Analysis of thickness of a hydrophobic fluoropolymer film based on electrowetting.

The electrowetting of water drops on a dielectric fluoropolymer film was studied experimentally. The dependence of the contact angles of the water drops on the applied voltage has been well explained in the low-voltage limit by using the classical Young-Lippmann theory. With this theory, the thicknesses of films coated on glass substrates by using a spin-coater were obtained indirectly by fitting the contact angle data and were confirmed by using X-ray reflectometry.

Nanostructured metal/carbon hybrids for electrocatalysis by direct carbonization of inverse micelle multilayers.

A synthetic strategy for the fabrication of graphitic carbon nanomaterials containing highly dispersed arrays of metal nanoparticles is reported. This synthetic strategy involves successive deposition of inverse micelle monolayers containing a metal precursor and reduction of the latter, followed by direct carbonization of the obtained multilayer structure of inverse micelles containing metal nanoparticles. Thus, a "direct-carbonization" concept, in which the block copolymer simultaneously serves as soft template and as carbon source, was combined with a multilayer buildup protocol.

Influence of charge densities of randomly sulfonated polystyrene surfaces on cell attachment and proliferation.

Attachment and proliferation of NIH-3T3 fibroblast cells on random polymer surfaces, polystyrene sulfonated acid (PSSAx) with five different degrees of sulfonation (x = 0%, 5%, 10%, 15% and 33%) and on a tissue culture polystyrene (TCPS) surface were studied. The surface properties, wettability and roughness were measured by water-contact angle and atomic force microscopy measurement. The wettability and surface roughness increased with increasing the content of sulfonic acid groups on the surfaces.

Interaction between zwitterionic and anionic surfactants: spontaneous formation of zwitanionic vesicles.

The physicochemical properties, such as critical micelle concentration (cmc), surface tension at cmc (γ(cmc)), and surface activity parameters of the mixtures of a new amino acid-based zwitterionic surfactant, N-(n-dodecyl-2-aminoethanoyl)-glycine (C(12)Gly) and an anionic surfactant, sodium dodecyl sulfate (SDS) at different molar fractions, X(1) (= [C(12)Gly]/([C(12)Gly] + [SDS])) of C(12)Gly were studied. A synergistic interaction was observed between the surfactants in mixtures of different X(1). The self-organization of the mixtures at different molar fractions, concentrations, and pH was investigated.

Physicochemical properties and microstructure formation of the surfactant mixtures of sodium N-(2-(n-dodecylamino)ethanoyl)-L-alaninate and SDS in aqueous solutions.

Aggregation behavior of a novel anionic amphiphilic molecule, sodium N-(2-(n-dodecylamino)ethanoyl)-L-alaninate (C(12)Ala), was studied in the presence of sodium dodecyl sulfate (SDS) surfactant at different [C(12)Ala]/[SDS] molar ratios and concentrations. The viscosity of aqueous SDS solution increased in the presence of C(12)Ala surfactant. The bulk viscosity of water was found to increase upon increase of both molar ratio and total surfactant concentration.

Fluorescence, circular dichroism, light scattering, and microscopic characterization of vesicles of sodium salts of three N-acyl peptides.

Aggregation behavior of three N-acyl peptide surfactants, sodium N-(4-n-dodecyloxybenzoyl)-L-alyl-L-valinate (SDBAV), L-valyl-L-alaninate (SDBVA), and L-valyl-L-valinate (SDBVV), were investigated. The amphiphiles have very low critical aggregation concentration (cac). Fluorescence anisotropy studies using 1,6-diphenyl-1,3,5-hexatriene (DPH) as a fluorescent probe indicated formation of bilayer aggregates in dilute solution.

A supramolecular hydrogel that responds to biologically relevant stimuli.

First demonstration of heat and pH-responsive hydrogel of SDS and a zwitterionic amphiphile, sodium N-(n-dodecyl-2-aminoethanoyl)-L-valinate with very low minimum gelation concentration.

Characterization of micelle formation of dodecyldimethyl-N-2-phenoxyethylammonium bromide in aqueous solution.

Aggregation behavior of dodecyldimethyl-N-2-phenoxyethylammonium bromide commonly called domiphen bromide (DB) was studied in aqueous solution. The Krafft temperature of the surfactant was measured. The surfactant has been shown to form micellar structures in a wide concentration range.

Giant vesicles of a single-tailed chiral cationic surfactant, (1R,2S)-(-)-N-dodecyl-N-methylephedrinium bromide, in water.

Self-assembly properties of a single-tailed chiral cationic surfactant, (1R,2S)-(-)-N-dodecyl-N-methylephedrinium bromide (DMEB), have been studied in water. The molecular self-assemblies of the amphiphile have been characterized by surface tension, fluorescence probes, light scattering, and microscopic techniques. The results have been compared with those of dodecyltrimethylammonium bromide (DTAB) surfactant.

Spontaneous formation of gel emulsions in organic solvents and commercial fuels induced by a novel class of amino acid derivatized surfactants.

A novel class of amphiphiles, sodium N-(n-dodecyl-2-aminoethanoyl)-l-amino acidate, have been synthesized. These amphiphiles have been shown to form oil-in-water-type gel emulsions with a high internal-phase ratio in organic solvents as well as in commercial fuels simply by agitation. No heating and cooling cycle was required for the formation of gels.

Cationic vesicles as chiral selector for enantioseparations of nonsteroidal antiinflammatory drugs by micellar electrokinetic chromatography.

A vesicle-forming chiral cationic surfactant (1R,2S)-(-)-N-dodecyl-N-methyl-ephedrinium bromide was evaluated as a pseudo-stationary phase in micellar electrokinetic chromatography (MEKC) for enantioseparation of eight non-steroidal anti-inflammatory drugs e.g., carprofen, flurbiprofen, fenoprofen, ibuprofen, indoprofen, ketoprofen, naproxen and suprofen by capillary electrophoresis.