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New restricted access materials based on microporous hypercrosslinked polystyrene have been developed. The materials are aimed to use as packings for solid-phase extraction cartridges to isolate low-molecular-weight analytes from biological fluids (for instance, blood plasma or serum). Two features distinguish these polymers from all known restricted access materials. The first one consists of the microporous hypercrosslinked polystyrene that not only exclude proteins from the sorbent phase but also do not adsorb them on the bead outer surface, and so they do not cause coagulation of blood protein components. Therefore, these materials do not require any chemical modification. The second distinguishing feature is the ability of hypercrosslinked sorbents to take up a wide variety of polar and nonpolar organic compounds. The sorbents were obtained in the form of beads of 60-70 μm in diameter by cross-linking styrene copolymers with 1, 2, and 3% divinylbenzene with monochlorodimethyl ether to 100, 150, and 200% cross-linking degree. The sorbents exhibit all typical properties of hypercrosslinked networks. They do not take up albumin, the major blood protein, and cytochrome C, representative of smaller protein molecules, but are capable of adsorbing drugs, vitamins, and phenyl carboxylic acids (markers of sepsis) from model aqueous solutions.

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A series of flexible hydrophobic siloxane aerogels were obtained by the hydrothiolation reaction in supercritical CO2 medium in the presence of a co‐solvent. The effect of the co‐solvent nature on the aerogel morphology and physico‐mechanical properties were studied. n‐Pentane, a propane/n‐butane mixture, CH2Cl2, dimethyl ether (DME) and 1,1,2‐trichloro‐1,2,2‐trifluoro‐ethane were used as the co‐solvents. The morphology of aerogel particles was studied by SEM. In the case of n‐pentane, propane/n‐butane mixture, CH2Cl2, or DME as the co‐solvents, aerogels with a density of 0.18–0.21 g/cm3 and an average particle size of 0.15‐5.35 μm were obtained. Depending on the morphology, the mechanical properties of aerogels change in the range of 0.2–0.75 MPa (Young's modulus), 38–68 % (compressibility) and 0.11–0.42 MPa (stress rupture). In the case of 1,1,2‐trichloro‐1,2,2‐trifluoro‐ethane as the co‐solvent, the aerogel with an inhomogeneous structure was obtained. All the aerogels studied have a large water contact angle in the range of 142°‐151°.