Shear Thickening Fluids Comparative Analysis Composed of Silica Nanoparticles in Polyethylene Glycol and Starch in Water

Abstract

Shear thickening fluid (STF) occurs in dispersions of highly condensed colloid particles and is categorized as a non-Newtonian fluid whose viscosity increases under shear loading which makes them beneficial in protective and impact resistance applications. The aim of this study is to synthesis two different STFs and characterize their microstructural properties to provide a data base for comparing the final macrobehavior of the two fluids under mechanical testing. Therefore, fumed silica and polyethylene glycol STF and starch with water STF-based dispersions were prepared. The particle size, zeta potential, SEM micrographs, and rheological analysis were performed for each type of STF. The effect of filler concentration was observed by using 10–30 weight% filling material. The rheological properties of STFs show higher viscosity measurements at same shear rates for starch/water STF than silica/PEG with maximum viscosity reaching 523.6 Pa s and 178.9 Pa s, respectively. Larger starch particle size over silica recorded as 303.7 nm and 16.49 nm, respectively, and zeta potential analysis recorded particle electrostatic charges as 22.6 mV and 12.8 mV, respectively, leading to more dispersion stability and obvious thickening effect at higher particle concentration leading to greater jump in viscosity at sudden shear rate. The results indicate the capability of trying more protective applications with more flexibility and less thickness when STF is implemented and a good database for the fluids to choose from according to their behavior.

Implementing Nanocomposite Shear Thickening Fluid to Improve The Impact Resistance of Polyamide Fabrics Against Intermediate Velocity Projectiles

“…The output of the characterization tests will be pointed out briefly while the detailed information is found in a previous publication [2]. The impact test results are shown in detail and discussed to clarify the significance of adding STF to Polyamide fabrics in impact resistance.…”

“…The viscosity range against the change in the shear rate of 10 to 30 wt% ratio of starch particles in distilled water. The highest viscosity achieved for starch 30% is 523.6 Pa.s [2].…”

“…The velocity of the projectile has been tested several times and recording its average value to be 40 m/s at air pressure equals 2 bar produced from the gas compressor attached. The kinetic energy of the projectile is determined from equation (1) as follows: Kinetic Energy = 0.5mv 2 (1) = 0.5 × 0.044 (kg) × 40^2 (m/sec) = 35.2 J. Where (m) is the mass of the projectile used in the test and (v) is the velocity of the projectile which is equal to 40 m/s.…”

“…Modern military operations and high-complexity weaponry need a continuous enhancement of improved ballistic protection armor systems that are adaptable, lightweight, comfortable, and have great energy absorption capabilities [1]. The great strength, durability, incombustibility, and capacity to protect Aramid-based fibers such as Kevlar and Twaron are most commonly utilized for safety without significantly limiting durability and user comfort [2], [3]. Several pieces of study have cited literature on the influencing elements on cloth ballistic performance [4].…”

Experimental Investigation of Blood Mimicking Fluid Viscosity for Application in 3D-Printed Medical Simulator

“…Essentially, the BMF samples containing starch shows shear thickening properties whereby the viscosity increases as the shear rate increases. This flow type is known as dilatant and is a type of non-Newtonian fluid behaviour that occurs due to the hydro clustering of colloidal particles contacting each other at higher shear frequencies whereby the contact forces tend to grow stronger [16]. The contact networks resist the applied shear forces and thus, introduces viscosity growth.…”