Multiscale Modeling of the Effects of Salt and Perfume Raw Materials on the Rheological Properties of Commercial Threadlike Micellar Solutions

作者：Xueming Tang, Weizhong Zou, Peter H. Koenig, Shawn D. McConaughy, Mike Weaver, David Eike, Michael J. Schmidt, Ronald G. Larson · 发表于：The Journal of Physical Chemistry B · 年份：2017 · DOI：10.1021/acs.jpcb.7b00257 · 被引用次数：62 · 研究领域：Surfactants and Colloidal Systems、Rheology and Fluid Dynamics Studies、Advanced Polymer Synthesis and Characterization

We link micellar structures to their rheological properties for two surfactant body-wash formulations at various concentrations of salts and perfume raw materials (PRMs) using molecular simulations and micellar-scale modeling, as well as traditional surfactant packing arguments. The two body washes, namely, BW-1EO and BW-3EO, are composed of sodium lauryl ethylene glycol ether sulfate (SLE n S, where n is the average number of ethylene glycol repeat units), cocamidopropyl betaine (CAPB), ACCORD (which is a mixture of six PRMs), and NaCl salt. BW-3EO is an SLE3S-based body wash, whereas BW-1EO is an SLE1S-based body wash. Additional PRMs are also added into the body washes. The effects of temperature, salt, and added PRMs on micellar lengths, breakage times, end-cap free energies, and other properties are obtained from fits of the rheological data to predictions of the “Pointer Algorithm” [ Zou, W.; Larson, R.G. J. Rheol. 2014, 58, 1−41], which is a simulation method based on the Cates model of micellar dynamics. Changes in these micellar properties are interpreted using the Israelachvili surfactant packing argument. From coarse-grained molecular simulations, we infer how salt modifies the micellar properties by changing the packing between the surfactant head groups, with the micellar radius remaining nearly constant. PRMs do so by partitioning to different locations within the micelles according to their octanol/water partition coefficient P OW and chemical structures, adjus...