jan 2013

High Strain Stretchable Solid Electrolytes, Sureyya Saricilar, Dennis Antiohos, Kewei Shu, Philip G. Whitten, Klaudia Wagner, Caiyun Wang, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Wearable electronic devices that can be integrated seamlessly into clothing for monitoring and feedback need to be not only flexible, but also stretchable with low stiffness. Currently there are few solid electrolytes that are sufficiently stretchable for wearable electronic devices. Here we report stretchable solid electrolytes that can be elastically stretched more than 500% of their original length with ionic conductivities as high as 7 x 10(-5) S cm(-1) and tensile breaking strengths larger than 1.5 MPa. These solid electrolytes consist of poly(methyl methacrylate) chemical networks solvated by an electrochemically stable ionic liquid. A stretchable supercapacitor was demonstrated by coating …

Go to article

Co2 Capture And Gas Separation On Boron Carbon Nanotubes, Qiao Sun, Meng Wang, Zhen Li, Yingying Ma, Aijun Du Jan 2013

Co2 Capture And Gas Separation On Boron Carbon Nanotubes, Qiao Sun, Meng Wang, Zhen Li, Yingying Ma, Aijun Du

Australian Institute for Innovative Materials - Papers

Concern about the increasing atmospheric CO2 concentration and its impact on the environment has led to increasing attention directed toward finding advanced materials and technologies suited for efficient CO2 capture, storage and purification of clean-burning natural gas. In this letter, we have performed comprehensive theoretical investigation of CO2, N2, CH4 and H2 adsorption on B2CNTs. Our study shows that CO2 molecules can form strong interactions with B2CNTs with different charge states. However, N2, CH 4 and H2 can only form very weak interactions with B 2CNTs. Therefore, the study demonstrates B2CNTs could sever as promising materials for CO2 capture and …

Go to article

Thermo-Magnetic Stability Of Superconducting Films Controlled By Nano-Morphology, V V. Yurchenko, K Ilin, J M. Meckbach, M Siegel, A J. Qviller, Y M. Galperin, Tom H. Johansen Jan 2013

Thermo-Magnetic Stability Of Superconducting Films Controlled By Nano-Morphology, V V. Yurchenko, K Ilin, J M. Meckbach, M Siegel, A J. Qviller, Y M. Galperin, Tom H. Johansen

Australian Institute for Innovative Materials - Papers

Appearance of dendritic magnetic flux avalanches in superconducting films, which are associated with thermo-magnetic instability (TMI), very often indicates serious limitations for the ultimate performance of superconducting devices made of type-II superconducting thin films. We demonstrate that the stability can be controlled by a thorough adjustment of samples morphology at nano-scale, which affects internal material parameters. By this, the metal coating, commonly used as for stabilization, becomes redundant. Most importantly, we directly show by the mean of magneto-optical imaging that introduction of nano-scaled disorder dramatically changes the mode of magnetic flux propagation in the superconductors, from uniform motion of individual …

Go to article

The Electrochemical Properties Of High-Capacity Sulfur/Reduced Graphene Oxide With Different Electrolyte Systems, Yunxiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou Jan 2013

The Electrochemical Properties Of High-Capacity Sulfur/Reduced Graphene Oxide With Different Electrolyte Systems, Yunxiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

The lithium/sulfur battery is a promising electrochemical system with high capacity, which is well-known to undergo a complex multistep reaction during the discharge process. Two types of electrolytes including poly (ethylene glycol) dimethyl ether (PEGDME)-based and 1.3 - dioxolane (DOL)/ dimethoxyethane (DME)-based electrolytes were investigated here. Furthermore, LiNO3 additive was introduced into the electrolyte in order to effectively eliminate the overcharge effect. The lithium sulfur battery with 1.0 M LiN(CF3SO2)2 in PEGME with 0.1 M LiNo3 shows highly stable reversible capacity of 624.8 mAh g-1 after 200 cycles and improved average coulombic efficiency of 98 percent.

