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- Polypyrrole (9)
- Graphene (8)
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Articles 1 - 30 of 40
Full-Text Articles in Physical Sciences and Mathematics
Aqueous Dispersions Of Reduced Graphene Oxide And Multi Wall Carbon Nanotubes For Enhanced Glucose Oxidase Bioelectrode Performance, Willo Grosse, Joffrey Champavert, Sanjeev Gambhir, Gordon G. Wallace, Simon E. Moulton
Aqueous Dispersions Of Reduced Graphene Oxide And Multi Wall Carbon Nanotubes For Enhanced Glucose Oxidase Bioelectrode Performance, Willo Grosse, Joffrey Champavert, Sanjeev Gambhir, Gordon G. Wallace, Simon E. Moulton
Gordon Wallace
Aqueous dispersions of reduced graphene oxide (rGO) and multi walled carbon nanotubes (MWCNT) were fabricated through a modified chemical reduction method. The significant advantage of the method developed here is the omission of any stabilising compound or organic solvent to obtain stable rGO-MWCNT dispersions. Significantly biological entities, in this case the enzyme glucose oxidase (GOx), can be successfully incorporated into the dispersion. These dispersions were characterised using XPS, SEM, zeta potential and particle size measurements which showed that the dispersion stability is not sacrificed with the addition of GOx, and significantly, the electrical properties of the rGO and MWCNTs are …
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 …
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
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 …
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.
Polypyrrole Doped With Redox-Active Poly(2-Methoxyaniline-5-Sulfonic Acid) For Lithium Secondary Batteries, Yang Yang, Caiyun Wang, Syed A. Ashraf, Gordon G. Wallace
Polypyrrole Doped With Redox-Active Poly(2-Methoxyaniline-5-Sulfonic Acid) For Lithium Secondary Batteries, Yang Yang, Caiyun Wang, Syed A. Ashraf, Gordon G. Wallace
Gordon Wallace
Polypyrrole is a promising electrode material for flexible/bendable energy storage devices due to its inherent fast redox switching, mechanical flexibility, easy processability and being environmentally benign. However, its low attainable capacity limits its practical applications. Here, we synthesise a polypyrrole/poly(2-methoxyaniline-5-sulfonic acid) (PPy/PMAS) composite by incorporating redox-active PMAS into a PPy matrix via an electropolymerization method. For comparison, polypyrrole containing the electrochemically inert dopant p-toluenesulfonate (PPy-pTS) was prepared under the same conditions. The resultant PPy/PMAS film shows greatly improved electrochemical properties by harnessing the contribution from PMAS, i.e. higher specific capacity, better rate capability and improved cycling stability when used as …
Fabrication Of Graphene Electrodes By Electrophoretic Deposition And Their Synergistic Effects With Pedot And Platinum, Widsanusan Chartarrayawadee, Simon E. Moulton, Chee O. Too, Gordon G. Wallace
Fabrication Of Graphene Electrodes By Electrophoretic Deposition And Their Synergistic Effects With Pedot And Platinum, Widsanusan Chartarrayawadee, Simon E. Moulton, Chee O. Too, Gordon G. Wallace
Gordon Wallace
This research presents a useful electrophoretic deposition (EPD) technique for electrode fabrication from an aqueous colloidal solution of graphene to produce graphene electrodes by the deposition of graphene on to indium-tin oxide (ITO) coated glass. Resultant graphene electrodes are composited with conducting polymer (PEDOT), and platinum nanoparticles, to investigate their synergistic effects. Firstly, PEDOT is composited with graphene by electropolymerization on to the graphene layer. The graphene/PEDOT electrodes demonstrate an improvement in electrochemical response in tetrabutylammonium perchlorate/ acetonitrile solution. Secondly, graphene electrodes are composited with platinum by EPD of platinum nanoparticles on to the graphene layer. The resultant graphene/platinum electrodes …
Quantifying Fibronectin Adhesion With Nanoscale Spatial Resolution On Glycosaminoglycan Doped Polypyrrole Using Atomic Force Microscopy, Amy Gelmi, Michael J. Higgins, Gordon G. Wallace
