| Research Abstract |
In this research project, we developed computer system for predicting phase behavior of associating polymers. Our system consists of two parts : (1) Fast derivation of phase diagrams by numerical calculation on the basis of our recent theory of associating polymers, and their visualization. (2) Monte Carlo simulation by using off-lattice bead-spring model chains for structural analysis of the state specified on the phase diagrams derived above.
In the first part, we input necessary system parameters such as chemical species of polymers, their degree of polymerization, their functionality (number of functional groups, their distribution on a chain), bending rigidity of a chain, association constant, and interaction parameter. Possibility of phase transitions such as macro- and microphase separation, gelation, liquid-crystallization, micellization, hydration, etc. We draw binodals, spinodals, sol/gel transition lines, microphase separation transition lines, CMC, nematic and smectic transition lines in the phase space.
In the second part, we carry out Monte Carlo simulation for the state specified on the phase plane by using bead-spring model chains. Polymer chains carry associative beads and non-associative b eads. After equilibriation, distribution of clusters, percolation properties, chain population of fundam ental association categories, etc. are evaluated. Typical snapshots are visualized. Specific systems which have been installed into the program so far are : <Nongelling Systems> Dimer Formation, Hydration, Side-Chain Association, Hydrogen-Bonded Liquid Crystals <Gelling Systems> Simple Gelation, Gelation with Multiple Junctions, 2-Component Gelation, Gelation coupled to Conformational Change, Hydrogen-Bonded Liquid Crystalline Networks
|
