Polymeric matrices pristine conducting

Shang et al. (61) used microemulsion polymerization to synthesize MWCNT-PMMA composites for gas sensor applications. Better dispersion, enhanced electrical conductivity and better sensor response was observed for in-situ fabricated composites compared to composites prepared by solution mixing. Ma et al. (62) performed in-situ polymerization of MWCNT-PMMA composites in the presence of an AC electric field to study dispersion and alignment of MWCNT in PMMA matrix induced by the electric field. Experimental evidences from in-situ optical microscopy, Raman spectroscopy, SEM and electrical conductivity showed that both dispersion and alignment qualities were significantly enhanced for oxidized MWCNT compared to pristine MWCNT. 

Early, in situ radical polymerization was used for the synthesis of poly(methyl methacrylate) (PMMA)-CNT composites [82]. In situ polymerization was performed using the radical initiator 2,2-azobisisobutyronitrile(AIBN). In this reaction, p-bonds in CNTs were initiated by AIBN, and therefore nanotubes could participate in PMMA polymerization to form a strong interface between the CNT and the PMMA matrix. PA6/CNT composites have been prepared by in situ polymerization of e-caprolactam in the presence of pristine and carboxylated CNTs. The e-caprolactam monomer was found to form an electron-transfer complex with CNTs and result in a homogeneous, polymerizable solution. The final composites can be spun into PA6/CNT fibers (Fig. 7) with excellent mechanical and electrical properties [83].This method is also suitable for the fabrication of thermosetting polymer composites with nanofillers. Bauhofer et al. [84] dispersed CNTs in an epoxy solution system based on a bisphenol-A epoxy resin and an amine hardener During nanocomposite curing, electric fields were used to induce the formation of aligned conductive nanotube networks. Recently, the in situ polymerization method... 

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