Synthesis and characterization of chloromethyl-calix[4]arene-grafted silylated clay nanocomposite

In this study, we report the synthesis and characterization of novel nanocomposite namely doubly functionalized chloromethyl-calix[4]arene-methoxy grafted silylated clay (SC-C[4]). The silylation of nanoclay (thickness of the sheets ≈ 1 nm) was performed using (3-aminopropyl)trimethoxysilane (APTMS) (height ≈ 4.55 A) coupling agent. The resulting organoclay was characterized by various techniques such as X-ray diffraction (XRD), infrared spectroscopy (IR), thermal gravimetric analysis (TGA), and 29Si and 13C solid-state NMR. The XRD results suggested the presence of a double layer of silanes molecules into the clay galleries of nanoclay minerals by increasing in the basal spacing. While the IR, 29Si and 13C solid-state NMR, and TGA analysis demonstrated the successful silylation of clay by the appearance of novel absorption bands, the changes in the chemical environment and the peaks degradation in the range 200 to 500  ° C related to aminosilane molecules, respectively. The calix[4]arenes derivatives were synthesized and characterized by IR spectroscopy and 1HNMR. The results showed that calix[4]arene was functionalized at the lower and upper rim. The grafting of the doubly functionalized calix[4]arene onto clay surfaces was performed through nucleophilic reaction. Structure, thermal properties of the nanocomposite SC-C[4] were also investigated. All data approved the successful grafting of para-chloromethyl-calix[4]arene-OMe onto clay surfaces.