Dissipative crystallization of sodium salts of carboxymethyl cellulose

Drying dissipative patterns were observed at room temperature on a cover glass, a watch glass, and a Petri glass dish during the course of dryness of aqueous solution of sodium salts of carboxymethyl cellulose (NaCMC) having different molecular weights in the presence of sodium chloride and in their absence. Without salt, the polymers were slightly hygroscopic and did not dry up completely on the substrates. Single crystals of the NaCMC without salt were short rodlike and quite similar to those of the other polysaccharides studied hitherto, i.e., hydroxypropyl cellulose and sodium dextran sulfate. Morphology of the polymer crystals were short rods, long dendritic rods, and/or hedrite assemblies depending on location in the dried film and in the presence of sodium chloride. Spoke-like orientation of the long dendritic rods appeared on a cover glass and a watch glass especially for NaCMC of low molecular weights.