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ИСТИНА ЦЭМИ РАН |
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As early as 1969, Davankov, Rogozhin and Tsyurupa applied and obtained patents for making “Macronet isoporous” polystyrene which proved to become the first representative of a whole new class of materials, hypercrosslinked polymeric networks. The general principle of their preparation reads: Formation of a highly expanded 3D rigid open-type network in the presence of large amounts of a thermodynamically good solvent. Basic distinguishing features of these polymers are: highly developed microporous structure with apparent Ssp up to 1000-2000 m2/g, increasing in volume (swelling) with any type of liquid media irrespective of their affinity to the polymer, extremely high adsorption ability toward both polar and nonpolar compounds. These rather unusual properties were soon recognized as essential for producing on an industrial scale a series of novel largely universal adsorbing materials. They found wide application in many industrial adsorption technologies. Not less interesting and efficient is their use in the capacity of a stable matrix for the preparation of various composites by incorporation of nanodispersed particles with, e.g., catalytic or magnetic properties. Moreover, the new materials opened ways to the development of some principally new processes and applications. Among them, to mention are: (I) manufacturing (also in Russia) of new hemosorbents with an unprecedented hemocompatibility and the ability of removing the whole complex of toxic blood contaminants, which already saved life to hundreds of patients with sepsis and acute poisonings; (ii) developing of principally new approach to separating mineral electrolytes (acids, bases and salts) according to the size of their hydrated ions, unique features of the method are that its productivity rises with the concentration of the initial mixture increasing and that the separated components experience significant self-concentration during their passage through the column with the nanoporous neutral polymer. It was further shown that it is possible to involve each phenyl ring of the initial polystyrene chains into the formation of more than one, in fact - up to five, crossbridges in the final hypercrosslinked network. Such products with the ultimate crosslinking density (200-500%) exhibit expressed ability to enter electronic interactions with polar and aromatic groups of numerous analytes, in addition to the usual hydrophobic interactions. Using the enhanced network density of such sorbents, it was possible to develop new “restricted access materials, RAMs” that efficiently adsorb small polar and non-polar molecules while rejecting proteins and other larger molecules. They selectively extract traces of target analytes directly from complex matrixes, as human plasma, thus facilitating analysis of drugs, their metabolites and sepses markers.