Early Organic Ion Exchange Materials

The first completely synthetic ion exchange resins were prepared by B. A. Adams and E. L. Holmes in 1935. The basis of their synthesis was the condensation polymerization of methanal (formaldehyde) with phenol or polysubstituted benzene compounds to give, after 

Thus once the required configuration of a fixed cation and mobile (exchangeable) counter-anion is achieved exchange may proceed con- 

---