Morphology of self-assembled polyvinyl alcohol/Silica nanocomposites studied with atomic force microscopy Zheng Peng 1,2 ( ), Ling Xue Kong 2 1 Chinese Agricultural Ministry Key Laboratory of Natural Rubber Processing, Agricultural Product Processing Research Institute at Chinese Academy of Tropical Agricultural Sciences, Zhanjiang 524001, China 2 Centre for Advanced Manufacturing Research, University of South Australia, Mawson Lakes, 5095 SA, Australia E-mail: zhengpeng8@yahoo.com; Fax: +86 759 2221586 Received: 24 January 2007 / Accepted: 1 March 2007 Published online: 15 March 2007 – © Springer-Verlag 2007 Summary Atomic force microscopy (AFM) is used for the morphology study of polyvinyl alcohol/silica (PVA/SiO 2 ) nanocomposites prepared by incorporating solution compounding and self-assembly technique. The results show that the strong particle- particle interaction of SiO 2 nanoparticles is greatly suppressed, and the SiO 2 nano- particles are homogenously distributed in PVA matrix as spheric nano-clusters. The average size of the SiO 2 nano-clusters is below 50 nm at low SiO 2 loadings (≤5 wt%). At higher SiO 2 contents, the particle aggregations can be clearly observed, and the average size of SiO 2 aggregates significantly reach up to 110 nm and 250 nm at SiO 2 content of 10 wt% and 15 wt%, respectively. AFM height profiles demonstrate that the surface heterogeneity of the nanocomposite is governed by the SiO 2 contents. The surface roughness evaluated as root mean square (RSM) of peak-to-valley height values shows that the surface becomes rougher as the SiO 2 content increases, particularly, a remarkable increase in surface roughness is found at the SiO 2 content of 10 wt%. 1. Introduction The latest developments in nanotechnology provide a unique opportunity to create revolutionary polymeric/inorganic nanocomposites (PINs) with significant properties [1-3], which only occur when their morphologies are organised at nano-scale. Nanoparticles, the “designer molecules” govern the macroscopic behaviour PINs, in which the way the nanoparticles and polymer arranged in the composites is essential to determine the properties of the PINs. Therefore, the morphology of nanocomposites or distribution pattern of nanoparticles in polymer matrix is one of the most important criteria for successful creation of nanocomposites. Atomic force microscopy (AFM) has become one of the most valuable tools for investigating the morphology of PINs [4, 5]. Among all microscopic techniques, AFM Polymer Bulletin 59, 207–216 (2007) DOI 10.1007/s00289-007-0756-y