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Full-Text Articles in Social and Behavioral Sciences

Bio-Ink For On-Demand Printing Of Living Cells, Cameron J. Ferris, Kerry J. Gilmore, Stephen Beirne, Donald Mccallum, Gordon G. Wallace, Marc In Het Panhuis Mar 2014

Bio-Ink For On-Demand Printing Of Living Cells, Cameron J. Ferris, Kerry J. Gilmore, Stephen Beirne, Donald Mccallum, Gordon G. Wallace, Marc In Het Panhuis

Gordon Wallace

Drop-on-demand bioprinting allows the controlled placement of living cells, and will benefit research in the fields of tissue engineering, drug screening and toxicology. We show that a bio-ink based on a novel microgel suspension in a surfactant-containing tissue culture medium can be used to reproducibly print several different cell types, from two different commercially available drop-on-demand printing systems, over long printing periods. The bio-ink maintains a stable cell suspension, preventing the settling and aggregation of cells that usually impedes cell printing, whilst meeting the stringent fluid property requirements needed to enable printing even from many-nozzle commercial inkjet print heads. This …


Ultrafast Charge And Discharge Biscrolled Yarn Supercapacitors For Textiles And Microdevices, Jae Ah Lee, Min-Kyoon Shin, Shi Hyeong Kim, Hyun U. Cho, Geoffrey Maxwell Spinks, Gordon G. Wallace, Marcio D. Lima, Xavier Lepro, Mikhail E. Kozlov, Ray H. Baughman, Seon Jeong Kim Mar 2014

Ultrafast Charge And Discharge Biscrolled Yarn Supercapacitors For Textiles And Microdevices, Jae Ah Lee, Min-Kyoon Shin, Shi Hyeong Kim, Hyun U. Cho, Geoffrey Maxwell Spinks, Gordon G. Wallace, Marcio D. Lima, Xavier Lepro, Mikhail E. Kozlov, Ray H. Baughman, Seon Jeong Kim

Gordon Wallace

Flexible, wearable, implantable and easily reconfigurable supercapacitors delivering high energy and power densities are needed for electronic devices. Here we demonstrate weavable, sewable, knottable and braidable yarns that function as high performance electrodes of redox supercapacitors. A novel technology, gradient biscrolling, provides fastion-transport yarn in which hundreds of layers of conducting-polymer-infiltrated carbon nanotube sheet are scrolled into similar to 20 mu m diameter yarn. Plying the biscrolled yarn with a metal wire current collector increases power generation capabilities. The volumetric capacitance is high (up to similar to 179 Fcm(-3)) and the discharge current of the plied yarn supercapacitor linearly increases …


A Nonconjugated Bridge In Dimer-Sensitized Solar Cells Retards Charge Recombination Without Decreasing Charge Injection Efficiency, Kenji Sunahara, Matthew J. Griffith, Takayuki Uchiyama, Pawel Wagner, David L. Officer, Gordon G. Wallace, Attila J. Mozer, Shogo Mori Mar 2014

A Nonconjugated Bridge In Dimer-Sensitized Solar Cells Retards Charge Recombination Without Decreasing Charge Injection Efficiency, Kenji Sunahara, Matthew J. Griffith, Takayuki Uchiyama, Pawel Wagner, David L. Officer, Gordon G. Wallace, Attila J. Mozer, Shogo Mori

Gordon Wallace

Dye sensitized solar cells (DSSCs) employing a dimer porphyrin, which was synthesised with two porphyrin units connected without conjugation, have shown that both porphyrin components can contribute to photocurrent generation, that is, more than 50 % internal quantum efficiency. In addition, the open-circuit voltage (Voc) of the DSSCs was higher than that of DSSCs using monomer porphyrins. In this paper, we first optimized cell structure and fabrication conditions. We obtained more than 80% incident photon to current conversion efficiency from the dimer porphyrin sensitized DSSCs and higher Voc and energy conversion efficiency than monomer porphyrin sensitized solar cells. To examine …


