Structure of a cationic surfactant layer at the silica-water interface. [Hexadecyltrimethylammonium bromide]

Journal Article · Tue May 01 04:00:00 EDT 1990 · Langmuir; (USA)

DOI:https://doi.org/10.1021/la00095a025· OSTI ID:6307188

Rennie, A R ^[1]; Lee, E M; Simister, E A; Thomas, R K ^[2]

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1. Institut Laue Langevin, Grenoble (France)
2. Univ. of Oxford (England)

The technique of specular reflection of neutrons has been used to study the structure of a layer of hexadecyltrimethylammonium bromide (C{sub 16}TAB) adsorbed at the interface between a plate of amorphous silica and solutions of C{sub 16}TAB. At concentrations of 1/3 and 2/3 the cmc (9 {times} 10{sup {minus}4} M), the structure which best fitted the reflectivity data can be described either as a defective bilayer or as flattened micelles. The thicknesses of the alkyl chain and head-group regions of the bilayer were found to be 28 {plus minus} 4 and 6 {plus minus} 2 {angstrom}, respectively. At 6 {times} 10{sup {minus}4} M, 80% of the interface was covered with bilayer, and this dropped to 35% at 3 {times} 10{sup {minus}4} M. At both coverages, the head-group area was found to be 30 {plus minus} 3 {angstrom}{sup 2}.

• OSTI ID: 6307188
• Journal Information: Langmuir; (USA), Journal Name: Langmuir; (USA) Vol. 6:5; ISSN LANGD; ISSN 0743-7463
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ADSORPTION
BROMIDES
BROMINE COMPOUNDS
CHALCOGENIDES
DATA
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
INFORMATION
MINERALS
NEUTRON SPECTROSCOPY
NUMERICAL DATA
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SORPTION
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
SURFACE PROPERTIES
SURFACTANTS