The influence of DC voltage on the conductivity of chloroprene rubber-carbon black composites for flexible resistive heating elements.

In order to acquire a flexible resistive heating element in the temperature range for human body heating, the influence of DC voltage on chloroprene rubber (CR) and carbon black (CB) composites has been investigated. Three conduction mechanisms have been found to occur in the range from 0.5 V to 10 V - charge velocity increase due to the increase of the electric field, matrix thermal expansion that results in decreased tunnelling currents and new electroconductive channel formation at voltages above 7.

Contact electrification between identical polymers as the basis for triboelectric/flexoelectric materials.

Polymer contact electrification offers the possibility to harvest mechanical energy using lightweight, flexible and low-cost materials, but the mechanism itself is still unresolved. Several recent studies confirm heterolytic covalent bond breaking as the mechanism for surface charge formation. Here it is shown that the reason for the formation of surface charge by contacting two identical polymers results from the fluctuation in the surface irregularities, and that contacted materials with a greater porosity or surface roughness differential result in a greater generation of surface charge.

BTEX detection with composites of ethylenevinyl acetate and nanostructured carbon.

By using a solvent-based method composites of ethylenevinyl acetate copolymer and carbon black (EVA-CB) were synthesized for sensing BTEX (benzene, toluene, ethylbenzene and xylene) vapours. The composites were characterized using atomic force microscopy (AFM) in an electroconductive mode. Gas sensing results show that EVA-CB can reproducibly detect BTEX and that the response increases linearly with vapour concentration.