We examine the effect of surfactants on the evolution of the shape of an initially nonspherical drop translating in an otherwise quiescent fluid at low Reynolds number. A combination of the boundary-integral method and a finite-difference scheme is used to solve the coupled fluid dynamics and surfactant transport problems, in conjunction with the Frumkin adsorption framework to account for the ...

Polycyclic aromatic hydrocarbon (PAH) contamination of the environment represents a serious threat to the health of humans and ecosystems. Given the human health effects of PAHs, effective and cost-competitive remediation technologies are required. Bioremediation has shown promise as a potentially effective and low-cost treatment option, but concerns about the slow process rate and bioavailabil...

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...

This paper reports the colorimetric and resonance scattering (RS)-based biosensor for the ultrasensitive detection of As(III) in aqueous solution via aggregating gold nanoparticles (AuNPs) by the special interactions between arsenic-binding aptamer, target and cationic surfactant. Aptamers and the cationic surfactant could assemble to form a supramolecule, which prevented AuNPs from aggregating...

The addition of low concentrations of the hydrotropic salt p-toluidine hydrochloride (PTHC) to solutions of the anionic surfactant sodium dodecyl sulfate (SDS) promotes the transition from spherical to rodlike micelles. NMR measurements confirm that the hydrotrope adsorbs at the micelle-water interface, thereby screening electrostatic repulsions between the surfactant headgroups. The sphere-to-...

The interactions and structure of complexes formed between bovine serum albumin (BSA) and the anionic surfactant sodium dodecyl sulfate has been investigated by spectroscopic probe techniques. Steady state and time-resolved fluorescence, electron spin resonance, and deuterium NMR spectroscopy have been employed as a multitechnique approach to investigate the structures which occur along the pro...

the interactions of β-lactoglobulin ab in the presence of cationic surfactants such as cetyltrimethylammonium bromide and cetyltrimethylammonium p-toluenesulfonate have been investigated using a variety of experimental techniques such as conductivity, uv-vis spectrophotometry and fluorimetry. the conductivity of surfactants aqueous solutions with β-lactoglobulin shows that the cmc of cationic s...

Surfactant protein (SP) A and SP-D are collagenous glycoproteins with multiple functions in the lung. Both of these proteins are calcium-dependent lectins and are structurally similar to mannose-binding protein and bovine conglutinin. Both form polyvalent multimeric structures for interactions with pathogens, cells, or other molecules. SP-A is an integral part of the surfactant system, binds ph...

The adsorption of surfactants onto a hydrophobic interface, already laden with a fixed number of amphiphilic macromolecules, is studied using the self consistent field calculation method of Scheutjens and Fleer. For biopolymers having unfavourable interactions with the surfactant molecules, the adsorption isotherms show an abrupt jump at a certain value of surfactant bulk concentration. Alterna...

We report on the interaction of pulmonary surfactant composed of phospholipids and proteins with nanometric alumina (Al2O3) in the context of lung exposure and nanotoxicity. We study the bulk properties of phospholipid/nanoparticle dispersions and determine the nature of their interactions. The clinical surfactant Curosurf, both native and extruded, and a protein-free surfactant are investigate...