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Selected Works

Gordon Wallace

2013

Hydrogels

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Preparation And Characterisation Of Graphene Composite Hydrogels, Nicholas J. Whiteside, Gordon G. Wallace, Marc In Het Panhuis May 2013

Preparation And Characterisation Of Graphene Composite Hydrogels, Nicholas J. Whiteside, Gordon G. Wallace, Marc In Het Panhuis

Gordon Wallace

Stable dispersions containing graphene and gellan gum are used to form composite films. Incorporation of graphene into the gellan gum matrix results in mechanical reinforcement and electrical conductivity at low and high graphene loading fractions, respectively. Graphene-containing gellan gum hydrogel films are prepared by immersion of composite films in Ca2+ cross-linking solutions. The resulting hydrogels are electrically conducting and exhibit reinforcement compared to the corresponding gellan gum hydrogels. 2013 Elsevier B.V.


Electrically Conductive, Tough Hydrogels With Ph Sensitivity, Sina Naficy, Joselito M. Razal, Geoffrey M. Spinks, Gordon G. Wallace, Philip G. Whitten Mar 2013

Electrically Conductive, Tough Hydrogels With Ph Sensitivity, Sina Naficy, Joselito M. Razal, Geoffrey M. Spinks, Gordon G. Wallace, Philip G. Whitten

Gordon Wallace

Electrically conductive, mechanically tough hydrogels based on a double network (DN) comprised of poly(ethylene glycol) methyl ether methacrylate (PPEGMA) and poly(acrylic acid) (PAA) were produced. Poly(3,4-ethylenedioxythiophene) (PEDOT) was chemically polymerized within the tough DN gel to provide electronic conductivity. The effects of pH on the tensile and compressive mechanical properties of the fully swollen hydrogels, along with their electrical conductivity and swelling ratio were determined. Compressive and tensile strengths as high as 11.6 and 0.6 MPa, respectively, were obtained for hydrogels containing PEDOT with a maximum conductivity of 4.3 S cm-1. This conductivity is the highest yet reported for hydrogel …


Inkjet Printing Of Self-Assembling Polyelectrolyte Hydrogels, Skander Limen, Donald Mccallum, Gordon G. Wallace, Marc In Het Panhuis, Paul Calvert Mar 2013

Inkjet Printing Of Self-Assembling Polyelectrolyte Hydrogels, Skander Limen, Donald Mccallum, Gordon G. Wallace, Marc In Het Panhuis, Paul Calvert

Gordon Wallace

Inkjet printing of alternate layers of anionic and cationic polyelectrolytes allows organized gels to form with structures similar to those made by layer-by-layer dipping methods but very much faster. Structures of gels formed using slow and fast inkjet printing systems are compared using elemental analysis, swelling and diffusion kinetics as characterization methods. After printing and washing, most sodium or chloride counter-ions are lost from the gel, leaving only the polymer complex. The swelling properties of the printed and washed gel depend on the deposition rate and on the ratio of the two polymers as originally printed.