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Full-Text Articles in Physical Sciences and Mathematics

Pegylation Of Platinum Bio-Electrodes, Zhilian Yue, Paul J. Molino, Xiao Liu, Gordon G. Wallace May 2013

Pegylation Of Platinum Bio-Electrodes, Zhilian Yue, Paul J. Molino, Xiao Liu, Gordon G. Wallace

Gordon Wallace

Controlling protein interactions at the implanted electrode interface is becoming an important strategy for the management of foreign body responses that have proven to be detrimental to the long-term performance of neural prosthesis. In this study, PEGylation was conducted on platinum bio-electrodes to render the surface protein-resistant. The PEGylated electrode was investigated using a quartz crystal microbalance-dissipation, electrochemical impedance spectroscopy and cyclic voltammetiy.


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

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

Gordon Wallace

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 …


The Nanostructure Of Three-Dimensional Scaffolds Enhances The Current Density Of Microbial Bioelectrochemical Systems, Victoria Flexer, Jun Chen, Bogdan C. Donose, Peter C. Sherrell, Gordon G. Wallace, Jurg Keller May 2013

The Nanostructure Of Three-Dimensional Scaffolds Enhances The Current Density Of Microbial Bioelectrochemical Systems, Victoria Flexer, Jun Chen, Bogdan C. Donose, Peter C. Sherrell, Gordon G. Wallace, Jurg Keller

Gordon Wallace

Bioelectrochemical systems encompass a range of electrochemical systems wherein microorganisms are used as biocatalysts. These range from classical microbial fuel cells to novel microbial electrosynthesis processes. The future of practical applications relies on increased performance. In all cases the development of new electrode materials is essential to overcome the low current densities of bioelectrochemical systems. Here we describe a new biocompatible, highly conductive three-dimensional scaffold electrode, NanoWeb-RVC, with a hierarchical porous structure, synthesized by direct growth of carbon nanotubes on a macroporous substrate. The nanostructure of these electrodes enhances the rate of bacterial extracellular electron transfer while the macrostructure ensures …


Preparation And Characterisation Of Graphene Composite Hydrogels, Nicholas J. Whiteside, Gordon G. Wallace, Marc In Het Panhuis May 2013

Preparation And Characterisation Of Graphene Composite Hydrogels, Nicholas J. Whiteside, Gordon G. Wallace, Marc In Het Panhuis

Gordon Wallace

Stable dispersions containing graphene and gellan gum are used to form composite films. Incorporation of graphene into the gellan gum matrix results in mechanical reinforcement and electrical conductivity at low and high graphene loading fractions, respectively. Graphene-containing gellan gum hydrogel films are prepared by immersion of composite films in Ca2+ cross-linking solutions. The resulting hydrogels are electrically conducting and exhibit reinforcement compared to the corresponding gellan gum hydrogels. 2013 Elsevier B.V.


Fabrication Of Polyaniline-Based Gas Sensors Using Piezoelectric Inkjet And Screen Printing For The Detection Of Hydrogen Sulfide, Karl H. Crowley, Aoife Morrin, Roderick L. Shepherd, Marc In Het Panhuis, Gordon G. Wallace, Malcolm R. Smyth, Anthony J. Killard Mar 2013

Fabrication Of Polyaniline-Based Gas Sensors Using Piezoelectric Inkjet And Screen Printing For The Detection Of Hydrogen Sulfide, Karl H. Crowley, Aoife Morrin, Roderick L. Shepherd, Marc In Het Panhuis, Gordon G. Wallace, Malcolm R. Smyth, Anthony J. Killard

Gordon Wallace

This work describes a fully printable polyaniline-copper (II) chloride sensor for the detection of hydrogen sulfide gas. The sensing device is composed of screen printed silver interdigitated electrode (IDE) on a flexible PET substrate with inkjet printed layers of polyaniline and copper (II) chloride. The sensor is employed as a chemiresistor with changes in measured current being correlated with concentration. On exposure to hydrogen sulfide, 2.5 ppmv (parts per million by volume) is clearly detectable with a linear relationship between measured current and concentration over the 10-100 ppmv region. The detection mechanism is discussed with respect to the hydrogen sulfide …


