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Highly ordered 3D-hexagonal mesoporous silica HMS-3 has been synthesized under alkaline condition at 277 K using tetraethyl orthosilicate as the silica source and cetyltrimethylammonium bromide as the structure-directing agent. Powder X-ray diffraction and HR TEM results revealed a 3D-hexagonal pore structure for this HMS-3 mesophase. Electron microscopy image analysis further suggested a uniform spherically packed nanoparticle morphology having a dimension of 200−300 nm for this mesoporous material. Nitrogen adsorption results showed a type IV isotherm with well-defined mesopores of ca. 2.2 nm dimension having very high surface area (1353 m2g−1) and moderately good pore volume (0.63 cc g−1). A very high cross-linking framework has been revealed from the high concentration of Q4species as seen from 29Si MAS NMR. This material showed considerably high H2adsorption capacity at 77 K under 1 bar atmospheric pressure vis-à-vis related pure silica MCM-41 (ca. 38% enhancement). At a pressure of 40 bar, the amount of H2adsorbed was ca. 2.0 wt %, which is comparable to good H2storage materials known in the literature. 3D-hexagonal pore openings with interconnected cagelike mesopores, very high surface area, and spherically packed nanoparticle morphology could be responsible for very high H2adsorption capacity of HMS-3 over other related mesoporous silica based materials.

A highly ordered 2D‐hexagonal mesoporous silica material is functionalized with 3‐aminopropyltriethoxysilane. This organically modified mesoporous material is grafted with a dialdehyde fluorescent chromophore, 4‐methyl‐2,6‐diformyl phenol. Powder X‐ray diffraction, transmission electron microscopy, N2sorption, Fourier transform infrared spectroscopy, and UV‐visible absorption and emission have been employed to characterize the material. This material shows excellent selective Zn2+sensing, which is due to the fluorophore moiety present at its surface. Fluorescence measurements reveal that the emission intensity of the Zn2+‐bound mesoporous material increases significantly upon addition of various concentrations of Zn2+, while the introduction of other biologically relevant (Ca2+, Mg2+, Na+, and K+) and environmentally hazardous transition‐metal ions results in either unchanged or weakened intensity. The enhancement of fluorescence is attributed to the strong covalent binding of Zn2+, evident from the large binding constant value (0.87 × 104M−1). Thus, this functionalized mesoporous material grafted with the fluorescent chromophore could monitor or recognize Zn2+from a mixture of ions that contains Zn2+even in trace amounts and can be considered as a selective fluorescent probe. We have examined the application of this mesoporous zinc(II) sensor to cultured living cells (A375 human melanoma and human cervical cancer cell, HeLa) by fluorescence microscopy.

A new extra large pore organic–inorganic hybrid silicoaluminophosphate (HSAPO-1) has been synthesized hydrothermally at 443 K by using 4,4′-trimethylene-dipiperidine (TMDP) as the single molecule template and bis(triethoxysilyl)ethane (BTEE) as the hybrid silicon precursor at almost neutral pH. The use of the organic-free silica precursor tetraethyl orthosilicate (TEOS) instead of BTEE in an otherwise identical synthesis gel also leads to the formation of a novel microporous silicoaluminophosphate (SAPO-L). Powder XRD, TEM-EDS, N2sorption, TGA, CHN and ICP-AES chemical analysis, 13C, 29Si, 27Al and 31P MAS NMR and FTIR spectroscopic tools were employed to characterize these novel materials.