| Abstract
| - In dilute heteropolymer solutions, a limited number of the chains, just like proteins, couldcollapse and associate to form a stable/metastable mesoglobular phase between single-chain globulesand macroscopic precipitates. Recently, we found that inserting more hydrophobic comonomers into athermally sensitive chain backbone surprisingly led to the formation of smaller mesoglobules in water.This apparent contradiction to our conventional wisdom can be satisfactorily explained in terms of theoverlooked viscoelastic effect; namely, hydrophobic association inside each mesoglobule increases the chainrelaxation time (τe). When it becomes much longer than the interaction time (τc) of two collidingmesoglobules, each mesoglobule behaves like a tiny nonadhesive “glass” ball. This stabilization mechanismis completely different from thermodynamic consideration in which one normally tries to make the particlesurface hydrophilic so that τc is reduced.
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