Physico-chemical studies of some aqueous surfactant solutions were carried out by employing conductance, surface tension and spectrofluorometric techniques. From conductivity and surface tension measurements, critical micelle concentration (CMC), counter-ion association (α), equivalent conductance at infinite dilution (٨0), surface excess concentration (Γ), minimum area per molecule (Amin), sur...

The effect of nonlinear interactions on the linear instability of shape fluctuations of a flat charged membrane immersed in a fluid is analyzed using a weakly nonlinear stability analysis. There is a linear instability when the surface tension reduces below a critical value for a given charge density, because a displacement of the membrane surface causes a fluctuation in the counterion density ...

We study the morphologies of single liquid droplets wetting a substrate in the presence of the line tension of the three-phase contact line. On a homogeneous substrate, the line tension leads to a discontinuous unbinding of the droplet if its volume is decreased below a critical value. For a droplet wetting a structured surface with a circular domain, a line tension contrast gives rise to disco...

a rhamnolipid–type biosurfactant production by pseudomonas aeruginosa mm1011 was studied in a miniaturized shaken bioreactor. the operational parameters, affecting the biosurfactant production in shaken bioreactors, such as shaking frequency (200, 250, 300 rpm), filling volume (50, 75, 100 ml), and aeration rate (0.2, 0.6, 1 vvm), were optimized using response surface methodology. the optimizat...

The effects of osmolarity, calcium concentration and cell-size liposomes in the subphase on the surface tension of phospholipid monolayers were investigated. The monolayers were spread from chloroform solutions of phosphatidic acid at air/water solution interface. The liposomes (of average diameter 3 micron) were formed from phosphatidic acid/egg lecithin (1:2) mixtures in water or 0.1 M water ...

The behavior of annealed branched polymers near adsorbing surfaces plays a fundamental role in many biological and industrial processes. Most importantly single stranded RNA in solution tends to fold up and self-bind to form a highly branched structure. Using a mean field theory, we both perturbatively and numerically examine the adsorption of branched polymers on surfaces of several different ...

α, ω-alkane-bis(n-myristoyloxyethyl-n, n-dimethyl)-diammonium bromide were synthesized and confirmed by ft-ir, ft-raman and 1h-nmr spectroscopy. surface tensions were measured by sigma 70 and conductivity meter ec-470c. critical micelle concentration values were 2.70×10-4∼3.05×10-4 mol/l. the krafft points were measured at 39.1 ~ 43.2℃. their inhibition effects on the corrosion of low carbon st...

The validity of the principle of corresponding states is investigated for the case of a potential with more than one intrinsic length scale. The planar surface tension of coexisting liquid and vapor phases of a fluid of Lennard-Jones atoms is studied as a function of the range of the potential using both Monte Carlo simulations and density functional theory (DFT). The interaction range is varie...