CAJ | 학술논문

Pillared clays(Ti-PILCs)were synthesized from Na-type montmorillonite through intercalation with polymeric hydroxy-titanium.The mechanism of the pillaring course was studied by means of magic angle spinning nuclear magnetic resonance(MAS NMR)and diffuse reflectance infrared spectroscopy(DRIFTS)techniques.DRIFTS suggested that after Ti-pillaring,the silicon-oxygen tetrahedral Si-O-Si bond and aluminum oxide octahedral Si-O-Al bond were broken.Meanwhile,NMR also showed the change of the silicon-oxygen tetrahedral structure and aluminum oxide octahedral structure in the pillared clay.In the pillaring process,the titanium hydroxy-oligomeric cations entered the layers of the montmorillonite by ion-exchange,the Si-O-Al bond of the raw clays were broken,the silicon-oxygen tetrahedron structure were overturned,and the reactive oxygen species(structural hydroxyl)reacted with titanium hydroxy-oligomeric cations to form Si-O-M bond.This led to the incorporation of pillaring species of Ti in the layers of the clay.After further heat treatment,the TiO_2 pillars were formed in the layers to obtain Ti-PILCs.