title: Synthesis of carboxyl-modified rod-like SBA-15 by rapid co-condensation.
abstract: Carboxyl-modified SBA-15 rod-like mesoporous materials have been synthesized by a facile rapid co-condensation of tetraethylorthosilicate (TEOS) and 2-cyanoethyltriethoxysilane (CTES), followed by hydrolysis of cyanide groups in sulfuric acid. The concentration of carboxylic groups was varied by changing the silica source ratio of CTES/TEOS from 0.05 to 0.3. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the uniform ordered mesoporous structure and rod-like morphology of SBA-15 have been preserved even at the high concentration of carboxylic groups employed. Characterization by Fourier transformed infrared spectroscopy (FTIR), solid-state NMR investigation indicated that carboxylic groups have been successfully grafted onto the surface of SBA-15 through siloxane bonds [(O(3))SiCH(2)CH(2)COOH. The negative charges of the modified SBA-15 materials were enhanced by the presence of the carboxylic groups on the surface. The capacity of lysozyme adsorption of the modified SBA-15 materials were found to be significantly improved as compared with pure silica SBA-15. The maximum amount of lysozyme adsorption on carboxyl-modified was increased with the pH of solution increased from 5.5 to 9.0.
authors.affiliation: Institute of Chemical and Engineering Sciences, A*STAR (Agency for Science, Technology and Research), Jurong Island, Singapore. shoucang_shen@ices.a-star.edu.sg
authors.forename: Shoucang
authors.initials: S
authors.lastname: Shen
authors.forename: Pui Shan
authors.initials: PS
authors.lastname: Chow
authors.forename: Sanggu
authors.initials: S
authors.lastname: Kim
authors.forename: Kewu
authors.initials: K
authors.lastname: Zhu
authors.forename: Reginald B H
authors.initials: RB
authors.lastname: Tan
mesh_terms: D000327:Adsorption; D002264:Carboxylic Acids / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D009113:Muramidase; D009570:Nitriles; D012821:Silanes; D012822:Silicon Dioxide / Q000138:chemical synthesis* / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014961:X-Ray Diffraction
chemical_list: D002264:Carboxylic Acids; D009570:Nitriles; C509969:SBA-15; D012821:Silanes; C503295:3-(triethoxysilyl)propionitrile; C040733:tetraethoxysilane; D012822:Silicon Dioxide; D009113:Muramidase