Go to article

Fusion Of Nacre, Mussel, And Lotus Leaf: Bio-Inspired Graphene Composite Paper With Multifunctional Integration, Da Zhong, Qinglin Yang, Lin Guo, S X. Dou, Kesong Liu, Lei Jiang Jan 2013

Fusion Of Nacre, Mussel, And Lotus Leaf: Bio-Inspired Graphene Composite Paper With Multifunctional Integration, Da Zhong, Qinglin Yang, Lin Guo, S X. Dou, Kesong Liu, Lei Jiang

Australian Institute for Innovative Materials - Papers

Multifunctional integration is an inherent characteristic for biological materials with multiscale structures. Learning from nature is an effective approach for scientists and engineers to construct multifunctional materials. In nature, mollusks (abalone), mussels, and the lotus have evolved different and optimized solutions to survive. Here, bio-inspired multifunctional graphene composite paper was fabricated in situ through the fusion of the different biological solutions from nacre (brick-and-mortar structure), mussel adhesive protein (adhesive property and reducing character), and the lotus leaf (self-cleaning effect). Owing to the special properties (self-polymerization, reduction, and adhesion), dopamine could be simultaneously used as a reducing agent for graphene oxide …

Go to article

Direct Observation Of Liquid-Like Behavior Of A Single Au Grain Boundary, Gilberto Casillas, Arturo Ponce, Jesus Velazquez-Salazar, M Jose-Yacaman Jan 2013

Direct Observation Of Liquid-Like Behavior Of A Single Au Grain Boundary, Gilberto Casillas, Arturo Ponce, Jesus Velazquez-Salazar, M Jose-Yacaman

Australian Institute for Innovative Materials - Papers

Behavior of matter at the nanoscale differs fromthat of the bulk due to confinement and surface effects. Here, we report a direct observation of liquid-like behavior of a single grain boundary formed by cold-welding Au nanoparticles, 40 nm in size, by mechanical manipulation in situ TEM. The grain boundary rotates almost freely due to the free surfaces and can rotate about 90 degrees. The grain boundary sustains more stress than the bulk, confirming a strong bonding between the nanoparticles.Moreover, this technique allows the measurement of the surface diffusion coefficient from experimental observations, which we compute for the Au nanoparticles. This …

Go to article

Flux Pinning Mechanism In Bafe1.9ni0.1as2 Single Crystals: Evidence For Fluctuation In Mean Free Path Induced Pinning, M Shahbazi-Manshadi, X L Wang, K Y Choi, S X. Dou Jan 2013

Flux Pinning Mechanism In Bafe1.9ni0.1as2 Single Crystals: Evidence For Fluctuation In Mean Free Path Induced Pinning, M Shahbazi-Manshadi, X L Wang, K Y Choi, S X. Dou

Australian Institute for Innovative Materials - Papers

The flux pinning mechanism of BaFe1.9Ni0.1As2 superconducting crystals have been investigated systematically by magnetic measurements up to 13 T at various temperatures. The field dependence of the critical current density, Jc, was analysed within the collective pinning model. A remarkably good agreement between the experimental results and theoretical dl pinning curve is obtained, which indicates that pinning in BaFe1.9Ni0.1As2 crystal originates from spatial variation of the mean free path. Moreover, the normalized pinning force density, Fp, curves versus h1/4B/Birr (Birr is the irreversibility field) were scaled using the Dew-Hughes model. Analysis suggests that point pinning alone cannot explain the observed …

Go to article

Bio-Ink Properties And Printability For Extrusion Printing Living Cells, Johnson H. Y Chung, Sina Naficy, Zhilian Yue, Robert Kapsa, Anita Quigley, Simon E. Moulton, Gordon G. Wallace Jan 2013

Bio-Ink Properties And Printability For Extrusion Printing Living Cells, Johnson H. Y Chung, Sina Naficy, Zhilian Yue, Robert Kapsa, Anita Quigley, Simon E. Moulton, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Additive biofabrication (3D bioprinting) makes it possible to create scaffolds with precise geometries, control over pore interconnectivity and architectures that are not possible with conventional techniques. Inclusion of cells within the ink to form a “bio-ink” presents the potential to print 3D structures that can be implanted into damaged/diseased tissue to promote highly controlled cell-based regeneration and repair. The properties of an ‘ink’ are defined by its formulation and critically influence the delivery and integrity of structure formed. Importantly, the ink properties need to conform to biological requirements necessary for the cell system that they are intended to support and …

Go to article

Highly Uniform Tio2/Sno2/Carbon Hybrid Nanofibers With Greatly Enhanced Lithium Storage Performance, Zunxian Yang, Qing Meng, Zaiping Guo, Xuebin Yu, Tailiang Guo, Rong Zeng Jan 2013

