How Can One Controllably Use of Natural Delta pH in Polyelectrolyte Multilayers?

Abstract

Most natural and synthetic polyelectrolytes (PEs) possess dissociable groups, and therefore the corresponding structures depend on pH. This enables manipulation of their properties, in special permeability, elasticity and swelling, and this can be made use of in many applications. The effect of individual polymer composition on the dissociation equilibrium is discussed. Different concentrations and pH values during the PE assembly affect concentration of charged groups per molecule on the dissociation equilibrium. Ionic strength also influences the protonation/deprotonation behavior of PE, that can be changed by adding different salt concentration but also varies with the concentration of charged groups in the polymer molecules. Electrostatic interactions of the polymer molecules strongly affect the dissociation equilibrium of weak PEs and, thus, layers architecture and properties that can be regulated by natural pH changes in such processes as self-healing, corrosion and antifouling, drug storage and delivery, etc.