Graphene Cryogel Papers With Enhanced Mechanical Strength For High Performance Lithium Battery Anodes, Kewei Shu, Caiyun Wang, Meng Wang, Chen Zhao, Gordon G. Wallace Mar 2014

Graphene Cryogel Papers With Enhanced Mechanical Strength For High Performance Lithium Battery Anodes, Kewei Shu, Caiyun Wang, Meng Wang, Chen Zhao, Gordon G. Wallace

Gordon Wallace

A porous graphene paper was prepared by pressing a graphene cryogel, followed by thermal reduction at 220 °C. The cryogel was formed by freeze-drying a solution containing chemically reduced graphene and graphene oxide (CRG/GO). The formed graphene cryogel papers deliver a much higher discharge capacity and rate capability than that from conventional graphene papers fabricated by filtration. These new structures have a discharge capacity higher than 400 mA h g−1 at a current density of 2000 mA g−1 in sharp contrast to 229 mA h g−1 at 50 mA g−1 obtained from conventional graphene papers. These greatly improved electrochemical properties …


Biofabrication: An Overview Of The Approaches Used For Printing Of Living Cells, Cameron J. Ferris, Kerry G. Gilmore, Gordon G. Wallace, Marc In Het Panhuis Mar 2014

Biofabrication: An Overview Of The Approaches Used For Printing Of Living Cells, Cameron J. Ferris, Kerry G. Gilmore, Gordon G. Wallace, Marc In Het Panhuis

Gordon Wallace

The development of cell printing is vital for establishing biofabrication approaches as clinically relevant tools. Achieving this requires bio-inks which must not only be easily printable, but also allow controllable and reproducible printing of cells. This review outlines the general principles and current progress and compares the advantages and challenges for the most widely used biofabrication techniques for printing cells: extrusion, laser, microvalve, inkjet and tissue fragment printing. It is expected that significant advances in cell printing will result from synergistic combinations of these techniques and lead to optimised resolution, throughput and the overall complexity of printed constructs.


Synthesis And Optimization Of Pedot:Pss Based Ink For Printing Nanoarrays Using Dip-Pen Nanolithography, Michal Wagner, Cathal O'Connell, David G. Harman, Ryan Sullivan, Ari Ivaska, Michael J. Higgins, Gordon G. Wallace Mar 2014

Synthesis And Optimization Of Pedot:Pss Based Ink For Printing Nanoarrays Using Dip-Pen Nanolithography, Michal Wagner, Cathal O'Connell, David G. Harman, Ryan Sullivan, Ari Ivaska, Michael J. Higgins, Gordon G. Wallace

Gordon Wallace

Due to the current interest in organic printable electronics, Dip-Pen Nanolithography (DPN) is increasingly being explored as a method to pattern electroactive materials such as conducting polymers (CPs) on the micro- and nanoscale. In general, printing process depends strongly on the ink-substrate properties and fundamental forces required to drive and stabilize the ink transfer to the substrate. Controlling these parameters is especially difficult when operating under the nanometer confinements of the DPN probe. For the printing of CPs, one step towards addressing these challenges is rational ink design, as the use of existing commercial-based inks may not be suitable for …


Modified Gellan Gum Hydrogels For Tissue Engineering Applications, Cameron J. Ferris, Kerry J. Gilmore, Gordon G. Wallace, Marc In Het Panhuis May 2013

Modified Gellan Gum Hydrogels For Tissue Engineering Applications, Cameron J. Ferris, Kerry J. Gilmore, Gordon G. Wallace, Marc In Het Panhuis

Gordon Wallace

Gellan gum is an anionic linear polysaccharide well known for its use as a multi-functional gelling, stabilising and suspending agent in a variety of foods and personal care products. In this Highlight, we explore the recently established directions for gellan gum hydrogels as materials for applications in tissue engineering. We highlight that modified gellan gum will be well suited for this purpose, providing that a number of remaining challenges are addressed.


