Synthesis of Protein A Conjugates with Silver Nanoparticles

The single-stage synthesis of the conjugates of protein A with silver nanoparticles is performed. The dependence of the dispersity of the prepared sols on the composition of reaction mixture is investigated by optical spectroscopy and transmission electron microscopy. The relative stability of the obtained preparations with respect to the coagulation by NaCl is estimated.     

Radiation curing of methacryloyloxyalkyl carbonates

The results of studying the radiation curing of methacryloyloxyalkyl carbonates (MC), a new type of oligomer, are presented. These oligomers are notable for their high rates of radiation curing. The radiation yield G(–M) is 2 × 10⁵ for MC and 2 × 10⁴ for triethylene glycol dimethyacrylate. The polymerization rate of MC appeared to be proportional, independent of the conversion degree, to the irradiation dose rate in the power of 0.9–1.0 (for dose rates ranging from 0.4 to 15 rad/s). In regard to the temperature dependence of the polymerization rate of MC for small conversion degrees, two temperature regions with different values of effective activation energy (18–20 kcal/mol and 2 kcal/mol, respectively) were observed. When an irradiated MC sample is being unfrozen, its polymerization occus in the region of devitrification (220–240°K). As distinct from mass polymerization, in the polymerization of MC solutions in acetone and benzol the mobility of growing chains increases so that the bimolecular termination becomes possible and the limiting conversion of double bonds is derived. Rather small irradiation doses necessary for curing MC and the proportionality of the radiation-induced polymerization rate to the dose rate make these oligomers valuable for various industrial applications.     

Kinetics of Radiation-Initiated Network Polymerization of Diethylene Glycol Bis(methacryloyloxyethyl carbonate) (OKM-2)

Non-steady-state kinetic measurements on the radiation-initiated polymerization of diethylene glycol bis(methacryloyloxyethyl carbonate) (OKM-2) were made over a wide range of conversions at various reaction temperatures. The polymer-chain propagation and termination rate constants were determined and compared with those for other monomers and oligomers.__________Translated from Khimiya Vysokikh Energii, Vol. 39, No. 5, 2005, pp. 339–342.Original Russian Text Copyright © 2005 by Kiryukhin.     

Imparting enhanced hydrophobicity to polyester fabrics: Formation of ultrathin water-repelling coatings on the fiber surface

A new technology for hydrophobization of synthetic fiber materials was described. This technological approach is based on formation of nanosized fluoropolymer coatings from solutions of low-molecularweight fraction of ultradispersed polytetrafluoroethylene and tetrafluoroethylene telomers. The mechanism of formation of protective coatings was described, and the properties of polyester materials thus modified were presented.     

Radiation-chemical synthesis and properties of tetrafluoroethylene telomeres in fluorine-containing solvents

The kinetics of radiation telomerization of tetrafluoroethylene in a series of fluorine-containing solvents was studied. A comparative analysis of their reactivity was carried out. The structure and some properties of the telomeres were studied by IR spectroscopy, thermogravimetric and elemental analysis, and electron microscopy.     

An NMR, DSC, and IR spectroscopy study of the composite formed during low-temperature postradiation polymerization of C2F4 in the presence of a 3D graphene material

By solid-state magic angle-spinning nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), and IR spectroscopy, polytetrafluoroethylene (PTFE) samples obtained by low-temperature (T = ?196°C) postradiation polymerization of tetrafluoroethylene (C₂F₄) and C₂F₄ mixtures with a 3D graphene material formed by the microwave exfoliation of graphite oxide films (MEGO) have been investigated. It has been shown that the melting point of PTFE in the PTFE-MEGO composite is 332.5°C, which is 8.8°C above the melting point of pure PTFE obtained under the same conditions. According to the measured values of specific enthalpy of melting ΔH _m (51.5 and 45.4 J/g), the degrees crystallinity (x _c) of 0.63 and 0.55 have been calculated for the pure polymer and the composite, respectively. It has been also found that none of the PTFE-containing samples examined has terminal CF₃ groups typical of PTFE prepared by conventional suspension polymerization.