1. Comparative study of carbon nanotube dispersion using surfactants Aqueous carbon nanotube dispersions were obtained by sonication tip using two cationic (DTAB and CTAB) and three anionic surfactants (SDDBS, SDS and SC). UV-Vis spectroscopy is a versatile method for characterizing the dispersion quality of CNTs in a solution. Bundles of MWCNTs are not active in the wavelength region between 2...

The interaction between λ--DNA and cationic surfactants with varying alkyl chain lengths was investigated. By dynamic light scattering method, the trimethyl-ammonium bromides-DNA complex formation was shown to be dependent on the length of the surfactant's alkyl chain. For surfactants with sufficient long alkyl chain (CTAB, TTAB, DTAB), the compacted particles exist with a size of ~60-110 nm at...

Surfactant-enhanced remediation technology has shown promising potential for removing residual organics from contaminated soils and groundwater. Using a homologous series of cationic surfactants, alkylpyridinium bromide, it was found that the molar solubilization ratio (MSR) for naphthalene decreases with decreasing carbon number in the hydrophobic tail. In contrast, with nonylphenyl ethoxylate...

Micellar-enhanced ultrafiltration (MEUF) was used to remove phenol from simulant aqueous solutions. The effect of groups difference of cationic surfactant on the solubilization of phenol was investigated through orthogonal experiment, namely, surfactants with the same length of hydrocarbon chain but different hydrophilic head group and vice versa. The effects on the solubilization of

Increased hydrophobicity of well-defined polyoxometalate clusters is possible through complexation with cationic surfactants in a one-pot reaction. The clusters, of toroid and spherical shape and colloidal dimensions, then organized into ordered, supramolecular assemblies, as shown schematically, are similar to classical liquid crystals. The increased solubility in organic media opens the door ...

Emulsified water is generally present in crude oil as a result of mixing occurring during production operations. The formation of emulsion leads to problems in production and also transportation. Therefore the need to break oil/water emulsions system through demulsification process using chemical surfactants for improved oil recovery operations. Selected cationic surfactants were effective in s...

The Binding behavior of acidic capsular polysaccharide (SPS), isolated from Klebsiella serotype K43 with oppositely charged dyes and surfactants have been studied by absorbance and emission spectroscopic studies. Each repeating unit of the SPS consists of three D-mannose, one D-galactose and one D-glucuronic acid residue. The anionic polymer exhibited chromtropic character and induced strong me...

The thermodynamic parameters of interaction between calf thymus histone H A and dodecyl trimethyl ammonium bromide (DTAB), a cationic surfactant, in aqueous solutions of pH 3.2, 6.4 and 10.0 were measured over a wide range of DTAB concentrations by equilibrium dialysis at 27°C and 37°C and are discussed. The data are used to determine the free energy from the Wyman binding potential theore...

Trypsin-dissociated HeLa and human amnion cells were employed to investigate the effects of an anionic, a cationic, and a non-ionic surfactant on cell reaggregation. All the surfactants inhibited the reaggregation process, the effect increasing with surfactant concentration, and becoming significant at concentrations of about 10(-6) M for the anionic surfactant and about 10(-5) M for the others...

magnetic cofe2o4 nanoparticles were synthesized via a simple chemical reaction using precipitation method. the obtained materials consist of ferrite particles with average diameter of 25 nm. the effect of different surfactants such as cationic, anionic and neutral on the morphology of the products was investigated. scanning electron microscopy was used to study the structure and particle size o...