Electrodeposition Of Pyrrole And 3-(4-Tert-Butylphenyl)Thiophene Copolymer For Supercapacitor Applications, Binbin Yue, Caiyun Wang, Pawel Wagner, Yang Yang, Xin Ding, David L. Officer, Gordon G. Wallace May 2013

Electrodeposition Of Pyrrole And 3-(4-Tert-Butylphenyl)Thiophene Copolymer For Supercapacitor Applications, Binbin Yue, Caiyun Wang, Pawel Wagner, Yang Yang, Xin Ding, David L. Officer, Gordon G. Wallace

Gordon Wallace

The electropolymerization of pyrrole (Py), 3-(4-tert-butylphenyl)thiophene (TPT) monomer or the mixed Py and TPT monomers on stainless steel mesh substrate were performed in 1 M LiClO4/acetonitrile solution. A much lower potential of 0.75 V was required for the co-electropolymerization of Py and TPT, in sharp contrast to that of 1.20 V for poly(3-(4-tert-butylphenyl)thiophene) (PTPT) formation. The resultant homopolymers and copolymer were characterized with FESEM and FTIR, and assembled into supercapacitors to investigate their electrochemical performances. The copolymer electrode delivered the highest specific capacitance of 291 F g−1 at a scan rate of 5 mV s−1, in comparison with that of …


Fabrication Of Polyaniline-Based Gas Sensors Using Piezoelectric Inkjet And Screen Printing For The Detection Of Hydrogen Sulfide, Karl H. Crowley, Aoife Morrin, Roderick L. Shepherd, Marc In Het Panhuis, Gordon G. Wallace, Malcolm R. Smyth, Anthony J. Killard Mar 2013

Fabrication Of Polyaniline-Based Gas Sensors Using Piezoelectric Inkjet And Screen Printing For The Detection Of Hydrogen Sulfide, Karl H. Crowley, Aoife Morrin, Roderick L. Shepherd, Marc In Het Panhuis, Gordon G. Wallace, Malcolm R. Smyth, Anthony J. Killard

Gordon Wallace

This work describes a fully printable polyaniline-copper (II) chloride sensor for the detection of hydrogen sulfide gas. The sensing device is composed of screen printed silver interdigitated electrode (IDE) on a flexible PET substrate with inkjet printed layers of polyaniline and copper (II) chloride. The sensor is employed as a chemiresistor with changes in measured current being correlated with concentration. On exposure to hydrogen sulfide, 2.5 ppmv (parts per million by volume) is clearly detectable with a linear relationship between measured current and concentration over the 10-100 ppmv region. The detection mechanism is discussed with respect to the hydrogen sulfide …


Nanostructured Carbon Electrodes, Gordon G. Wallace, Jun Chen, Dan Li, Simon E. Moulton, Joselito M. Razal Mar 2013

Nanostructured Carbon Electrodes, Gordon G. Wallace, Jun Chen, Dan Li, Simon E. Moulton, Joselito M. Razal

Gordon Wallace

In its conducting form, carbon has proven to be a versatile, robust and high performing electrode material in areas such as energy conversion, energy storage and even medical bionics. In our laboratories we have been interested in the fabrication and utilization of nanostructured electrodes based on more recently discovered forms of carbon. These include carbon nanotubes and graphene.