Highly Uniform Tio2/Sno2/Carbon Hybrid Nanofibers With Greatly Enhanced Lithium Storage Performance, Zunxian Yang, Qing Meng, Zaiping Guo, Xuebin Yu, Tailiang Guo, Rong Zeng

Australian Institute for Innovative Materials - Papers

Highly uniform, relatively large area TiO2/SnO 2/carbon hybrid nanofibers were synthesized by a simple method based on thermal pyrolysis and oxidation of an as-spun titanium-tin/polyacrylonitrile nanoweb composite in an argon atmosphere. This novel composite features the uniform dispersion and encapsulation of highly uniform nanoscale TiO 2/SnO2 crystals in a porous carbon matrix. The high porosity of the nanofiber composite material, together with the conductive carbon matrix, enhanced the electrochemical performance of the TiO 2/SnO2/carbon nanofiber electrode. The TiO 2/SnO2/carbon nanofiber electrode displays a reversible capacity of 442.8 mA h g-1 for up to 100 cycles, and exhibits excellent rate capability. …

Go to article

Limiting Thermomagnetic Avalanches In Superconducting Films By Stop-Holes, F Colauto, J I. Vestgarden, A M H De Andrade, A A M Oliveira, Wilson Aires Ortiz, Tom H. Johansen Jan 2013

Limiting Thermomagnetic Avalanches In Superconducting Films By Stop-Holes, F Colauto, J I. Vestgarden, A M H De Andrade, A A M Oliveira, Wilson Aires Ortiz, Tom H. Johansen

Australian Institute for Innovative Materials - Papers

It is demonstrated that circular holes in superconducting films of Nb can arrest the propagation of thermomagnetic avalanches. The effect was found over a range of temperatures where the material is susceptible to this instability. For other hole shapes, like square and triangular, the sharp corners provoke secondary avalanches, thus extending the breakdown. Making use of circular stop-holes can become a practical way to limit thermomagnetic breakdown in superconducting films.

Go to article

One-Pot Green Synthesis Of Ag Nanoparticles-Decorated Reduced Graphene Oxide For Efficient Nonenzymatic H2o2 Biosensor, Mingyan Wang, Tao Shen, Meng Wang, Dongen Zhang, Jun Chen Jan 2013

One-Pot Green Synthesis Of Ag Nanoparticles-Decorated Reduced Graphene Oxide For Efficient Nonenzymatic H2o2 Biosensor, Mingyan Wang, Tao Shen, Meng Wang, Dongen Zhang, Jun Chen

Australian Institute for Innovative Materials - Papers

Ag nanoparticles (AgNP) with an average size of 12 nm are successfully decorated on the reduced graphene oxide (rGO) sheets through a simple one-pot hydrothermal method using gallic acid as the reducing agent. This AgNP/rGO hybrid has been successfully applied in the catalytic performance toward the reduction of H2O2. The nonenzymatic sensor demonstrates a linear relationship in a wide concentration range of 0.05-5 mM (R=0.999), and a high sensitivity of 255 μA cm-2 mM-1 to the detection of H2O2.

Go to article

Enhancing Superconducting Properties Of Mgb2 Pellets By Addition Of Amorphous Magnetic Ni-Co-B Nanoparticles, Mislav Mustapic, Josip Horvat, Md Shahriar Hossain, Zeljko Skoko, S X. Dou Jan 2013

Enhancing Superconducting Properties Of Mgb2 Pellets By Addition Of Amorphous Magnetic Ni-Co-B Nanoparticles, Mislav Mustapic, Josip Horvat, Md Shahriar Hossain, Zeljko Skoko, S X. Dou

Australian Institute for Innovative Materials - Papers

Amorphous magnetic Ni-Co-B nanoparticles with an average size of 5 nm were added to precursor powders of MgB2 superconductor. The preparation procedure for MgB2 pellets was optimized for obtaining the best critical current density (Jc) at elevated magnetic fields. Addition of Ni-Co-B decreases the Jc for heat treatment of precursor powders at 650 ° C. Heat treatments at 770 ° C and higher improve Jc at 20 and 5 K. This improvement occurs at both temperatures through the increase of the effective connectivity between MgB2 crystals. Vortex pinning was enhanced at 5 K, but not at 20 K. Ni-Co-B nanoparticles …

Go to article

First Prev Next Last