Visualization of carbon nanotubes dispersion in composite by using confocal laser scanning microscopy

•Visualization of various carbon nanotubes in polymer composites by CLSM.•Modification of carbon nanotubes for better dispersibility in polymer matrix.•Labelling of nanotubes via combination of ATRP and fluorescent nitroxide.•Applicability and the limitations of CLSM for evaluation of polymer nanocomposites.

Nanocomposites of polystyrene-block-polyisoprene-block-polystyrene triblock copolymer (SIS) and various types of neat and polystyrene-modified carbon nanotubes (CNT-PS) were prepared and distribution of the CNT-PS throughout the polymer matrix was evaluated using confocal laser scanning microscopy (CLSM). The Nanoamor MWCNT-PS with highest thickness of 25–60 nm were readily visualized using both reflection mode without necessity of fluorescent labelling and fluorescent mode after addition of free dye to the nanocomposite. Visualization of Nanocyl MWCNT-PS with thickness of 8–18 nm and SWCNT-PS was achieved after covalent labelling of the CNT-PS with benzothioxanthene fluorescent dye. The CLSM can serve as a non-invasive method for evaluation of quality of dispersion of nanofillers on quite large area and at various depth of polymer film.

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