Slowdown of translational and reorientational dynamics of water confined in Newton black films (NBFs) is revealed by molecular dynamics simulations. As a film becomes thinner, both translational and reorientational dynamics become slower. The polarization of water molecules in the macroscopic electrostatic field across the NBF and the coordination of Na(+) ions and surfactant anionic groups aro...

Nanosized hydroxyapatite (HA) powders have been synthesized by an inverse microemulsion system using cyclohexane, an anionic surfactant and aqueous solutions of calcium nitrate tetrahydrate and biammonium hydrogen phosphate in the presence of anionic and caionic polyelectrolyte with the inducement of ultrasound irradiation. Prepared HA in presence of anionic polyelectrolyte has a different morp...

Photon correlation spectroscopy and rheological measurements are performed to investigate the microscopic dynamics and mechanical responses of aqueous solutions of triblock copolymers and aqueous mixtures of triblock copolymers and anionic surfactants. Increasing the concentration of triblock copolymers results in a sharp increase in the magnitude of the complex moduli characterising the sample...

Cellulose nanofibrils (CNFs) present unique opportunities for rheology modification in complex fluids. Here we systematically consider the effect of ionic and non-ionic surfactants on the rheology of dilute CNF suspensions. Neat suspensions are transparent yield-stress fluids which display strong shear thinning and power-law dependence of modulus on concentration, G' ∼ c(2.1). Surfactant additi...

The nature and strength of the interactions between a cationic fluorophore, Rhodamine 123 (R123), and surfactants of different head charge are investigated. Series of absorption and fluorescence emission spectra and of fluorescence decays are measured. R123 does not interact with the monomers of both nonionic and cationic surfactants but it presents affinity to their micelles. A partition equil...

In this study, the solubilization of two organic dyes, Sudan I (1-Phenylazo-2-naphtol) and Quinizarin (1,4-Dihydroxyanthraquinone), was studied in the presence of different types of surfactants (2 polymerics, 2 nonionics, 2 anionic, and one cationic) using UV-Vis spectroscopy. The effects of temperature, pH and addition of different electrolytes (NaCl, Na2CO3, NaI, NaOH, NaSCN) on dye solubiliz...

A systematic study has been performed employing the use of a cationic surfactant didodecyldimethylammonium bromide (DDAB), an anionic surfactant sodium lignosulfonate (SLS) and water for Enhanced Oil Recovery (EOR) from the underground porous media of the depleting oil field of Naharkotiya, Duliajan, in the Upper Assam basin, India. The strong electrostatic interaction between the oppositely ch...

ruthenium dioxide nanoparticles (ruo2 ) with an average particle size of 50 nm are readily synthesized from rucl3.xh2o via the precipitation process in the presence of in-situ sodium octanoate as anionic surfactant. the phase composition, morphology, lattice parameters and size of nanoparticles in these products are characterized by fourier transform infrared spectroscopy (ft-ir), x-ray diffrac...

Some inactive precursor proteins, or zymogens, contain small, amino terminus, homopolymeric regions of Asp that neutralize the cationic charge of the active protein during synthesis. After posttranslational cleavage, the anionic propeptide fragment may exhibit antimicrobial activity. To demonstrate this, ovine trypsinogen activation peptide, and frog (Xenopus laevis) PYL activation peptide, bot...