Nanostructured Carbon Electrodes, Gordon G. Wallace, Jun Chen, Dan Li, Simon E. Moulton, Joselito M. Razal Mar 2013

Nanostructured Carbon Electrodes, Gordon G. Wallace, Jun Chen, Dan Li, Simon E. Moulton, Joselito M. Razal

Gordon Wallace

In its conducting form, carbon has proven to be a versatile, robust and high performing electrode material in areas such as energy conversion, energy storage and even medical bionics. In our laboratories we have been interested in the fabrication and utilization of nanostructured electrodes based on more recently discovered forms of carbon. These include carbon nanotubes and graphene.


Electrochemical Afm : Understanding The Electromaterial-Cellular Interface, Amy Gelmi, Michael J. Higgins, Scott T. Mcgovern, Gordon G. Wallace Mar 2013

Electrochemical Afm : Understanding The Electromaterial-Cellular Interface, Amy Gelmi, Michael J. Higgins, Scott T. Mcgovern, Gordon G. Wallace

Gordon Wallace

Organic conducting polymers are emerging as an exciting new class of biomaterial that can be used to enhance and control the growth of mammalian cells for tissue regeneration and engineering applications


Microsecond Dye Regeneration Kinetics In Efficient Solid State Dye-Sensitized Solar Cells Using A Photoelectrochemically Deposited Pedot Hole Conductor, Attila J. Mozer, Dillip K. Panda, Sanjeev Gambhir, B. Winther-Jensen, Gordon G. Wallace Mar 2013

Microsecond Dye Regeneration Kinetics In Efficient Solid State Dye-Sensitized Solar Cells Using A Photoelectrochemically Deposited Pedot Hole Conductor, Attila J. Mozer, Dillip K. Panda, Sanjeev Gambhir, B. Winther-Jensen, Gordon G. Wallace

Gordon Wallace

Microsecond dye-regeneration kinetics was observed in efficient solid state dye-sensitized solar cells using photoelectrochemically deposited poly(3,4-ethylenedioxythiophene (PEDOT) hole conductors using transient absorption spectroscopy. The dye-regeneration rate is orders of magnitude slower than the case using the I-/I3- redox couple or commonly used small molecule hole conductor and is attributed to the low dye to PEDOT ratio within the films.


Crosslinking Neat Ultrathin Films And Nanofibres Of Ph-Responsive Poly(Acrylic Acid) By Uv Radiation, Adrian Gestos, Philip G. Whitten, Geoffrey Maxwell Spinks, Gordon G. Wallace Mar 2013

Crosslinking Neat Ultrathin Films And Nanofibres Of Ph-Responsive Poly(Acrylic Acid) By Uv Radiation, Adrian Gestos, Philip G. Whitten, Geoffrey Maxwell Spinks, Gordon G. Wallace

Gordon Wallace

Electrospun polyelectrolyte hydrogel nanofibres are being developed for many applications including artificial muscles, scaffolds for tissue engineering, wound dressings and controlled drug release. For electrospun polyelectrolytes, a post-spinning crosslinking process is necessary for producing a hydrogel. Typically, radiation or thermal crosslinking routines are employed that require multifunctional crosslinking molecules and crosslink reaction initiators (free radical producers). Here, ultraviolet subtype-C (UVC) radiation was employed to crosslink neat poly(acrylic acid) (PAA) nanofibres and films to different crosslink densities. Specific crosslink initiators or crosslinking molecules are not necessary in this fast and simple process providing an advantage for biological applications. Scanning probe microscopy …


Advanced Microwave-Assisted Production Of Hybrid Electrodes For Energy Applications, Peter Sherrell, Jun Chen, Joselito M. Razal, Ivan P. Nevirkovets, Carol Crean, Andrew I. Minett, Gordon G. Wallace Mar 2013

Advanced Microwave-Assisted Production Of Hybrid Electrodes For Energy Applications, Peter Sherrell, Jun Chen, Joselito M. Razal, Ivan P. Nevirkovets, Carol Crean, Andrew I. Minett, Gordon G. Wallace

