Macromolecules with amphiphilic monomer units at interface of two immiscible liquids

• Published in: The Journal of chemical physics 2017-11, Vol.147 (18), p.184902-184902
• Main Authors: Glagoleva, A. A., Vasilevskaya, V. V.
• Format: Article
• Language: English
• Subjects: Adsorption; Computer simulation; Degree of polymerization; Grafting; Liquids; Localization; Macromolecules; Monomers; Parameters; Polymerization; Scaling laws; Selectivity
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.5001880

The adsorption of macromolecules with amphiphilic monomer units at the liquid-liquid interface was studied. The amphiphilic structure of monomer units with groups selectively interacting with α and β liquids was described by the A-graft-B dumbbell model. The calculations were performed for the symmetrical interaction of A and B groups with liquids, different selectivity parameters ξ and degree of polymerization N. The simulations indicate a three-step adsorption scenario, including non-adsorbed, weak and strong localization states. It was shown that the adsorption of (A-graft-B) N macromolecules obeys scaling laws developed to describe the adsorption of the alternating (AB) N copolymer at the liquid-liquid interface with critical selectivity parameter ξc of transition into the weak localization state depending on the degree of polymerization as N −1/5; critical selectivity parameter ξ∞ of transition to the strong localization regime non-depending on the degree of polymerization; and relative change of perpendicular R z radius of gyration varying as a power function of ξN 1/5: R z (ξ)/R z (0) ∼ (ξN1/5) ρ and ρ = −2ν/(1 − v). Meanwhile, (A-graft-B) N macromolecules have much lower ξc and ξ∞ values and thus are more prospective for practical applications.