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Surface deposition and phase behavior of oppositely charged polyion-surfactant ion complexes. Delivery of silicone oil emulsions to hydrophobic and hydrophilic surfaces.

Clauzel M, Johnson ES, Nylander T, Panandiker RK, Sivik MR, Piculell L - ACS Appl Mater Interfaces (2011)

Bottom Line: The effect on the deposition of dilution of the bulk solution in contact with the surface was also investigated by gradual replacement of the bulk solution with 1 mM aqueous NaCl.The largest amount of deposited material after dilution was found for hydrophilic silica and for the least-hydrophobic cationic polymers.For the least-hydrophobic polyions, no significant codeposition of silicone oil was detected at hydrophobized silica after dilution if the initial SDS concentration was high.

View Article: PubMed Central - PubMed

Affiliation: Physical Chemistry, Kemicentrum, Lund University, Box 124, SE-221 00, Lund, Sweden. maryline.clauzel@gmail.com

ABSTRACT
The adsorption from mixed polyelectrolyte-surfactant solutions at hydrophobized silica surfaces was investigated by in situ -ellipsometry, and compared to similar measurements for hydrophilic silica surfaces. Three synthetic cationic copolymers of varying hydrophobicity and one cationic hydroxyethyl cellulose were compared in mixtures with the anionic surfactant sodium dodecylsulfate (SDS) in the absence or presence of a dilute silicone oil emulsion. The adsorption behavior was mapped while stepwise increasing the concentration of SDS to a polyelectrolyte solution of constant concentration. The effect on the deposition of dilution of the bulk solution in contact with the surface was also investigated by gradual replacement of the bulk solution with 1 mM aqueous NaCl. An adsorbed layer remained after complete exchange of the polyelectrolyte/surfactant solution for aqueous NaCl. In most cases, there was a codeposition of silicone oil droplets, if such droplets were present in the formulation before dilution. The overall features of the deposition were similar at hydrophobic and hydrophilic surfaces, but there were also notable differences. SDS molecules adsorbed selectively at the hydrophobized silica surface, but not at the hydrophilic silica, which influenced the coadsorption of the cationic polymers. The largest amount of deposited material after dilution was found for hydrophilic silica and for the least-hydrophobic cationic polymers. For the least-hydrophobic polyions, no significant codeposition of silicone oil was detected at hydrophobized silica after dilution if the initial SDS concentration was high.

No MeSH data available.


Related in: MedlinePlus

Evolution of the adsorbed amount (open circles) and thickness (filled squares) of the layer adsorbed on hydrophobized silica from 100 ppm AA/MAPTAC dissolved in 3 mM SDS, 1 mM NaCl during dilution of the bulk solution. Dilution with 1 mM NaCl started at t = 0.
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fig4: Evolution of the adsorbed amount (open circles) and thickness (filled squares) of the layer adsorbed on hydrophobized silica from 100 ppm AA/MAPTAC dissolved in 3 mM SDS, 1 mM NaCl during dilution of the bulk solution. Dilution with 1 mM NaCl started at t = 0.

Mentions: Figure 4 displays typical features for formulations where the surfactant concentration before dilution was at cmax. Specifically, the figure shows the time-dependent adsorption at a hydrophobic surface for an emulsion-free formulation of AA/MAPTAC in 3 mM SDS. Immediately after adding the formulation to the cuvette, there was a very rapid increase in adsorbed amount, followed by a more gradual build-up over a significant time period. The relative variation in thickness of the adsorbed layer during the slow build-up phase was smaller than the variation in the adsorbed amount. For some systems, a constant thickness was reached immediately after the initial steep increase.


Surface deposition and phase behavior of oppositely charged polyion-surfactant ion complexes. Delivery of silicone oil emulsions to hydrophobic and hydrophilic surfaces.

Clauzel M, Johnson ES, Nylander T, Panandiker RK, Sivik MR, Piculell L - ACS Appl Mater Interfaces (2011)

Evolution of the adsorbed amount (open circles) and thickness (filled squares) of the layer adsorbed on hydrophobized silica from 100 ppm AA/MAPTAC dissolved in 3 mM SDS, 1 mM NaCl during dilution of the bulk solution. Dilution with 1 mM NaCl started at t = 0.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211372&req=5

fig4: Evolution of the adsorbed amount (open circles) and thickness (filled squares) of the layer adsorbed on hydrophobized silica from 100 ppm AA/MAPTAC dissolved in 3 mM SDS, 1 mM NaCl during dilution of the bulk solution. Dilution with 1 mM NaCl started at t = 0.
Mentions: Figure 4 displays typical features for formulations where the surfactant concentration before dilution was at cmax. Specifically, the figure shows the time-dependent adsorption at a hydrophobic surface for an emulsion-free formulation of AA/MAPTAC in 3 mM SDS. Immediately after adding the formulation to the cuvette, there was a very rapid increase in adsorbed amount, followed by a more gradual build-up over a significant time period. The relative variation in thickness of the adsorbed layer during the slow build-up phase was smaller than the variation in the adsorbed amount. For some systems, a constant thickness was reached immediately after the initial steep increase.

Bottom Line: The effect on the deposition of dilution of the bulk solution in contact with the surface was also investigated by gradual replacement of the bulk solution with 1 mM aqueous NaCl.The largest amount of deposited material after dilution was found for hydrophilic silica and for the least-hydrophobic cationic polymers.For the least-hydrophobic polyions, no significant codeposition of silicone oil was detected at hydrophobized silica after dilution if the initial SDS concentration was high.

View Article: PubMed Central - PubMed

Affiliation: Physical Chemistry, Kemicentrum, Lund University, Box 124, SE-221 00, Lund, Sweden. maryline.clauzel@gmail.com

ABSTRACT
The adsorption from mixed polyelectrolyte-surfactant solutions at hydrophobized silica surfaces was investigated by in situ -ellipsometry, and compared to similar measurements for hydrophilic silica surfaces. Three synthetic cationic copolymers of varying hydrophobicity and one cationic hydroxyethyl cellulose were compared in mixtures with the anionic surfactant sodium dodecylsulfate (SDS) in the absence or presence of a dilute silicone oil emulsion. The adsorption behavior was mapped while stepwise increasing the concentration of SDS to a polyelectrolyte solution of constant concentration. The effect on the deposition of dilution of the bulk solution in contact with the surface was also investigated by gradual replacement of the bulk solution with 1 mM aqueous NaCl. An adsorbed layer remained after complete exchange of the polyelectrolyte/surfactant solution for aqueous NaCl. In most cases, there was a codeposition of silicone oil droplets, if such droplets were present in the formulation before dilution. The overall features of the deposition were similar at hydrophobic and hydrophilic surfaces, but there were also notable differences. SDS molecules adsorbed selectively at the hydrophobized silica surface, but not at the hydrophilic silica, which influenced the coadsorption of the cationic polymers. The largest amount of deposited material after dilution was found for hydrophilic silica and for the least-hydrophobic cationic polymers. For the least-hydrophobic polyions, no significant codeposition of silicone oil was detected at hydrophobized silica after dilution if the initial SDS concentration was high.

No MeSH data available.


Related in: MedlinePlus