ISSN:
0098-1273
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The surface tension γ of four copolymer latices, of their respective serums, and of aqueous solutions of dispersant alone were measured at various dilutions. By extrapolating the surface excess of dispersant (calculated by the Gibbs adsorption equation) both at the aqueous solution surface and at the serum surfaces to 1/c = 0 (c being the bulk concentration of dispersant) the same limiting site area Alim per adsorbed molecule was determined. Amounts of dispersant adsorbed by copolymer particles at various dilutions were determined from differences between the known total concentrations of the dispersant in latex and in serum at the same γ. These values were then extrapolated to the maximum adsorption at 1/c = 0 in latex. The surface area of copolymer particles was determined therefrom by using Alim. The average particle radius calculated this way agrees reasonably well with electron microscope measurements. Thus it appears that the method for determining latex particle surface area by surfactant titration may be calibrated by means of the Gibbs adsorption equation, provided one uses Alim and not the site area at the critical micelle concentration of dispersant.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1976.180140808
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