Phase behavior of symmetric linear multiblock copolymers

¹ Faculty of Physics, University of Vienna - Boltzmanngasse 5, A-1090 Vienna, Austria, EU
² Institute for Theoretical Physics and Center for Computational Materials Science, Vienna University of Technology Hauptstraße 8-10, A-1040 Vienna, Austria, EU
³ Vienna Computational Materials Laboratory - Sensengasse 8/12, A-1090 Vienna, Austria, EU
⁴ Department of Materials Science, University of Patras - 26504 Patras, Greece, EU

^a panagiotis.theodorakis@univie.ac.at

Received: 8 December 2010
Accepted: 1 February 2011

Abstract

Molecular-dynamics simulations are used to study the phase behavior of a single linear multiblock copolymer with blocks of A- and B-type monomers under poor solvent conditions, varying the block length N, number of blocks n, and the solvent quality (by variation of the temperature T). The fraction f of A-type monomers is kept constant and equal to 0.5, and always the lengths of A and B blocks are equal (N_A = N_B = N), as well as the number of blocks (n_A = n_B). We identify the three following regimes where: i) full microphase separation between blocks of different type occurs (all blocks of A-type monomers form a single cluster, while all blocks of B-type monomers form another); ii) full microphase separation is observed with a certain probability; and iii) full microphase separation cannot take place. For a very high number of blocks n and very high N (not accessible to our simulations) further investigation is needed.