Synthesis of nanosized PAA/titania hybrid composites—Experiment and modeling

A stable colloid of nanosized PAA/titania hybrid has been successfully prepared, in which chelating bond was evidenced by FTIR spectra. Moreover, TGA curves indicated the degree of chelation to be increased with an increase of PAA content. SEM micrographs demonstrated that the size of hybrid aggregates would be smaller at increased ratio of PAA to titania, because the higher amount of PAA would decrease the degree of aggregation and inhibit the titania growth. A new sol–gel kinetic model for partially chelated titanium alkoxide by PAA has been proposed to simulate the experimental results. Based on this sol–gel kinetic model which takes into account the effect of chelation, the concentration of water, Ti–OR, Ti–OH, and (Ti–O)–Ti bonds during sol–gel reaction could be calculated. The variation of number of particles at different reaction times could also be shown. Finally, the size of hybrid aggregates at different degrees of chelation could be qualitatively described. The simulated results from this model were in agreement with the observation from SEM micrographs. # 2007 Elsevier Ltd and Techna Group S.r.l. All rights reserved.