Characteristics, Compression, and Buffering Performance of Pomelo-Like Hierarchical Capsules Containing Shear Thickening Fluid

Abstract

In this study, a double-walled and pomelo-like hierarchical shear thickening fluid (STF) is successfully encapsulated using the simple and environment-friendly calcium alginate encapsulation technique by instilling STF into sodium alginate (SA) and crosslinking by calcium chloride solution. The encapsulated STF has a pomelo-like structure with a shell thickness of 2.9 μm and core pores with a size of 21.43 μm. The effect of the size of STF capsules (2.10, 1.89, 1.86, 1.83, 1.73, and 1.63 mm) is explored in terms of thermal stability, swelling capacity, mechanical property, and release performance. The buffering performance of different sizes of STF-containing capsules is also investigated. The pomelo-like STF capsules can withstand a processing temperature of 250 °C. With a decrease in particle size, the compression strain energy slowly increases first and then rapidly enhances. The kinetic release of pomelo-like STF capsules conforms to Fickian diffusion. STF-containing capsules with a diameter of 1.83 mm present the greatest thermal stability, the highest STF amount, the maximum swelling coefficient, and the fastest kinetic diffusion. STF-containing capsules also have an improved buffering performance in PU foam. This capsule has the best comprehensive performance and can adapt to diversified applications, such as personnel armor and other protective sports equipment.

Two‐step foaming process for fabrication of flexible polyurethane foam composites with spring‐like air‐layer structure

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“…In order to address the limited reusability of conventional PU foam, our research team developed a composite structure by combining fabric with PU foam. 35,[40][41][42] We discovered that the fabric reinforcement significantly enhanced the overall strength and elasticity of the foam composite. Through our investigation, we determined that a hexagonal warp-knit fabric structure with a side length and wall thickness of 1 cm exhibited the best cushioning performance.…”

Optimization of encapsulation parameters for sodium alginate capsules: A study on the effect of temperature and gear pump rotation speed on capsule production and quality

“…Bennacef et al and Li et al (2019). These studies describe methods, which produce capsules ranging from 500 μm to 1 mm in size.…”

Preparation and characterization of imidazolyl ionic liquid‐based shear thickening dispersion system

“…Only when the two ingredients are mixed, a stable shear thickening system with low initial viscosity can be formed. [16][17][18] Shenoy and Wagner added a small amount of PEG with different relative molecular weight (MW = 4000, 6000, and 10,000) to STF with PEG (MW = 400) as the dispersion medium. Through rheological property test, it was found that the shear thickening behavior of STF increased with the relative molecular weight and content of PEG.…”