Electrochemical Afm : Understanding The Electromaterial-Cellular Interface, Amy Gelmi, Michael J. Higgins, Scott T. Mcgovern, Gordon G. Wallace Mar 2013

Electrochemical Afm : Understanding The Electromaterial-Cellular Interface, Amy Gelmi, Michael J. Higgins, Scott T. Mcgovern, Gordon G. Wallace

Gordon Wallace

Organic conducting polymers are emerging as an exciting new class of biomaterial that can be used to enhance and control the growth of mammalian cells for tissue regeneration and engineering applications


Microsecond Dye Regeneration Kinetics In Efficient Solid State Dye-Sensitized Solar Cells Using A Photoelectrochemically Deposited Pedot Hole Conductor, Attila J. Mozer, Dillip K. Panda, Sanjeev Gambhir, B. Winther-Jensen, Gordon G. Wallace Mar 2013

Microsecond Dye Regeneration Kinetics In Efficient Solid State Dye-Sensitized Solar Cells Using A Photoelectrochemically Deposited Pedot Hole Conductor, Attila J. Mozer, Dillip K. Panda, Sanjeev Gambhir, B. Winther-Jensen, Gordon G. Wallace

Gordon Wallace

Microsecond dye-regeneration kinetics was observed in efficient solid state dye-sensitized solar cells using photoelectrochemically deposited poly(3,4-ethylenedioxythiophene (PEDOT) hole conductors using transient absorption spectroscopy. The dye-regeneration rate is orders of magnitude slower than the case using the I-/I3- redox couple or commonly used small molecule hole conductor and is attributed to the low dye to PEDOT ratio within the films.


Crosslinking Neat Ultrathin Films And Nanofibres Of Ph-Responsive Poly(Acrylic Acid) By Uv Radiation, Adrian Gestos, Philip G. Whitten, Geoffrey Maxwell Spinks, Gordon G. Wallace Mar 2013

Crosslinking Neat Ultrathin Films And Nanofibres Of Ph-Responsive Poly(Acrylic Acid) By Uv Radiation, Adrian Gestos, Philip G. Whitten, Geoffrey Maxwell Spinks, Gordon G. Wallace

Gordon Wallace

Electrospun polyelectrolyte hydrogel nanofibres are being developed for many applications including artificial muscles, scaffolds for tissue engineering, wound dressings and controlled drug release. For electrospun polyelectrolytes, a post-spinning crosslinking process is necessary for producing a hydrogel. Typically, radiation or thermal crosslinking routines are employed that require multifunctional crosslinking molecules and crosslink reaction initiators (free radical producers). Here, ultraviolet subtype-C (UVC) radiation was employed to crosslink neat poly(acrylic acid) (PAA) nanofibres and films to different crosslink densities. Specific crosslink initiators or crosslinking molecules are not necessary in this fast and simple process providing an advantage for biological applications. Scanning probe microscopy …


Advanced Microwave-Assisted Production Of Hybrid Electrodes For Energy Applications, Peter Sherrell, Jun Chen, Joselito M. Razal, Ivan P. Nevirkovets, Carol Crean, Andrew I. Minett, Gordon G. Wallace Mar 2013

Advanced Microwave-Assisted Production Of Hybrid Electrodes For Energy Applications, Peter Sherrell, Jun Chen, Joselito M. Razal, Ivan P. Nevirkovets, Carol Crean, Andrew I. Minett, Gordon G. Wallace

Gordon Wallace

Carbon nanotubes are one of the most prominent materials in research for creating electrodes for portable electronics. When coupled with metallic nanoparticles the performance of carbon nanotube electrodes can be dramatically improved. Microwave reduction is an extremely rapid method for producing carbon nanotube-metallic nanoparticle composites, however this technique has so far been limitied to carbon nanotube soot. An understanding of the microwave process and the interactions of metallic nanoparticles with carbon nanotubes has allowed us to extend this promising functionalisation route to pre-formed CNT elelctrode architectures. Nanoparticle reduction onto pre-formed architectures reduces metallic nanoparticle waste as particles are not formed …


Photoelectrochemical Cell Study On Closely Arranged Vertical Nanorod Bundles Of Cdse And Zn Doped Cdse Films, D Soundararajan, J K. Yoon, J S. Kwon, Y I. Kim, S H. Kim, J H. Park, Y J. Kim, D -Y Park, B C. Kim, G G. Wallace, J M. Ko Mar 2013

