The drop and bubble profile methods are used to study the viscoelasticity modulus of C14EO8 aqueous solutions within a wide concentration range. To determine the equilibrium concentration of the surfactant in the drop bulk, the correction is introduced for the surfactant losses caused by its adsorption on the drop surface. It is shown that with this correction the frequency dependencies of the viscoelasticity modulus measured by either of the two experimental techniques are almost the same. The theoretical model is used, which describes the surfactant dilational rheology assuming the diffusion-governed adsorption. The experimental data for C14EO8 solutions is described by the reorientation model that assumes the two states of surfactant molecules with different molar areas in the surface layer and the intrinsic compressibility of the molecules.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/la401262w | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The dynamic and equilibrium surface tension for drops of aqueous CEO solutions at the interface to pure air or pentane, hexane, heptane and toluene saturated air, and the dynamic surface tension of pure water at these interfaces are presented. Two theoretical models were employed: both assuming a diffusion controlled adsorption of the surfactant, and either a diffusion or kinetic barrier governed adsorption of the alkanes. The experimental results are best described by the model which implies a diffusion control for the CEO molecules and the existence of a kinetic barrier for the alkane molecules.
View Article and Find Full Text PDFViscoelasticity moduli of aqueous C14EO8 solutions as studied by drop and bubble profile methods.
Langmuir
June 2013
Donetsk Medical University, 83003 Donetsk, Ukraine.
The drop and bubble profile methods are used to study the viscoelasticity modulus of C14EO8 aqueous solutions within a wide concentration range. To determine the equilibrium concentration of the surfactant in the drop bulk, the correction is introduced for the surfactant losses caused by its adsorption on the drop surface. It is shown that with this correction the frequency dependencies of the viscoelasticity modulus measured by either of the two experimental techniques are almost the same.
View Article and Find Full Text PDFSurface dilational viscoelasticity of C14EO8 micellar solution studied by bubble profile analysis tensiometry.
Langmuir
June 2008
Medical Physicochemical Centre, Donetsk Medical University, 16 Ilych Avenue, 83003 Donetsk, Ukraine, Unilever R&D Port Sunlight, Quarry Road East, Bebington, CH63 3JW, UK.
The experimental dependences of viscoelasticity modulus and phase angle as a function of frequency for various C 14EO8 concentrations at the critical micelle concentration (cmc) of 7 micromol/L and far above the cmc (up to 70 x cmc) were studied using the buoyant bubble profile analysis method. With increasing C14EO8 concentration the viscoelasticity modulus decreases and the phase angle increases. At the highest surfactant concentrations, the phase angle was more than 45 degrees .
View Article and Find Full Text PDFDilational rheology of serum albumin and blood serum solutions as studied by oscillating drop tensiometry.
Colloids Surf B Biointerfaces
March 2008
Donetsk Medical University, 16 Ilych Avenue, 83003 Donetsk, Ukraine.
Oscillating drop experiments with a drop profile analysis tensiometer provide the dilational elasticity and viscosity of surface layer. Model experiments for blood serum, composed of HSA and the non-ionic surfactant C(14)EO(8), are used to demonstrate the theoretical approach for calculating the visco-elasticity of mixed adsorption layers from the adsorption characteristics of the single components. Experiments with real serum samples taken from patients choledocholithiasis-based benign obstructive jaundice before and after re-canalisation of the biliary tract demonstrate that the visco-elasticity of the respective adsorption layers is very sensitive of the successful surgery.
View Article and Find Full Text PDFDynamic surface tension of micellar solutions in the millisecond and submillisecond time range.
J Colloid Interface Sci
October 2006
Medical Physicochemical Centre, Donetsk Medical University, 16 Ilych Avenue, 83003 Donetsk, Ukraine.
The analysis of the available bubble life times and dead times for the bubble pressure tensiometer BPA-1S shows that dynamic surface tensions can be measured also for surfactant solutions at concentrations many times higher than the corresponding CMC. For the three nonionic surfactants Triton X-100, Triton X-45, and C14EO8 experiments are performed for solutions with a concentration of up to 200 times the CMC (C14EO8). Comparison of the experimental data with micelle kinetics models yields rate constants for the fast micelle dissolution process, which are in a good agreement with values obtained by other experimental methodologies.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!