Thin films of hydrophobically modified poly(N,N-dimethylacrylamide).
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.
Beija
Mariana
M
Centro de Química-Física Molecular, Instituto Superior Técnico, 1049-001 Lisbon, Portugal.
Relógio
Paula
P
Charreyre
Marie-Thérèse
MT
Gonçalves da Silva
A M
AM
Brogueira
P
P
Farinha
J P S
JP
Martinho
J M G
JM