Conducting polymer nanocomposites filled with carbon nanotubes (CNTs) have attracted great interest in developing flexible sensors. This paper reported the preparation of cotton-based CNT foam by using a chemical vapor deposition method. The prepared foam was incorporated into epoxy or polydimethylsiloxane (PDMS) to fabricate corresponding nanocomposites. The results showed that CNT foam exhibited excellent adsorption performance for liquid polymer, thus eliminating the variations on the dispersion, concentration and formation of CNT networks in nanocomposites. CNT/Epoxy nanocomposites had a comparable electrical conductivity (1.2 S/m) with that of CNT foam (1.5 S/m), and a much higher value than that of CNT/PDMS counterpart (0.06 S/m). Interesting, CNT/Epoxy showed a negative piezoresistance, whereas the one with PDMS had a positive effect. It was found that the Poisson's ratio of the matrix and its wettability with nanofiller controlled the contact and tunneling resistance in the system, which in turn affecting piezoresistive behavior of bulky nanocomposites.

填充有碳纳米管 (CNT) 的导电聚合物纳米复合材料在开发柔性传感器方面引起了极大的兴趣。本文报道了采用化学气相沉积法制备棉基碳纳米管泡沫。将制备的泡沫掺入环氧树脂或聚二甲基硅氧烷（PDMS）中以制造相应的纳米复合材料。结果表明，CNT泡沫对液态聚合物表现出优异的吸附性能，从而消除了纳米复合材料中CNT网络的分散、浓度和形成的变化。CNT/Epoxy 纳米复合材料的电导率 (1.2 S/m) 与 CNT 泡沫 (1.5 S/m) 相当，并且比 CNT/PDMS 对应物 (0.06 S/m) 高得多。有趣的是，CNT/Epoxy 显示出负压阻，而具有 PDMS 的则具有积极作用。