Memory effects on the interfacial characteristics of dioctadecyldimethylammonium bromide monolayers at the air-water interface

被引:35
作者
da Silva, AMG
Romao, RS
Caro, AL
Patino, JMR
机构
[1] Inst Super Tecn, Ctr Quim Estrutural, P-1049001 Lisbon, Portugal
[2] Univ Seville, Fac Quim, Dept Ingn Quim, E-41012 Seville, Spain
关键词
dioctadecyldimethylammonium; monolayers; BAM observation; relaxation; morphology and reflectivity;
D O I
10.1016/j.jcis.2003.11.002
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 [物理化学]; 081704 [应用化学];
摘要
The structural and dynamic characteristics of dioctadecyldimethylammonium bromide (DODAB) monolayers on a pure water subphase were investigated by surface film balance, Brewster angle microscopy, and relaxation in area and surface pressure at constant surface pressure and area, respectively. The first compression-expansion cycle of the monolayer is not reversible and the second pi-A compression isotherm deviates to larger molecular areas relative to the first one. At a microscopic level this hysteresis may be assigned to an irreversible hydration of the ammonium groups of DODAB. The morphology and reflectivity of DODAB monolayers during compression and expansion on the monolayer depend on the monolayer history. Bright domains randomly dispersed were observed during compression before collapse. Surprisingly, this random distribution of domains changes into a fractal-like structure during the monolayer expansion in a narrow range of surface pressures. This morphology does not form when the monolayer is previously compressed above the collapse surface pressure. 2D foam-like structure is often observed when the film is expanded at maximum area. Relaxation phenomena in DODAB monolayers are attributed to monolayer reorganization and nucleation of liquid-condensed domains from the liquid-expanded phase. These time-dependent processes are irreversible. (C) 2003 Elsevier Inc. All rights reserved.
引用
收藏
页码:417 / 425
页数:9
相关论文
共 38 条
[1]
MOLECULAR-DYNAMICS SIMULATIONS OF DIOCTADECYLDIMETHYLAMMONIUM CHLORIDE MONOLAYERS [J].
ADOLF, DB ;
TILDESLEY, DJ ;
PINCHES, MRS ;
KINGDON, JB ;
MADDEN, T ;
CLARK, A .
LANGMUIR, 1995, 11 (01) :237-246
[2]
Phase behavior of synthetic amphiphile vesicles investigated by calorimetry and fluorescence methods [J].
Benatti, CR ;
Tiera, MJ ;
Feitosa, E ;
Olofsson, G .
THERMOCHIMICA ACTA, 1999, 328 (1-2) :137-142
[3]
Structural and thermal characterization of dioctadecyldimethylammonium bromide dispersions by spin labels [J].
Benatti, CR ;
Feitosa, E ;
Fernandez, RM ;
Lamy-Freund, MT .
CHEMISTRY AND PHYSICS OF LIPIDS, 2001, 111 (02) :93-104
[4]
CARRERA SC, 1999, COLLOID SURFACE B, V12, P175
[5]
DIHEXADECYL PHOSPHATE MONOLAYERS - INTRALAYER AND INTERLAYER INTERACTIONS [J].
CLAESSON, P ;
CARMONARIBEIRO, AM ;
KURIHARA, K .
JOURNAL OF PHYSICAL CHEMISTRY, 1989, 93 (02) :917-922
[6]
Adsorption of inorganic polyanions along a Langmuir film: A Brewster angle microscopic study [J].
Cuvillier, N ;
Bernon, R ;
Doux, JC ;
Merzeau, P ;
Mingotaud, C ;
Delhaes, P .
LANGMUIR, 1998, 14 (19) :5573-5580
[7]
Effect of the spreading procedure on the formation of cationic-anionic mixed monolayers [J].
da Silva, AMG ;
Viseu, MI ;
Campos, CS ;
Rechena, T .
THIN SOLID FILMS, 1998, 320 (02) :236-240
[8]
da Silva AMG, 1998, COLLOID SURFACE A, V144, P191
[9]
daSilva AMG, 1996, LANGMUIR, V12, P4442
[10]
DASILVA AMG, 2001, P 8 EUR C ORG FILMS