Macromolecular Theory and Simulations

How to control the channel membrane formation in self-assembly and nonsolvent induced phase separation method? Dissipative particle dynamics is used to predict the effects of polymer concentration, block ratio, and solvent exchange rate on the structure of porous membrane. The mechanism of microphase separation process is obtained from this fundamental research by the self-assembling process of polystyrene-block-poly(4-vinyl pyridine) block copolymer.

Effect of polydispersity on particle penetration into polydisperse brushes is studied on the basis of theoretical analysis. It shows that the brush surface of the polydisperse brush is softer, and small particles can easily and deeply penetrate into it. Therefore, polydisperse brushes can accommodate more particles, especially for those with high polydispersity.

Reversible copolymerization at constant comonomer concentrations can lead either to product of the infinite number average degree of polymerization DP_n with low dispersity Ð (at monomer concentrations above equilibrium ones) or with Ð = 1+(π – 2)/2 (at equilibrium concentrations for infinite DP_n), or to equilibrium copolymer of DP_n < ∞ and Ð ≈ 2, as observed in batch systems.

By using different kinetic rate constants for the four reactions involved in an otherwise conventional model for A₂ + B₂ step-growth polymerization, the attainment of ultrahigh molecular weights at stoichiometric imbalance ratios smaller than one, observed in superacid catalyzed polyhydroxyalkylations of isatin and modified isatin with biphenyl and terphenyl, is adequately explained. Good agreement between model predictions and experimental data is obtained.

The epitaxial relationship and nucleation kinetics regarding the single gyroid nanostructure in ABC triblock terpolymers are investigated using self-consistent field theory combined with the string method. The results demonstrate the significant potential of the order–order phase transition to fabricate functional materials with multiply continuous network nanostructure by regulating the kinetic pathways.