Photoelectrochemical Cell Study On Closely Arranged Vertical Nanorod Bundles Of Cdse And Zn Doped Cdse Films, D Soundararajan, J K. Yoon, J S. Kwon, Y I. Kim, S H. Kim, J H. Park, Y J. Kim, D -Y Park, B C. Kim, G G. Wallace, J M. Ko

Gordon Wallace

Closely arranged CdSe and Zn doped CdSe vertical nanorod bundles were grown directly on FTO coated glass by using electrodeposition method. Structural analysis by XRD showed the hexagonal phase without any precipitates related to Zn. FE-SEM image showed end capped vertically aligned nanorods arranged closely. From the UV-vis transmittance spectra, band gap energy was found to vary between 1.94 and 1.98 eV due to the incorporation of Zn. Solar cell parameters were obtained by assembling photoelectrochemical cells using CdSe and CdSe:Zn photoanodes, Pt cathode and polysulfide (1M Na2S + 1M S + 1M NaOH) electrolyte. The efficiency was found to …


Electrochemical Actuation Properties Of A Novel Solution-Processable Polythiophene, Yanzhe Wu, Amy M. Ballantyne, Pawel Wagner, Dezhi Zhou, Geoffrey M. Spinks, David Officer, Gordon G. Wallace Mar 2013

Electrochemical Actuation Properties Of A Novel Solution-Processable Polythiophene, Yanzhe Wu, Amy M. Ballantyne, Pawel Wagner, Dezhi Zhou, Geoffrey M. Spinks, David Officer, Gordon G. Wallace

Gordon Wallace

No abstract provided.


Catalytic Solar Water Splitting Inspired By Photosynthesis. Homogeneous Catalysts With A Mechanical ("Machine-Like") Action, Gerhard F. Swiegers, G Charles Dismukes, Leone Spiccia, Robin Brimblecombe, Annette Koo, Jun Chen, Gordon G. Wallace Mar 2013

Catalytic Solar Water Splitting Inspired By Photosynthesis. Homogeneous Catalysts With A Mechanical ("Machine-Like") Action, Gerhard F. Swiegers, G Charles Dismukes, Leone Spiccia, Robin Brimblecombe, Annette Koo, Jun Chen, Gordon G. Wallace

Gordon Wallace

Chemical reactions may be controlled by either: the minimum threshold energy that must be overcome during collisions between reactant molecules / atoms (the Activation Energy, Ea), or: the rate at which reactant collisions occur (the Collision Frequency, A) (for reactions with low Ea). Reactions of type (2) are governed by the physical, mechanical interaction of the reactants. Such mechanical processes are unusual, but not unknown in molecular catalysts. We examine the catalytic action and macroscopic properties of several abiological mechanical catalysts and show that they display distinct similarities to enzymes in general. An abiological model of the Photosystem II Water …


Flexible And Compressible Goretex-Pedot Membrane Electrodes For Solid-State Dye-Sensitized Solar Cells, Attila J. Mozer, Dillip K. Panda, Sanjeev Gambhir, Anthony C. Romeo, Bjorn Winther-Jensen, Gordon G. Wallace Mar 2013

Flexible And Compressible Goretex-Pedot Membrane Electrodes For Solid-State Dye-Sensitized Solar Cells, Attila J. Mozer, Dillip K. Panda, Sanjeev Gambhir, Anthony C. Romeo, Bjorn Winther-Jensen, Gordon G. Wallace

Gordon Wallace

A porous, flexible electrode based on a PTFE (Teflon) membrane (Goretex) coated with a metallic current collector and a conducting polymer (poly(3,4-ethylenedioxythiophene), PEDOT) has been developed for applications in solidstate dye-sensitized solar cells. Its low sheet resistance and compressibility make it an ideal electrode on uneven TiO2 surfaces with high efficiency and reproducibility. The porous nature of the electrode enables the feed-through of reactants and treatment agents, which opens up exciting opportunities to interface these photoelectrochemical devices with electrocatalytic, energy conversion, and storage systems. Postfabrication bonding of the photoanode and the Goretex-Au-PEDOT electrode is demonstrated.


