The Interaction of Hair Fibers with Alkali Bromide Solutions

The study investigates how hair fibers interact with alkali bromide solutions, revealing that these salts are absorbed by hair in a manner dependent on the salt's activity in the solution, and that the presence of salt increases water absorption in hair. The internal molality of the solution within the hair fiber is greater than the external molality, suggesting strong localized absorption forces. The absorption process disrupts the fiber's physical structure, and both absorption rates and equilibrium uptakes decrease with higher temperatures. The study suggests that existing models do not adequately describe the absorption process, indicating the need for a more complex model that accounts for ionic interactions, a variety of absorption sites, competition between water and ions, and fiber swelling.