Alkyltrimethylammonium surfactants

Alkyltrimethylammonium surfactants, such as hexadecyltrimethylammonium chloride (HTAC) [6, 9, 38-41], hexadecyltrimethylammonium hydroxide (HTAH) [38, 42], hexadecyltrimethylammonium bromide (HTAB) [43-46], te-tradecyltrimethylammonium bromide (TTAB) [47], pentadecyltriethylammon-... 

OH -C Cl < MeS04 < Br < NO3. The shape and thickness of the monolayer of cetrimide (197c) formed at the air-water interface was determined by neutron reflection. The total thickness of the monolayer was estimated to be 2.1 0.2 nm, of which 1.0 nm is immersed in water six water molecules are associated with each molecule of surfactant436. Similar studies were performed for various C10 to (jx alkyltrimethylammonium surfactants. Interpretation of the neutron reflection results included an estimate... 

R Hansson and M. Akngren Interaction of Alkyltrimethylammonium Surfactants with Polyacrylate and Poly(Styrenesulfonate) in Aqueous Solution Phase Behavior and Surfactant Aggregation Numbers. Langmuir 10, 2115 (1994). 

M. Ahngren, P. Hansson, E. Mukhtar, and S. van Stam Aggregation of Alkyltrimethylammonium Surfactants in Aqueous Poly(Styrenesulfonate) Solutions. Langmuir 8, 2405 (1992). 

The physical chemical behavior of betaine esters of long-chain alcohols shows strong similarities to the common, closely related alkyltrimethylam-monium surfactants both in dilute and concentrated aqueous systems, hi consistence with the findings about CMC s of surfactants containing normal ester bonds (see above) it has been found that the CMC for a betaine ester with a hydrocarbon chain of n carbons is very close to the value for an alkyltrimethylammonium chloride surfactant with a hydrocarbon chain of n + 2 carbons [32], The binary phase diagram of dodecyl betainate-water has an appearance very similar to that of an alkyltrimethylammonium surfactant with a hydrophobic tail of a similar size [30]. 

Warnheim, T. and Jonsson, A. (1988) Phase-diagrams of alkyltrimethylammonium surfactants in some polar-solvents. /. Colloid Interface Scl, 125, 627-633. 

Hansson P, Almgren M. Interaction of alkyltrimethylammonium surfactants with poly(acrylate) and poly(styrenesulfonate) in aqueous solution. Phase behavior and surfactant aggregation numbers. Langmuir 1994 10 2115-2124. 

Almgren M, Hansson P, Mukhtar E, van Stam J. Aggregation of alkyltrimethylammonium surfactants in aqueous poly(styrenesulfonate) solutions. Langmuir 1992 8 2405-2412. 

Zirconia. Mesoporous zirconia was first reported by Knowles and Hudson with cationic alkyltrimethylam-monium surfactants. Starting from zirconium sulfate or propoxide, Schiith and Ciesla et al. synthesized hexagonal mesoporous zirconia using alkyltrimethylammonium surfactants as templates. Reddy and Sayari obtained hexagonal or lamellar phases of mesostructured zirconia using quaternary ammonium surfactants and acidified primary alkylamine. 

Synthesis of Periodic Mesoporous Silica Under Basic Conditions in the Presence cf Alkyltrimethylammonium Surfactants... 

One ean envision at least three related phenomenological approaches to understanding how this aggregate morphology arises. First, cylindrical surface aggregates can be regarded as a compromise between the curvature favored by intermolecular interactions (i.e. free curvature , which is spherical for alkyltrimethylammonium surfactants [2])... 

Adsorption of alkyltrimethylammonium surfactants above the cmc on the surface of silica have been investigated using a variety of techniques [18,19, 36-39], and the surface aggregates have been variously interpreted as bilayer patches [18,19,36,37] and globular micelles... 

Why do alkyltrimethylammonium surfactants form roughly spherical aggregates on silica but cylindrical aggregates on mica The answer probably lies in the far greater density of electrostatic adsorption sites available on mica. Zeta potential measurements [40] in 1 mM KCl have shown that at pH 6 (a typical imaging condition), the surface potentials % of silica and mica are —80 and —120 mV, respectively. Using the Grahame equation... 

Coran, S. A., M. Bambagiotti-Alberti, V. Giannellini, G. Moneti, G. Pieraccini, A. Raffaelli, Continuous flow FAB and ion spray ionization techniques for the simultaneous determination of alkyltrimethylammonium surfactants by MS, Rapid Commun. Mass Spectrom., 1998, /2, 281-284. 

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