Selective Removal of Radical Polymerizable Monomers from Aqueous Methanol Solutions by Fluoroalkyl End-capped Vinyltrimethoxysilane Oligomer Composites

摘要

Fluoroalkyl end-capped vinyltrimethoxysilane oligomeric silica/α-, β-, γ-cyclodextrin polymers (CDPs) composites [R_F-(VM-SiO_(3/2))_n-RF/CDPs; R_f = CF(CF_3)OC_3F_7] possessing a superoleophilic/superhydrophobic characteristic on their surface were applied to the removal of a variety of radical polymerizable monomers, such as styrene, alkyl methacry-lates [CH_2 = CMeC(= O)OR; R = (CH_2)_n; n=1, 2, 4, 6], 2-hydroxypropyl methacrylate, acrylic acid, N, N-dimethylacrylamide, N-isopropylacrylamide, acryloylmorpholine, and N-(1,1-dimethyl-3-oxobutyl)acrylamide from aqueous methanol solutions. In these monomers, more oleophilic monomers such as styrene, butyl methacrylate and hexyl methacrylate were found to exhibit a higher removal ability than that of lower oleophilic or hydrophilic monomers under similar conditions. In addition, the removal ability of these monomers by the RF-(VM-SiO_(3/2))_n-R_F/CDPs composites was superior to that of the original CDPs under similar conditions. The R_F-(VM-SiO_(3/2))_n-R_F oligomeric silica nanoparti-cles possessing a similar superoleophilic/superhydrophobic property on their surface, which were prepared under the sol-gel reaction of the corresponding oligomer under alkaline conditions, were found to give a lower removal ability of the oleophilic monomers from aqueous methanol solutions than that of the R_F-(VM-SiO_(3/2))_n-R_F/CDPs composites; however, the R_F-(VM-SiO_(3/20)_n-R_F oligomeric silica nanoparticles were able to provide a higher removal ability toward the fluorinated monomers compared to that of the corresponding fluorinated CDPs composites.