Effects of associated anion on hydrophilicity of quaternary ammonium cellulose

Quaternary ammonium celluloses, formed by introduction of cations and anions in nonaqueous media, were used to elucidate effects of associated ions on the hydrogen‐bonded cellulose–water matrix. Exchangers were characterized by wet analyses, potentiometric and conductometric titrations, and by ESCA. Techniques of optical and electron microscopy were used to observe exchangers when immersed in water. A given quaternary ammonium cellulose is more soluble or dispersible in water when its anion is large and hydrophobic as is iodide or thiocyanate. When associated with the small chloride ions that are hydrated, the quarternary exchangers do not disperse regardless of cation size. All exchangers with crosslinked quaternary groups are insoluble. Data indicate that accommodation of a large hydrophobic cation and hydrophobic, polarizable anion within a cagelike structure surrounded by water more highly structured than bulk water results in swelling and dispersion.