title: Binding, structure, and dynamics of hydrophobic polymers near patterned self-assembled monolayer surfaces.
abstract: We use molecular dynamics simulations to study the binding, conformations, and dynamics of a flexible 25-mer hydrophobic polymer near well-defined patterned self-assembled monolayers containing a hydrophobic strip (with -CH3 head-groups) having different widths in a hydrophilic (-OH) background. We show that the polymer binds favorably to hydrophobic strips of all widths, including the subnanometer ones comprising 3, 2, or even 1 row of -CH3 head-groups, with the binding strength varying from about 107 to 25 kJ/mol for the widest to the narrowest strip. Near wide hydrophobic patches containing 5 or more -CH3 rows, pancakelike conformations are dominant, whereas hairpinlike structures become preferred ones near the narrower strips. In the vicinity of the narrowest 1-row strip, the polymer folds into semiglobular conformations, thus maintaining sufficient contact with the strip while sequestering its hydrophobic groups away from water. We also show that the confinement makes the translational dynamics of the polymer anisotropic as well as conformational dependent. Our results may help to understand and manipulate the self-assembly and dynamics of soft matter, such as polymers, peptides, and proteins, at inhomogeneous patterned surfaces.
authors.affiliation: The Howard P. Isermann Department of Chemical and Biological Engineering and The Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Li
authors.forename: Shekhar
authors.initials: S
authors.lastname: Garde
mesh_terms: D057927:Hydrophobic and Hydrophilic Interactions; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D011108:Polymers