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Physical Sciences and Mathematics Commons

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Selected Works

Gordon Wallace

2014

High

Articles 1 - 5 of 5

Full-Text Articles in Physical Sciences and Mathematics

Tensile Testing Of Individual Glassy, Rubbery And Hydrogel Electrospun Polymer Nanofibres To High Strain Using The Atomic Force Microscope, Adrian Gestos, Philip G. Whitten, Geoffrey M. Spinks, Gordon G. Wallace Mar 2014

Tensile Testing Of Individual Glassy, Rubbery And Hydrogel Electrospun Polymer Nanofibres To High Strain Using The Atomic Force Microscope, Adrian Gestos, Philip G. Whitten, Geoffrey M. Spinks, Gordon G. Wallace

Gordon Wallace

The production and use of polymer nanofibre assemblies prepared by electrospinning is now widespread. It is known that the tensile properties of electrospun polymer fibres can be different to those of bulk polymers. Here, we report a general method for measuring the tensile properties of individual electrospun nanofibres that employs a commercial atomic force microscope. Methods for preparing samples, force calibration and calculation of tensile stress and strain are described along with error estimation. By appropriate choice of AFM cantilever, it is shown that the tensile stress-strain curves can be measured for glassy, rubbery and gel polymer nanofibres. Testing can …


Cell Attachment And Proliferation On High Conductivity Pedot-Glycol Composites Produced By Vapour Phase Polymerisation, Elise M. Stewart, Manrico Fabretto, Mischa Mueller, Paul J. Molino, Hans J. Griesser, Robert D. Short, Gordon G. Wallace Mar 2014

Cell Attachment And Proliferation On High Conductivity Pedot-Glycol Composites Produced By Vapour Phase Polymerisation, Elise M. Stewart, Manrico Fabretto, Mischa Mueller, Paul J. Molino, Hans J. Griesser, Robert D. Short, Gordon G. Wallace

Gordon Wallace

High conductivity poly(3,4-ethylene dioxythiophene) (PEDOT) was synthesised using vacuum vapour phase polymerization (VVPP). The process produces PEDOT composites which incorporate glycol within the polymer. To assess biocompatibility, a suite of analytical techniques were utilised in an effort to characterise the level of glycol present and its impact on cell attachment and proliferation. A small decrease in fibroblast cell attachment and proliferation was observed with increasing glycol content within the PEDOT composite. Keratinocyte cell attachment and proliferation by comparison showed an increase. As such, the results herein indicate that cell attachment and proliferation depends on the individual cell lines used and …


High Strain Stretchable Solid Electrolytes, Sureyya Saricilar, Dennis Antiohos, Kewei Shu, Philip G. Whitten, Klaudia Wagner, Caiyun Wang, Gordon G. Wallace Mar 2014

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

Gordon Wallace

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 …


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 Mar 2014

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

Gordon Wallace

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 …


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, …