Competitive adsorption, phase segregation, and molecular motion at a solid-liquid interface studied by scanning tunneling microscopy

被引：56

作者：

Baker, RT ^{[1
]}

Mougous, JD ^{[1
]}

Brackley, A ^{[1
]}

Patrick, DL ^{[1
]}

机构：

[1] Western Washington Univ, Dept Chem, Bellingham, WA 98225 USA

来源：

LANGMUIR | 1999年 / 15卷 / 14期

关键词：

D O I：

10.1021/la981658h

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Binary mixtures of 4'-octyl-4-biphenylcarbonitrile (8CB) and n-tetracontane (C40H82) deposited-as crystalline monolayers from a bulk fluid droplet on a graphite substrate were found to undergo nanometer-scale phase segregation into pure 8CB and pure alkane domains. Film morphology, molecular ordering, and domain motion were studied using scanning tunneling microscopy. Alkane adsorption was favored in the early stages of film growth, which was followed by a period of gradual annealing in which 8CB displaced alkane molecules from the surface. The structure and composition of the monolayer show that in films deposited from a bulk fluid with a 600:1 molar ratio of 8CB/-tetracontane 8CB adsorption is thermodynamically favored. However, n-tetracontane had a significantly larger nucleation rate, leading to high alkane surface coverage shortly after film formation. Quantitative rate measurements of alkane domain replacement by 8CB have been made and correlated with the microscopic structure of the 8CB-alkane interface.

引用

页码：4884 / 4891

页数：8

共 27 条

[1]

ADAMSON AW, 1976, PHYSICAL CHEM SURFAC

[2] ANISOTROPIC MOLECULAR-DYNAMICS IN THE VICINITY OF ORDER-DISORDER TRANSITIONS IN ORGANIC MONOLAYERS [J].

ASKADSKAYA, L ;

RABE, JP .

PHYSICAL REVIEW LETTERS, 1992, 69 (09) :1395-1398

[3] PHASE-BEHAVIOR OF 2-COMPONENT SELF-ASSEMBLED MONOLAYERS OF ALKANETHIOLATES ON GOLD [J].

FOLKERS, JP ;

LAIBINIS, PE ;

WHITESIDES, GM ;

DEUTCH, J .

JOURNAL OF PHYSICAL CHEMISTRY, 1994, 98 (02) :563-571

[4] IMAGING OF LIQUID-CRYSTALS USING A TUNNELLING MICROSCOPE [J].

FOSTER, JS ;

FROMMER, JE .

NATURE, 1988, 333 (6173) :542-545

[5] Probe microscopy of organics, an update [J].

Frommer, JE .

THIN SOLID FILMS, 1996, 273 (1-2) :112-115

[6]

Giddings J.C., 1991, Unified separation science

[7] SELECTIVE ADSORPTION AT GRAPHITE/HYDROCARBON INTERFACES [J].

GROSZEK, AJ .

PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL AND PHYSICAL SCIENCES, 1970, 314 (1519) :473-&

[8]

HALL DG, 1990, NATO ASI SER C-MATH, V324, P857

[9] IMAGING ALKANE LAYERS AT THE LIQUID GRAPHITE INTERFACE WITH THE SCANNING TUNNELING MICROSCOPE [J].

MCGONIGAL, GC ;

BERNHARDT, RH ;

THOMSON, DJ .

APPLIED PHYSICS LETTERS, 1990, 57 (01) :28-30

[10] Competitive adsorption of polymer and surfactants on solid substrates [J].

Moudgil, BM ;

Prakash, TS .

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 1998, 133 (1-2) :93-97

← 1 2 3 →