We have characterized the phase behavior of mixtures of the cationic surfactant cetyltrimethylammonium bromide (CTAB) and the organic salt 3-sodium-2-hydroxy naphthoate (SHN) over a wide range of surfactant concentrations using polarizing optical microscopy and X-ray diffraction. A variety of liquid crystalline phases, such as hexagonal, lamellar with and without curvature defects, and nematic,...

Transfection of an anionic polynucleotide through a negatively charged membrane is an important problem in genetic engineering. The direct association of cationic surfactant to DNA decreases the effective negative charge of the nucleic acid, allowing the DNA-surfactant complex to approach a negatively charged membrane. The paper develops a theory for solutions composed of polyelectrolyte, salt,...

Individual and sequential adsorption of the anionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant Triton X-100 on cationic and anionic polystyrene latexes has been examined. Both latex samples, although charged differently (-16.2 and +11.0&mgr;C cm(-2)), must be considered hydrophobic polymer colloids. The adsorbed amounts of both surfactants on cationic and anionic latexe...

The electrostatic coadsorption of the synthetic polypeptide poly-L-glutamic acid (pGlu) and the cationic hemicyanine surfactant trans-4-[4-(dibutylamino)styryl]-1-methylpyridinium iodide (D-CH3) is observed at the water/1,2-dichloroethane (DCE) interface with the spectroscopic technique of optical second-harmonic generation (SHG). The adsorption isotherm of D-CH3 to the water/DCE interface is o...

The interaction between methyl red (azo dye) and cetylpyridinium chloride (cationic surfactant) in the methanol-water system were studied using a spectrophotometric technique. Variable parameters like constant dye concentration its structure, surfactant concentration, pH, absorbance, solvent composition studied. Using UV-Vis technique, critical micelle concentrations (CMCs) of measured with red...

The effect of ethanol on the surface properties of bolaamphiphiles and their mixed systems with oppositely charged conventional surfactants is studied and compared with the corresponding conventional surfactant systems. It is found that both the bolaamphiphile and the conventional surfactant have the similar variation tendency of γcmc and Γ∞ in the single surfactant system. However, in the cati...

The effect of surfactants on the treatment of chemical mechanical polishing (CMP) wastewater by electro-coagulation-flotation (ECF) process was studied. Two surfactants, cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfate (SDS) were employed in this study to compare the effect of cationic (CTAB) and anodic (SDS) surfactants on ECF. The cationic surfactant can enhance the removal of ...

We examined the synthesis and characterization of polymer micelle using polymerizable cationic gemini surfactant (surfmer). Here, cationic gemini surfmer (GS) was newly synthesized and characterized. Also, a “monomer”-type surfmer (MS) was synthesized and characterized for comparison. The equilibrium properties in water and in the presence of 0.1 M NaBr were investigated by means of surface ten...

Adsorption and desorption of sulfamethoxazole (SMX) at water-sediment interfaces from Taihu Lake, China, were investigated in this study. The effects of a cationic surfactant, cetyltrimethylammonium bromide (CTAB), and an anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), on the adsorption/desorption processes were also studied. Results show that adsorption and desorption could be well...

Zeta potential, effective diameter and sedimentation rate of TiO2 (Degussa P-25) suspension were studied in the presence of NaCl and anionic (sodium dodecyl sulfate, SDS) or cationic (dodecyltrimethylammonium bromide, DTAB; tetradecyltrimethylammonium bromide, TTAB; and hexadecyltrimethylammonium bromide, CTAB) surfactant, as well as lecithin (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC)....