Quantifying Fibronectin Adhesion With Nanoscale Spatial Resolution On Glycosaminoglycan Doped Polypyrrole Using Atomic Force Microscopy, Amy Gelmi, Michael J. Higgins, Gordon G. Wallace
Gordon Wallace
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 …
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
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
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 …
Surface Properties And Interaction Forces Of Biopolymer-Doped Conductive Polypyrrole Surfaces By Atomic Force Microscopy, Jani M. Pelto, Suvi P. Haimi, Aliisa S. Siljander, Susanna S. Miettinen, Kirsi M. Tappura, Michael J. Higgins, Gordon G. Wallace
Surface Properties And Interaction Forces Of Biopolymer-Doped Conductive Polypyrrole Surfaces By Atomic Force Microscopy, Jani M. Pelto, Suvi P. Haimi, Aliisa S. Siljander, Susanna S. Miettinen, Kirsi M. Tappura, Michael J. Higgins, Gordon G. Wallace
Gordon Wallace
Surface properties and electrical charges are critical factors elucidating cell interactions on biomaterial surfaces. The surface potential distribution and the nanoscopic and microscopic surface elasticity of organic polypyrrole-hyaluronic acid (PPy-HA) were studied by atomic force microscopy (AFM) in a fluid environment in order to explain the observed enhancement in the attachment of human adipose stem cells on positively charged PPy-HA films. The electrostatic force between the AFM tip and a charged PPy-HA surface, the tip-sample adhesion force, and elastic moduli were estimated from the AFM force curves, and the data were fitted to electrostatic double-layer and elastic contact models. The …
A Merocyanine-Based Conductive Polymer, Klaudia K. Wagner, Michele Zanoni, Anastasia Elliott, Pawel W. Wagner, Robert P. Byrne, Larisa Florea, Dermot Diamond, Keith Gordon, Gordon G. Wallace, David L. Officer
A Merocyanine-Based Conductive Polymer, Klaudia K. Wagner, Michele Zanoni, Anastasia Elliott, Pawel W. Wagner, Robert P. Byrne, Larisa Florea, Dermot Diamond, Keith Gordon, Gordon G. Wallace, David L. Officer
Gordon Wallace
We report the first example of a conducting polymer with a merocyanine incorporated into the polymer backbone by electropolymerisation of a spiropyran moiety covalently linked between two alkoxythiophene units. Utilising the known metal coordination capabilities of merocyanines, introduction of cobalt ions into the electropolymerisation led to an enhancement of the conductivity, morphology and optical properties of the polymer films.
Electrically Conductive Coatings Of Nickel And Polypyrrole/Poly(2- Methoxyaniline-5-Sulfonic Acid) On Nylon Lycra® Textiles, B C. Kim, P C. Innis, Gordon G. Wallace, C T.J Low, F C. Walsh, W J. Cho, K H. Yu
Electrically Conductive Coatings Of Nickel And Polypyrrole/Poly(2- Methoxyaniline-5-Sulfonic Acid) On Nylon Lycra® Textiles, B C. Kim, P C. Innis, Gordon G. Wallace, C T.J Low, F C. Walsh, W J. Cho, K H. Yu
Gordon Wallace
Woven nylon Lycra® has been coated with finely-divided electroless nickel-phosphorus, polypyrrole and electroless nickel/polypyrrole to produce flexible and electrically conductive textiles. The coated textiles were tested for their electrochemical activity, electrical resistivity and resistivity in response to mechanical strain. Pre-dyeing the textile with poly(2-methoxyaniline-5-sulfonic acid) (PMAS) prior to electroless metallization by electroless nickel and via chemical polymerization of polypyrrole was found to be beneficial in enhancing the resultant coating as well as stabilizing surface resistance responses when exposed to a wide range of strain. The mass gain due to the nickel coating was found to increase linearly with deposition time. …
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
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
Gordon Wallace
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 have …
Colour Tunable Electrochromic Devices Based On Pprodot-(Hx)2 And Pprodot-(Ethx)2 Polymers, Bo Weng, Syed Ashraf, Peter C. Innis, Gordon G. Wallace
Colour Tunable Electrochromic Devices Based On Pprodot-(Hx)2 And Pprodot-(Ethx)2 Polymers, Bo Weng, Syed Ashraf, Peter C. Innis, Gordon G. Wallace
