Heterocyclic Grafting Functionalization of Silica Nanoparticles: Fabrication, Morphological Investigation and Application for PVA Nanocomposites

In this study, Knoevenagel condensation reaction was performed to prepare a new designed silane coupling agent from the reaction of the synthetic 4-H pyran derivative (EA) and 3-isocyanatopropyl triethoxysilane. The surface modification of silica nanoparticles by novel modifier was achieved by sol-gel technology. Also, in the next step, PVA/silica nanocomposites have been fabricated to investigate the chemical and physical properties of the new decorated nanoparticles. The surface modification of silica nanoparticles reduced the aggregation of nanoparticles effectively using newly prepared silane coupling agent and showed the enhanced performance for host matrix. FT-IR analysis demonstrated that the six membered ring moieties have been covalently bonded to the surface of the SiO2 nanoparticles. The PVA/SiO2 nanocomposites including 2, 5, 10 and 15 wt% nano contents have been prepared. Characterization of the prepared samples with FT-IR, field emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM) confirmed the synthesis of the nanocomposites with good dispersion properties for nanoparticles. The particles size of ornamented nanoparticles in nanocomposites are about 50-60 nm as characterized by FE-SEM and AFM analyses.