[P1-52] Structural and dynamical properties of star block-copolymers in shear flow.
Star block-copolymers (SBCs) have been demonstrated to constitute self-assembling building blocks with specific softness, functionalization, shape, and flexibility. In this work, we studied the structural and dynamical behavior of an isolated SBC under a shear flow by means of particle-based multiscale simulations (MD+MPCD) covering a wide range of system parameters, which include the functionality (number of arms of the star), the amphiphilicity degree, and the solvent quality. We systematically analyzed the conformational properties of low-functionality SBC, as well as the formation of attractive patches on their corona as a function of the shear rate. Three mechanisms of patch reorganization under shear were identified, which determine the dependence of the patch numbers and orientations on the shear rate, namely, free arms joining existing patches, a fusion of medium-sized patches into bigger ones, and fission of large patches into two smaller ones at high shear rates [1]. As well as, the dynamics of the SBC was investigated by means of the so-called Eckart’s frame, which allows separating pure rotational and vibrational motions [2,3]. It is shown that SBCs display a richer structural and dynamical behavior than athermal star polymers in a shear flow [4] and therefore they are also interesting candidates to tune the viscoelastic properties of complex fluids. Because the conformation and dynamics of single SBCs are expected to be preserved in low-density bulk phases, the presented results are the first step in understanding and predicting the rheological properties of semidilute suspensions of this kind of polymers.
[1] Jaramillo-Cano et al. J. Phys. Chem. B (2018) In press
[2] Sablic et al. Soft Matter 13: 6988 (2017)
[3] Jaramillo-Cano et al. (2018) In preparation
[4] Ripoll et al. Phys. Rev. Lett. 96: 188302 (2006)
[1] Jaramillo-Cano et al. J. Phys. Chem. B (2018) In press
[2] Sablic et al. Soft Matter 13: 6988 (2017)
[3] Jaramillo-Cano et al. (2018) In preparation
[4] Ripoll et al. Phys. Rev. Lett. 96: 188302 (2006)