Gordon Wallace

Carbon nanotubes are one of the most prominent materials in research for creating electrodes for portable electronics. When coupled with metallic nanoparticles the performance of carbon nanotube electrodes can be dramatically improved. Microwave reduction is an extremely rapid method for producing carbon nanotube-metallic nanoparticle composites, however this technique has so far been limitied to carbon nanotube soot. An understanding of the microwave process and the interactions of metallic nanoparticles with carbon nanotubes has allowed us to extend this promising functionalisation route to pre-formed CNT elelctrode architectures. Nanoparticle reduction onto pre-formed architectures reduces metallic nanoparticle waste as particles are not formed …


Photoelectrochemical Cell Study On Closely Arranged Vertical Nanorod Bundles Of Cdse And Zn Doped Cdse Films, D Soundararajan, J K. Yoon, J S. Kwon, Y I. Kim, S H. Kim, J H. Park, Y J. Kim, D -Y Park, B C. Kim, G G. Wallace, J M. Ko Mar 2013

Photoelectrochemical Cell Study On Closely Arranged Vertical Nanorod Bundles Of Cdse And Zn Doped Cdse Films, D Soundararajan, J K. Yoon, J S. Kwon, Y I. Kim, S H. Kim, J H. Park, Y J. Kim, D -Y Park, B C. Kim, G G. Wallace, J M. Ko

Gordon Wallace

Closely arranged CdSe and Zn doped CdSe vertical nanorod bundles were grown directly on FTO coated glass by using electrodeposition method. Structural analysis by XRD showed the hexagonal phase without any precipitates related to Zn. FE-SEM image showed end capped vertically aligned nanorods arranged closely. From the UV-vis transmittance spectra, band gap energy was found to vary between 1.94 and 1.98 eV due to the incorporation of Zn. Solar cell parameters were obtained by assembling photoelectrochemical cells using CdSe and CdSe:Zn photoanodes, Pt cathode and polysulfide (1M Na2S + 1M S + 1M NaOH) electrolyte. The efficiency was found to …


Electrochemical Actuation Properties Of A Novel Solution-Processable Polythiophene, Yanzhe Wu, Amy M. Ballantyne, Pawel Wagner, Dezhi Zhou, Geoffrey M. Spinks, David Officer, Gordon G. Wallace Mar 2013

Electrochemical Actuation Properties Of A Novel Solution-Processable Polythiophene, Yanzhe Wu, Amy M. Ballantyne, Pawel Wagner, Dezhi Zhou, Geoffrey M. Spinks, David Officer, Gordon G. Wallace

Gordon Wallace

No abstract provided.


Catalytic Solar Water Splitting Inspired By Photosynthesis. Homogeneous Catalysts With A Mechanical ("Machine-Like") Action, Gerhard F. Swiegers, G Charles Dismukes, Leone Spiccia, Robin Brimblecombe, Annette Koo, Jun Chen, Gordon G. Wallace Mar 2013

Catalytic Solar Water Splitting Inspired By Photosynthesis. Homogeneous Catalysts With A Mechanical ("Machine-Like") Action, Gerhard F. Swiegers, G Charles Dismukes, Leone Spiccia, Robin Brimblecombe, Annette Koo, Jun Chen, Gordon G. Wallace

Gordon Wallace

Chemical reactions may be controlled by either: the minimum threshold energy that must be overcome during collisions between reactant molecules / atoms (the Activation Energy, Ea), or: the rate at which reactant collisions occur (the Collision Frequency, A) (for reactions with low Ea). Reactions of type (2) are governed by the physical, mechanical interaction of the reactants. Such mechanical processes are unusual, but not unknown in molecular catalysts. We examine the catalytic action and macroscopic properties of several abiological mechanical catalysts and show that they display distinct similarities to enzymes in general. An abiological model of the Photosystem II Water …


Flexible And Compressible Goretex-Pedot Membrane Electrodes For Solid-State Dye-Sensitized Solar Cells, Attila J. Mozer, Dillip K. Panda, Sanjeev Gambhir, Anthony C. Romeo, Bjorn Winther-Jensen, Gordon G. Wallace Mar 2013

