SLE3S-water system: a linear rheological characterisation

Abstract

Surfactant-water mixtures display a complex rheological behaviour, with changes in parameters such as viscosity and moduli of several orders of magnitude as a consequence of phase changes, depending on their concentration and temperature: this criticism heavily affects different industrial processes. In our work, linear rheological behaviour of aqueous mixtures of a commercial anionic surfactant, sodium lauryl ether sulphate, is investigated in a range of temperature (30–60 °C) and surfactant concentration (20–72%wt) of technological relevance. Four phases with different texture are identified by polarised light microscopy: micellar, hexagonal, cubic and lamellar, all showing a shear-thinning behaviour. Rheological parameters of cubic phase show a net jump in a relatively narrow temperature range, suggesting a temperature-induced phase change. The systematic analysis of the rheological behaviour of this widely used surfactant system, reported here for the first time, can be of fundamental support for many industrial applications. Graphical Abstract

Designing Advanced Drug Delivery Systems: Core-Shell Alginate Particles through Electro-Fluid Dynamic Atomization

“…Viscosity (η, Pa•s) and viscoelastic properties play a crucial role in the EFDA to process the polymer solutions, affecting the morphology of microparticles [34]. For instance, the higher viscosity of solutions generates larger and spherical microparticles, while lower viscosities generate smaller particles [35]. Detailed rheological characterization was conducted to better understand how these properties contribute to the process.…”

“…Rheological measurements for both alginate samples (Hv and Lv) were conducted at room temperature (25 °C) using a stress-controlled rheometer (Anton Paar Physica MCR 301 Instruments, Graz, Austria) equipped with a double gap measuring geometry (DG26.7/TI-SN9317). Temperature control was achieved using a Peltier cooler/heater connected to an external circulating water bath (Lauda) [ 35 ]. Prior to the measurements, the samples underwent a pre-shear process at a shear rate of 200 1/s for 1 min to eliminate any potential loading effects.…”

Designing Advanced Drug Delivery Systems: Core-Shell Alginate Particles through Electro-Fluid Dynamic Atomization

“…Rheological measurements for both alginate samples (Hv and Lv) were conducted at room temperature (25°C) using a stress-controlled rheometer (Anton Paar Physica MCR 301 Instruments) equipped with a double gap measuring geometry (DG26.7/TI-SN9317). Temperature control was achieved using a Peltier cooler/heater connected to an external circulating water bath (Lauda) [64]. Prior to the measurements, the samples underwent a pre-shear process at a shear rate of 200 1/s for 1 minute to eliminate any potential loading effects.…”

Effects of shear-induced crystallization on the complex viscosity of lamellar-structured concentrated surfactant solutions

“…34 Recently, Ferraro et al investigated the linear rheological behavior of aqueous SLE 3 S solutions (25–72 wt%) from 30–60 °C and used polarized optical microscopy to report the presence of four phases (micellar (L1), hexagonal (H), cubic (V1) and lamellar (Lα)) at room temperature. 35…”