A critical review of adsorption methods that are currently used in the characterization of ordered organic−inorganic nanocomposite materials is presented, and the adsorption methodology that is potentially useful for this characterization, but has not yet been applied, is discussed. The ordered organic−inorganic nanocomposites include surface-functionalized ordered mesoporous materials (OMMs) with siliceous frameworks (synthesized either via postsynthesis surface modification or via direct co-condensation method), periodic mesoporous organosilicas, and surfactant-containing OMMs. This review covers the methods for determination of the specific surface area and pore volume. The available methods for mesopore size analysis are critically compared and evaluated, with special emphasis on the recent developments related to the application of advanced computational methods for studying adsorption in porous media and to the direct modeling of adsorption using highly ordered surface-functionalized OMMs as model a...

Gas adsorption characterization of ordered organic-inorganic nanocomposite materials

Mesoporous organic-inorganic hybrid materials, a new class of materials characterized by large specific surface areas and pore sizes between 2 and 15 nm, have been obtained through the coupling of inorganic and organic components by template synthesis. The incorporation of functionalities can be achieved in three ways: by subsequent attachment of organic components onto a pure silica matrix (grafting), by simultaneous reaction of condensable inorganic silica species and silylated organic compounds (co-condensation, one-pot synthesis), and by the use of bissilylated organic precursors that lead to periodic mesoporous organosilicas (PMOs). This Review gives an overview of the preparation, properties, and potential applications of these materials in the areas of catalysis, sorption, chromatography, and the construction of systems for controlled release of active compounds, as well as molecular switches, with the main focus being on PMOs.

Silica-based mesoporous organic-inorganic hybrid materials.

The area of periodic mesoporous materials prepared by cooperative assembly in the presence of amphiphile molecules underwent dramatic growth. Among the silica-based materials, many types may be reg...

Periodic Mesoporous Silica-Based Organic−Inorganic Nanocomposite Materials

Site Heterogeneous Catalysts: Strategies, Methods, Structures, and Activities Christophe Copeŕet,*,† Aleix Comas-Vives,† Matthew P. Conley,† Deven P. Estes,† Alexey Fedorov,† Victor Mougel,† Haruki Nagae,†,‡ Francisco Nuñ́ez-Zarur,† and Pavel A. Zhizhko†,§ †Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1−5, CH-8093 Zürich, Switzerland ‡Department of Chemistry, Graduate School of Engineering Science, Osaka University, CREST, Toyonaka, Osaka 560-8531, Japan A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str. 28, 119991 Moscow, Russia

Surface Organometallic and Coordination Chemistry toward Single-Site Heterogeneous Catalysts: Strategies, Methods, Structures, and Activities

The disclosure relates to methods of printing indicia on a substrate using a tip array comprised of elastomeric, compressible polymers. The tip array can be prepared using conventional photolithographic methods and can be tailored to have any desired number and/or arrangement of tips. Numerous copies (e.g., greater than 15,000, or greater than 11 million) of a pattern can be made in a parallel fashion in as little as 40 minutes.

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Polymer pen lithography

Disilazane reagents of type HN(SiR1R22)2 carrying organic substituents R1,2 = H, Me, Ph, n-Bu, n-Oct, Vin (Vin = vinyl) of varying longitudinal and lateral extension are reacted with high quality MCM-41 samples of different pore sizes, i.e., effective pore diameters of 2.8 and 3.8 nm according to the BJH pore size analysis of the desorption branch. The reaction of the standard silylating reagent hexamethyldisilazane, HN(SiMe3)2, is shown to be controlled by the amount of added silylamine and the contact time, resulting in effective pore size engineering. Calculations from elemental analysis revealed that the degree of silylation (silylation efficiency) and hence the surface hydroxyl consumption depend on the steric bulk/shape of the groups R. The surface coverage varies from 0.74 to 1.85 silyl groups/nm2. The sterically least demanding tetramethyldisilazane, HN(SiHMe2)2, is the most efficient silylating reagent, while silyl groups with bulky phenyl substituents produce the lowest surface coverage featurin...

Thomas Röser

Papers

Surface Characterization and Functionalization of MCM-41 Silicas via Silazane Silylation