纤维素/聚乙烯醇/聚苯胺阻燃气凝胶传感器的制备及性能

Preparation and Properties of Cellulose/Polyvinyl Alcohol/Polyaniline Flame Retardant Aerogel Sensor

为制备一种兼具良好阻燃性能和传感性能的复合材料,文中使用聚乙烯醇(PVA)和微晶纤维素(MCC)制成的水凝胶作为基底(MP),采用原位聚合法制备了纤维素/聚乙烯醇/聚苯胺气凝胶(MPP),并对气凝胶的结构特征、阻燃性能和传感性能进行了测试与分析。结果表明,聚苯胺附着在气凝胶的表面和空隙中,赋予了气凝胶良好的导电性,电导率高达0.34 S/m,比MP提高了约4个数量级。同时,随着聚苯胺的加入,气凝胶的内部结构更加密实,MPP_(1.25)可以承受1.7 MPa的拉伸变形。更重要的是,MPP_(1.25)具有良好的阻燃效果,极限氧指数高达29.2%,热释放率和总热释放率相比MP分别降低了250%和14%。最后,由于MPP_(1.25)的多孔形貌,气凝胶具有良好的传感性能,不仅能够监测人体手指关节运动,还能依据不同质量反馈出不同的电信号,表明MPP_(1.25)气凝胶在可穿戴传感器上具有长远的发展潜力。

In order to prepare a new composite material with good flame retardant and sensing properties,the hydrogel made of polyvinyl alcohol(PVA)and microcrystalline cellulose(MCC)was used as substrate(MP),and the cellulose/polyvinyl alcohol/polyaniline aerogel(MPP)was prepared by in-situ polymerization method.Then,the structural characteristics,flame retardancy and sensing properties of aerogel were analyzed comprehensively.The results show that the adhesion of polyaniline to the surface and void of the aerogel gives the aerogel a good conductivity of 0.34 S/m,which is about 4 orders of magnitude higher than that of MP.At the same time,with the addition of polyaniline,the internal structure of the aerogel is more dense,and MPP_(1.25) can withstand the tensile deformation of 1.7 MPa.More importantly,MPP_(1.25) has a good flame retardant effect,the limiting oxygen index is as high as 29.2%,and the heat release rate and total heat release rate are reduced by 250%and 14%compared with MP,respectively.Finally,due to the porous morphology of MPP_(1.25),the aerogel has good sensing performance,which can not only monitor the movement of human finger joints,but also feedback different electrical signals according to different weights,indicating that MPP_(1.25) aerogel has long-term development potential in wearable sensors.