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Full-Text Articles in Engineering

Wet-Spinning Of Pedot:Pss/Functionalized-Swnts Composite: A Facile Route Toward Production Of Strong And Highly Conducting Multifunctional Fibers, Rouhollah Jalili, Joselito M. Razal, Gordon G. Wallace Mar 2014

Wet-Spinning Of Pedot:Pss/Functionalized-Swnts Composite: A Facile Route Toward Production Of Strong And Highly Conducting Multifunctional Fibers, Rouhollah Jalili, Joselito M. Razal, Gordon G. Wallace

Gordon Wallace

With the aim of fabricating multifunctional fibers with enhanced mechanical properties, electrical conductivity and electrochemical performance, we develop wet-spinning of composite formulation based on functionalized PEG-SWNT and PEDOT:PSS. The method of addition and loading are directly correlated to the quality and the ease of spinnability of the formulation and to the mechanical and electrical properties of the resultant fibers. Both the fiber modulus (Y) and strength (σ) scaled linearly with PEG-SWNT volume fraction (Vf). A remarkable reinforcement rate of dY/dVf = 417 GPa and dσ/dVf = 4 GPa were obtained when PEG-SWNTs at Vf ≤ 0.02. Further increase of PEG-SWNTs …


Exploiting High Quality Pedot:Pss-Swnt Composite Formulations For Wet-Spinning Multifunctional Fibers, Rouhollah Jalili, Joselito M. Razal, Gordon G. Wallace Mar 2014

Exploiting High Quality Pedot:Pss-Swnt Composite Formulations For Wet-Spinning Multifunctional Fibers, Rouhollah Jalili, Joselito M. Razal, Gordon G. Wallace

Gordon Wallace

In order to exploit the inherent properties of carbon nanotubes (CNT) in any polymer composite, systematic control of carbon nanotube loading and protocols that mitigate against CNT bundling are required. If such composites are to be rendered in fiber form via wet-spinning, then CNT bundling during the coagulation process must also be avoided. Here we have achieved this by utilizing highly exfoliated single walled carbon nanotubes (SWNT) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonicacid) (PEDOT:PSS) to obtain wet-spinnable composite formulations at various nanotube volume fractions (Vf). The addition of only 0.02 Vf of aggregate-free and individually dispersed SWNT resulted in a significant enhancement of modulus, …


Direct Synthesis Of Rgo/Cu2o Composite Films On Cu Foil For Supercapacitors, Xiangmao Dong, Kun Wang, Chongjun Zhao, Xiuzhen Qian, Shi Chen, Zhen Li, Hua-Kun Liu, S X. Dou Mar 2014

Direct Synthesis Of Rgo/Cu2o Composite Films On Cu Foil For Supercapacitors, Xiangmao Dong, Kun Wang, Chongjun Zhao, Xiuzhen Qian, Shi Chen, Zhen Li, Hua-Kun Liu, S X. Dou

Shi Xue Dou

Reduced graphene oxide/cuprous oxide (RGO/Cu2O) composite films were directly synthesized on the surface of copper foil substrates through a straight redox reaction between GO and Cu foil via a hydrothermal approach. Characterization of the resultant composites with X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and field emission scanning electron microscope (FESEM) confirms the formation of Cu2O and reduction of GO, in which Cu2O nanoparticles were well covered by RGO. The resultant composites (referred to as RGO/Cu2O/Cu) were directly used as electrodes for supercapacitors, and their electrochemical performance was assessed by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectrometry …


Three-Dimensional-Network Li3v2(Po4) 3/C Composite As High Rate Lithium Ion Battery Cathode Material And Its Compatibility With Ionic Liquid Electrolytes, Jiantie Xu, Shulei Chou, Cuifeng Zhou, Qinfen Gu, Hua-Kun Liu, S X. Dou Mar 2014

Three-Dimensional-Network Li3v2(Po4) 3/C Composite As High Rate Lithium Ion Battery Cathode Material And Its Compatibility With Ionic Liquid Electrolytes, Jiantie Xu, Shulei Chou, Cuifeng Zhou, Qinfen Gu, Hua-Kun Liu, S X. Dou

