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[en] The swelling of macromolecules in a good solvent arises from excluded volume interactions between pairs of monomer units on a single polymer chain. As the polymer concentration increases, the excluded volume effect is screened and diminished, and in the limit of the bulk polymer, the conformation of a single chain can be described as an unperturbed random coil as originally predicted by Flory and verified by numerous SANS measurements. Since the early 1970s, developments in polymer solution theory involving the application of scaling methods have led to an upsurge of interest in this area, although only one systematic experimental study of chain dimensions as a function of concentration, c, has been hitherto attempted. That study showed that for polystyrene in CS2 the radius of gyration R/sub g/ varied as c/sup -0.25/ in apparent agreement with the then current prediction of scaling laws. Since that time, there have been reports of many violations of scaling laws which should be valid in principle only in the asymptotic limit of infinite molecular weight
[en] Present article is devoted to study of spectral characteristics and properties of polymer material surface using in micro fluidic devices. The analysis of some spectral characteristics and properties of polymer material surface using in micro fluidic devices before and after plasma processing has been conducted. On the basis of carried out studies it has been defined that processing by high frequency plasma in argon medium leads to change of polymer material surface.
[en] A radiation curable coating composition comprising (i) an adduct of a monoethylenically unsaturated carboxylic acid or hydroxy alkyl ester thereof with an anhydride containing at least 3 carbon atoms and selected from monoepoxides, lactones, and mixtures thereof, the adduct containing an average of at least 1 mole of anhydride per mol of hydroxy ester and an average of at least 2 moles of anhydride per mol of acid, (ii) a polyacrylate