Organic Bionics, Gordon G. Wallace, Simon E. Moulton, Caiyun Wang Mar 2013

Organic Bionics, Gordon G. Wallace, Simon E. Moulton, Caiyun Wang

Gordon Wallace

Bionic technology involves the efficient integration of biology and electronics and is providing the basis for significant improvements in a number of medical treatments. The use of organic conducting polymers to provide a compatible multifunctional platform to interface the world of biology and electronics has attracted an increasing amount of attention over the past 15 years. This paper will discuss advances being made in the development of organic bionics and their application to improved health strategies. © 2010 Copyright SPIE - The International Society for Optical Engineering.


Direct Exfoliation Of Graphite With A Porphyrin - Creating Functionalizable Nanographene Hybrids, Jenny Malig, Adam W. I Stephenson, Pawel Wagner, Gordon G. Wallace, David L. Officer, Dirk M. Guldi Mar 2013

Direct Exfoliation Of Graphite With A Porphyrin - Creating Functionalizable Nanographene Hybrids, Jenny Malig, Adam W. I Stephenson, Pawel Wagner, Gordon G. Wallace, David L. Officer, Dirk M. Guldi

Gordon Wallace

Exfoliation of graphite was achieved using a free-base porphyrin 1 resulting in an efficient fabrication of single-layer nanographene (NG)-1 hybrid platelets that can be further functionalized with other nanomaterials. The novel nanographene-porphyrin hybrids reveal efficient charge transfer in the excited state.


Charge Transport In Dye-Sensitized Solar Cells Based On Flame-Made Tio2 Nanoparticles, George Tsekouras, Masanori Miyashita, Yung Kent Kho, Wey Yang Teoh, Attila J. Mozer, Rose Amal, Shogo Mori, Gordon G. Wallace Mar 2013

Charge Transport In Dye-Sensitized Solar Cells Based On Flame-Made Tio2 Nanoparticles, George Tsekouras, Masanori Miyashita, Yung Kent Kho, Wey Yang Teoh, Attila J. Mozer, Rose Amal, Shogo Mori, Gordon G. Wallace

Gordon Wallace

The fundamental understanding on charge-transport properties of flame-synthesized TiO2 in dye-sensitized solar cells (DSSCs) is established in this work. By employing a one-step flame spray pyrolysis (FSP), predominantly anatase TiO2 nanoparticles with average nanoparticle sizes between 11 and 36 nm were achieved by varying the rate of combustion enthalpy (through varying liquid precursor feed flow rates) and using either an “openflame” or “enclosed-flame” configuration. Electron diffusion coefficient (D), electron lifetime (τ ), open circuit voltage (Voc ), and capacitance (C) measurements carried out on FSP TiO2 -based DSSCs demonstrated that interband charge trap density decreased with increase in particle size. …


The Reclamation Of Boston Harbor: A Scientist's Perspective, Gordon T. Wallace Jr. Mar 2013

The Reclamation Of Boston Harbor: A Scientist's Perspective, Gordon T. Wallace Jr.

Gordon Wallace

A major effort, costing in the neighborhood of $2 billion, is under way to restore the environmental quality of Boston Harbor. While Boston Harbor is unquestionably one of the most polluted urban estuaries in the world, it is also one of the least understood with respect to the basic physics, chemistry, and biology involved. This information is essential for the purpose of identifying processes that control the transport, effect, and fate of contaminants entering the estuary. Failure to obtain this information may lead to continued inappropriate and unnecessarily expensive solutions to a complex environmental problem. An effective solution will require …


