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Start Over Descriptor "Surfactant concentrations" Topic surfactants
3 results on '"Surfactant concentrations"'

1. Surfactant‐mediated synthesis of polyhydroxybutyrate (PHB) nanoparticles for sustained drug delivery.

Author

Pachiyappan, Senthilkumar, Shanmuganatham Selvanantham, Dawn, Kuppa, Sree Samanvitha, Chandrasekaran, Saipriya, and Samrot, Antony Vincent

Abstract

In this study, polyhydroxybutyrate (PHB) nanoparticles were synthesised following nanoprecipitation method having different solvents and surfactant (Tween 80) concentrations. In this study, PHB nanoparticles were encapsulated with curcumin and subjected for sustained curcumin delivery. Both the curcumin loaded and unloaded PHB nanoparticles were characterised using FTIR, SEM, and AFM. Sizes of the particles were found to be between 60 and 300 nm. The drug encapsulation efficiency and in vitro drug release of the nanoparticles were analysed. Antibacterial activity and anticancer activity were also evaluated. The LC50 values of most of the nanoparticles were found to be between 10 and 20 µg/100 µl, anticancer activity of curcumin loaded PHB nanoparticles were further confirmed by AO/PI staining and mitochondrial depolarisation assay. [ABSTRACT FROM AUTHOR]

Published
2019
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2. Surfactant destabilization and non-linear phenomena in two-fluid shear flows at small Reynolds numbers

Author

Kalogirou, Anna, Papageorgiou, Demetrios T., Smyrlis, Yiorgos-Sokratis, Kalogirou, Anna [0000-0002-4668-7747], and Smyrlis, Yiorgos-Sokratis [0000-0001-9126-2441]

Subjects
Two-fluid, Materials science, Surfactants, Asymptotic analysis, Linearly implicit method, Marangoni instabilities, Surface active agents, Instability, Insoluble surfactants, Reynolds number, Physics::Fluid Dynamics, Shear flow, Non-linear phenomena, symbols.namesake, Optics, Pulmonary surfactant, Traveling wave, Flow dynamics, Spatiotemporal chaos, Nonlocal, Surfactant concentrations, Travelling waves, Two-phase flows, Pseudo differential, Numerical experiments, business.industry, Applied Mathematics, Mechanics, Marangoni instability, Condensed Matter::Soft Condensed Matter, Nonlinear system, Shear (geology), Nonlinear evolutions, Local surfaces, symbols, business, Two fluid
Abstract

The flow of two superposed fluids in a channel in the presence of an insoluble surfactant is studied. Asymptotic analysis when one of the layers is thin yields a system of coupled weakly non-linear evolution equations for the film thickness and the local surface surfactant concentration. Film and main flow dynamics are coupled through a non-local term, and in the absence of surfactants the model is nonlinearly stable with trivial large time solutions. Instability arises due to the presence of surfactants and the pseudo-differential non-linear system is solved numerically by implementing accurate linearly implicit methods. Extensive numerical experiments reveal that the dynamics are mostly organized into travelling or time-periodic travelling wave pulses, but spatiotemporal chaos is also supported when the length of the system is sufficiently large. © The authors 2012. 77 3 351 360 Cited By :3

Published
2012

3. The influence of SDS and CTAB surfactants on the surface morphology and surface topography of electroless Ni-P deposits

Author

R. Elansezhian, P. Kesavan Nair, and B. Ramamoorthy

Subjects
Surfactants, Electroless nickel, Diffusers (optical), Surface finish, Surface active agents, Industrial and Manufacturing Engineering, Nickel alloys, Nickel deposits, chemistry.chemical_compound, Pulmonary surfactant, Coating, Nickel, Surface properties, Surface roughness, Smooth surfaces, Ammonium compounds, Protective coatings, Cetyl tri methyl ammonium bromide, Metals and Alloys, Phosphorus, Electroless plating, Computer Science Applications, Modeling and Simulation, Machine vibrations, Electroless Ni-P coatings, Electroless Ni-P, Alkaline baths, Ammonium bromide, Morphology (linguistics), Materials science, Friction, Inorganic chemistry, chemistry.chemical_element, engineering.material, Sodium deposits, Surface topography, Sodium dodecyl sulphate, Surfactant concentrations, Engineering geology, Concentration (process), Sodium, Metal analysis, Coated samples, chemistry, Chemical engineering, Ceramics and Composites, engineering, Surface morphology
Abstract

The effect of surfactants sodium dodecyl sulphate (SDS) and cetyltrimethyl ammonium bromide (CTAB) on the surface roughness, surface morphology and surface topography of electroless nickel (EN)-phosphorus surface protective coating obtained from an alkaline bath is presented in this paper. In this study the influence of surfactant concentrations on the surface roughness of coated samples were investigated. It was observed that the surface roughness, surface morphology and surface topography of Ni-P coating were clearly influenced by the addition of surfactants SDS and CTAB. EN deposits with addition of surfactant SDS and CTAB at a concentration of 0.6 g/l produce a smooth surface and the average roughness (Ra) value is 1.715 ?m for SDS and 1.607 ?m for CTAB which is less than the Ra value of EN deposit without surfactant addition (1.885 ?m). The mean average roughness (Ra) value with addition of surfactant is 1.796 ?m. EN deposit with addition of surfactants consists of a significant fraction of particles of nickel. In the presence of SDS, fine nickel particles have dispersed uniformly on the substrate surface resulting in smoother surface finish of the deposited layers. In the presence of CTAB, at lower concentrations (upto 0.6 g/l) coalescence of nickel particles have been deposited on the substrate surface and at the higher concentration (above 0.6 g/l) uniformly improved surface finish of the deposited layer is resulted. The complete experimental details, results obtained and their analysis are presented in this paper. � 2008 Elsevier B.V. All rights reserved.

Published
2009

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