Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
Articles 61 - 68 of 68
Full-Text Articles in Physical Sciences and Mathematics
Photocatalytic Oxidation Of Methanol Using Titanium Dioxide/Single-Walled Carbon Nanotube Composite, Jun Chen, Carol M. Lynam, Chonlada Dechakiatkrai, Gordon G. Wallace, Sukon Phanichphant
Photocatalytic Oxidation Of Methanol Using Titanium Dioxide/Single-Walled Carbon Nanotube Composite, Jun Chen, Carol M. Lynam, Chonlada Dechakiatkrai, Gordon G. Wallace, Sukon Phanichphant
Gordon Wallace
Titanium dioxide/single-walled carbon nanotube TiO2/SWNT composites were prepared for photocatalytic applications. Thecomposites were characterized using UV-visible and Raman spectroscopy, zeta-potential measurements, cyclic voltammetrycoupled with a photoreactor, scanning electron microscopy, and transmission electron microscopy coupled with energy dispersiveX-ray spectroscopy. The photocatalytic activity of TiO2 and the TiO2/SWNT composite was investigated using the photo-oxidationof methanol in sulfuric acid as supporting electrolyte. The results indicate that the TiO2/SWNT composite enhances the photocatalyticactivity compared to TiO2 alone. Electrochemical studies of the TiO2/SWNT composite were also carried out in varioussupporting electrolytes and the presence of SWNTs was shown to increase the current achieved in voltammetric …
Nanoelectrodes: Energy Conversion And Storage, Gordon G. Wallace, Jun Chen, Attila J. Mozer, Maria Forsyth, Douglas R. Mcfarlane, Caiyun Wang
Nanoelectrodes: Energy Conversion And Storage, Gordon G. Wallace, Jun Chen, Attila J. Mozer, Maria Forsyth, Douglas R. Mcfarlane, Caiyun Wang
Gordon Wallace
Nanosized materials are known to take on peculiar properties compared to the bulk material. Their electronic and mechanical properties are known to improve e.g. higher electrical conductivity and greater strength. Their electrochemical redox properties can change dramatically, e.g. in the case of Ag°, the E° value for Ag°→Ag+ + e can change by up to half a volt as the particle size decreases. Nanodimensional materials also have an extraordinarily high surface area to volume ratio. All of these properties would bring beneficial effects if they could be retained when the material is assembled into a structure capable of being used …
Direct Ascorbic Acid Detection With Ferritin Immobilized On Single-Walled Carbon Nanotubes, Chonlada Dechakiatkrai, Jun Chen, Carol M. Lynam, Kwang Min Shin, Seon Jeong Kim, Sukon Phanichphant, Gordon G. Wallace
Direct Ascorbic Acid Detection With Ferritin Immobilized On Single-Walled Carbon Nanotubes, Chonlada Dechakiatkrai, Jun Chen, Carol M. Lynam, Kwang Min Shin, Seon Jeong Kim, Sukon Phanichphant, Gordon G. Wallace
Gordon Wallace
Ferritin protein was noncovalently immobilized onto single-walled carbon nanotubes (SWNTs). This SWNT/ferritin composite was characterized using cyclic voltammetry, UV-visible spectroscopy, Raman spectroscopy, and high-resolution transmission electron microscopy. The use of the SWNT/ferritin film as an amperometric biosensor was demonstrated by sensing ascorbic acid in phosphate-buffered saline solution with a sensitivity of 767 uAmg. It demonstrated that ferritin protein bound to SWNTs enhances the oxidation reaction of ascorbic acid over 11-fold.
Sensor Response Of Polypyrrole Trilayer Benders As A Function Of Geometry, Stephen John, Gursel Alici, Geoffrey M. Spinks, John D. W. Madden, Gordon G. Wallace
Sensor Response Of Polypyrrole Trilayer Benders As A Function Of Geometry, Stephen John, Gursel Alici, Geoffrey M. Spinks, John D. W. Madden, Gordon G. Wallace
Gordon Wallace
Trilayer polypyrrole benders are capable of generating voltages and currents when applied with an external force or displacement, demonstrating potential as mechanical sensors. Previous work has identified the effects of dopant and electrolyte on the sensor output, and a 'deformation induced ion flux' model was proposed. The current work aims to identify the change in sensor response with input amplitude and bender geometry as a function of frequency. The current and charge output from the trilayer benders were found to increase proportionally with input displacement and bender strain for multiple input frequencies, indicating linearity. Sensitivities of the current and charge …
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.
Levetiracetam-Loaded Biodegradable Polymer Implants In The Tetanus Toxin Model Of Temporal Lobe Epilepsy In Rats, Amy J. Halliday, Toni E. Campbell, Timothy S. Nelson, Karen J. Mclean, Gordon G. Wallace, Mark J. Cook
Levetiracetam-Loaded Biodegradable Polymer Implants In The Tetanus Toxin Model Of Temporal Lobe Epilepsy In Rats, Amy J. Halliday, Toni E. Campbell, Timothy S. Nelson, Karen J. Mclean, Gordon G. Wallace, Mark J. Cook
Gordon Wallace
Approximately one-third of people with epilepsy receive insufficient benefit from currently available anticonvulsant medication, and some evidence suggests that this may be due to a lack of effective penetration into brain parenchyma. The current study investigated the ability of biodegradable polymer implants loaded with levetiracetam to ameliorate seizures following implantation above the motor cortex in the tetanus toxin model of temporal lobe epilepsy in rats. The implants led to significantly shorter seizures and a trend towards fewer seizures for up to 1 week. The results of this study indicate that drug-eluting polymer implants represent a promising evolving treatment option for …
Autopolymerization Of Pyrrole In The Presence Of A Host/Guest Calixarene, David A. Reece, Jennifer M. Pringle, Stephen F. Ralph, Gordon G. Wallace
Autopolymerization Of Pyrrole In The Presence Of A Host/Guest Calixarene, David A. Reece, Jennifer M. Pringle, Stephen F. Ralph, Gordon G. Wallace
Gordon Wallace
Aqueous solutions containing pyrrole and calix-6-arenehexasulfonic acid were found to undergo polymerization in the absence of either a chemical oxidant or electrochemical oxidation. The product was an unstable colloidal suspension consisting of spherical polypyrrole particles measuring ≥500 nm in diameter. Conductivity measurements showed the material to be insulating, while cyclic voltammetry studies demonstrated that it was electroactive. Infrared spectroscopy and microanalysis confirmed that the polypyrrole produced was doped with calix-6-arenehexasulfonic acid. When the reaction was repeated using solutions containing stabilizing agents, stable colloidal dispersions were obtained. These were shown by both particle size analysis and transmission electron microscopy to contain …