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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

Effect of diluting a formulation of 100 ppm AA/MAPTAC,10 mM of SDS and 1 mM NaCl, without (filled circles) or with (open circles) 400 ppm silicone emulsion on the deposition onto (a) hydrophilic and (b) hydrophobized silica. Time zero corresponds to the beginning of the dilution process with 1 mM NaCl at a rate of 5 mL/min, for a cuvette volume of 5 mL and a stirring rate of 300 rpm.
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fig5: Effect of diluting a formulation of 100 ppm AA/MAPTAC,10 mM of SDS and 1 mM NaCl, without (filled circles) or with (open circles) 400 ppm silicone emulsion on the deposition onto (a) hydrophilic and (b) hydrophobized silica. Time zero corresponds to the beginning of the dilution process with 1 mM NaCl at a rate of 5 mL/min, for a cuvette volume of 5 mL and a stirring rate of 300 rpm.

Mentions: For systems with initial surfactant concentrations at or above crediss, a transient peak in adsorbed amount was generally observed on dilution of the bulk solution. This feature was also observed in previous investigations, where it was also found that the magnitude of the transient peak decreased if the surfactant concentration was increased above crediss.14,31 Figure 5 shows examples of pronounced transient peaks for AA/MAPTAC in 10 mM SDS, in the presence or absence of 400 ppm silicone emulsion, both on hydrophilic and hydrophobized silica surfaces. The results in Figure 5 highlight a new feature, compared to previous investigations, namely, that the dilution-induced deposition may be quite different on hydrophilic and hydrophobic surfaces. On the hydrophilic surface, there was initially only a low adsorbed amount (0.3–0.5 mg/m2), with a net increase resulting from the dilution of the bulk solution in contact with the surface. There was a much higher final adsorbed amount after dilution from the formulation with silicone oil emulsion (1.8 mg/m2) than from the one without (0.8 mg/m2). On hydrophobized silica, however, there was no difference in adsorbed amount, neither before nor after diluting the formulations with or without emulsion. Moreover, in both cases, there was a net decrease in adsorbed amount on rinsing, from 1.4 mg/m2 to 1.1 mg/m2. Interestingly, however, a large transient adsorption peak appeared on rinsing from these mixtures, reaching as high as 2.6 mg/m2. The fine structures of the transient peaks indicate that there was a difference in the transient deposition from mixtures with or without emulsion. This transient difference was even more evident in the thicknesses of the adsorbed layers (not shown).


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)

Effect of diluting a formulation of 100 ppm AA/MAPTAC,10 mM of SDS and 1 mM NaCl, without (filled circles) or with (open circles) 400 ppm silicone emulsion on the deposition onto (a) hydrophilic and (b) hydrophobized silica. Time zero corresponds to the beginning of the dilution process with 1 mM NaCl at a rate of 5 mL/min, for a cuvette volume of 5 mL and a stirring rate of 300 rpm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig5: Effect of diluting a formulation of 100 ppm AA/MAPTAC,10 mM of SDS and 1 mM NaCl, without (filled circles) or with (open circles) 400 ppm silicone emulsion on the deposition onto (a) hydrophilic and (b) hydrophobized silica. Time zero corresponds to the beginning of the dilution process with 1 mM NaCl at a rate of 5 mL/min, for a cuvette volume of 5 mL and a stirring rate of 300 rpm.
Mentions: For systems with initial surfactant concentrations at or above crediss, a transient peak in adsorbed amount was generally observed on dilution of the bulk solution. This feature was also observed in previous investigations, where it was also found that the magnitude of the transient peak decreased if the surfactant concentration was increased above crediss.14,31 Figure 5 shows examples of pronounced transient peaks for AA/MAPTAC in 10 mM SDS, in the presence or absence of 400 ppm silicone emulsion, both on hydrophilic and hydrophobized silica surfaces. The results in Figure 5 highlight a new feature, compared to previous investigations, namely, that the dilution-induced deposition may be quite different on hydrophilic and hydrophobic surfaces. On the hydrophilic surface, there was initially only a low adsorbed amount (0.3–0.5 mg/m2), with a net increase resulting from the dilution of the bulk solution in contact with the surface. There was a much higher final adsorbed amount after dilution from the formulation with silicone oil emulsion (1.8 mg/m2) than from the one without (0.8 mg/m2). On hydrophobized silica, however, there was no difference in adsorbed amount, neither before nor after diluting the formulations with or without emulsion. Moreover, in both cases, there was a net decrease in adsorbed amount on rinsing, from 1.4 mg/m2 to 1.1 mg/m2. Interestingly, however, a large transient adsorption peak appeared on rinsing from these mixtures, reaching as high as 2.6 mg/m2. The fine structures of the transient peaks indicate that there was a difference in the transient deposition from mixtures with or without emulsion. This transient difference was even more evident in the thicknesses of the adsorbed layers (not shown).

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