Macromolecules association

Molecularly motivated empiricisms, such as the solubility parameter concept, have been valuable in dealing with mixtures of weakly interacting small molecules where surface forces are small. However, they are completely inadequate for mixtures that involve macromolecules, associating entities like surfactants, and rod-like or plate-like species that can form ordered phases. New theories and models are needed to describe and understand these systems. This is an active research area where advances could lead to better understanding of the dynamics of polymers and colloids in solution, the rheological and mechanical properties of these solutions, and, more generally, the fluid mechaiucs of non-Newtonian liquids. 

The precipitation of a polymer can be regarded as a solvophobic phenomenon the interactions between polymer and solvent molecules are diminished by lowering the temperature or adding nonsolvent until they are weaker than the intra- and inter-molecular interactions between polymer segments. If the thermodynamic quality of the solvent has decreased beyond a certain limit, the macromolecules associate and... 

The property of the polymers in question to form nonspherical nanostructures was confirmed in experimental studies. Shih et al. [29] synthesized alternating copolymers of 1-alkenes with maleic anhydride. The maleic anhydride units were hydrolyzed to maleic acid units. Fully hydrolyzed macromolecules associated into microstructures of cylindrical and ellipselike shape. The cylindrical shape was characteristic of copolymers with octadecene and hexadecene moieties, while the copolymers with lower alkene copolymers (tetradecene, dodecene, decene, octene) formed ellipsoidal structures. Wataoka et al. [30] investigated the formation of nonspherical helices in a system of maltopentaose-carrying polystyrene (PS). The polymer was synthesized via the homopolymerization of vinylbenzyl maltopentaose amide (Scheme 3). 

Constantz, B., and Weiner, S. (1988) Acidic macromolecules associated with the mineral phase of Scleractinian coral skeletons. J. Exp. Zool. 248, 253-258. 

---