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Articles 1 - 15 of 15
Full-Text Articles in Physical Sciences and Mathematics
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
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 …
Surface And Biomolecular Forces Of Conducting Polymers, Michael J. Higgins, Gordon G. Wallace
Surface And Biomolecular Forces Of Conducting Polymers, Michael J. Higgins, Gordon G. Wallace
Gordon Wallace
In this review, we provide insight into the surface forces of conducting polymers, a class of intelligent materials that offer unique strategies for controlling biomolecular interactions in wide-ranging biomedical applications. Critical to the success of these applications is that the polymer interface is exposed to biological fluids whose interactions are controlled through the polymer surface chemistry and electrochemical switching of the surface properties. There is, however, little known about the intermolecular and surface forces that govern these interactions. Therefore, the purpose of this review is to more closely examine the forces that mediate interactions with biological entities, including forces such …
Multifunctional Conducting Fibres With Electrically Controlled Release Of Ciprofloxacin, Dorna Esrafilzadeh, Joselito M. Razal, Simon E. Moulton, Elise M. Stewart, Gordon G. Wallace
Multifunctional Conducting Fibres With Electrically Controlled Release Of Ciprofloxacin, Dorna Esrafilzadeh, Joselito M. Razal, Simon E. Moulton, Elise M. Stewart, Gordon G. Wallace
Gordon Wallace
We hereby present a new method of producing coaxial conducting polymer fibres loaded with an antibiotic drug that can then be subsequently released (or sustained) in response to electrical stimulation. The method involves wet-spinning of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) fibre, which served as the inner core to the electropolymerised outer shell layer of polypyrrole (Ppy). Ciprofloxacin hydrochloride (Cipro) was selected as the model drug and as the dopant in the Ppy synthesis. The release of Cipro in phosphate buffered saline (PBS) from the fibres was controlled by switching the redox state of Ppy.Cipro layer. Released Cipro under passive and stimulated conditions …
Microstructures Of Conducting Polymers: Patterning And Actuation Study, Babita Gaihre, Bo Weng, Syed A. Ashraf, Geoffrey M. Spinks, Peter C. Innis, Gordon G. Wallace
Microstructures Of Conducting Polymers: Patterning And Actuation Study, Babita Gaihre, Bo Weng, Syed A. Ashraf, Geoffrey M. Spinks, Peter C. Innis, Gordon G. Wallace
Gordon Wallace
The conducting polymers exhibit electrochemically driven expansion and shrinkage due to ingress and egress of dopant ions in response to potential applied. In this paper, we report on patterning of microdots and microsquares of polypyrrole (PPy), poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,3-dihexyl-3-4-dihydro-2H-thieno[3,4b][1,4]-dioxepine PProDOT(Hx) 2 and their behaviour under voltage change. Stainless steel mesh was used to deposit microdots and inkjet-printed cellulose girds were used to deposit microsqures of the conducting polymers on the ITO surface. It was found that PPy showed distinct actuation in the z direction while colour change was prominent in the case of PEDOT and PProDOT(Hx)2.