Resolving Sub-Molecular Binding And Electrical Switching Mechanisms Of Single Proteins At Electroactive Conducting Polymers, A Gelmi, M J. Higgins, Gordon G. Wallace Mar 2013

Resolving Sub-Molecular Binding And Electrical Switching Mechanisms Of Single Proteins At Electroactive Conducting Polymers, A Gelmi, M J. Higgins, Gordon G. Wallace

Gordon Wallace

Polymer-based electrodes for interfacing biological tissues are becoming increasingly sophisticated. Their many functions place them at the cross-roads of electromaterials, biomaterials, and drug-delivery systems. For conducting polymers, the mechanism of conductivity requires doping with anionic molecules such as extracellular matrix molecules, a process that distinguishes them as biomaterials and provides a means to control interactions at the cellular-electrode interface. However, due to their complex structure, directly observing the selective binding of target molecules or proteins has so far eluded researchers. This situation is compounded by the polymer's ability to adopt different electronic states that alter the polymer-dopant interactions. Here, the …


Remarkable Synergistic Effects In A Mixed Porphyrin Dye-Sensitized Tio2 Film, Attila J. Mozer, Gordon G. Wallace, David L. Officer, Matthew Griffith, Pawel W. Wagner, Klaudia K. Wagner, George Tsekouras, Shogo Mori, Ying Dong Mar 2013

Remarkable Synergistic Effects In A Mixed Porphyrin Dye-Sensitized Tio2 Film, Attila J. Mozer, Gordon G. Wallace, David L. Officer, Matthew Griffith, Pawel W. Wagner, Klaudia K. Wagner, George Tsekouras, Shogo Mori, Ying Dong

Gordon Wallace

A remarkable 300% efficiency enhancement driven by a matching increase in the short circuit current was observed in a mixed porphyrin dye-sensitized solar cell constructed from two dyes in a 3:1 ratio. Absorbed photon-to-current conversion efficiency measurements indicate an improved charge injection yield for both dyes in the mixture. Several possible origins for the observed performance enhancement are discussed.


Enhanced Performance Of Dye Sensitized Solar Cells Utilizing Platinum Electrodeposit Counter Electrodes, Attila J. Mozer, George Tsekouras, Gordon G. Wallace Mar 2013

Enhanced Performance Of Dye Sensitized Solar Cells Utilizing Platinum Electrodeposit Counter Electrodes, Attila J. Mozer, George Tsekouras, Gordon G. Wallace

Gordon Wallace

Enhanced performance was observed for dye-sensitized solar cells (DSSCs) utilizing counter electrodes based on Pt electrodeposits compared to counter electrodes based on sputtered Pt. Scanning electron microscopy of Pt electrodeposits revealed that the use of an initial cathodic overpotential pulse followed by steady electrodeposition at a mild cathodic potential yielded ∼40nm particles, compared to ∼600nm particles when no such pulse was used. Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) of electrode materials suggested that Pt electrodeposits would give enhanced performance as DSSC counter electrodes compared to sputtered Pt, and this was confirmed by device testing. EIS characterization of DSSCs under …


Emulsion-Coaxial Electrospinning: Designing Novel Architectures For Sustained Release Of Highly Soluble Low Molecular Weight Drugs, Lucie Viry, Simon E. Moulton, Tony Romeo, Courtney Suhr, Damia Mawad, Mark Cook, Gordon G. Wallace Mar 2013

Emulsion-Coaxial Electrospinning: Designing Novel Architectures For Sustained Release Of Highly Soluble Low Molecular Weight Drugs, Lucie Viry, Simon E. Moulton, Tony Romeo, Courtney Suhr, Damia Mawad, Mark Cook, Gordon G. Wallace

Gordon Wallace

In drug therapy, most therapeutic drugs are of low molecular weight and could freely diffuse in the biological milieu depending on the administration route applied. The main reason for the development of polymeric drug carriers is to obtain desired effects such as sustained therapy, local and controlled release, prolonged activity and reduction of side effects. Alternatively, polymeric carriers can be made bioerodible in order to be eliminated by natural ways after a certain time of therapy. Core-shell fibres from coaxial spinneret or emulsion electrospinning are good candidates for the development of such devices; however difficulties remain especially in controlling the …


