Manipulating perfume delivery to the interface using polymer–surfactant interactions

Abstract

Enhanced delivery of perfumes to interfaces is an important element of their effectiveness in a range of home and personal care products. The role of polyelectrolyte-surfactant mixtures to promote perfume adsorption at interfaces is explored here. Neutron reflectivity, NR, was used to quantify the adsorption of the model perfumes phenylethanol, PE, and linalool, LL, at the air-water interface in the presence of the anionic surfactant sodium dodecylsulfate, SDS, and the cationic polyelectrolytes, poly(dimethyldiallyl ammonium chloride), polydmdaac, and poly(ethyleneimine), PEI. The strong SDS-polydmdaac interaction dominates the surface adsorption in SDS-polymer-perfume (PE, LL) mixtures, such that the PE and LL adsorption is greatly suppressed. For PEI-SDS-perfume mixtures the PEI-LL interaction competes with the SDS-PEI interaction at all pH at the surface and significant LL adsorption occurs, whereas for PE the PEI-SDS interaction dominates and the PE adsorption is greatly reduced. The use of the strong surface polyelectrolyte-ionic surfactant interaction to manipulate perfume adsorption at the air-water interface has been demonstrated. In particular the results show how the competition between polyelectrolyte, surfactant and perfume interactions at the surface and in solution affect the partitioning of perfumes to the surface.

Structure of surfactant and phospholipid monolayers at the air/water interface modeled from neutron reflectivity data

“…e.g. 9,10,11,13,14,25,26 In the case of a deuterated surfactant or phospholipid in air contrast matched water, structural implications of the model deviate significantly from the physical picture that is supported by the validated robust model. It has been shown that in cases where structural details are interpreted explicitly, a single-layer interfacial model without surface roughness may over-estimate the mono-layer thickness by around one third, while a single-layer model with surface roughness may under-estimate the thickness by around one quarter.…”

“…Zero 11 or rather low 12 layer roughness values have continued to be used in some studies, and inclusion or not of the parameter in applied models is not even mentioned in others to this day. 13,14 Such an approach may have originated as a result of the lower neutron flux over the accessible range in the momentum transfer normal to the interface, Qz, on early instruments and/or the assumption that inclusion of roughness in a model is simply a consequence of not having split the system into enough layers. 15 Such an approach is seemingly in contradiction to the capillary wave roughness of ~ 2.8 Å for a bare air/water interface resulting from thermal fluctuations, 16,17 and its inverse square root dependence on the surface tension resulting in values of ~ 4 Å for monolayers of the surfactants SDS and dodecyltrimethylammonium bromide (C12TAB).…”

Intermolecular Interactions in Polyelectrolyte and Surfactant Complexes in Solution

“…Surfactants are used in detergents [1,2], emulsions [3,4], waste-water treatment [5], and more and their performance can be bolstered with the addition of polymers to the formulation. While surfactants and their micelles can change the surface tension, phase behavior and rheology of a solution [3,6,7], the addition of polymers, particularly charged polymers (polyelectrolytes), has been shown to enhance bulk and interfacial properties for a variety of applications [8,9,10,11,12,13,14], including cosmetics [15], perfumes [16,17], biofuel extraction [18] and oil recovery [19,20].…”

Adsorption of monoterpene alcohols at the water–air interface

“…the rate of release and evaporation of PRMs from a base formulation or from surfaces they are applied on. Accordingly, the enhanced delivery of perfumes to interfaces is of vital importance for their effectiveness in a wide range of home and personal care products (Bradbury et al 2016;Penfold et al 2017). Therefore, for full description of PRMs properties in a fragrance blend and their performance in consumer products, it is necessary to explain their adsorption at various interfaces, particularly at the water-air one.…”