Flexible And Compressible Goretex-Pedot Membrane Electrodes For Solid-State Dye-Sensitized Solar Cells, Attila J. Mozer, Dillip K. Panda, Sanjeev Gambhir, Anthony C. Romeo, Bjorn Winther-Jensen, Gordon G. Wallace

Gordon Wallace

A porous, flexible electrode based on a PTFE (Teflon) membrane (Goretex) coated with a metallic current collector and a conducting polymer (poly(3,4-ethylenedioxythiophene), PEDOT) has been developed for applications in solidstate dye-sensitized solar cells. Its low sheet resistance and compressibility make it an ideal electrode on uneven TiO2 surfaces with high efficiency and reproducibility. The porous nature of the electrode enables the feed-through of reactants and treatment agents, which opens up exciting opportunities to interface these photoelectrochemical devices with electrocatalytic, energy conversion, and storage systems. Postfabrication bonding of the photoanode and the Goretex-Au-PEDOT electrode is demonstrated.


Organic Bionics, Gordon G. Wallace, Simon E. Moulton, Caiyun Wang Mar 2013

Organic Bionics, Gordon G. Wallace, Simon E. Moulton, Caiyun Wang

Gordon Wallace

Bionic technology involves the efficient integration of biology and electronics and is providing the basis for significant improvements in a number of medical treatments. The use of organic conducting polymers to provide a compatible multifunctional platform to interface the world of biology and electronics has attracted an increasing amount of attention over the past 15 years. This paper will discuss advances being made in the development of organic bionics and their application to improved health strategies. © 2010 Copyright SPIE - The International Society for Optical Engineering.


Direct Exfoliation Of Graphite With A Porphyrin - Creating Functionalizable Nanographene Hybrids, Jenny Malig, Adam W. I Stephenson, Pawel Wagner, Gordon G. Wallace, David L. Officer, Dirk M. Guldi Mar 2013

Direct Exfoliation Of Graphite With A Porphyrin - Creating Functionalizable Nanographene Hybrids, Jenny Malig, Adam W. I Stephenson, Pawel Wagner, Gordon G. Wallace, David L. Officer, Dirk M. Guldi

Gordon Wallace

Exfoliation of graphite was achieved using a free-base porphyrin 1 resulting in an efficient fabrication of single-layer nanographene (NG)-1 hybrid platelets that can be further functionalized with other nanomaterials. The novel nanographene-porphyrin hybrids reveal efficient charge transfer in the excited state.


Charge Transport In Dye-Sensitized Solar Cells Based On Flame-Made Tio2 Nanoparticles, George Tsekouras, Masanori Miyashita, Yung Kent Kho, Wey Yang Teoh, Attila J. Mozer, Rose Amal, Shogo Mori, Gordon G. Wallace Mar 2013

Charge Transport In Dye-Sensitized Solar Cells Based On Flame-Made Tio2 Nanoparticles, George Tsekouras, Masanori Miyashita, Yung Kent Kho, Wey Yang Teoh, Attila J. Mozer, Rose Amal, Shogo Mori, Gordon G. Wallace

Gordon Wallace

The fundamental understanding on charge-transport properties of flame-synthesized TiO2 in dye-sensitized solar cells (DSSCs) is established in this work. By employing a one-step flame spray pyrolysis (FSP), predominantly anatase TiO2 nanoparticles with average nanoparticle sizes between 11 and 36 nm were achieved by varying the rate of combustion enthalpy (through varying liquid precursor feed flow rates) and using either an “openflame” or “enclosed-flame” configuration. Electron diffusion coefficient (D), electron lifetime (τ ), open circuit voltage (Voc ), and capacitance (C) measurements carried out on FSP TiO2 -based DSSCs demonstrated that interband charge trap density decreased with increase in particle size. …


A Battery Composed Of A Polypyrrole Cathode And A Magnesium Alloy Anode-Toward A Bioelectric Battery, Yong Kong, Caiyun Wang, Yang Yang, Chee O. Too, Gordon G. Wallace Mar 2013

A Battery Composed Of A Polypyrrole Cathode And A Magnesium Alloy Anode-Toward A Bioelectric Battery, Yong Kong, Caiyun Wang, Yang Yang, Chee O. Too, Gordon G. Wallace

