14—THE ADSORPTION OF WATER BY WOOL Part IV—THE INFLUENCE OF COMBINED ACID ON THE AFFINITY OF WOOL FOR WATER

Abstract

The water-adsorption capacity of acid-containing wools is less than that of untreated wool at corresponding relative humidities, except, in certain cases, at humidities approaching saturation. Of the eight acids examined, the greatest effect is produced by picric acid and the least by sulphuric acid, the former being specially effective because the nitro groups are able to co-ordinate with —OH and =NH groups, as well as with the —NH⁺ ₃ ions of salt linkages, which are normally heavily hydrated. Only a small part of the fall in regain is due to back-titration of the —COO⁻ ions of salt linkages.