TY - JOUR
T1 - Phase behavior of rigid, amphiphilic star polymers
AU - Koch, Christian
AU - Panagiotopoulos, Athanassios Z.
AU - Lo Verso, Federica
AU - Likos, Christos N.
PY - 2013/8/21
Y1 - 2013/8/21
N2 - We determine the phase behavior of rigid, amphiphilic diblock copolymer stars in solution, by employing a lattice model and applying Grand Canonical Monte Carlo simulations as well as histogram reweighting techniques. Previous studies on these systems [C. Koch et al., Mol. Phys., 2011, 109, 3049] have found that for fully flexible chains with a moderate functionality ranging from f = 3 to f = 10 and with a solvophilic A-block smaller than or equal to the solvophobic B-block, the solution undergoes a liquid-gas macrophase separation with a well-defined critical point. We find that the introduction of chain rigidity alters the critical parameters: the higher the stiffness, the higher the critical temperature Tc and the lower the critical density c. Furthermore, we find that for high rigidities and densities beyond c, the molecules arrange in cubic, columnar and lamellar ordered phases whose domain of stability depends on molecular architecture and block incompatibility. For even higher densities the system remelts again into another fluid phase. The resulting rich phase diagrams of star polymers that feature amphiphilicity and high rigidity are a manifestation of the character of these hybrid molecules as polymer-based, soft patchy colloids.
AB - We determine the phase behavior of rigid, amphiphilic diblock copolymer stars in solution, by employing a lattice model and applying Grand Canonical Monte Carlo simulations as well as histogram reweighting techniques. Previous studies on these systems [C. Koch et al., Mol. Phys., 2011, 109, 3049] have found that for fully flexible chains with a moderate functionality ranging from f = 3 to f = 10 and with a solvophilic A-block smaller than or equal to the solvophobic B-block, the solution undergoes a liquid-gas macrophase separation with a well-defined critical point. We find that the introduction of chain rigidity alters the critical parameters: the higher the stiffness, the higher the critical temperature Tc and the lower the critical density c. Furthermore, we find that for high rigidities and densities beyond c, the molecules arrange in cubic, columnar and lamellar ordered phases whose domain of stability depends on molecular architecture and block incompatibility. For even higher densities the system remelts again into another fluid phase. The resulting rich phase diagrams of star polymers that feature amphiphilicity and high rigidity are a manifestation of the character of these hybrid molecules as polymer-based, soft patchy colloids.
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U2 - 10.1039/c3sm51135a
DO - 10.1039/c3sm51135a
M3 - Article
AN - SCOPUS:84880876986
SN - 1744-683X
VL - 9
SP - 7424
EP - 7436
JO - Soft Matter
JF - Soft Matter
IS - 31
ER -