Masaaki Yanagi

Functionalized mesoporous dendritic silica hybrids as base catalysts with volatile organic compound elimination ability

A post-synthetic process to create functionalized mesoporous dendritic silicas with a high density of tertiary amino groups is presented. Polyamidoamine periodic dendrimers up to the second generation were grown inside the channels of mesoporous hybrids. The results demonstrate that the novel polyamidoamine dendritic mesoporous benzene-silicas with highly hydrophobic crystal-like pore wall structures and the polyamidoamine dendritic mesoporous silicas with amorphous pore wall structures are very effective catalysts in Knoevenagel condensation due to enhanced hydrophobic interactions in the pore framework system, and also are effective adsorbents for volatile organic compound (VOC) removal.

Self-assembly of cubic phenylene bridged mesoporous hybrids from allylorganosilane precursors

The synthesis of three-dimensional (Pm3n) cubic phenylene-bridged hybrid mesoporous silica material using a novel allylorganosilane precursor 1,4-bis(triallylsilyl)phenylene and cetyltrimethylammoniumchloride (C16TMACl) as a structure-directing agent in acidic medium is presented. Sulfonic acid functionalized derivatives of these materials are effective in Friedel–Crafts acylation reactions and in controlling the atmosphere emission of volatile organic compounds, which are responsible for ground level ozone, air toxicity and smog.

An alternate approach to the preparation of versatile sulfonic acid functionalized periodic mesoporous silicas with superior catalytic applications

A novel approach for the synthesis of sulfonic acid functionalized periodic mesoporous silicas via covalent attachment of 2-(3,4 epoxycyclohexyl)ethyltrimethoxysilane or 3-glycidoxypropyltrimethoxysilane followed by reaction with sulfite ions and mild hydrochloric acid is presented. The materials demonstrated superior catalytic performance in esterification, acylation, and condensation reactions. The hydrophobic nature along with the crystalline pore wall structure of these materials are advantageous in increasing reaction rates by altering local water concentration and helpful in adjusting the modest active sites and surface properties. The materials also showed the higher stability and easily recyclable.