A procedure for the synthesis of monodisperse spherical mesoporous silica particles (MSMSPs) via the controlled coagulation of silica/surfactant clusters into spherical aggregates with mean diameters of 250-1500 nm has been developed. The synthesis is fast (taking less than 1 h) because identical clusters are simultaneously formed in the reaction mixture. The results of microscopic, x-ray diffraction, adsorption and optical measurements allowed us to conclude that the clusters are ∼15 nm in size and have hexagonally packed cylindrical pore channels. The channel diameters in MSMSPs obtained with cethyltrimethylammonium bromide and decyltrimethylammonium bromide as structure-directing agents were 3.1 ± 0.15 and 2.3 ± 0.12 nm, respectively. The specific surface area and the pore volume of MSMSP were, depending on synthesis conditions, 480-1095 m(2) g(-1) and 0.50-0.65 cm(3) g(-1). The MSMSP were used to grow opal-like photonic-crystal films possessing a hierarchical macro-mesoporous structure, with pores within and between the particles. A selective filling of mesopore channels with glycerol, based on the difference between the capillary pressures in macro- and mesopores, was demonstrated. It is shown that this approach makes it possible to control the photonic bandgap position in mesoporous opal films by varying the degree of mesopore filling with glycerol.

It has been experimentally shown that water vapor thermal treatment of silicate glasses with silver ions introduced by ion exchange leads to the formation of a silver nanoparticle layer with a high packing density on the glass surface. The results of studying the morphology of samples by atomic force and electron microscopy and X-ray spectral analysis of the composition of nanoparticles, as well as the optical density and luminescence spectra in different stages of the treatment, are presented. Mechanisms explaining the processes responsible for silver nanoparticle formation upon water vapor thermal treatment on the glass surface after ion exchange are proposed.

The formation of silver nanoparticles in photothermorefractive glasses during electron irradiation and subsequent heat treatment is experimentally studied. The optical density spectra of samples at various stages of heat treatment are compared. The formation of metallic nanoparticles is shown to occur during both electron irradiation and subsequent heat treatment. Nanoparticles are localized in layers parallel to the surface. At the initial stage of nanoparticle formation, the key role is played by the appearance of a negative bulk charge in the near-surface layer in glass, which results in the field-assisted migration of positive metal ions and a characteristic layered distribution of metallic nanoparticles in the glass volume.

We have developed a colloidal crystal templating method for preparation of diamond films with 2D and 3D ordered porous structures. The technological process involved breaks down into (a) impregnation into the pores of silica colloidal crystal (opal) films of detonation nanodiamond (DND) particles from their hydrosol; (b) microwave plasma-enhanced chemical vapor deposition (MWPECVD) regrowth with diamond of pores with high DND filling; (c) Ar(+) ion dry etching of fragments of shells of coalesced diamond crystallites which form in the course of MWPECVD on the surface of the SiO(2) beads making up the outer surface of a film and (d) wet etching of the SiO(2) template in aqueous HF solution. The final samples are either connected to the substrate or free-standing films of various thicknesses having 2D or 3D ordered porous structures. The morphology of the diamond films fabricated by this method replicates the pore network of the opal template. Raman measurements confirm the diamond structure of the synthesized ordered porous material.

The potentialities of vertical anisotropic etching of (110) silicon for the fabrication of one-dimensional photonic crystal with a high refractive index contrast have been studied. It is shown that advances toward the near-IR spectral range are limited by the mechanical strength of thin silicon walls. The device structures obtained consist of 50 trenches, 114 µm deep, with 1.8-µm-thick Si walls (structure period 8 µm). Their reflectance spectra in the wavelength range 2.5–16.5 µm show good agreement with calculation results, although the main photonic band gap at λ≈28±10 µm remained outside the spectral region of measurements.