Porous single crystals of Cr 2 O 3 and Co 3 O 4 templated by mesoporous silicas, SBA-15 and KIT-6, have been fabricated. Specimens at different stages of crystal growth were characterized by using XRD and high-resolution transmission electron microscopy. The final products of oxide porous single crystals were also characterized by nitrogen adsorption/desorption experiments. A multiseed formation mechanism can eventually be established. The present investigation revealed that the original mesostructures in SBA-15 and KIT-6 were negatively replicated by the crystals of oxides, and therefore, the dimension of the building blocks (nanorods or nanowires) in the porous crystals of oxides depends on the pore diameter of the silica. It was also found that a mesopore system, regarded as a nanoreactor, had a significant influence on the size and morphology of produced oxide particles and on the route and temperature of the crystallization.

Following the designed synthesis of mesoporous silica materials, such as MCM-41 and MCM-48 with small pore sizes (2-4 nm), [1] which are templated by quaternary ammonium cationic surfactants with different chain lengths, numerous ordered large-pore (8-30 nm) mesoporous silicas, such as SBA-15 and SBA-16, [2] have been synthesized by using blockcopolymer nonionic surfactants as templates. Recently, a series of ordered rodlike mesoporous carbon materials have been synthesized by using mesoporous silica materials with a large range of pore diameters, such as MCM-48 and SBA-15, as hard templates.[3] Furthermore, it has been reported that new two-dimensional hexagonal mesoporous carbon materials with connected tubelike pores can be synthesized with large-pore mesoporous silica SBA-15. [4] The mesoporous material, with a bicontinuous cubic structure of Ia3 d symmetry, is one of the most interesting materials among the varied mesoporous silica materials reported to date. The independent and intricately interwoven three-dimensional networks of mesoporous channels are much more attractive for use as adsorbents and catalyst supports than the two-dimensional channels of hexagonal mesoporous silica MCM-41 and SBA-15. In spite of the recent discovery of large-pore cubic Ia3 d mesoporous silica, [5a-c] the hydrothermal method for synthesizing a highly ordered material has not been fully developed. Therefore, the devel-

The fabrication of meso/macroporous monoliths by partial fusion of mesoporous silica spheres with the use of the pulsed current processing (PCP) method was demonstrated. Mesoporous silica spheres have been prepared by evaporation-driven surfactant templating in microdroplets. The PCP method can simultaneously subject powder bodies to a rapid temperature increase and a compressive stress. By keeping the fusing temperature low, it was possible to form a continuous body where the particles were connected by necks formed at the surface of the particles, while the mesoporous structure was retained within the particles. The structure, porosity, necking, and mechanical properties of the fused mesoporous particles are strongly dependent on the applied pressure and temperature. This novel approach allows for flexible and independent tailoring of the bimodal pore structure together with rapid production of mechanically stable monoliths of arbitrary shape and is of interest in various applications, e.g., as membranes, sensors, catalyst support, slow-release agents, chromatography, and groundwater treatment.

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Here, we report the design of a hybrid inorganic/organic mesoporous material through simultaneous pore engineering and hydrophobic surface modification of the intramesochannels to improve the uptake of superparamagnetic maghemite nanocrystals via impregnation techniques. The mesoporous material of the SBA-15 type was functionalized in situ with thiol organo-siloxane groups. Restricting the addition of the thiol organo-siloxane to 2 mol % yielded an inorganic/organic hybrid material characterized by large pores and a well-ordered hexagonal p6mm mesophase. The hydrophobic surface modification promoted the incorporation of 7.5 nm maghemite (gamma-Fe2O3) nanocrystals, prepared through temperature-controlled decomposition of iron pentacarbonyl in organic solvents. The hydrophobic, oleic acid capped superparamagnetic maghemite nanocrystals were incorporated into the porous network via wet impregnation from organic suspensions. Combining diffraction, microscopy, and adsorption data confirmed the uptake of the nanocrystals within the intramesochannels of the silica host. Magnetization dependencies on magnetic field at different temperatures show a constriction in the loop around the origin, which indicates immobilization of maghemite nanocrystals inside the thiol-functionalized silica host.

Following the designed synthesis of mesoporous silica materials, such as MCM-41 and MCM-48 with small pore sizes (2-4 nm), [1] which are templated by quaternary ammonium cationic surfactants with different chain lengths, numerous ordered large-pore (8-30 nm) mesoporous silicas, such as SBA-15 and SBA-16, [2] have been synthesized by using blockcopolymer nonionic surfactants as templates. Recently, a series of ordered rodlike mesoporous carbon materials have been synthesized by using mesoporous silica materials with a large range of pore diameters, such as MCM-48 and SBA-15, as hard templates.[3] Furthermore, it has been reported that new two-dimensional hexagonal mesoporous carbon materials with connected tubelike pores can be synthesized with large-pore mesoporous silica SBA-15. [4] The mesoporous material, with a bicontinuous cubic structure of Ia3 d symmetry, is one of the most interesting materials among the varied mesoporous silica materials reported to date. The independent and intricately interwoven three-dimensional networks of mesoporous channels are much more attractive for use as adsorbents and catalyst supports than the two-dimensional channels of hexagonal mesoporous silica MCM-41 and SBA-15. In spite of the recent discovery of large-pore cubic Ia3 d mesoporous silica, [5a-c] the hydrothermal method for synthesizing a highly ordered material has not been fully developed. Therefore, the devel-

The purpose of this work is to study the kinetics of self-assembly in the formation mechanism of anionic templated mesoporous solids (AMS-n) during the first few seconds of the synthesis as well as to demonstrate the use of alternating ion current (AIC) conductivity measurements to follow the self-assembly in complex hybrid systems. The formation of different AMS-n caged-type mesostructures through the delayed addition of the silica source is demonstrated and explained in terms of the interaction between the co-structure-directing agent (CSDA) and the oppositely charged surfactant headgroup regions. Our findings, supported by transmission electron microscopy, 29Si magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, dynamic light scattering (DLS) measurements, and powder X-ray diffraction suggest that the interaction of the CSDA with the surfactant headgroup occurs within seconds after its addition to the synthesis gel leading to interaction between the polymerizing CSDAs and the oppositely charged micelle and to an increase in the micelle-CSDA aggregate size. Both DLS and AIC measurements agree that this process occurs within the first 1000 s after addition of the CSDA to the synthesis gel at room temperature. In addition to the mechanistic study it was found that the intermediate materials are comprised of a three-layer entity. Time-dependent 29Si MAS NMR studies reveal that an organo-silica layer forms around the micelles prior to a condensed outer inorganic shell of silica.

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