Amine-Functionalized Natural Rubber/Mesostructured Silica Nanocomposites for Adsorptive Removal of Clofibric Acid in Aqueous Phase oleh Satit Yousatit, Witsarut Rungruangwattanachot, Natthakit Yuwawanitchakorn, Sakdinun Nuntang, Patiparn Punyapalakul, Chawalit Ngamcharussrivichai