TPT January 2020

G LOBA L MARKE T P L AC E

The University of British Columbia-Okanagan (UBC-O) has used graphene to enhance the performance of aluminium casting alloys. UBC-O blended small volumes of graphene with an aluminium powder, which was then subjected to spark plasma sintering. Preliminary results indicate that a relatively small graphene loading resulted in a significant increase in the electrical conductivity of the material. Aluminium with higher conductivity could have vast industrial applications. Test work will continue to optimise the graphene loading for optimal conductivity of the aluminium, together with improvements in its thermal and mechanical properties. Preliminary results on the use of graphene in an epoxy corrosion-inhibiting coating for steel are also encouraging, after testing four steel samples, one uncoated, one coated with epoxy only, one coated with an epoxy-graphite mixture, and one with an epoxy-graphene mixture. The four samples were exposed to a corrosive saline solution for ten days, after which the surface corrosion was examined and quantified. The uncoated steel was found to have 100 per cent of its surface corroded; the epoxy-coated surface was 67 per cent corroded; the epoxy-graphite mix showed 93 per cent surface corrosion; and the epoxy-graphene coated surface was only 3 per cent corroded. The results will be followed up by additional tests to optimise the graphene loading required in an epoxy resin that provides an effective anti-corrosion coating. Recyc l ing The economic benefits of a circular scrap economy A new study, conducted by economic impact specialists John Dunham and Associates on behalf of the Institute of Scrap Recycling Industries (ISRI) demonstrates how recycling helps power the US economy. In addition to the obvious positive environmental benefits, the recycling industry is said to be responsible for over 531,500 jobs with an overall economic impact of nearly $110bn. Joe Pickard, chief economist for ISRI, commented: “In the US, we continue to process more material into valuable com- modities, seven per cent of which is used right here by Ameri- can manufacturers. With the innovation and new technologies coming online, this trend is expected to continue upward.” The study found that in 2019, 164,154 jobs are being directly supported by the recycling and brokerage operations of the scrap industry in the USA, with an estimated 367,356 jobs indirectly supported through suppliers and the indirect impact of expenditure.

material for plastic bags. “This shows that the sustainable option does not sacrifice quality,” says Ms Hughes, who now moves on to the international division of the competition to be judged by Dyson’s founder, the British inventor James Dyson. With over half of single-use plastics eventually landing in the world’s oceans, reducing waste from single-use plastics has become an environmental priority for individuals and governments. In August, India announced plans to ban six single-use plastic products: bags, cups, plates, small bottles, straws and some sachets. The move, India’s most sweeping plastics regulation to date, is expected to reduce the country’s plastic consumption by up to ten per cent. Tensile strength – splitting hairs The need to use more renewable materials, and to reduce global dependence on petrochemicals, is making demands of materials scientists. New research, published in the International Journal of Computational Materials Science and Surface Engineering , explained how a mathematical model was used to optimise the tensile strength of a new composite. The composite is made from polyester, and uses human hair as the reinforcing component. Eshwara Prasad, of Hyderabad’s Jawaharlal Nehru Technological University, working with Divakara Rao and Udaya Kiran from the J B Institute of Engineering and Technology, prepared polymer-based composites using chopped fibres of human hair, between 10mm and 50mm long, at rates of 5 per cent and 25 per cent by weight. Data from tensile strength testing of the experimental composites was used to develop a model that can be used to optimise the formulation of new composites. Other natural fibres could be incorporated into semi-synthetic composites for materials science and engineering applications, but the strength of the component, keratin, and its ready availability, makes human hair particularly attractive. A single strand of hair could hold 100g (3oz) in weight, and in theory the combined hair of an average whole head could support up to 8,400kg (18,518lb). Weight for weight, hair may not be as strong as steel, but it has a strength similar to reinforced glass fibres or Kevlar, as used to make bulletproof vests. Graphene research continues to impress and enthuse materials scientists ZEN Graphene Solutions, of Canada, has announced the results of further research and development into using a ZEN Graphene additive in a sintered aluminium metal composite, and of graphene in a corrosion-inhibiting coating.

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JANUARY 2020