Gordon Wallace
The most commonly used method to tune the colour transition states of an ECD is to modify the chemical structure of the electrochromic polymers to achieve the desired transparent to dark state switching colours. However, this approach can present significant synthetic challenges that typically result in a compromise in device performance parameters such as contrast range or stability as well as solvent processability. In this study we have investigated tuning the dark-state colour of an ECD (at +0.8 V) by solution mixing poly(3,3-dihexyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine) (PProDOT-(Hx)2), which has an excellent contrast performance but with an esthetically undesirable purple colour transition, with poly(3,3-bis(2-ethylhexyl)-3,4-dihydro-2H-thieno …
Surface Modification Of Polypyrrole/Biopolymer Composites For Controlled Protein And Cellular Adhesion, Paul J. Molino, Binbin Zhang, Gordon G. Wallace, Timothy Hanks
Surface Modification Of Polypyrrole/Biopolymer Composites For Controlled Protein And Cellular Adhesion, Paul J. Molino, Binbin Zhang, Gordon G. Wallace, Timothy Hanks
Gordon Wallace
The ability to control the interaction between proteins and cells with biomaterials is critical for the effective application of materials for a variety of biomedical applications. Herein, the surface modification of the biological dopant dextran sulphate-doped polypyrrole (PPy-DS) with poly(ethylene glycol) to generate a biomaterial interface that is highly resistant to protein and cellular adhesion is described. Thiolated poly(ethylene glycol) (PEG-thiol) was covalently bound to PPy-DS backbone via a thiol-ene reaction. The surface resistance to an extracellular matrix protein fibronectin increased with increasing molecular weight and concentration of PEG-thiol, and was further optimised via increasing the reaction temperature and the …
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
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 …
Organic Bionics: Molecules, Materials And Medical Devices, Gordon G. Wallace, Simon E. Moulton
Organic Bionics: Molecules, Materials And Medical Devices, Gordon G. Wallace, Simon E. Moulton
Gordon Wallace
The uses of bionic devices that can improve the quality of human life are presented. Significant among them are the bionic ear or the bionic eye which has helped to regain use of important sensory organs. Bionics is the use of a biological entity and electronic devices that are put together to create the required implant.
Controlled Delivery For Neuro-Bionic Devices, Zhilian Yue, Simon E. Moulton, Mark Cook, Stephen O'Leary, Gordon G. Wallace
Controlled Delivery For Neuro-Bionic Devices, Zhilian Yue, Simon E. Moulton, Mark Cook, Stephen O'Leary, Gordon G. Wallace
Gordon Wallace
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.
Facile Synthesis Of Reduced Graphene Oxide/Mwnts Nanocomposite Supercapacitor Materials Tested As Electrophoretically Deposited Films On Glassy Carbon Electrodes, Widsanusan Chartarrayawadee, Simon E. Moulton, Chee O. Too, Byung C. Kim, Rao Yepuri, Anthony C. Romeo, Gordon G. Wallace
Facile Synthesis Of Reduced Graphene Oxide/Mwnts Nanocomposite Supercapacitor Materials Tested As Electrophoretically Deposited Films On Glassy Carbon Electrodes, Widsanusan Chartarrayawadee, Simon E. Moulton, Chee O. Too, Byung C. Kim, Rao Yepuri, Anthony C. Romeo, Gordon G. Wallace
Gordon Wallace
This paper reports on a facile synthesis method for reduced graphene oxide (rGO)/multi-walled carbon nanotubes (MWNTs) nanocomposites. The initial step involves the use of graphene oxide to disperse the MWNTs, with subsequent reduction of the resultant graphene oxide/MWNTs composites using l-ascorbic acid (LAA) as a mild reductant. Reduction by LAA preserves the interaction between the rGO sheets and MWNTs. The dispersion-containing rGO/MWNTs composites was characterized and electrophoretically deposited anodically onto glassy carbon electrodes to form high surface area films for capacitance testing. Pseudo capacitance peaks were observed in the rGO/MWNTs composite electrodes, resulting in superior performance with capacitance values up …
