The Synthesis, Characterization And Application Of The Mesoporous Molecular Sieve Ti-HMS

Ti-HMS is a kind of Ti-containing mesoporous molecular sieve reported by Pinnavaia'sgroup in 1994, which possesses wormlike structure. Because Ti-HMS is syhthesized undermild conditions, in addition, the template can be removed and recovered through theextraction of organic solvent, synthesis, characterization and application of Ti-HMS hasattracted much attention.In this paper, Ti-HMS was synthesized at ambient temperature using dodecylamine(DDA) as template, tetraethylorthosilicate (TEOS) as silicon source, tetrabutylorthotitanate(TBOT) as titanium source. The effect of salts such as TPABr, NaCl and KBr on the synthesisof Ti-HMS was investigated. The molecular sieve was characterized by XRD, UV-Vis and N₂physical adsorption. After adding the salts, the crystallinity of mesoporous molecular sievedecreases, but the amount of framework titanium does not change. The addition of TPABrimproves the hydrothermal stability of Ti-HMS.We added hexane, heptane and octane into the synthesis system, and examined theenlarging pore size effect of the n-alkane on Ti-HMS. It has been shown that the Ti-HMSprepared with the addition of alkanes have lower crystallinity and the content of frameworktitanium than the original sample. The physical adsorption results exhibit that the porediameter of Ti-HMS, as well as the surface area and pore volume, enlarge with the addition ofalkanes. In addition, with the increase of dosage of alkanes, the pore diameter of Ti-HMSsamples also increase. Thus-obtained samples exhibit higher activities than the originalTi-HMS in the oxidative removal of 4, 6-DMDBT, which can be attributed to the larger porediameter.In now days, the research of drug sustained and controlled release preparation is still thehot topic in the medicinal field. The usage of mesoporous molecular sieves breaks a new pathin this area. In this thesis, ibuprofen was carried on HMS and Ti-HMS using hexane as thesolvent. It has been shown that the framework titanium can improve the adsorption ofibuprofen onto the molecular sieve and the loading amount of ibuprofen increases with theincrease of pore size of Ti-HMS.