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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
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 …
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 …
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 …
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 …
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 …
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 …
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. …
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 …