Surfactant and Water Ordering in Triacontanol Monolayers at the Water−Hexane Interface

Tikhonov, A. M.; Schlossman, Mark L.

doi:10.1021/jp0271817

Cited by 36 publications

(80 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to our earlier study, monolayers of n-alkanols with 20, 22, 24, and 30 carbon atoms at the n-hexane/water interface are disordered (at P=1 atm), even at the lowest accessible temperatures (down to the temperature at which the alkanols precipitate from the bulk solution) [7,8]. The structure normal to the interface of the C m -alkanol monolayer in this low temperature phase can be described as consisting of two or three slabs, where each slab is characterized by its thickness and electron density.…”

Section: Introductionmentioning

confidence: 88%

Vaporization and layering of alkanols at the oil/water interface

Tikhonov¹,

Schlossman²

2007

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

This study of adsorption of normal alkanols at the oil/water interface with x-ray reflectivity and tensiometry demonstrates that the liquid to gas monolayer phase transition at the hexane/water interface is thermodynamically favorable only for long-chain alkanols. As the alkanol chain length is decreased, the change in excess interfacial entropy per area ΔS a σ decreases to zero. Systems with small values of ΔS a σ form multi-molecular layers at the interface instead of the monolayer formed by systems with much larger ΔS a σ . Substitution of n-hexane by n-hexadecane significantly alters the interfacial structure for a given alkanol surfactant, but this substitution does not change fundamentally the phase transition behavior of the monolayers. These data show that the critical alkanol carbon number, at which the change in excess interfacial entropy per area decreases to zero, is approximately six carbons larger than the number of carbons in the alkane solvent molecules.2

show abstract

Section: Introductionmentioning

confidence: 88%

Vaporization and layering of alkanols at the oil/water interface

Tikhonov¹,

Schlossman²

2007

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…7 In contrast, the flexible hydrocarbon n-alkanol tails are disordered and may allow hexane to penetrate the tail region. 5,6 These comparative measurements reported recently highlight the importance of conformational entropy (arising from tail flexibility) and enthalpic contributions (that contribute to the surfactant solubility) in determining the molecular ordering of the surfactant assembly. The surfactant ordering in the example above is dominated by the tails of the surfactants.…”

Section: Introductionmentioning

confidence: 91%

“…These other data sets for triacontanol have been previously published. 5,6 Additional data for triacontanoic acid, including the temperature and pH dependence, will be presented in future publications. Figure 1 illustrates X-ray reflectivity measured from triacontanoic acid and triacontanol monolayers at the water-hexane interface.…”

Section: Data and Analysismentioning

confidence: 99%

“…5,6 Two of these layers represent the electron density along the alkyl tail; the third layer represents the region of the -CH 2 OH headgroups. The maximum electron density in the headgroup region, F max ) 1.13(0.01, is comparable for the triacontanol and triacontanoic acid monolayers.…”

Section: Data and Analysismentioning

confidence: 99%

“…[5][6][7] On the water surface, these surfactants form ordered monolayers with rigid-rod all-trans tails for both fluorocarbon and hydrocarbon tail surfactants. [5][6][7] Although individual fluorocarbon n-alkanols are rigid by nature, the hydrocarbon n-alkanols have flexible tails. The formation of rigid-rod monolayers for the surfactants with flexible tails indicates that attractive forces between the tails can overcome any disordering tendency resulting from the flexibility of the alkyl tail.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Tail Ordering Due to Headgroup Hydrogen Bonding Interactions in Surfactant Monolayers at the Water−Oil Interface

et al. 2006

Self Cite

View full text Add to dashboard Cite

Interactions between surfactants, and the resultant ordering of surfactant assemblies, can be tuned by the appropriate choice of head-and tailgroups. Detailed studies of the ordering of monolayers of long-chain n-alkanoic and n-alkanol monolayers at the water-vapor interface have demonstrated that rigid-rod all-trans ordering of the tailgroups is maintained upon replacing the alcohol with a carboxylic acid headgroup. In contrast, at the water-hexane liquid-liquid interface, we demonstrate that substitution of the -CH 2 OH with the -COOH headgroup produces a major conformational change of the tailgroup from disordered to ordered. This is demonstrated by the electron density profiles of triacontanol (CH 3 (CH 2 ) 29 OH) and triacontanoic acid (CH 3 (CH 2 ) 28 COOH) monolayers at the water-hexane interface, as determined by X-ray reflectivity measurements. Molecular dynamics simulations illustrate the presence of hydrogen bonding between the triacontanoic acid headgroups that is likely responsible for the tail ordering. A simple free energy illustrates the interplay between the attractive hydrogen bonding and the ordering of the tailgroup.

show abstract

Selfassembly of α,ω‐dithiols on surfaces and metal dithiol heterostructures

Hamoudi

Esaulov

2016

Annalen der Physik

View full text Add to dashboard Cite

α,ω-Dithiols present an interesting case of molecules with two reactive terminal -SH groups (HS-R-SH) that allow their use as binders between different metallic entities. They have thus been used in molecular electronics conduction measurements, in "nanogap" electrodes of interest in plasmonics, as building blocks of more complex structures such as metal intercalated superlattices and in the formation of metalized organic thin films, including doped graphene type films. There exist however many problems, because the molecules may end up in undesirable configurations with both thiol terminals bound to the same metal particle/substrate or link with other molecules to produce "multi-molecule" or "multilayer" structures. This report discusses various key questions on dithiol linking with metal surfaces and the quest of protocols of making problem free dithiol metal structures. It then describes the use of dithiols and their SAMs to produce various metal organic heterostructures useful for molecular electronics and formation of doped metalized organic thin films. We discuss the build up of these structures by self assembly and lithography, their chemical composition and functional properties.

show abstract

Surfactant and Water Ordering in Triacontanol Monolayers at the Water−Hexane Interface

Cited by 36 publications

References 30 publications

Vaporization and layering of alkanols at the oil/water interface

Vaporization and layering of alkanols at the oil/water interface

Tail Ordering Due to Headgroup Hydrogen Bonding Interactions in Surfactant Monolayers at the Water−Oil Interface

Selfassembly of α,ω‐dithiols on surfaces and metal dithiol heterostructures

Contact Info

Product

Resources

About