Colloidal properties of surface functionalized nanocube-TiO2/poly(3-octylthiophene) core/shell conducting nanocomposite

Abstract

The aim of this study was to prepare a conducting nanocomposite from poly(3-octylthiophene, P3OT) and nanocube-TiO2 particles. For this purpose, firstly nanocube-TiO2 particles were synthesized by hydrothermal method and then surface functionalized by the self assembly of 3-aminopropyltriethoxysilane and 3-thiophene acetic acid, respectively, to obtain covalently bonded nanocube-TiO2/P3OT core/shell nanocomposite. The samples were characterized by ATR–FTIR spectroscopy, elemental analysis, TGA, XRD, XPS, SEM, TEM, contact angle, and conductivity measurements. Electrokinetic properties of nanocube-TiO2 and nanocube-TiO2/P3OT core/shell nanocomposite dispersions were determined by zeta(ζ)-potential measurements in aqueous medium by taking the effects of time, pH, various electrolytes, surfactants, and temperature into account. It was observed that pH was effective on the ζ-potentials of TiO2 in water; but showed slight changes with the presence of cationic (NaCl, BaCl2, AlCl3) and anionic (NaCl, Na2SO4) electrolytes. Increased pH values were observed to shift the ζ-potentials of TiO2/P3OT nanocomposite dispersions to more negative values. Further, effects of surfactants (sodium dodecyl sulfate, SDS, cetyltrimethylbromide, CTAB, TritonX-100) on the ζ-potentials of nanocube-TiO2 and nanocube-TiO2/P3OT nanocomposite dispersions were examined.