In Vitro Growth And Differentiation Of Primary Myoblasts On Thiophene Based Conducting Polymers, Anita F. Quigley, Klaudia K. Wagner, Magdalena Kita, Kerry J. Gilmore, Michael J. Higgins, Robert D. Breukers, Simon E. Moulton, Graeme M. Clark, Anthony Penington, Gordon G. Wallace, David L. Officer, Robert M. Kapsa
In Vitro Growth And Differentiation Of Primary Myoblasts On Thiophene Based Conducting Polymers, Anita F. Quigley, Klaudia K. Wagner, Magdalena Kita, Kerry J. Gilmore, Michael J. Higgins, Robert D. Breukers, Simon E. Moulton, Graeme M. Clark, Anthony Penington, Gordon G. Wallace, David L. Officer, Robert M. Kapsa
Gordon Wallace
Polythiophenes are attractive candidate polymers for use in synthetic cell scaffolds as they are amenable to modification of functional groups as a means by which to increase biocompatibility. In the current study we analysed the physical properties and response of primary myoblasts to three thiophene polymers synthesized from either a basic bithiophene monomer or from one of two different thiophene monomers with alkoxy functional groups. In addition, the effect of the dopants pTS- and ClO4 - was investigated. In general, it was found that pTS- doped polymers were significantly smoother and tended to be more hydrophilic than their ClO 4 …
Conducting Polymer Coated Neural Recording Electrodes, Alexander R. Harris, Simon Morgan, Jun Chen, Robert M. Kapsa, Gordon G. Wallace, Antonio Paolini
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 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
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 …
Nanostructured Electrically Conducting Biofibres Produced Using A Reactive Wet-Spinning Process, Javad Foroughi, Geoffrey M. Spinks, Gordon G. Wallace
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 …
Conducting Polymer Nanoparticles Synthesized In An Ionic Liquid By Chemical Polymerisation, J.M. Pringle, Orawan Ngamna, Jun Chen, Gordon G. Wallace, Maria Forsyth, Douglas Macfarlane
Conducting Polymer Nanoparticles Synthesized In An Ionic Liquid By Chemical Polymerisation, J.M. Pringle, Orawan Ngamna, Jun Chen, Gordon G. Wallace, Maria Forsyth, Douglas Macfarlane
Gordon Wallace
Ionic liquids are ideal media for the synthesis and application of conducting polymers as they can exhibit excellent oxidative and reductive stability, allowing access to potentials outside the smaller electrochemical window of molecular solvent/electrolyte systems. Here we report the first use of an ionic liquid for the chemical synthesis of poly(pyrrole), poly(thiophene) and poly(terthiophene) using a variety of oxidants. The polymers have been analysed by UV–vis spectroscopy, cyclic voltammetry and dynamic light scattering, which shows the particles to be <500 nm diameter. TEM analysis shows the individual poly(thiophene) particles to be <100 nm.
Inkjet And Extrusion Printing Of Conducting Poly(3,4-Ethylenedioxythiophene) Tracks On And Embedded In Biopolymer Materials, Charles A. Mire, Animesh Agrawal, Gordon G. Wallace, Paul Calvert, Marc In Het Panhuis
Inkjet And Extrusion Printing Of Conducting Poly(3,4-Ethylenedioxythiophene) Tracks On And Embedded In Biopolymer Materials, Charles A. Mire, Animesh Agrawal, Gordon G. Wallace, Paul Calvert, Marc In Het Panhuis
Gordon Wallace
Two printing methods, extrusion and inkjet, are used to deposit tracks of PEDOT/PSS conducting polymer onto biopolymer films with a view to prepare implantable tissue mimics containing electronic devices. Extruded tracks offer lower printing resolution, but better electrical characteristics compared to inkjet printed tracks. The biopolymer–ink interaction results in narrower printed tracks compared to those on glass. This affects the final conductivity, which is lower for printed tracks on biopolymer than for lines printed on glass, due to the part of the track lying below the surface. Extrusion printing is used to embed tracks into a biopolymer matrix, resulting in …
6 Ghz Microstrip Patch Antennas With Pedot And Polypyrrole Conducting Polymers, Akhilesh Verma, Bo Weng, Roderick L. Shepherd, Christophe Fumeaux, Van Tan Truong, Gordon G. Wallace, Bevan D. Bates
6 Ghz Microstrip Patch Antennas With Pedot And Polypyrrole Conducting Polymers, Akhilesh Verma, Bo Weng, Roderick L. Shepherd, Christophe Fumeaux, Van Tan Truong, Gordon G. Wallace, Bevan D. Bates
Gordon Wallace
Two 6 GHz microstrip patch antennas made from conducting polymers with relatively low DC conductivity such as PEDOT (10000 S/m) and PPy (2000 S/m) are presented. The performance of these patch antennas is compared with a similar copper patch antenna. The results indicate that it is possible to obtain reasonable performance albeit with modest radiation efficiencies. The PEDOT antenna achieved a maximum gain of 2.2 dB, while the PPy antenna reached a gain of 3.8 dB, as against 6.0 dB for a corresponding Cu patch antenna The results confirm the potential of polymer materials for microwave antennas and suggest that …
Conducting Polymers With Fibrillar Morphology Synthesized In A Biphasic Ionic Liquid/Water System, J.M. Pringle, Orawan Ngamna, Carol M. Lynam, Gordon G. Wallace, Maria Forsyth, Douglas Macfarlane
Conducting Polymers With Fibrillar Morphology Synthesized In A Biphasic Ionic Liquid/Water System, J.M. Pringle, Orawan Ngamna, Carol M. Lynam, Gordon G. Wallace, Maria Forsyth, Douglas Macfarlane
Gordon Wallace
The synthesis of poly(pyrrole), poly(terthiophene), and poly(3,4-ethylenedioxythiophene) with unusual fibrillar morphologies has been achieved by chemical polymerization in a biphasic ionic liquid/water system. Use of aqueous gold chloride as the oxidant, with the monomers dissolved in a hydrophobic ionic liquid, allows the polymerization to occur at the ionic liquid/water interface. The resultant conducting polymer fibrils are, on average, 50−100 nm wide and can be thousands of nanometers long. The polymers produced in this ionic liquid system are compared to those synthesized in a biphasic chloroform/water system.
