State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050, People’s Republic of China; Department of Materials Science and Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200233, People’s Republic of China; and National Engineering Research Center for Nanotechnology, 28 East Jiangchuan Road, Shanghai 200241, People’s Republic of China

On the synergetic catalytic effect in heterogeneous nanocomposite catalysts.

Mesoporous silica nanoparticles as nanocarriers.

A novel boronic acid functionalized mesoporous silica, which holds the attractive features of high surface area and large accessible porosity, was developed to enrich glycopeptides. This is the first time that mesoporous material has been introduced into glycoproteome. In comparison to direct (traditional) analysis, this novel method enabled 2 orders of magnitude improvement in the detection limit of glycopeptides. The unbiased nature of organo-boronic acid groups also made this method applicable to all kinds of glycopeptides regardless of their sizes, structures, and hydrophilicities.

Highly specific enrichment of glycopeptides using boronic acid-functionalized mesoporous silica.

Highly ordered aluminum-containing mesoporous silica (Al-MCM-41) was prepared using attapulgite clay mineral as a Si and Al source. Mesoporous complexes embedded with CuO nanoparticles were subsequently prepared using various copper sources and different copper loadings in a direct synthetic route. The resulting CuO/Al-MCM-41 composite possessed p6mm hexagonally symmetry, well-developed mesoporosity, and relatively high BET surface area. In comparison to pure silica, these mesoporous materials embedded with CuO nanoparticles exhibited smaller pore diameter, thicker pore wall, and enhanced thermal stability. Long-range order in the aforementioned samples was observed for copper weight percentages as high as 30%. Furthermore, a significant blue shift of the absorption edge for the samples was observed when compared with that of bulk CuO. H2-TPR measurements showed that the direct-synthesized CuO/Al-MCM-41 exhibited remarkable redox properties compared to the post-synthesized samples, and most of the CuO nanoparticles were encapsulated within the mesoporous structures. The possible interaction between CuO and Al-MCM-41 was also investigated.

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CuO nanoparticles encapsulated inside Al-MCM-41 mesoporous materials via direct synthetic route

Layered silicates, whose frameworks are composed of only SiO4 tetrahedra, provide many interesting properties through covalent modification of interlayer SiOH/SiO−groups. This review summarizes covalent modifications of layered silicates, such as magadiite, kanemite, kenyaite, layered octosilicate (RUB-18 or ilerite), and layered zeolitic materials (or their precursors). Interlayer silanol groups can be modified with various silylation reagents including alkyl, amino, and thiol groups. Anion exchangeable layered hybrids are obtained by immobilization of imidazolium groups, and are exfoliated into monolayer nanosheets in water. New crystalline silicate structures are obtained by precisely designed silylation of octosilicate. Silanol groups of layered silicates are esterified with some alcohols. Condensation of silanol groups in the same layer is effective for intercalation of bulky nonionic surfactants. Topotactic conversion through interlayer condensation of silanol groups leads to the formation of 3-D zeolite structures. Expansion of the pores of zeolites is achieved by pillaring through covalent modification. These covalent modifications of layered silicates make it possible to design for practical applications.

Materials design of layered silicates through covalent modification of interlayer surfaces

Direct synthesis (co-condensation reaction) and post-synthesis reaction (grafting) are combined for the first time to efficiently fabricate bifunctionalized ordered mesoporous materials (OMMs). Ethylenediamine-containing OMMs (ED-MCM-41) were first synthesized via direct synthesis and then further modified by the phenyl (PH) group in a supercritical fluid (SCF) medium via grafting reaction, resulting in OMMs with ED and PH groups (PH-ED-MCM-41). X-ray diffraction (XRD) patterns, N2 sorption properties, transmission electron microscopy (TEM), 29Si and 13C magic angle spinning (MAS) NMR, chemical analysis, and hydrothermal treatment were used to characterize the bifunctionalized materials. Experiments show that bifunctionalized OMMs can be efficiently prepared by modifying the directly synthesized monofunctionalized OMMs via grafting reaction in a supercritical fluid medium. Both functional groups are distributed uniformly at the surfaces. The advantage of bifunctionalized OMMs over monofunctionalized OMMs was illustrated by introducing thiol groups into ED-MCM-41 materials and the subsequent formation of CdS nanocrystals inside thiol- and ED-functionalized MCM-41 (HS-ED-MC-41). Because of the variety of the functional groups that can be introduced into OMMs by direct synthesis or post-synthesis reaction, it is expected that the present strategy could provide a generally applicable approach to the design of OMMs with two functional groups.

Z.-L. Hua

Papers

Synthesis and Characterization of Bifunctionalized Ordered Mesoporous Materials