| 摘要: | 研究期間：10108~10207;This proposal aims to synthesize and characterize mesoporous silica materials and periodic mesoporous organosilicas (PMOs) functionalized with a variety of acidic functional groups including carboxylic acid groups (-COOH), sulfonic acid groups (-SO3H) and phosphonic acid groups (-PO3H2). These materials will be prepared by so called “direct synthesis route”, in which the organosilanes containing these acidic functional groups will condense with some conventional silica sources such as TEOS, BTEE and BTEB templated by surfactant molecules under suitable acidic conditions. First, we will investigate the influence of the loading of functional groups on the structuring ordering of the resultant materials in a systematic way. A variety of characterization techniques, including Powder X-ray, nitrogen adsorption-desorption, TGA, SEM, TEM, and solid-state NMR techniques, will be employed to characterize the materials thus obtained. In particular, solid-state NMR techniques such as multiple nuclear (1H, 13C, 29Si and 31P) measurements, ultrafast magic angle spinning for 1H (spinning speed up to 60 kHz), 2D heteronuclear correlation spectroscopy (HETCOR), 2D double quantum spectroscopy, and rotational echo double resonance (REDOR, e.g., 31P-29Si and 31P-13C) will be implemented to explore the possible interaction between the acidic functional groups and nearby silicon species in the silica framework. A combination of solid-state NMR experiments and DFT calculations will be employed to probe the local structure and framework distribution of acidic functionalized mesoporous silicas and PMOs. NMR distance measurements involving relatively isolated spin pairs such as 31P-29Si and 31P-13C allowed accurate distance information to be obtained. Further, a better understanding of the distribution of these functional groups may be obtained, which will be very helpful for applications of these materials in various research fields such as environmental remediation, adsorption, catalysis, and drug delivery, etc. We aim to synthesize the following materials and to address the following issues: (1) synthesize mesoporous materials with high loading of acidic functional groups. These functional groups include sulfonic, carboxylic, and phosphonic acid groups and the materials include SBA-15, MCM-48, SBA-1, KIT-6, and PMOs. (2) explore potential applications of these materials in the fields of drug delivery, catalysis, and protein immobilization. |
