Highly untangled multiwalled carbon nanotube@polyhedral oligomeric silsesquioxane ionic hybrids: Synthesis, characterization and nonlinear optical properties

Highly de-bundled multiwalled carbon nanotube (MWCNT) polymer nanohybrids were obtained via ionic assembling of a novel POSS-polyimidazolium-ionic liquid (POSS = polyhedral oligomeric silsesquioxanes) with oxidized MWCNTs. The synthesis, accomplished by a simple bilayer chloroform/water metathetical reaction process, was promoted by the high surfactant properties of POSS-imidazolium-polyionic liquid, which assisted the effective de-bundling, dispersion and purification of the as prepared POSS@MWCNT polymers in organic media, via a surface coating mechanism. The presence of remarkably intense radial breathing modes (RBMs) in Raman spectra, both in solution and as solid, corroborates the effectiveness of the de-bundling process induced by the amphiphilic POSS polymeric ionic liquid (polyIL). This was, further, substantiated by scanning and transmission electron microscopy images. The nonlinear optical (NLO) behavior of POSS@MWCNT was investigated by Z-scan technique, which revealed a remarkable susceptibility χ(3) of 2.38·10−7 esu mainly due to a dispersive effect. A good optical limiting (OL) performance, under a 532 nm pulsed excitation, was observed as well.