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Articles 1 - 10 of 10
Full-Text Articles in Physical Sciences and Mathematics
Conducting Sensitive Research In The Present And Past Tense: Recounting The Stories Of Current And Former Child Domestic Workers, Natascha Klocker
Conducting Sensitive Research In The Present And Past Tense: Recounting The Stories Of Current And Former Child Domestic Workers, Natascha Klocker
Natascha Klocker
In recent years, scholarship on children's work has increasingly incorporated the perspectives of working children. Although laudable, this shift toward children's inclusion in research has concentrated on those employed at the time of data collection. Former child workers have largely been overlooked as a source of information. This paper reflects on research conducted with current and former child domestic workers in Tanzania. The child domestic working experiences reported by those two groups diverged markedly: those who had already ceased employment reported far higher rates of dissatisfaction with child domestic work, and far more experiences of exploitation and abuse, than those …
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.
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.
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
Professor Weihua Li
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.
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
Professor Weihua Li
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.
Normal Stiffness Calibration Of Microfabricated Tri-Layer Conducting Polymer Actuators, Michael J. Higgins, Gursel Alici
Normal Stiffness Calibration Of Microfabricated Tri-Layer Conducting Polymer Actuators, Michael J. Higgins, Gursel Alici
Gursel Alici
This paper reports on the stiffness characterization of microfabricated tri-layer conducting polymer (PPy) actuators. The rectangular, polypyrrole microactuators, which could operate both in aqueous and non-aqueous media, were fabricated using an excimer laser ablation technique that provided high throughput production and did not require cleanroom facilities. The microactuators were fixed at one end with electrical contacts and the other was end free to act as an electroactive microcantilever beam. An atomic force microscope (AFM) was used to measure the microactuator deflection under a range of normal forces applied by the AFM cantilever. A modified reference spring constant calibration method was …