Influence of surfactants on shear-thickening behavior in concentrated polymer dispersions

Abstract

Concentrated dispersions consisting of 310 nm poly(styrene-ethylacrylate) nanospheres and ethylene glycol, which exhibited pronounced shearthickening behavior, were prepared in this work. The influence of surfactants on their shear-thickening behavior was investigated, which indicated that the surfactants affected the shear-thickening behavior by changing the surface force and interparticle force. Various surfactants, such as cationic, anionic, nonionic, and zwitterionic surfactants were added to the shear-thickening fluid (STF) and their rheological properties were measured. The results indicated that all kinds of surfactants could enhance shear-thickening behavior by changing their electrostatic, steric, or lubrication interaction, especially for nonionic surfactant Triton X-100 (TX100) and cationic surfactant cetyltrimethyl ammonium bromide (CTAB). TX100 led to the maximum viscosity up to 1,650 Pa s and CTAB enhanced the maximum viscosity up to 1,000 Pa s when the introduced surfactants were only 2 and 0.3 %, both values were nearly five times larger than the neat STFs. A plausible explanation for the enhancing mechanism by different kinds of surfactants was discussed.

High strain-rate dynamic mechanical properties of Kevlar fabrics impregnated with shear thickening fluid

“…As a type of non-newton fluid, the viscosity of STF increases dramatically when the shear rate exceeds a critical value. After easing the applied shear rate, the STF can recover from solid like state to the initial fluid state [4][5][6][7][8].…”

Effects of silica morphology on the shear‐thickening behavior of shear thickening fluids and stabbing resistance of fabric composites

“…In this process, the STF absorbs a large amount of shock energy to induce a buffering and damping effect. Several colloidal suspensions have been confirmed to behave as STFs, including starch in water, precipitated calcium carbonate, poly(methyl methacrylate) (PMMA), poly(styrene‐ethylacrylate) copolymer (PSt‐EA), and silica in polyethylene glycol (PEG) or ethylene glycol . In particular, highly concentrated stabilized suspensions of silica particles in PEG exhibits a large discontinuous shear thickening effect and storage stability.…”

Rate-dependent and self-healing conductive shear stiffening nanocomposite: a novel safe-guarding material with force sensitivity

“…[26,27] nanowires-based wearable multifunctional sensors which could detect strain, pressure and finger touch with fast response time and high sensitivity. [31,32] Based on the unique mechanical properties, ST materials have been applied in vibration controlling, damping and body armor. Due to the sensitive rate dependent property, a number of attention has been paid to develop high performance ST materials.…”