Abstract: In order to obtain flexible strain films with good sensing and ductility, reduced graphene oxide/silver nanoparticles (rGO/AgNPs)micro nano composite conductive materials were prepared by amidation crosslinking and in-situ reduction assembly between amino terminated hyperbranched polymer (HBP-NH₂), graphene oxide (GO)and silver nitrate (AgNO₃), and then introduced into modified polyvinyl alcohol (PVA). A flexible strain piezoresistive sensing film which can monitor strain was prepared by tape casting method. It is found that rGO/AgNPs micro nano composite conductive filler is evenly dispersed in the modified PVA film system. In the case of large strain (87.5%), the resistance change rate of rGO/AgNPs/modified PVA film is up to 497.4% and the sensitivity factor is 5.68. In addition, it also shows good stability and repeatability in cyclic tensile and variable speed tensile tests, and shows relatively stable electrical signal change output when monitoring the large-scale bending movement of human fingers. This study has certain reference significance for the preparation, structure and performance regulation of micro nano composite flexible piezoresistive strain sensor.

Key words: reduced graphene oxide, silver nanoparticles, polyvinyl alcohol, strain sensing film

摘要： 为了获得具有良好传感性以及延展性的柔性应变薄膜,通过端氨基超支化聚合物(HBP-NH₂)与氧化石墨烯(GO)、硝酸银(AgNO₃)之间的酰胺化交联以及原位还原组装作用制备了还原氧化石墨烯/纳米银颗粒(rGO/AgNPs)微纳复合导电材料,而后将其引入改性聚乙烯醇(PVA)基体中,采用流延成膜法制备了一种可监测应变的柔性应变压阻式传感薄膜。研究发现:rGO/AgNPs微纳复合导电填料均匀地分散在改性PVA薄膜体系中,在大应变量87.5%情况下,该薄膜电阻变化率最高可达497.4%,灵敏度为5.68。此外,该薄膜在循环拉伸和变速拉伸测试中展现了良好的稳定性和可重复性,且在监测人体手指大幅度弯曲运动时,也表现出相对稳定的电信号变化输出。

关键词: 还原氧化石墨烯, 纳米银颗粒, 聚乙烯醇, 应变传感薄膜