Dynamics of polymer-grafted vesicles in shear flow. (June 2015)

• Record Type: Journal Article
• Authors: Deng, Zhenyu; Zhang, Dong; Zhang, Linxi
• Is Part Of: Materials today communications. Volume 3(2015)
• Page Start: 130
• Page End: 136
• Publication Date: 2015-06
• Subjects: Vesicle -- Molecular dynamics method -- Shear flow -- Dynamics; Materials science -- Periodicals; 620.11
• DOI: 10.1016/j.mtcomm.2015.01.004
• Languages: English
• ISSNs: 2352-4928

Abstract

Graphical abstract: The anchoring of polymer chains to the vesicles can effectively control the dynamical behaviors of the vesicles in shear flow, and the vesicle motions in shear flow depend on the shear rates, the ratio δ = L / R between the grafted chain length ( L ) and the vesicle radius ( R ) as well as the grafting positions. In a strong shear flow, a new steady translational motion of vesicles along the flow direction is observed for long grafting polymer chains. Abstract: A nonequilibrium molecular dynamics (NEMD) method is employed to study dynamical behaviors of a two-dimensional (2D) vesicle grafted by two polymers in shear flow. Besides tumbling, trembling, and tank-treading, a new translating motion of polymer-grafted vesicles is observed, which mainly depends on the shear rate, the polymer length and the grafting position. In the translating regime, the grafting polymers stretch away from the vesicle, both the vesicle and the fully stretched polymers keep the translational motion with the same velocity, and the expected rotation or circulation of the vesicle in shear flow is eliminated. This investigation can help us to understand the complexity of vesicle motions in shear flows.