Gordon Wallace

A bioelectric battery can be implanted into the human body and relies on oxygen in the internal body fluid to produce electrical energy. In this work, a battery that uses polypyrrole doped with a biological polyelectrolyte (dextran sulfate, an anti-coagulant) as the cathode and bioresorbable Mg alloy (AZ61) as the anode was developed. This battery exhibited a discharge capacity of 565 mA h g-1 in phosphate buffered saline (PBS, pH = 7.4), a commonly used electrolyte in biological research; offering a specific energy density of similar to 790W h kg-1. The electrochemical properties of the cathode, anode and battery itself …


The Mechanical And The Electrical Properties Of Conducting Polypyrrole Fibers, Javad Foroughi, Shaban R. Ghorbani, Germanas Peleckis, Geoffrey M. Spinks, Gordon G. Wallace, Xiaolin Wang, S X. Dou Mar 2013

The Mechanical And The Electrical Properties Of Conducting Polypyrrole Fibers, Javad Foroughi, Shaban R. Ghorbani, Germanas Peleckis, Geoffrey M. Spinks, Gordon G. Wallace, Xiaolin Wang, S X. Dou

Gordon Wallace

The mechanical and the electrical properties of polypyrrole (PPy) fibers and electrochemically deposited PPy films were studied. It was found that the PPy fibers showed a significantly higher strength than the PPy films due to better orientation of the molecular structure. The electrochemically prepared PPy films had a higher electrical conductivity than that of the fibers at high temperature. At low temperature, the PPy fibers showed the higher conductivity. The conductivity results were analyzed in the frame of the three-dimensional variable range hopping model. The results showed that at room temperature the average hopping distance for the fibers was about …


The Reclamation Of Boston Harbor: A Scientist's Perspective, Gordon T. Wallace Jr. Mar 2013

The Reclamation Of Boston Harbor: A Scientist's Perspective, Gordon T. Wallace Jr.

Gordon Wallace

A major effort, costing in the neighborhood of $2 billion, is under way to restore the environmental quality of Boston Harbor. While Boston Harbor is unquestionably one of the most polluted urban estuaries in the world, it is also one of the least understood with respect to the basic physics, chemistry, and biology involved. This information is essential for the purpose of identifying processes that control the transport, effect, and fate of contaminants entering the estuary. Failure to obtain this information may lead to continued inappropriate and unnecessarily expensive solutions to a complex environmental problem. An effective solution will require …


Remarkable Synergistic Effects In A Mixed Porphyrin Dye-Sensitized Tio2 Film, Attila J. Mozer, Gordon G. Wallace, David L. Officer, Matthew Griffith, Pawel W. Wagner, Klaudia K. Wagner, George Tsekouras, Shogo Mori, Ying Dong Mar 2013

Remarkable Synergistic Effects In A Mixed Porphyrin Dye-Sensitized Tio2 Film, Attila J. Mozer, Gordon G. Wallace, David L. Officer, Matthew Griffith, Pawel W. Wagner, Klaudia K. Wagner, George Tsekouras, Shogo Mori, Ying Dong

Gordon Wallace

A remarkable 300% efficiency enhancement driven by a matching increase in the short circuit current was observed in a mixed porphyrin dye-sensitized solar cell constructed from two dyes in a 3:1 ratio. Absorbed photon-to-current conversion efficiency measurements indicate an improved charge injection yield for both dyes in the mixture. Several possible origins for the observed performance enhancement are discussed.


Polypyrrole Coated Nylon Lycra Fabric As Stretchable Electrode For Supercapacitor Applications, Binbin Yue, Caiyun Wang, Xin Ding, Gordon G. Wallace Mar 2013

Polypyrrole Coated Nylon Lycra Fabric As Stretchable Electrode For Supercapacitor Applications, Binbin Yue, Caiyun Wang, Xin Ding, Gordon G. Wallace

