Physico-chemical studies of polymeric carriers

Summary Acid-base titration of poly/N-vinylpyrrolidone-co-maleic acid/ alternating copolymer was followed by densitometry in order to detect chain conformation transition found potentiometrically. Apparent molar volume () values of the polymer were calculated for step-by-step titrated polymer samples. The effect of copolymer concentration on the conformational transition was also determined by measuring water diluted samples of each titration step. A continous increasing of was found in the case of KOH titrant, both in titration and in dilution. When NaOH was applied as a titrant, a very different profile was obtained. A minimum in vs. concentration occured in the vicinity of the half neutralization point of the dibasic polyacid.     

Correction of spectrum of turbulence in the measurement by a conduction anenometer

The equivalent spectral characteristic of the sensor of a conduction anenometer with external magnetic field is determined. Its use is demonstrated for the correction of the spectrum of turbulent velocity fluctuations.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 31, No. 2, pp. 243–247, August, 1976.