Morphology of hydrogen-bonding polymer complex aggregates formed from dilute solutions by freeze-defreeze method.

Morphology of aggregates separated from dilute aqueous solutions of hydrogen-bonding polymer comlex systems by rapid freezing at -78°C followed by defreezing was studied by scanning electron microscopy. Polymer complexes with weak cooperative interaction gave no precipitates and those with moderate interaction yielded aggregates in fibrous form. Polymer complexes with strong interaction gave aggregates of network structure which was probably formed from the modulated structure developed by spinodal decomposition during the rapid freezing treatment of the solution.