A New Simulation Algorithm with Revised “Association Criteria” for Studying the Association of Heteroarm Star Copolymers

Abstract

Summary: A new computational algorithm for dynamic lattice Monte Carlo simulations of the associative behavior of heteroarm copolymers in selective solvents was developed and optimized for efficient and relatively fast simulation studies. The algorithm is based on the Siepmann and Frenkel variant of the bias self‐avoiding walk procedure. Simultaneously, a new criterion for recognition of an associate was proposed. The first results on the micellization of heteroarm star copolymers are presented. magnified image

Monte Carlo Simulation Studies of the Size and Shape of Linear and Star‐Branched Copolymers Embedded in a Tetrahedral Lattice

“…In Figure 9 the average cosine of the angle b between vectors c X and c Y is shown, where c Z is defined as the vector from the center of the miktoarm star to the center of mass of an individual sort, i.e., of the segments of all arms of type Z (Z ¼ X or Y). [10,11] Due to geometrical reasons hcos bi is negative throughout but the rapid decrease toward a value À1 is clearly indicative of a spatial separation of arms belonging to different sorts.…”

“…Apart from experimental characterization, numerical investigations of model chains are the most direct approach to study these systems. Therefore, a lot of effort has been put into the investigation of block copolymer and miktoarm stars based on lattice Monte Carlo algorithms [5][6][7][8][9][10][11][12][13][14][15][16] as well as molecular dynamics, [17][18][19][20][21][22] in many cases focusing the attention to a quantitative description or the graphical presentation of microdomains.…”

Self‐Assembly of Heteroarm Star Copolymers – A Monte Carlo Study

“…The self‐assembly of heteroarm star copolymers ( f A Na , f B Nb ) in selective solvents (good solvent for blocks A and bad solvent for blocks B) is studied by a new version of the dynamic lattice Monte Carlo simulation method described in detail in our recent paper 26. This method was optimized for studying the copolymers in selective solvents.…”

“…These random clusters can be observed, for example, in homopolymer solutions in a good solvent; that is, under conditions where there does not exist any reason for self‐assembly. In this paper, we use the improved recognition criterion developed in our earlier study 26. This criterion discerns better between the real and random associates.…”

“…Recently we studied the solution behavior of stars with 20 short polystyrene and 20 long polyvinylpyridine arms in 1,4‐dioxane‐methanol mixture24 in detail and also the self‐assembly of polystyrene‐poly(2‐vinylpyridine) heteroarm stars with different number and length of arms in aqueous media experimentally by dynamic light scattering 12. To be able to interpret the observed behavior unambiguously, we performed a Monte Carlo study of the conformation behavior of heteroarm stars with a high number of long arms25 and we started to study their association behavior in selective solvents 26…”