Nanosized silica particles were modified with PEG or PPG
through UV-photopolymerization. Various analytical methods
were used to comprehensively characterize the unmodified and
modified silica particles. The surface modification of silica
particles changed some properties on the surface, i.e., electric
charge and hydrophilic nature. Modified silica particles showed
a larger weight loss at 500 8C in TG analysis and a lower zeta
potential value than that of unmodified silica particles. The
silica particles modified with polymers showed a lower water
vapor adsorption than that of pure silica particles due to a more
hydrophobic surface. The electrical conductivity measurement
which was developed in this study was capable of verifying the
surface modification by polymers, since the modified particles
had a lower value of electric conductivity than that of pure silica
particles. These results indicate that the surface modification of
silica particles via UV-photopolymerization with polymers was
carried out successfully and that the modification made the
silica particle surface more hydrophobic.