Electrocatalytic Reduction Of Carbon Dioxide By Cobalt-Phthalocyanine-Incorporated Polypyrrole, Jun Chen, Gordon G. Wallace, Jiaxing Lu, Aijian Zhang, Weimin Zhang Mar 2013

Electrocatalytic Reduction Of Carbon Dioxide By Cobalt-Phthalocyanine-Incorporated Polypyrrole, Jun Chen, Gordon G. Wallace, Jiaxing Lu, Aijian Zhang, Weimin Zhang

Gordon Wallace

In the quest for catalysts for the electrocatalytic reduction of , a cobalt phthalocyanine/polypyrrole (CoPc/PPy) composite electrode has been developed. The electrode is prepared by drop casting CoPc onto the PPy film from the CoPc/tetrahydrofuran solution (1 mg/mL). The onset potential for reduction occurred at potentials 160 mV more positive than observed with a simple PPy electrode. Furthermore, in the potentiostatic electrolysis, the catalytic current for reduction at CoPc/PPy was very stable, with a higher current density and current efficiency when compared to the PPy electrode.


Elastic Conducting Carbon Nanotube-Laden Sibs Fibers, Alberto J. Granero, Joselito M. Razal, Gordon G. Wallace, Marc In Het Panhuis Mar 2013

Elastic Conducting Carbon Nanotube-Laden Sibs Fibers, Alberto J. Granero, Joselito M. Razal, Gordon G. Wallace, Marc In Het Panhuis

Gordon Wallace

We report a facile method to produce elastic conducting fibers using a continuous flow wet-spinning approach. The spun fibers were highly stretchable, similar to the elastomeric polymer used.


Beads, Boats And Switches: Making Things Happen With Molecular Photoswitches, Robert P. Byrne, Silvia Scaramagnani, Michael J. Higgins, Gordon G. Wallace, Dermot Diamond Mar 2013

Beads, Boats And Switches: Making Things Happen With Molecular Photoswitches, Robert P. Byrne, Silvia Scaramagnani, Michael J. Higgins, Gordon G. Wallace, Dermot Diamond

Gordon Wallace

In this paper we present recent results obtained with a stimulus-responsive materials based on the photo-switchable behaviour exhibited by spiro-cyclic derivatives. Our results suggest that these highly novel materials offer unique capabilities hitherto inaccessible using conventional materials. In particular, we will focus on photocontrolled guest binding and release, inherent signalling of status, photo-actuation and solvent driven motion of small structures as examples of the fascinating behaviour of these exceptional materials. Copyright 2009 IEEE NANO Organizers.


Smart Nanotextiles: A Review Of Materials And Applications, Gordon G. Wallace, Danilo De Rossi, Yanzhe Wu, King-Tong Lau, Shirley Coyle, Dermot Diamond Mar 2013

Smart Nanotextiles: A Review Of Materials And Applications, Gordon G. Wallace, Danilo De Rossi, Yanzhe Wu, King-Tong Lau, Shirley Coyle, Dermot Diamond

Gordon Wallace

The development of smart nanotextiles has the potential to revolutionize the functionality of our clothing and the fabrics in our surroundings. Nanoscale manipulation results in new functionalities for intelligent textiles, including self-cleaning, sensing, actuating, and communicating. This is made possible by such developments as new materials, fibers, and finishings; inherently conducting polymers; carbon nanotubes; and antimicrobial nanocoatings. These additional functionalities have numerous applications, encompassing healthcare, sports, military applications, and fashion. The wearer and the surrounding environment may be monitored in an innocuous manner, giving continuous updates of individual health status or environmental hazards. More generally, smart textiles become a critical …