Intrinsically Stretchable Supercapacitors Composed Of Polypyrrole Electrodes And Highly Stretchable Gel Electrolyte, Chen Zhao, Caiyun Wang, Zhilian Yue, Kewei Shu, Gordon G. Wallace
Intrinsically Stretchable Supercapacitors Composed Of Polypyrrole Electrodes And Highly Stretchable Gel Electrolyte, Chen Zhao, Caiyun Wang, Zhilian Yue, Kewei Shu, Gordon G. Wallace
Gordon Wallace
There has been an emerging interest in stretchable power sources compatible with flexible/wearable electronics. Such power sources must be able to withstand large mechanical strains and still maintain function. Here we report a highly stretchable H3PO4-poly(vinyl alcohol) (PVA) polymer electrolyte obtained by optimizing the polymer molecular weight and its weight ratio to H3PO4 in terms of conductivity and mechanical properties. The electrolyte demonstrates a high conductivity of 3.4 x 10-3 S cm-1, and a high fracture strain at 410% elongation. It is mechanically robust with a tensile strength of 2 MPa and a Young's modulus of 1 MPa, and displays …
Scalable One-Step Wet-Spinning Of Graphene Fibers And Yarns From Liquid Crystalline Dispersions Of Graphene Oxide: Towards Multifunctional Textiles, Rouhollah Jalili, Seyed Hamed Aboutalebi, Dorna Esrafilzadeh, Roderick L. Shepherd, Jun Chen, Sima Aminorroaya-Yamini, Konstantin Konstantinov, Andrew I. Minett, Joselito M. Razal, Gordon G. Wallace
Scalable One-Step Wet-Spinning Of Graphene Fibers And Yarns From Liquid Crystalline Dispersions Of Graphene Oxide: Towards Multifunctional Textiles, Rouhollah Jalili, Seyed Hamed Aboutalebi, Dorna Esrafilzadeh, Roderick L. Shepherd, Jun Chen, Sima Aminorroaya-Yamini, Konstantin Konstantinov, Andrew I. Minett, Joselito M. Razal, Gordon G. Wallace
Gordon Wallace
Key points in the formation of liquid crystalline (LC) dispersions of graphene oxide (GO) and their processability via wet-spinning to produce long lengths of micrometer-dimensional fibers and yarns are addressed. Based on rheological and polarized optical microscopy investigations, a rational relation between GO sheet size and polydispersity, concentration, liquid crystallinity, and spinnability is proposed, leading to an understanding of lyotropic LC behavior and fiber spinnability. The knowledge gained from the straightforward formulation of LC GO "inks" in a range of processable concentrations enables the spinning of continuous conducting, strong, and robust fibers at concentrations as low as 0.075 wt%, eliminating …
Optical Switching Of Protein Interactions On Photosensitive-Electroactive Polymers Measured By Atomic Force Microscopy, Amy Gelmi, Michele Zanoni, Michael J. Higgins, Sanjeev Gambhir, David L. Officer, Dermot Diamond, Gordon G. Wallace
Optical Switching Of Protein Interactions On Photosensitive-Electroactive Polymers Measured By Atomic Force Microscopy, Amy Gelmi, Michele Zanoni, Michael J. Higgins, Sanjeev Gambhir, David L. Officer, Dermot Diamond, Gordon G. Wallace
Gordon Wallace
The ability to switch the physico-chemical properties of conducting polymers opens up new possibilities for a range of applications. Appropriately functionalised materials can provide routes to multi-modal switching, for example, in response to light and/or electrochemical stimuli. This capability is important in the field of bionics wherein remote and temporal control of the properties of materials is becoming attractive. The ability to actuate a film via photonic stimuli is particularly interesting as it facilitates the modulation of interactions between host binding sites and potential guest molecules. In this work, we studied two different poly-terthiophenes: one was functionalised with a spiropyran …
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 …
Evaluation Of Encapsulating Coatings On The Performance Of Polypyrrole Actuators, Sina Naficy, Nicholas Stoboi, Philip G. Whitten, Geoffrey M. Spinks, Gordon G. Wallace
Evaluation Of Encapsulating Coatings On The Performance Of Polypyrrole Actuators, Sina Naficy, Nicholas Stoboi, Philip G. Whitten, Geoffrey M. Spinks, Gordon G. Wallace
