ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Study of the velocity of swelling of the sodium salt of carboxymethylcellulose in aqueous solutions of electrolytes

J. Polavka, L. Lapčík, V. Kellö, L. Hebort, and M. Vyšný

Department of Physical Chemistry, Slovak Technical University, CS-812 37Bratislava

Abstract: The influence of aqueous solutions of electrolytes on the velocity of swelling of the sodium salt of carboxymethylcellulose (NaCMC) was studied. Carboxy­methylcellulose was partially plastified by 13 % addition of glycerol (referred to the mass of NaCMC). It has been found that the transport process of diffusion of the solution of electrolyte into the solid sample obeys the Fick's law. The measured apparent mean diffusion coefficients D of the investigated systems are in the interval (1.5 x 10^-10 m² s^-1; 9.5 x 10^-10 m² s^-1  ). Their values decrease with increasing concentration of the solution of electrolyte. Similarly, they also decrease with the magnitude of charge and radius of the solvated ions. An analogous trend was also exhibited by the measured values of molar conductivities. The values of activation energy of swelling Es and isothermal activation volume work RA6s are in the intervals (15 x 10³ J mol^-1 ; 25 x 10³ J mol^-1 ) and ( 8 x 10³ J mol^-1; 12 x 10³ J mol^-1).

Full paper in Portable Document Format: 385a619.pdf

Chemical Papers 38 (5) 619–628 (1984)