АННОТАЦИЯ
The molecular dynamics parameters and hydrophobicity of the surface of Silasorb silica gel particles covalently modified with alkyl CnH2n + 1 groups differing in length (n = 2, 8, 18) were studied by electron paramagnetic resonance using spin probes of different structures, sizes, and electrical charges. It has been shown that the hydrocarbon shells of the silica gel microparticles in liquid suspensions provide high rotational and conformational mobility and a very high hydrophobicity of the environment for the incorporated molecules. Some regularities in the dependences of the rotational mobility, orientation ordering, and environmental hydrophobicity have on the hydrocarbon shell thickness have been established for spin probes of different structures: a radical containing an aromatic residue which models a fluorescent sensor molecule, lipid spin probes sensitive to the microviscosity and orientation ordering, and positively charged probes sensitive to electrostatic interactions. It has been found that the rotational mobility of the lipid spin probes sharply decreases upon removing the solvent and recovers in the presence of water or water-ethanol vapors. The high values of rotational mobility and environmental hydrophobicity for the spin probes located in the hydrocarbon shell of the Silasorb particles, which are dispersed in suspensions or in the solvent vapors, allow one to conclude that these microparticles can be perspective matrices for molecular optical chemosensors for analytes in solutions or the gas phase. © 2011 Pleiades Publishing, Ltd.
ЦИТАТА
Ionova, I.V. Adsorption and molecular dynamics of spin probes on hydrophobizated silica gel microparticles: EPR spin-label study / I.V. Ionova, M.V. Alfimov, V.A. Livshits // Nanotechnologies in Russia. – 2011. – Т. 6. – № 1-2. – P. 88-95
