Charge Modification as a Mechanism for Tunable Properties in Polymer–Surfactant Complexes

Polymers

Robert Dalgliesh¹  Wasiu Abdullahi²  Peter Charles Griffiths²  Christopher Hill²  Martin Crossman³ 

[1] ISIS Neutron and Muon Source, STFC, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxford OX11 0QX, UK;School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK;Unilever Research, Port Sunlight, Quarry Road East, Bebington, Wirral CH63 3JW, UK;

关键词: polyelectrolyte–surfactant interactions;    small-angle neutron scattering;    complexation;    charge modification;   

DOI  :  10.3390/polym13162800

来源: DOAJ

【 摘 要 】

Oppositely charged polymer–surfactant complexes are frequently explored as a function of phase space defined by the charge ratio Z, (where Z = [${+}_{polymer}]/\left[{-}_{surfactant}\right]$), commonly accessed through the surfactant concentration. Tuning the phase behaviour and related properties of these complexes is an important tool for optimising commercial formulations; hence, understanding the relationship between Z and bulk properties is pertinent. Here, within a homologous series of cationic hydroxyethyl cellulose (cat-HEC) polymers with minor perturbations in the degree of side chain charge modification, phase space is instead explored through $\left[{+}_{polymer}\right]$ at fixed C${}_{polymer}$. The nanostructures were characterised by small-angle neutron scattering (SANS) in D${}_2$O solutions and in combination with the oppositely charged surfactant sodium dodecylsulfate (h- or d-SDS). Scattering consistent with thin rods with an average radius of ∼7.7 Å and length of ∼85 Å was observed for all cat-HEC polymers and no significant interactions were shown between the neutral HEC polymer and SDS (C${}_{SDS}$ < CMC). For the charge-modified polymers, interactions with SDS were evident and the radius of the formed complexes grew up to ∼15 Å with increasing Z. This study demonstrates a novel approach in which the Z phase space of oppositely charged polymer–surfactant complexes can be controlled at fixed concentrations.

【 授权许可】

Unknown