Gordon Wallace

Wearable electronics offer the combined advantages of both electronics and fabrics. Being an indispensable part of these electronics, lightweight, stretchable and wearable power sources are strongly demanded. Here we describe a daily-used nylon lycra fabric coated with polypyrrole as electrode for stretchable supercapacitors. Polypyrrole was synthesized on the fabric via a simple chemical polymerization process with ammonium persulfate (APS) as an oxidant and naphthalene-2,6-disulfonic acid disodium salt (Na2NDS) as a dopant. This material was characterized with FESEM, FTIR, tensile stress, and studied as a supercapacitor electrode in 1.0 M NaCl. This conductive textile could endure 1000 stretching cycles with 100% …


Enhanced Performance Of Dye Sensitized Solar Cells Utilizing Platinum Electrodeposit Counter Electrodes, Attila J. Mozer, George Tsekouras, Gordon G. Wallace Mar 2013

Enhanced Performance Of Dye Sensitized Solar Cells Utilizing Platinum Electrodeposit Counter Electrodes, Attila J. Mozer, George Tsekouras, Gordon G. Wallace

Gordon Wallace

Enhanced performance was observed for dye-sensitized solar cells (DSSCs) utilizing counter electrodes based on Pt electrodeposits compared to counter electrodes based on sputtered Pt. Scanning electron microscopy of Pt electrodeposits revealed that the use of an initial cathodic overpotential pulse followed by steady electrodeposition at a mild cathodic potential yielded ∼40nm particles, compared to ∼600nm particles when no such pulse was used. Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) of electrode materials suggested that Pt electrodeposits would give enhanced performance as DSSC counter electrodes compared to sputtered Pt, and this was confirmed by device testing. EIS characterization of DSSCs under …


Printing Nanomaterials Using Non-Contact Printing, Charles Mire, Marc In Het Panhuis, Paul D. Calvert, Gordon G. Wallace Mar 2013

Printing Nanomaterials Using Non-Contact Printing, Charles Mire, Marc In Het Panhuis, Paul D. Calvert, Gordon G. Wallace

Gordon Wallace

We report on the use of inkjet, extrusion, and capillary printing of poly(3,4 ethylenedioxythiophene)/ poly(sodium 4-styrene-sulfonate) (PEDOT/PSS) to create structures that could be used in a flexible, implantable bionic device. Resistance values as low as 250 kΩ are demonstrated, with little deviation under as much as 1.5% strain. The results show PEDOT/PSS can be a suitable material for printed bionic devices.


Electrically Conductive, Tough Hydrogels With Ph Sensitivity, Sina Naficy, Joselito M. Razal, Geoffrey M. Spinks, Gordon G. Wallace, Philip G. Whitten Mar 2013

Electrically Conductive, Tough Hydrogels With Ph Sensitivity, Sina Naficy, Joselito M. Razal, Geoffrey M. Spinks, Gordon G. Wallace, Philip G. Whitten

Gordon Wallace

Electrically conductive, mechanically tough hydrogels based on a double network (DN) comprised of poly(ethylene glycol) methyl ether methacrylate (PPEGMA) and poly(acrylic acid) (PAA) were produced. Poly(3,4-ethylenedioxythiophene) (PEDOT) was chemically polymerized within the tough DN gel to provide electronic conductivity. The effects of pH on the tensile and compressive mechanical properties of the fully swollen hydrogels, along with their electrical conductivity and swelling ratio were determined. Compressive and tensile strengths as high as 11.6 and 0.6 MPa, respectively, were obtained for hydrogels containing PEDOT with a maximum conductivity of 4.3 S cm-1. This conductivity is the highest yet reported for hydrogel …


Nanostructured Electrically Conducting Biofibres Produced Using A Reactive Wet-Spinning Process, Javad Foroughi, Geoffrey M. Spinks, Gordon G. Wallace Mar 2013

Nanostructured Electrically Conducting Biofibres Produced Using A Reactive Wet-Spinning Process, Javad Foroughi, Geoffrey M. Spinks, Gordon G. Wallace

Gordon Wallace

Electrically conducting, robust fibres comprised of both an alginate (Alg) biopolymer and a polypyrrole (PPy) component have been produced using reactive wet-spinning. Using this approach polypyrrole-biopolymer fibres were also produced with single-walled carbon nanotubes (CNTs), added to provide additional strength and conductivity. The fibres produced containing CNTs show a 78% increase in ultimate stress and 25% increase in elongation to break compared to PPy-alginate fibre. These properties are essential for studies involving the use of electrical stimulation to promote nerve regrowth and/or muscle regeneration. The resultant a novel fibres had been evaluated to develop a viable system in incorporating biological …


