Structure of Organic−Inorganic Nanohybrids Incorporating Titanium(IV) Oxoalkoxyacylate Nanoclusters: A SANS Study

Abstract

The small angle neutron scattering (SANS) technique was used to investigate the structure of nanohybrids consisting of a poly(methylmethacrylate) (PMMA) and one of two types of titanium(IV) nanoclusters. Cluster 1, [Ti6O4](OC2H5)8(CH2=CCH3COO)8, with polymerizable MMA ligands, formed covalent bonds with the polymer chains during the copolymerization, whereas cluster 2, [Ti6O4](OC2H5)8(CH3COO)8, had no polymerizable linkers and was blended into the polymeric matrix purely as a filler. In this study, SANS with contrast variation was used to investigate the size, shape and aggregation of the clusters in the hybrid materials, and their effect on the structure of the matrix. A polydispersed core-diffusion zone model was employed to explain the scattering contribution from the titanium clusters in both nanohybrid materials. No significant differences between the structures of the two nanohybrids were found. The fitted models suggest that the interface region between the cluster and matrix (the diffusion zone) is heavily occupied by the PMMA chains; however, they do not penetrate into the core region (titanium cluster).