Synthesis of organic–inorganic sorbent containing phenylboronic acid as glucose-binding ligand

A copolymer with N-allylaminophenylboronic acid has been synthesized from a water-soluble N-vinylpyrrolidone–acrolein diethyl acetal copolymer. Immobilization of the obtained copolymer on silica gel afforded an organic–inorganic sorbent capable of sorbing glucose from model solutions.     

Synthesis of complexes of N-vinylpyrrolidone–vinylamine or N-vinylpyrrolidone–allylamine containing macrocyclic polyligand 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate (DOTA) with gallium-68 isotope and estimation of their in vivo distribution

Russian Chemical Bulletin - A method for radiolabeling the water-soluble N-vinylpyrrolidone copolymers with N-vinyl- and N-allylamine containing bifunctional chelation unit...     

Influence of the molecular weight and structural organization of cationic polyelectrolytes on protein flocculation

A complex on-line procedure based on combined use of integral (spectroturbidimetry) and differential (nephelometry) light scattering methods was applied to studying the size and formation kinetics of dispersed particles in solutions containing a protein and synthetic cationic soluble polymers. The influence of pH of the medium and of the molecular weight and structural organization of polymers on the floccule size and flocculation kinetics was evaluated.     

The effect of chiral doping in achiral smectic liquid crystals on the de Vries characteristics: smectic layer thickness,electro-optics and birefringence

An addition of chiral dopant to two achiral smectic liquid crystals from a homologous series, by varying weight percentages with known low values of layer shrinkage, leads to chiral smectic-C* phase with a finite value of the spontaneous polarisation. The electro-optical response arising from changes in the induced apparent tilt angle brought about by a weak electric field in the SmA* phase gives rise to power law dependency on the reduced temperature. The critical exponent γ of the power law depends on the dopant concentration but its value is found to be greater than the typical value of 1.32. This implies that the short-range correlation extends from two dimensions to three dimensions in these materials in the SmA phase. The layer thickness of smectic layers in the guest–host system remains unaltered up to the 15 wt % addition of the chiral dopant to two achiral smectics. The system thus retains the low layer shrinkage of the achiral smectic as evidenced by measurements of the layer thickness from X-ray scattering and thickness measurements from optical interferometry. Results on the optical birefringence and the apparent tilt angle lead us to the conclusion of having successfully obtained chiral smectic materials for devices with de Vries characteristics by chiral doping.     

Phenomenon of apokamp discharge

A new phenomenon has been discovered where a bend of a plasma channel becomes of a source of one or several diffuse jets that have a length (at a given voltage) up to 4–6 cm and are directed across the plasma channel at a pulse-periodic spark discharge in air under normal conditions. The phenomenon is called apokamp discharge (apokamp). The spectrum of radiation of the apokamp includes primarily the bands of electron-vibrational transitions of the second positive system of molecular nitrogen. The conditions of the formation of apokamp have been experimentally revealed and it has been established that it consists of plasma bunches moving from the plasma channel at each pulse at a velocity of about 220 km/s.     

IR spectra and structure of poly(vinylamide) complexes with hydrogen peroxide

The IR spectra of anhydrous thin films of hydrogen peroxide complexes with cyclic and aliphatic poly(N-vinylamides) have been studied. Splitting of a band due to stretching vibrations of C=O groups in the IR spectra of the poly(vinylcaprolactam) complex is accounted for by the resonance interaction of v _C=O vibrations of two monomer units linked by a hydrogen peroxide molecule. The formation of a N-H···O=C intramolecular hydrogen bond between neighboring polymer units is responsible for the observed low absorption of hydrogen peroxide by N-vinylamide polymers and copolymers. The energy E _H of hydrogen bonds formed between hydrogen peroxide and polymer chain fragments has been estimated by quantum-mechanical calculations. Depending on the complex structure, the value of E _H varies from 13 to 29 kJ/mol.