Shi Xue Dou

A high performance Li3V2(PO4)3 cathode material for lithium ion batteries was synthesized by the microwave-assisted hydrothermal method followed by a post annealing process. The synchrotron X-ray diffraction analysis results confirmed that single-phase Li3V2(PO4)3 with monoclinic structure was obtained. Scanning electron microscope and transmission electron microscope images revealed that the as-prepared Li3V 2(PO4)3 was composed of nanowires and microsized particles. Electrochemical results demonstrated that the Li 3V2(PO4)3 electrode measured at 10 C after 500 cycles can deliver discharge capacities of 85.4 mAh g-1 and 103.4 mAh g-1, with a capacity retention of 99.3% and 95.9%, in the voltage ranges of 3.0-4.3 …


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 Mar 2014

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

Shi Xue Dou

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 …


Microstructure And Metal-Dielectric Transition Behaviour In A Percolative Al2o3-Fe Composite Via Selective Reduction, Zidong Zhang, Runhua Fan, Zhicheng Shi, Kelan Yan, Zhijia Zhang, Xiaolin Wang, S X. Dou Mar 2014

Microstructure And Metal-Dielectric Transition Behaviour In A Percolative Al2o3-Fe Composite Via Selective Reduction, Zidong Zhang, Runhua Fan, Zhicheng Shi, Kelan Yan, Zhijia Zhang, Xiaolin Wang, S X. Dou

Shi Xue Dou

The electromagnetic (EM) medium plays a key role in many areas, such as communications, stealth technology, etc. Different EM properties are required for different applications. In this paper, we have obtained tunable EM properties in an Al2O3-Fe composite via selective reduction. By adjusting the content of one functional component, the composite shows totally different EM properties, in accordance with the predictions of effective medium theory. Hybrid EM behaviour is obtained near the percolation threshold, which has a close relationship with its microstructure.


Three-Dimensional-Network Li3v2(Po4) 3/C Composite As High Rate Lithium Ion Battery Cathode Material And Its Compatibility With Ionic Liquid Electrolytes, Jiantie Xu, Shulei Chou, Cuifeng Zhou, Qinfen Gu, Hua-Kun Liu, S X. Dou Jan 2014

Three-Dimensional-Network Li3v2(Po4) 3/C Composite As High Rate Lithium Ion Battery Cathode Material And Its Compatibility With Ionic Liquid Electrolytes, Jiantie Xu, Shulei Chou, Cuifeng Zhou, Qinfen Gu, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

A high performance Li3V2(PO4)3 cathode material for lithium ion batteries was synthesized by the microwave-assisted hydrothermal method followed by a post annealing process. The synchrotron X-ray diffraction analysis results confirmed that single-phase Li3V2(PO4)3 with monoclinic structure was obtained. Scanning electron microscope and transmission electron microscope images revealed that the as-prepared Li3V 2(PO4)3 was composed of nanowires and microsized particles. Electrochemical results demonstrated that the Li 3V2(PO4)3 electrode measured at 10 C after 500 cycles can deliver discharge capacities of 85.4 mAh g-1 and 103.4 mAh g-1, with a capacity retention of 99.3% and 95.9%, in the voltage ranges of 3.0-4.3 …


Direct Synthesis Of Rgo/Cu2o Composite Films On Cu Foil For Supercapacitors, Xiangmao Dong, Kun Wang, Chongjun Zhao, Xiuzhen Qian, Shi Chen, Zhen Li, Hua-Kun Liu, S X. Dou Jan 2014

Direct Synthesis Of Rgo/Cu2o Composite Films On Cu Foil For Supercapacitors, Xiangmao Dong, Kun Wang, Chongjun Zhao, Xiuzhen Qian, Shi Chen, Zhen Li, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

