Study of Film Formation From PS Latex/TiO2 Nanocomposites; Effect of Latex Size and TiO2 Content

Abstract

In this work, we investigated the film formation from polystyrene (PS) latex/TiO2 nanocomposites using the steady state fluorescence (SSF) and UV-vis (UVV) techniques depending on PS particle size and TiO2 content. The structural properties of films were characterized by scanning electron microscope (SEM). The films were prepared from pyrene (P)-labeled PS particles (SmPS: 203 nm; LgPS: 382 nm) by covering them with different layers of TiO2 by dip-coating method and then annealed at elevated temperatures. Two film series (SmPS/TiO2 and LgPS/TiO2) were prepared and seven different films were studied in various TiO2 contents for each series. Scattered (I-sc), fluorescence (I-P), and transmitted (I-tr) light intensities were measured after each annealing step to monitor the stages of film formation. Results showed that, SmPS/TiO2 films undergo complete film formation independent of TiO2 content. However, no film formation occurs above a certain TiO2 content in LgPS/TiO2 films. SEM images showed that SmPS/TiO2 films have highly well-ordered microporous structures with increasing TiO2 content after extraction of PS polymer whereas LgPS/TiO2 composites show no porous structure for high TiO2 content. Our experiments also showed that porous TiO2 films with different sizes could be successfully prepared using this technique. (C) 2014 Society of Plastics Engineers