Fascinating morphological behavior of A2-star-(B-alt-C) molecules in the melts and solutions
Journal
Macromolecular Symposia
Journal Volume
279
Journal Issue
1
Pages
96-102
Date Issued
2009
Author(s)
Abstract
Abstract We employ dissipative particle dynamics (DPD) to examine the self‐assembling behavior of A 2 ‐ star ‐(B‐ alt ‐C) molecules in the melt and solution states. When these molecules are in the melts, we successfully observe various types of hierarchical structure‐within‐structures, such as A‐formed spheres in the matrix formed by B and C alternating layers, hexagonally packed A‐formed cylinders in the matrix with B and C segregated layers, B and C alternating layers‐within‐lamellae, coaxial B and C alternating domains within hexagonally packed BC‐formed cylinders, and concentric BC‐alternating domains within BC‐formed spheres, by increasing the A composition. These hierarchical structures by varying the composition are reported theoretically for the first time in the copolymer systems consisting of the alternating blocks, and in good agreement with the most recent experimental work by Matsushita and co‐workers ( Macromolecules 2007 , 40 , 4023). Generally speaking, the small‐length‐scale B and C segregated domains are in parallel to the large‐length‐scale structures for the melt case. While when a selective solvent is added, we find that varying the solvent selectivity and the amount of solvent can induce the molecules to form quite different morphological patterns, such as the so‐called segmented worm like micelles.
Type
journal article