Reduced graphene oxide/cuprous oxide (RGO/Cu2O) composite films were directly synthesized on the surface of copper foil substrates through a straight redox reaction between GO and Cu foil via a hydrothermal approach. Characterization of the resultant composites with X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and field emission scanning electron microscope (FESEM) confirms the formation of Cu2O and reduction of GO, in which Cu2O nanoparticles were well covered by RGO. The resultant composites (referred to as RGO/Cu2O/Cu) were directly used as electrodes for supercapacitors, and their electrochemical performance was assessed by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectrometry …


A Germanium/Single-Walled Carbon Nanotube Composite Paper As A Free-Standing Anode For Lithium-Ion Batteries, Jun Wang, Jiazhao Wang, Ziqi Sun, Xuanwen Gao, Chao Zhong, Shulei Chou, Hua-Kun Liu Jan 2014

A Germanium/Single-Walled Carbon Nanotube Composite Paper As A Free-Standing Anode For Lithium-Ion Batteries, Jun Wang, Jiazhao Wang, Ziqi Sun, Xuanwen Gao, Chao Zhong, Shulei Chou, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

Paper-like free-standing germanium (Ge) and single-walled carbon nanotube (SWCNT) composite anodes were synthesized by the vacuum filtration of Ge/SWCNT composites, which were prepared by a facile aqueous-based method. The samples were characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Electrochemical measurements demonstrate that the Ge/SWCNT composite paper anode with the weight percentage of 32% Ge delivered a specific discharge capacity of 417 mA h g−1 after 40 cycles at a current density of 25 mA g−1, 117% higher than the pure SWCNT paper anode. The SWCNTs not only function as a flexible mechanical support for …


Strain-Responsive Polyurethane/Pedot:Pss Elastomeric Composite Fibers With High Electrical Conductivity, Mohammad Ziabari Seyedin, Joselito M. Razal, Peter C. Innis, Gordon G. Wallace Jan 2014

Strain-Responsive Polyurethane/Pedot:Pss Elastomeric Composite Fibers With High Electrical Conductivity, Mohammad Ziabari Seyedin, Joselito M. Razal, Peter C. Innis, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

It is a challenge to retain the high stretchability of an elastomer when used in polymer composites. Likewise, the high conductivity of organic conductors is typically compromised when used as filler in composite systems. Here, it is possible to achieve elastomeric fiber composites with high electrical conductivity at relatively low loading of the conductor and, more importantly, to attain mechanical properties that are useful in strain-sensing applications. The preparation of homogenous composite formulations from poly­urethane (PU) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) that are also processable by fiber wet-spinning techniques are systematically evaluated. With increasing PEDOT:PSS loading in the fiber composites, the Young's …


Performance Enhancement Of Single-Walled Nanotube-Microwave Exfoliated Graphene Oxide Composite Electrodes Using A Stacked Electrode Configuration, Dennis Antiohos, Mark S. Romano, Joselito M. Razal, Stephen Beirne, Phil Aitchison, Andrew I. Minett, Gordon G. Wallace, Jun Chen Jan 2014

Performance Enhancement Of Single-Walled Nanotube-Microwave Exfoliated Graphene Oxide Composite Electrodes Using A Stacked Electrode Configuration, Dennis Antiohos, Mark S. Romano, Joselito M. Razal, Stephen Beirne, Phil Aitchison, Andrew I. Minett, Gordon G. Wallace, Jun Chen

Australian Institute for Innovative Materials - Papers

We report the development of a stacked electrode supercapacitor cell using stainless steel meshes as the current collectors and optimised single walled nanotubes (SWNT)-microwave exfoliated graphene oxide (mw rGO) composites as the electrode material. The introduction of mw rGO into a SWNT matrix creates an intertwined porous structure that enhances the electroactive surface area and capacitive performance due to the 3-D hierarchical structure that is formed. The composite structure was optimised by varying the weight ratio of the SWNTs and mw rGO. The best performing ratio was the 90% SWNT-10% mw rGO electrode which achieved a specific capacitance of 306 …


