Assembly of organized molecular structures in ordered mesoporosity has shown to be a very powerful approach to synthesize novel functional nanoscale materials. This approach allows rational design of a wide range of material properties, such as pore dimension, surface chemistry, stereochemistry, spatial distribution of functionality, etc. This paper discusses molecular conformations and assembly mechanisms and illustrates the principles involved in fabricating sophisticated molecular structures in the pore channels. First, an introduction highlights the important progress in synthesizing and understanding ordered mesoporous materials and in incorporating functional molecules and groups in these mesoporous materials. Next, the molecular conformations of simple alkyl chains are discussed as related to chain lengths and pore geometry. The pore size, as well as the uniformity of the porosity, can affect how the long-chain molecules are assembled. Homogeneous molecular layers can be formed in 10 nm pores. Smaller pore sizes cause pore clogging and chain entanglement. Larger pore sizes increase the degree of pore irregularity and produce disordered multilayer coating. Molecules with intermediate chain lengths form better molecular layer structures. Detailed mechanisms of monolayer formation are studied, and a stepwise growth model is proposed. The step-growth mechanism is due to the surface roughness of the pore channels and is believed to be universal in forming “monolayers” involving surfaces that are not atomically smooth. Finally, the development of multifunctional nanoporous materials is described. Examples include multifunctionalized catalysts, hierarchical size-and-shape selective nanoporous materials with tunable micropatterns and microcavities. The assembly of multifunctional groups and structures will allow us to develop sophisticated nanoscale materials with “enzyme mimic” and “biomimic” properties.

Wood tissues with ordered cellular structurecan be mineralized using the simple surfactant‐templated sol‐gel process presented here. Hierarchical porous ceramic materials that are a faithful reproduction of the biological tissue and that also contain organized nanoporous channels are obtained. The Figure shows a mineralized poplar sample after calcination (see also inside front cover).

No abstract

The work describes a simple and convenient process for highly efficient and direct DNA separation with functionalized silica-coated magnetic nanoparticles. Iron oxide magnetic nanoparticles and silica-coated magnetic nanoparticles were prepared uniformly, and the silica coating thickness could be easily controlled in a range from 10 to 50 nm by changing the concentration of silica precursor (TEOS) including controlled magnetic strength and particle size. A change in the surface modification on the nanoparticles was introduced by aminosilanization to enhance the selective DNA separation resulting from electrostatic interaction. The efficiency of the DNA separation was explored via the function of the amino-group numbers, particle size, the amount of the nanoparticles used, and the concentration of NaCl salt. The DNA adsorption yields were high in terms of the amount of triamino-functionalized nanoparticles used, and the average particle size was 25 nm. The adsorption efficiency of aminofunctionalized nanoparticles was the 4-5 times (80-100%) higher compared to silica-coated nanoparticles only (10-20%). DNA desorption efficiency showed an optimum level of over 0.7 M of the NaCl concentration. To elucidate the agglomeration of nanoparticles after electrostatic DNA binding, the Guinier plots were calculated from small-angle X-ray diffractions in a comparison of the results of energy diffraction TEM and confocal laser scanning microscopy. Additionally, the direct separation of human genomic DNA was achieved from human saliva and whole blood with high efficiency.