用于压力传感的还原氧化石墨烯/丝蛋白基多孔复合材料

利用丝蛋白能够在还原氧化石墨烯片层上发生选择性聚集的特性,制备了还原氧化石墨烯片层上富集有丝蛋白微纤且分散性良好的还原氧化石墨烯片和丝蛋白混合溶液,并通过冷冻以及低温乙醇处理的方法得到一系列不同比例的还原氧化石墨烯/丝蛋白基多孔复合材料.随后,采用溶液浸泡的方法在多孔材料表面再次沉积还原氧化石墨烯,以进一步提高还原氧化石墨烯/丝蛋白基多孔复合材料的压敏导电性.系统观察和测试结果表明,还原氧化石墨烯的引入,不仅使得多孔材料内部出现了相应的微纳结构,同时也提高了多孔材料的力学性能.还原氧化石墨烯/丝蛋白基多孔复合材料在完全湿态下兼具较好的强度和弹性,可以在0%~80%的压缩应变之间实现良好的压缩回复效果和压力传感性能.其中,最佳比例下的还原氧化石墨烯/丝蛋白基多孔复合材料在低压力下的灵敏度可达0.15 kPa?1,在0~17.3 kPa范围内能够高效工作并且具有优异的电学稳定性和耐疲劳性.因此,还原氧化石墨烯/丝蛋白基多孔复合材料因其高灵敏度、宽工作范围、结构可调以及可塑性好等诸多优点,有望在柔性压力传感方面获得较好的应用.

Pressure Sensing Material Based on Reduced Graphene Oxide/Silk Fibroin Sponge

A well dispersed aqueous suspension of reduced graphene oxide(RGO)enriched with silk fibroin nanofibrils and regenerated silk fibroin(RSF)was properly prepared,taking the advantage of the so called selective aggregation of silk fibroin nanofibrils on reduced graphene oxide nanosheets,and then a series of composited sponges with different proportions of RGO and RSF were obtained by the process of freezing and ethanol treatment at low temperature.To improve the pressure-sensitive conductivity of those composited sponges,the extra RGO nanosheets were deposited on the surface of the sponge by solution immersion.SEM observation and mechanical testing showed that the introduction of RGO not only made the corresponding micro/nano structure in RSF based sponge benefit the adhering of extra RGO nanosheets,but also favorited to the mechanical properties of the sponge.Moreover,the RGO/RSF sponges displayed significant strength and elasticity under the completely wet state,and could achieve good compression recovery effect and pressure sensing performance between compression strain of 0%?80%.Among them,the sensitivity of such composited sponge with the optimal proportion of the component could reach 0.15 kPa?1 regarding its resistance change under low pressure.Also,it worked efficiently under the pressure in the range of 0?17.3 kPa and presented excellent electrical stability and durability.Therefore,such pressure sensing material based on RGO/RSF sponge is expected to apply in energy-saving and environmental friendly flexible electronic devices due to its high sensitivity,wide working range,adjustable structure,renewability,good plasticity and so on.