Synthesis and Characterization of Halloysite-Polyvinyl Alcohol-Metal Oxides Nanocomposites via Surfactant Aid Sol-Gel Reaction and Study Some of their Applications
Halloysite nanotubes–polyvinyl alcohol-metal oxide (HNTs–PVA-MO) was synthesized using sol-gel method. The metal oxides used in this work were MO: CoO, NiO, CuO and ZnO. When prepared with each other metal oxides, six nanocomposites were obtained with halloysite and PVA. HNTs were functionalized by exploiting the different charges between the inner positive and the outer negative surfaces; accordingly, a selective adsorption is pursued by employing anionic and cationic surfactants, its cylindrical shape, its abundance in nature and its cheapness, which made it distinctive and abundant in uses. The composite of one polymer were modified by treating HNTs with using malonic acid (MA) as a crosslinked, in the presence of HNTs with sodium dodecyl sulfate (SDS), The SDS is a good dispersing agent for HNTs in aqueous solution. Despite that, the XRD spectra do not show a significant difference, the decrease in peak intensity could be attributed to the addition of semi-crystalline PVA and the amorphous MO. The images taken by FESEM show the possible effects of MA on the morphology and internal feature of HNTs–PVA composite treated by MA by showing the deformation of the matrix, and average diameter 94.25 nm, while with MO, to get less than 61.77nm like [HNTs: PVA/ZnO: CuO/ MA: SDS]. The BET surface area decreased to 35.94m2/gm compared to the neat HNTs at 53.3 m2/gm. This result is considered a breakthrough in enhancing the properties of HNTs-PVA, and treatment by MA crosslinking may attribute to the size and the number of the pores. And when using metal oxides, it decreased significantly, and some of the compounds may reach 0.73m2/g. The characterization of HNTs–PVA composite and using crosslinked may lead to a better understanding of these new composites as a precursor to possible applications in the anti-cancer, anti-bacterial and anti-oxidant.