Emulsion-Coaxial Electrospinning: Designing Novel Architectures For Sustained Release Of Highly Soluble Low Molecular Weight Drugs, Lucie Viry, Simon E. Moulton, Tony Romeo, Courtney Suhr, Damia Mawad, Mark Cook, Gordon G. Wallace Mar 2013

Emulsion-Coaxial Electrospinning: Designing Novel Architectures For Sustained Release Of Highly Soluble Low Molecular Weight Drugs, Lucie Viry, Simon E. Moulton, Tony Romeo, Courtney Suhr, Damia Mawad, Mark Cook, Gordon G. Wallace

Gordon Wallace

In drug therapy, most therapeutic drugs are of low molecular weight and could freely diffuse in the biological milieu depending on the administration route applied. The main reason for the development of polymeric drug carriers is to obtain desired effects such as sustained therapy, local and controlled release, prolonged activity and reduction of side effects. Alternatively, polymeric carriers can be made bioerodible in order to be eliminated by natural ways after a certain time of therapy. Core-shell fibres from coaxial spinneret or emulsion electrospinning are good candidates for the development of such devices; however difficulties remain especially in controlling the …


Electrocatalytic Reduction Of Carbon Dioxide By Cobalt-Phthalocyanine-Incorporated Polypyrrole, Jun Chen, Gordon G. Wallace, Jiaxing Lu, Aijian Zhang, Weimin Zhang Mar 2013

Electrocatalytic Reduction Of Carbon Dioxide By Cobalt-Phthalocyanine-Incorporated Polypyrrole, Jun Chen, Gordon G. Wallace, Jiaxing Lu, Aijian Zhang, Weimin Zhang

Gordon Wallace

In the quest for catalysts for the electrocatalytic reduction of , a cobalt phthalocyanine/polypyrrole (CoPc/PPy) composite electrode has been developed. The electrode is prepared by drop casting CoPc onto the PPy film from the CoPc/tetrahydrofuran solution (1 mg/mL). The onset potential for reduction occurred at potentials 160 mV more positive than observed with a simple PPy electrode. Furthermore, in the potentiostatic electrolysis, the catalytic current for reduction at CoPc/PPy was very stable, with a higher current density and current efficiency when compared to the PPy electrode.


Vapor Phase Polymerization Of Edot From Submicrometer Scale Oxidant Patterned By Dip-Pen Nanolithography, Cathal D. O'Connell, Michael J. Higgins, Hiroshi Nakashima, Simon E. Moulton, Gordon G. Wallace Mar 2013

Vapor Phase Polymerization Of Edot From Submicrometer Scale Oxidant Patterned By Dip-Pen Nanolithography, Cathal D. O'Connell, Michael J. Higgins, Hiroshi Nakashima, Simon E. Moulton, Gordon G. Wallace

Gordon Wallace

Some of the most exciting recent advances in conducting polymer synthesis have centered around the method of vapor phase polymerization (VPP) of thin films. However, it is not known whether the VPP process can proceed using significantly reduced volumes of oxidant and therefore be implemented as part of nanolithography approach. Here, we present a strategy for submicrometer scale patterning of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) via in situ VPP. Attolitre (10-18 L) volumes of oxidant "ink" are controllably deposited using dip-pen nanolithography (DPN). DPN patterning of the oxidant ink is facilitated by the incorporation of an amphiphilic block copolymer thickener, …


Elastic Conducting Carbon Nanotube-Laden Sibs Fibers, Alberto J. Granero, Joselito M. Razal, Gordon G. Wallace, Marc In Het Panhuis Mar 2013

Elastic Conducting Carbon Nanotube-Laden Sibs Fibers, Alberto J. Granero, Joselito M. Razal, Gordon G. Wallace, Marc In Het Panhuis

Gordon Wallace

We report a facile method to produce elastic conducting fibers using a continuous flow wet-spinning approach. The spun fibers were highly stretchable, similar to the elastomeric polymer used.