Adsorption of Mixtures of a Pegylated Lipid with Anionic and Zwitterionic Surfactants at Solid/Liquid

Abstract

This work explores the association of a pegylated lipid (DSPE-PEG) with different anionic and zwitterionic surfactants (pseudo-binary and pseudo-ternary polymer+ surfactant mixtures), and the adsorption of the polymer + surfactant aggregates onto negatively charged surfaces, with a surface charge density similar to that existing on the damaged hair epicuticle. Dynamic light scattering and zeta potential measurements shows that, in solution, the polymer + surfactant association results from an intricate balance between electrostatic and hydrophobic interactions, which leads to the formation of at least two different types of micellar-like polymer + surfactant aggregates. The structure and physicochemical properties of such aggregates were found strongly dependent on the specific nature and concentration of the surfactant. The adsorption of the polymer + surfactant aggregates onto negatively charged surface was studied using a set of surface-sensitive techniques (quartz crystal microbalance with dissipation monitoring, ellipsometry and Atomic Force Microscopy), which allows obtaining information about the adsorbed amount, the water content of the layers and the topography of the obtained films. Ion-dipole interactions between the negative charges of the surface and the oxyethylene groups of the polymer + surfactant aggregates appear as the main driving force of the deposition process. This is strongly dependent on the surfactant nature and its concentration, with the impact of the latter on the adsorption being especially critical when anionic surfactant are incorporated within the aggregates. This study opens important perspectives for modulating the deposition of a poorly interacting polymer onto negatively charged surfaces, which can impact in the fabrication on different aspects with technological and industrial interest.

Biodegradable Amphoteric Surfactants in Titration-Ultrasound Formulation of Oil-in-Water Nanoemulsions: Rational Design, Development, and Kinetic Stability

“…Generally, in formulations with a lower concentration of surfactants, the zeta potential values were the highest from −14 to −29 mV. The observed phenomenon is in a good correlation with the earliest studies on the zeta potential behavior of betaine-type surfactants [26]. Although these nanoemulsions showed potentially higher stability, their too small droplet size (65-78 nm) for cosmetic and pharmaceutical applications [1], made it possible to select formulations with optimally better physicochemical parameters in terms of size, polydispersity, and stability for further experiments (Table 1).…”

“…earliest studies on the zeta potential behavior of betaine-type surfactants [26]. Althoug these nanoemulsions showed potentially higher stability, their too small droplet size (6 78 nm) for cosmetic and pharmaceutical applications [1], made it possible to sele formulations with optimally better physicochemical parameters in terms of siz polydispersity, and stability for further experiments (Table 1).…”

Polyelectrolyte Multilayered Capsules as Biomedical Tools

“…This is possible by the incorporation of small ions in the LbL films, thus allowing the compensation of the charge excess emerging from the deposition of the polyelectrolytes [106,109,123,124]. Thus, it is possible to define the compensation of the multilayer charge as a function of the role of small ions in the neutralization process, which leads to two different mechanisms for charge compensation [125][126][127][128]: (i) Intrinsic and (ii) extrinsic. The former charge compensation mechanism is characterized by the perfect matching between the charges deposited in adjacent layers.…”

Polyelectrolyte Multilayers on Soft Colloidal Nanosurfaces: A New Life for the Layer-By-Layer Method

“…Therefore, a contribution counter-balancing the charge excess is mandatory to result in multilayers with a zero net charge at the macroscopic scale (beyond the Debye length). This makes it necessary to incorporate small ions in the multilayer to compensate the excess of charge appearing from the unpaired polyelectrolyte segments of the layers [ 102 , 104 , 142 , 143 ], which results in two different compensation mechanisms depending on the contribution of the small ions in ensuring the electro-neutrality of the multilayer [ 144 , 145 , 146 , 147 ]: (i) intrinsic, and (ii) extrinsic [ 141 ].…”