Ultralight and Flexible MWNTs/Polyimide Hybrid Aerogels for Elastic Conductors. Issue 9 (30th June 2017)

• Record Type: Journal Article
• Authors: Wang, Yanan; Ge, Qiyan; Chen, Xueli; Qi, Shengli; Tian, Guofeng; Wu, Dezhen
• Is Part Of: Macromolecular materials and engineering. Volume 302:Issue 9(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-06-30
• Subjects: mechanical properties -- MWNTs‐OH -- polyimide -- press‐sensitivity -- shrinkage; Plastics -- Periodicals; Polymers -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1002/mame.201700082
• Languages: English
• ISSNs: 1438-7492

Abstract

Abstract : The introduction of hydroxyl multi‐walled carbon nanotubes (MWNTs‐OH) reduces the shrinkage and cost notably, endows the nanocompoiste with stress‐sensitvity. The three characteristic regions can be identified in loading‐unloading curve of PI‐80 nanocomposite clearly. Interestingly, the variation trend of the electric resistance with compressive strain plots is consistent with the loading‐unloading curve, which shows great potential for various applications. Abstract : Aerogels have showed tremendous potential applications because of its unique and outstanding properties. Herein, a novel two‐step approach to form self‐assembly nanocomposite aerogels driven by the strong interactions between water‐soluble polyimide (PI) precursor polyamic acid salt (PAAs) and hydroxyl multiwalled carbon nanotubes (MWNTs‐OH) is reported. The PI therein constitutes the framework of the nanocomposite and raises the strength of the cell walls, which endows aerogels with superelasticity and robustness. The MWNTs‐OH is distributed uniformly into water via physical ultrasonic method followed by blending with PAA molecular. During the imidization process, electrically insulating polyamic acid (PAA)/MWNTs‐OH aerogels are converted to conductive PI/MWNTs‐OH nanocomposite aerogels owning to the removal of their oxygenic functional groups of OH functionalized MWNTs. Moreover, adding multi‐walled carbon nanotube (MWNTs) contributes to the reduction of shrinkage notably, which can be evidenced by scanning electron microscopy measurement and density data. The nanocomposite aerogels display a high elastic modulus, high compressive stress, superior robustness, and high stress‐sensitive electrical conductivity. Interestingly, the variation trend of the electric resistance with compressive strain ( R / R 0 –ε) plots is consistent with the compressive stress–strain (σ–ε) curves, which can be explained by the "interface contact spots" theory. And this finding could facilitate the development of polymer‐based nanocomposite aerogels as elastic conductors for various applications.