Sorption of Dissolved Substances

Upon contact with aqueous solutions, cellulosic materials behave as potymeric sorbents extracting the dissolving substances from the solutions. Among the various solutions, aqueous solutions of alkalis, dyes and some other substances are often used for processing of cellulose. The sorption of dissolved substances from aqueous solutions was studied at 25°C using the cellulose samples with various structural characteristics. 

The research was shown, the sorption value of sodium, potassium and lithium hydroxide by a cellulose sample rises linearly with increasing of the concentration of the hydroxide up to 2 mol/L. Furthermore, the main structural factor promoting the sorption of the hydroxide is the degree of amorphicity of cellulose, T(Fig. 7.34). 

Dependence of sorption value on concentration of hydroxide solutions for some cellulose samples. 

In the textile industry, the quality of mercerization process is usually estimated by means of sorption of barium hydroxide by cellulose from saturated solution. A characteristic of the process quality is a barium index BI = 100% where A and A  

As follows from investigations, the amorphicity degree of cellulose also affects the sorption of some other dissolved substances such as dyes (e.g., brilliant green], iodine, etc. 

---