关键词: 纳米芳纶纤维, 碳纳米管, 气凝胶纤维, 电磁屏蔽

Abstract: The aerogel, a porous material with low density and large specific surface area, has promising applications in environmental treatment, catalytic carriers, energy storage devices, etc. It has been proposed that aerogels are shaped into one-dimensional fibres, which may lead to some good properties such as good flexibility and small density. This facilitates the design and manufacture of textiles. In the past decade, efforts have been devoted to the development of aerogel fibers such as graphene aerogel fibres, titanium oxide aerogel fibres, silica aerogel fibers and cellulose aerogel fibers with multiple different functions. Graphene aerogel composite fibers with tunable thermal conversion and storage under multiple stimuli offer a wide range of applications in next-generation wearable systems. Cellulose aerogel fibers have high mechanical strength and low thermal conductivity at room temperature. When combined with phase change materials, nickel and fluorocarbon (FC) resins, aerogel fibers can also be used as phase change fibers, conductive fibers and hydrophobic textiles. Aramid nano fibers (ANFs for short) are polymeric nanofibers with high porosity, large specific surface area, high aspect ratio and unique nano-scale effects. These excellent properties make them promising for many emerging applications. ANFs are prepared as aerogel fibers and made to be used as a base material to compound with other materials to prepare high performance aerogel fibers. This can solve some of the problems of excellent performance materials that cannot be moulded due to poor mechanical properties.
In recent years, more and more scholars have been preparing various high performance materials into aerogel fibers. 
In this paper, carbon nanotubes (CNTs), a conductive material, were dispersed in the same system with ANF through DMSO and the effects of different CNT contents on the properties of aerogel fibers were discussed. Based on the electrical conductivity of the aerogel fibres, their electromagnetic shielding properties were investigated. The mechanical properties and electrical conductivity of the fibers were tested to determine the optimum parameters of CNT within the experimental range. The results show that when the content of CNT in the dispersion reaches 25%, the fiber has a breaking strength of 7.29 MPa and the electromagnetic shielding effectiveness reaches 18 dB. The CNT/ANF composite aerogel fiber can shield 80 % of electromagnetic waves and meet the industrial requirements.

Key words: nano-aramid fibers, carbon nanotubes, aerogel fibers, electromagnetic shielding