Novel Germanium/Polypyrrole Composite For High Power Lithium-Ion Batteries, Xuanwen Gao, Wenbin Luo, Chao Zhong, David Wexler, Shulei Chou, Hua-Kun Liu, Zhicong Shi, Guohua Chen, Kiyoshi Ozawa, Jiazhao Wang Jan 2014

Novel Germanium/Polypyrrole Composite For High Power Lithium-Ion Batteries, Xuanwen Gao, Wenbin Luo, Chao Zhong, David Wexler, Shulei Chou, Hua-Kun Liu, Zhicong Shi, Guohua Chen, Kiyoshi Ozawa, Jiazhao Wang

Australian Institute for Innovative Materials - Papers

Nano-Germanium/polypyrrole composite has been synthesized by chemical reduction method in aqueous solution. The Ge nanoparticles were directly coated on the surface of the polypyrrole. The morphology and structural properties of samples were determined by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Thermogravimetric analysis was carried out to determine the polypyrrole content. The electrochemical properties of the samples have been investigated and their suitability as anode materials for the lithium-ion battery was examined. The discharge capacity of the Ge nanoparticles calculated in the Ge-polypyrrole composite is 1014 mAh g-1 after 50 cycles at 0.2 C rate, which is …


Rapid Synthesis Of Li4ti5o12/Graphene Composite With Superior Rate Capability By A Microwave-Assisted Hydrothermal Method, Yi Shi, Jie Gao, Hector D. Abruna, Hua-Kun Liu, Huijun Li, Jiazhao Wang, Yuping Wu Jan 2014

Rapid Synthesis Of Li4ti5o12/Graphene Composite With Superior Rate Capability By A Microwave-Assisted Hydrothermal Method, Yi Shi, Jie Gao, Hector D. Abruna, Hua-Kun Liu, Huijun Li, Jiazhao Wang, Yuping Wu

Australian Institute for Innovative Materials - Papers

Li4Ti5O12 microspheres composed of nanoflakes wrapped in graphene nanosheets have been synthesized by an advanced microwave-hydrothermal (MW-HT) method for the preparation following by an annealing step. Microwave-assisted synthesis processes are appealing, as they can rapidly synthesize materials with a high degree of control of particle size and morphology at low cost. The resultant composite reveals a unique loose structure which could avoid the restacking of graphene sheets and offer rapid lithium ion diffusion paths. Therefore the Li4Ti5O12/graphene electrode has highly desirable properties: a specific capacity approaching the theoretical value, stable cycling, and exceptional rate capability. The composite also can be …


Spin Memristive Magnetic Tunnel Junctions With Coo-Zno Nano Composite Barrier, Qiang Li, Ting-Ting Shen, Yan-Ling Cao, Kun Zhang, Shi-Shen Yan, Yu-Feng Tian, Shi-Shou Kang, Ming-Wen Zhao, You-Yong Dai, Yan-Xue Chen, Guo-Lei Liu, Liang-Mo Mei, Xiaolin Wang, Peter Grunberg Jan 2014

Spin Memristive Magnetic Tunnel Junctions With Coo-Zno Nano Composite Barrier, Qiang Li, Ting-Ting Shen, Yan-Ling Cao, Kun Zhang, Shi-Shen Yan, Yu-Feng Tian, Shi-Shou Kang, Ming-Wen Zhao, You-Yong Dai, Yan-Xue Chen, Guo-Lei Liu, Liang-Mo Mei, Xiaolin Wang, Peter Grunberg

Australian Institute for Innovative Materials - Papers

The spin memristive devices combining memristance and tunneling magnetoresistance have promising applications in multibit nonvolatile data storage and artificial neuronal computing. However, it is a great challenge for simultaneous realization of large memristance and magnetoresistance in one nanoscale junction, because it is very hard to find a proper spacer layer which not only serves as good insulating layer for tunneling magnetoresistance but also easily switches between high and low resistance states under electrical field. Here we firstly propose to use nanon composite barrier layers of CoO-ZnO to fabricate the spin memristive Co/CoO-ZnO/Co magnetic tunnel junctions. The bipolar resistance switching ratio …