title: Thin films of hydrophobically modified poly(N,N-dimethylacrylamide).
abstract: The behavior of a poly(N,N-dimethylacrylamide) hydrophobically modified by incorporating 0.33 mol % of a pyrenyl derivative, [4-(1-pyrenyl)butyl]amine hydrochloride (PY) and 3.56 mol % of dodecylamine (DO) has been studied at the air/water interface. Surface pressure-area isotherm measurements show that the film is initially anchored by the hydrophobic groups at the air-water interface with a pancake-like structure and, with increasing surface pressure, evolves to a quasi mushroom structure, finally reaching a brush configuration at high pressures. Monolayers of this polymer were transferred to silica substrates using the Langmuir-Blodgett (LB) technique at 5, 15, and 25 mN.m(-1). The properties of the LB films were studied by steady-state and time-resolved fluorescence as well as by atomic force microscopy. The results show that the aggregates formed at low pressures are disrupted by pressure increase, while the water-soluble poly(N,N-dimethylacrylamide) becomes dissolved in the water subphase.
authors.affiliation: Centro de Química-Física Molecular, Instituto Superior Técnico, 1049-001 Lisbon, Portugal.
authors.forename: Mariana
authors.initials: M
authors.lastname: Beija
authors.forename: Paula
authors.initials: P
authors.lastname: Relógio
authors.forename: Marie-Thérèse
authors.initials: MT
authors.lastname: Charreyre
authors.forename: A M
authors.initials: AM
authors.lastname: Gonçalves da Silva
authors.forename: P
authors.initials: P
authors.lastname: Brogueira
authors.forename: J P S
authors.initials: JP
authors.lastname: Farinha
authors.forename: J M G
authors.initials: JM
authors.lastname: Martinho