Gordon Wallace
Conjugated polymer actuators are electroactive materials capable of generating force and movement in response to an applied external voltage. Many potential biomedical and industrial applications require these actuators to operate in a liquid environment. However, immersion of uncoated conducting polymer actuators in non-electrolyte liquids greatly reduces their operating lifetime. Here, we demonstrate the use of spray coating as an effective and simple method to encapsulate polypyrrole (PPy) tri-layer bending actuators. Poly(styrene-b-isobutylene-b-styrene) (SIBS) was used as an encapsulating, compliant spray coating on PPy actuators. A significant enhancement in actuator lifetime in both air and water was observed by encapsulating the actuators. …
Exploiting High Quality Pedot:Pss-Swnt Composite Formulations For Wet-Spinning Multifunctional Fibers, Rouhollah Jalili, Joselito M. Razal, Gordon G. Wallace
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, …
Carbon Nanotube-Reduced Graphene Oxide Composites For Thermal Energy Harvesting Applications, Mark S. Romano, Na Li, Dennis Antiohos, Joselito M. Razal, Andrew Nattestad, Stephen Beirne, Shaoli Fang, Yongsheng Chen, Rouhollah Jalili, Gordon G. Wallace, Ray Baughman, Jun Chen
Carbon Nanotube-Reduced Graphene Oxide Composites For Thermal Energy Harvesting Applications, Mark S. Romano, Na Li, Dennis Antiohos, Joselito M. Razal, Andrew Nattestad, Stephen Beirne, Shaoli Fang, Yongsheng Chen, Rouhollah Jalili, Gordon G. Wallace, Ray Baughman, Jun Chen
Gordon Wallace
By controlling the SWNT-rGO electrode composition and thickness to attain the appropriate porosity and tortuosity, the electroactive surface area is maximized while rapid diffusion of the electrolyte through the electrode is maintained. This leads to an increase in exchange current density between the electrode and electrolyte which results in enhanced thermocell performance.
Electrochemically Synthesized Stretchable Polypyrrole/Fabric Electrodes For Supercapacitor, Binbin Yue, Caiyun Wang, Xin Ding, Gordon G. Wallace
Electrochemically Synthesized Stretchable Polypyrrole/Fabric Electrodes For Supercapacitor, 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 cotton fabric coated with polypyrrole as electrode for stretchable supercapacitors. Polypyrrole was synthesized on the Au coated fabric via an electrochemical polymerization process with p-toluenesulfonic acid (p-TS) as dopant from acetonitrile solution. This material was characterized with FESEM, tensile stress, and studied as a supercapacitor electrode in 1.0 M NaCl. This conductive textile electrode can sustain up to 140% strain without electric failure. It delivers a high specific …
Novel Nanographene/Porphyrin Hybrids-Preparation, Characterization, And Application In Solar Energy Conversion Schemes, Daniel Kiessling, Ruben D. Costa, Georgios Katsukis, Jenny Malig, Fabian Lodermeyer, Sebastian Feihl, Alexandra Roth, Leonie Wibmer, Matthias Kehrer, Michel Volland, Pawel W. Wagner, Gordon G. Wallace, David L. Officer, Dirk M. Guldi
Novel Nanographene/Porphyrin Hybrids-Preparation, Characterization, And Application In Solar Energy Conversion Schemes, Daniel Kiessling, Ruben D. Costa, Georgios Katsukis, Jenny Malig, Fabian Lodermeyer, Sebastian Feihl, Alexandra Roth, Leonie Wibmer, Matthias Kehrer, Michel Volland, Pawel W. Wagner, Gordon G. Wallace, David L. Officer, Dirk M. Guldi
Gordon Wallace
Four novel nanographene/porphyrin hybrids were prepared, characterized, and probed in solar energy conversion schemes. Exfoliation of graphite by means of immobilizing four different porphyrins onto the basal plane of graphene is accompanied by distinct electronic interactions in both the ground and the excited states. In the ground state, a strong loss in oscillator strength goes hand-in-hand with a notable broadening of the porphyrin transitions and, as such, attests to the shift of electron density from the electron donating porphyrins to nanographene. In the excited state, a nearly quantitative quenching of the porphyrin fluorescence is indicative of full charge transfer. The …