The microstructure, specific area, and mechanical properties of various samples of "nematically ordered" aerogels whose strands are almost parallel to each other at macroscopic distances have been studied. The strong anisotropy of such aerogels distinguishes them from standard aerogels, which are synthesized by solgel technology, and opens new possibilities for physical experiments.

Fibrin is a well-known tool in tissue engineering, but the structure of its modifications created to improve its properties remains undiscussed despite their importance, e.g. in designing biomaterials that ensure cell migration and lumenogenesis.

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The dependence of the structure of a phospholipid layer (DSPC and SOPC) adsorbed on a hydrosol substrate on the concentration of NaOH in a solution of 5-nm silica particles has been studied by X-ray reflectrometry with the use of synchrotron radiation. Profiles of the electron density (polarizability) have been reconstructed from the experimental data within a model-independent approach. According to these profiles, the thickness of the lipid film can vary from a monolayer (∼ 35Å) to several bilayers (∼ 450Å). At the volume concentration of NaOH of ∼ 0.5 mol/L, the film on the hydrosol surface is a macroscopically flat phospholipid membrane (bilayer) with a thickness of ∼ 60Å and with areas of 45 ± 2 and 49 ± 3Å 2 per DSPC and SOPC molecule, respectively. * tikhonov@kapitza.ras.ru

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The structure of the adsorbed layer of alkali ions on the surface of colloidal silica solutions with a particle size of 27 nm has been studied by reflectometry and diffuse scattering of synchrotron radiation with a photon energy of about 71 keV. Electron density profiles in the direction perpendicular to the surface have been reconstructed from experimental data and spectra of the correlation function of heights in the surface plane have been obtained. The revealed deviation of the integral and frequency characteristics of the roughness spectra of the silica sol surface from predictions of the capillary-wave theory is of a fundamental character. This deviation is due to the contribution from roughnesses with low spatial frequencies ν < 10 −4 nm 1 and to the interference of diffuse scattering from different layer interfaces of the surface structure.

The ordering of a multilayer consisting of DSPC bilayers on a silica sol substrate is studied within the model-independent approach to the reconstruction of profiles of the electron density from X-ray reflectometry data. It is found that the electroporation of bilayers in the field of anion silica nanoparticles significantly accelerates the process of their saturation with Na + and H2O, which explains both a relatively small time of formation of the structure of the multilayer of (1 − 7) × 10 5 s and 13% excess of the electron density in it.

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