A Novel and Versatile Grafting Procedure: Toward the Highest Possible Sulfonation Degree of Mesoporous Silica. (14th February 2018)

• Record Type: Journal Article
• Authors: Timm, Jana; Marschall, Roland
• Is Part Of: Advanced sustainable systems. Volume 2:Number 3(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-02-14
• Subjects: acidic solids -- CVD methods -- grafting -- ordered mesoporous silica -- sulfonation; Sustainable living -- Periodicals; Sustainability -- Periodicals; Green technology -- Periodicals; Periodicals; 628
• DOI: 10.1002/adsu.201700170
• Languages: English
• ISSNs: 2366-7486

Abstract

Abstract: A unique method for the postsynthetic functionalization of ordered mesoporous silica materials is described. The functionalization is done via a chemical vapor deposition‐type method and leads to the quantitative reaction of isolated surface silanol groups of mesoporous silica materials with organosilane molecules. The result is a highly sulfonated material by anchorage of 3‐mercaptopropyltrimethoxysilane molecules and subsequent oxidation of the thiol groups to sulfonic acid groups. Ordered mesoporous KIT‐6 and SBA‐15 are chosen as model systems. The sulfonated material exhibits a functionalization degree of 1.05 resp. 1.32 molecules nm −2, which is on the maximum of the theoretical achievable functionalization density resulting in high ion exchange capacities of 1.22 and 1.12 mmol g −1 . The versatility and mildness of this method opens up functionalization possibilities for a wide range of other materials, which could be sulfonated or otherwise modified with silanes, and tailored for the further application in catalysis or as solid‐state proton conductors. Abstract : The quantitative reaction of 3‐mercaptopropyltrimethoxysilane (MPTMS) molecules with silanol groups on the surface of ordered mesoporous silica via new chemical vapor deposition (CVD)‐type grafting approach is demonstrated. The CVD method is generalizable for silica materials due to mild, and solvent‐free reaction conditions. The highest theoretical anchorage of MPTMS molecules per nm 2 is practically achieved for the first time.