High molar mass amphiphilic block copolymer enables alignment and dispersion of unfunctionalized carbon nanotubes in melt-drawn thin-films

作者：Arras Matthias M L; He Bojia; Jandt Klaus D^*

来源：Polymer, 2017, 127: 15-27.

DOI：10.1016/j.polymer.2017.08.030

• Carbon nanotubes (CNTs)
• Block copolymer (BCP)
• Alignment
• Dispersion
• Poly(2-vinylpyridine) (P2VP)

To extensively control the nanofiller arrangement (location, orientation, shape) is still a bottleneck for multi-wall carbon nanotube (MWCNT) nanocomposites. Here, we demonstrate simultaneous control of alignment (orientation) and dispersion (location) of pristine, i.e., unfunctionalized MWCNTs using a high molar mass (HMM) amphiphilic block copolymer (BCP). We tested whether a HMM BCP in a selective solvent (i) disperses MWCNTs (ii) disperses MWCNTs by similar mechanisms to low molar mass BCPs and (iii) is melt-drawable to align the well dispersed MWCNTs. The dispersibility of MWCNTs within poly(styrene)-block-poly(2-vinylpyridine) (PS-b-P2VP) ((M) over bar (w)approximate to 500 kg/mol) and its homopolymers in (non-)selective solvents was investigated by sedimentation experiments, transmission electron microscopy and visible/near-infrared spectroscopy. Through BCP micelle mediated steric stabilization, HMM PS-b-P2VP led to a highly stable MWCNT dispersion, which is explained in two simple graphical models. Using the melt-drawing technique, the well dispersed MWCNT/PS-b-P2VP dispersion was processed into a nanocomposite with a high degree of MWCNT alignment and dispersion. HMM BCPs are of significance for structural MWCNT/polymer nanocomposites, typically containing HMM polymers.

• 出版日期2017-10-3