Crystallization of poly(ethylene oxide) embedded with surface-modified SiO2 nanoparticles

The crystallization of poly(ethylene oxide) (PEO) in the presence of silica nanoparticles (SiO2 NPs) was investigated in terms of heterogeneous nucleation of SiO2 NPs using polarizing optical microscopy and differential scanning calorimetry. The content and surface functionality of SiO2 NPs were considered as the main factors affecting crystallization, and the effect of annealing time and temperature was also examined. The SiO2 NPs acted as heterogeneous nucleates during the crystallization process, thereby enhancing the nucleation density and limiting the spherulitic growth rate. A kinetics study of non-isothermal crystallization showed that the crystallization rate of 5 wt% SiO2/PEO nanocomposite was ca 2.1 times higher than that of neat PEO. In addition, among various surface-functionalized SiO2 nanoparticles, alkyl-chain-functionalized SiO2 NPs were favorable for achieving a higher crystallization rate due to the enhanced compatibility between the SiO2 NPs and PEO chains. (c) 2012 Society of Chemical Industry