Synthesis, Modeling, And Characterization Of Conducting Polymers, Geoffrey M. Spinks, Lianbin Zhao, Weihua Li, Yanzhe Wu, Dezhi Zhou, Gordon G. Wallace
Synthesis, Modeling, And Characterization Of Conducting Polymers, Geoffrey M. Spinks, Lianbin Zhao, Weihua Li, Yanzhe Wu, Dezhi Zhou, Gordon G. Wallace
Gordon Wallace
This paper presents synthesis and characterization of polypyrrole based conducting polymers in terms of electronic and mechanical disciplines. Using the electrochemical polymerization approach, conducting polymer samples with different dimensions (length, width, and thickness) was fabricated. For each sample, both sinusoidal and step excitations were used to study its mechanical and electrical properties. An equivalent electric circuit based on constant phase element (CPE) is proposed to model such responses. Electrochemical impedance spectroscopy (EIS) method was used to identify the relationship between the dimensions of conducting polymers and model elements parameters.
Comparative Displacement Study Of Bilayer Actuators Comprising Of Conducting Polymers, Fabricated From Polypyrrole, Poly(3,4- Ethylenedioxythiophene) Or Poly(3,4-Propylenedioxythiophene), Babita Gaihre, Syed Ashraf, Geoffrey M. Spinks, Peter C. Innis, Gordon G. Wallace
Comparative Displacement Study Of Bilayer Actuators Comprising Of Conducting Polymers, Fabricated From Polypyrrole, Poly(3,4- Ethylenedioxythiophene) Or Poly(3,4-Propylenedioxythiophene), Babita Gaihre, Syed Ashraf, Geoffrey M. Spinks, Peter C. Innis, Gordon G. Wallace
Gordon Wallace
The stress gradient generated due to electrochemical oxidation/reduction of a conducting polymer in a bilayer actuator causes a bending movement. Here we report a comparative study of the displacement of bilayer actuators prepared using different conducting polymers. The effects of conducting polymers obtained from electrochemical or chemical synthesis route: different polymers (polypyrrole (PPy), poly(3,4-ethylenedioxythiophene) PEDOT and poly(3,3-dihexyl-3-4-dihydro-2H-thieno[3,4b][1,4]-dioxepine [PProDOT(Hx) 2]); and different electrolytes (0.1 M lithium trifluromethanesulfonate/propylenecarbonate (LiTFSI/PC) and 1-ethyl-3-methyl imidazolium trifluromethanesulfonate (EMITFSI)) on the displacement amplitude and displacement patterns of these actuators were investigated and compared. The results indicate that the bilayer actuator consisting of an electrochemically synthesized conducting polymer …
Photoelectrochemical Cells Based On Inherently Conducting Polymers, Gordon G. Wallace, Chee O. Too, David L. Officer, Paul C Dastoor
Photoelectrochemical Cells Based On Inherently Conducting Polymers, Gordon G. Wallace, Chee O. Too, David L. Officer, Paul C Dastoor
Gordon Wallace
This review of photoelectrochemical cells (PECs) based on inherently conducting polymers (ICPs) deals with the mechanisms of operation and the various factors that influence the overall efficiency of PECs. The factors addressed include ICP composition and oxidation state, the use of nanostructured surfaces and interfaces, and the PEC electrolyte and redox mediator.