Self-Assembled Monolayers on Polymer Surfaces:  Kinetics, Functionalization, and Photopatterning

Abstract

Monolayers of bifunctional bolaamphiphiles were self-assembled on a polymeric substrate (spin-coated film of poly(allylamine hydrochloride)). Various features of the novel bifunctional, well-ordered, and relatively stiff monolayer and the subsequent reactions of the exposed benzoyl azide groups were investigated. The characterization of the monolayers and the kinetics of self-assembly was determined via reflection−absorption infrared spectroscopy and ellipsometry. Atomic force microscopy and ellipsometry were used to measure roughness and thickness, respectively. From molecular modeling and ellipsometry, the bolaaphiphiles in the monolayers were found to be inclined at an angle of about 68° to the normal. In addition, the monomolecular layers appeared to be fairly crystalline. Serial functionalization of the exposed benzoyl azide groups with dansyl-cadaverine in the liquid phase followed by propylamine in the gas phase illustrated a stable, dense, well-ordered, two-dimensional monomolecular layer of bolaamphiphiles. Photopatterning, via UV irradiation of exposed benzoyl azide groups, was also demonstrated. The novelty of the surface modification procedure described here is the extraordinary ease with which self-assembly took place and the stability of the resulting monolayers which formed a highly reactive new surface suitable for further modification. Arranging molecules in a tidy ordered array on a polymeric surface is a main result of this work.

Structural perturbation of a dipalmitoylphosphatidylcholine (DPPC) bilayer by warfarin and its bolaamphiphilic analogue: A molecular dynamics study

“…Synthetic bolaform species have found application as bilayer membrane stabilizers, synthetic ion channels 5-8 , and as additives in drug delivery formulations 1, 9 . They are also of considerable interest in monolayer functionalization of solid surfaces 10-12 .…”

Properties of phospholipid monolayer deposited on a fluorinated polyurethane

“…To date, there is only a limited number of publications addressing the construction of monolayer on polymers. Bohme et al [45] used bola-amphiphile molecules for the prepation of LB monolayers on the surface of spin-coated poly(allylamine hydrochloride) film. Uchida et al [46] have built up a sodium sulfonate head/alkyl tail amphiphile on a polystyrene film successively by the hydrophobic interaction between the alkyl tails of the amphiphile and the polystyrene.…”

Derivatization, characterization, and tribological behavior of an amine-terminated polymer surface

“…The resulting polymer film would not only be stably combined with the substrate via the polar groups, but also exposed a hydrophobic surface with low surface energy. Though many efforts have been made on the chemical derivatization of functional polymer surface [16][17][18][19][20][21][22][23], few works are engaged in tribological studies. With this perspective in mind, we selected branched polyethyleneimine {abridged as PEI,-[C 2 H 5 NHC 2 H 5 N(C 2 H 5 NH 2 )C 2 H 5 NH] n -} to carry out our research on the derivatization, characterization, and tribological behavior of an amine-terminated polymer surface.…”