Friday, 26 March 11:00am – 12:00pm

This seminar will be delivered via Zoom – Please email chemistry.researchsupport@sydney.edu.au for zoom link and password.

Speaker: Dr Saffron Bryant; Royal Melbourne Institute of Technology

Host: Dr Derrick Roberts and Professor Greg Warr

Title: Eutectogels: Everything your gels have been missing

Bio: Dr Saffron Bryant studied biomedical science in North Queensland before coming to The University of Sydney and completing a PhD under the supervision of Professor Greg Warr. Her project focused on seeing if life could evolve without water (it can). After finishing her PhD, Saffron went to The University of Bath where she participated in an industry-partnered project examining rheological modifiers. In 2020 she moved back to Australia to take up a Postdoc position at RMIT University under Professor Gary Bryant (no, not related) where she is developing and testing new cryoprotective molecules. Most of all she dreams of having a lab of her own to fully explore her many mad ideas.

Abstract: Lonogels offer huge potential for a number of applications including wearable electronics and soft sensors. However, their synthesis has been limited and often relies on non-renewable or non-biocompatible components. Here we present a novel two-component ionogel made using just deep eutectic solvents (DESs) and cellulose. DESs offer a non-volatile alternative to hydrogels with highly tuneable properties including conductivity and solvation of compounds with widely varying hydrophobicity. DESs can be easily made from cheap, biodegradable and biocompatible components. This research presents the characterisation of a series of soft conductive gels made from deep eutectic solvents (DESs), specifically choline chloride-urea and choline chloride-glycerol, with the sole addition of TEMPO-oxidised cellulose nanofibrils (OCNF). A more liquid-like rather than gel-like conductive material could be made by using the DES betaine-glycerol. OCNF are prepared from sustainable sources, and are non-toxic, and mild on the skin, forming gels without the need for surfactants or other gelling agents. These gels are shear thinning with conductivities up to 1.7 mS cm^-1 at ~26 °C. Given the thousands of possible DESs, this system offers unmatched tunability and customisation for properties such as viscosity, conductivity, and yield behaviour.