Dissipative Particle Dynamics Simulation of Polymers Adsorption under Shear
Advancing the chemical engineering fundamentals
Interfacial & Colloidal Phenomena - II (T2-6b)
Keywords: Polymer adsorption, Dissipative particle dynamics, Mesocale-simulation
Polymers adsorbed onto surfaces have application in many important technical problems, wetting, adhesion, colloid stabilization and lubrication. In the present work, dissipative particle dynamics (DPD) is used to simulate the adsorption of block copolymers on solid-liquid interface. In order to investigate the protect effect of block copolymers, some beads R are added to the simulation system which are needed to repel away from the solid surface. This study was motivated by the problem of controlling the agglomerative effect of soot in lubricating oil.
The simulation shows that the block copolymer adsorbed on the solid surface will performed as an adsorbent deactivator. An effective barrier will form by the adsorbed block copolymer molecules to prevent the adsorption of other molecules or tiny particles represented by beads R in the simulation system. The adsorption amount of beads R at a certain R concentration can be calculated to evaluate the protect effect of block copolymers. The effects molecular structure, concentration, interactions with solid wall and solvents of block copolymer are inspected. The adsorption amount of beads R will decrease rapidly with increasing the concentration of block copolymer, or with decreasing the repulsion parameter between the preferential block and the solid surface. Moreover, the barrier formed by block copolymers appears to be greater as the polymeric chain length increases or as the block copolymer is more soluble. A better protect effect can be obtained by using diblock copolymer, rather than using tri-block copolymer. The shear to the simulation system will weaken the effective barrier formed by the block copolymer, the beads R will be more likely to adsorb onto the solid surface with the increase of the shear rate.
Presented Thursday 20, 09:45 to 10:05, in session Interfacial & Colloidal Phenomena - II (T2-6b).
