High sensitivity of multi-sensing materials based on reduced graphene oxide and natural rubber: The synergy between filler segregation and macro-porous morphology. (22nd March 2021) - Zhan, Yanhu
Abstract: Elastomeric conductive composites (ECCs) based on carbonaceous fillers are very attractive and play a significant role in the field of smart sensors due to their excellent flexibility, high and wide-spectrum sensitivity as well as fast response to external stimuli. In this study, a lightweight and multi-sensing composite based on reduced graphene oxide/natural rubber (rGO/NR), is fabricated by a facile and cost-effective approach that combines the rGO assembling on rubber latex particles by graphene oxide in-situ reduction and mild drying of the resulting hydrogels. The resulting composites exhibit a reliable porous structure whereas the rGO is spatially distributed in a three-dimensional segregated morphology that percolates the samples. The composites are characterized by a low percolation threshold (<0.45 vol%), high sensitivity to compression strain (gauge factor equal to 77.64), organic solvents (i.e. toluene and tetrahydrofuran) and temperature (range of detectability is 35–90 °C). The elastomeric composites are proposed for the realization of innovative multi-purpose, wide-spectrum and high-sensitivity wearable sensors for monitoring the motion and temperature of human body in real time. Graphical abstract: Image 1 Highlights: Segregated rGO network are constructed in macro-porous natural rubber (NR) matrix. Segregated rGO network improves the electrical conductivity of porous composites. The composites were used as strain, liquids, temperature and wearable sensors. Combining segregated network and porous structure enhances sensors' sensitivity.