Effect of addition of different nano-clays on the fumed silica-polyethylene glycol based shear-thickening fluids

Abstract Developing the shear thickening fluids (STF) which can be used for soft body armours requires an in depth study of various parameters related to its constituents so that a high critical viscosity along with high critical shear rate can be obtained. Shape of the constituting particles is one such important parameter. Elongated and nanosize particles provide high critical viscosity to the fluid, whereas spherical particles show high critical shear rates. STF were prepared using halloysite (Hal) nanotubes of different concentrations with fumed silica (spheres) and their rheological properties were studied. A better non-flocculated structure was obtained at 1% Hal in 20% fumed silica composition, exhibiting a critical viscosity of 25 Pas at a critical shear rate 160 s−1 as compared to that of only spherical particle STF (10 Pas and 200 s−1). The oscillatory tests revealed that this composition, with a better consistent reproducible behaviour and better stability than the STF without Hal, would be suitable as a high impact resistant material. Gel formation does not take place, rather the fluid behaves like a dispersed sol, making it a better choice for using with protective fabrics. The rheology was studied at different temperatures ranging from 0°C to 55°C.

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Rheology of Fumed Silica and Polyethylene Glycol Shear Thickening Suspension with Nanoclay as an Additive

Defence Science Journal ◽

10.14429/dsj.69.12420 ◽

2019 ◽

Vol 69 (4) ◽

pp. 402-408 ◽

Cited By ~ 1

Author(s):

Mansi Singh ◽

Sanjeev K Verma ◽

Ipsita Biswas ◽

Rajeev Mehta

Keyword(s):

Steady State ◽

Polyethylene Glycol ◽

Fumed Silica ◽

Shear Thickening ◽

Dynamic State ◽

Shear Thickening Fluid ◽

Organically Modified ◽

The Difference ◽

Critical Viscosity ◽

Stability And Consistency

Shear thickening properties of fumed silica-polyethylene glycol (PEG) with shear thickening fluid (STF) of different concentrations and with an organically modified clay, Nanomer I.28 E as nano-additive have been investigated by both steady-state and dynamic state rheology. Difference in rheology if instead of nanoclay, an equal wt% of additional fumed silica is added to 20 per cent fumed silica-PEG200 STF, has been studied. At 25 °C, in case of addition of nanoclay the increase in critical viscosity is less than that observed for same additional amount of fumed silica. Interestingly, an opposite result is seen at higher temperatures i.e. 45 °C and 55 °C. Moreover, the difference in steady-state and dynamic state viscosity values decreases on addition of nanoclay. It is noted that an increase in concentration of clay increases the value of dynamic parameters whereas for STF of only fumed silica particles the values are constant irrespective of the change in concentration. More importantly, ease of processing, elasticity, stability and consistency of rheological results of STF increases to a significant extent on addition of relatively inexpensive nano-additive.

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Tensile and flexural properties of glass and carbon fibre composites reinforced with silica nanoparticles and polyethylene glycol

Journal of Industrial Textiles ◽

10.1177/1528083719827368 ◽

2019 ◽

Vol 49 (6) ◽

pp. 809-832

Author(s):

Erdem Selver

Keyword(s):

Polyethylene Glycol ◽

Carbon Fibre ◽

Silica Nanoparticles ◽

Composite Laminates ◽

Shear Thickening ◽

Flexural Properties ◽

Fibre Composites ◽

Fabric Composites ◽

Shear Thickening Fluids ◽

Carbon Fibre Composites

This paper attempts to show the effect of silica nanoparticles and polyethylene glycol mixture (shear thickening fluids) on tensile and flexural properties (3-point bending) of glass and carbon fibre-reinforced thermoset composite laminates. The shear thickening fluids were prepared by combination of silica nanoparticles and polyethylene glycol using various silica contents (10–20 wt%). A viscometer was used to evaluate the shear thickening characteristics and viscosity of shear thickening fluids increased by increasing the silica content. Shear thickening fluids were impregnated on the host of glass and carbon fabrics and subsequently converted to composite laminates using vacuum infusion method with an epoxy matrix. It was found that shear thickening fluids-treated carbon and glass fabric composites exhibited up to 10% and 12% higher tensile strength than neat composites whilst the tensile modulus increased about 24%. Shear thickening fluids-treated fabric composites exhibited slower damage propagation compared to brittle nature of untreated fabric composites. However, lower flexural strength with higher energy absorption (up to 27%) were obtained after using shear thickening fluids for both carbon and glass fibre composites.

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New analysis and correlation between steady and oscillatory tests in fumed silica-based shear thickening fluids

Rheologica Acta ◽

10.1007/s00397-019-01161-z ◽

2019 ◽

Vol 58 (10) ◽

pp. 647-655 ◽

Cited By ~ 1

Author(s):

Andres G. Moron ◽

Maria Jesus L. Boada ◽

Beatriz L. Boada ◽

Vicente Diaz

Keyword(s):

Fumed Silica ◽

Shear Thickening ◽

Shear Thickening Fluids

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Comparison of rheological behaviors with fumed silica-based shear thickening fluids

Korea-Australia Rheology Journal ◽

10.1007/s13367-016-0020-9 ◽

2016 ◽

Vol 28 (3) ◽

pp. 197-205 ◽

Cited By ~ 20

Author(s):

Alain D. Moriana ◽

Tongfei Tian ◽

Vitor Sencadas ◽

Weihua Li

Keyword(s):

Fumed Silica ◽

Shear Thickening ◽

Rheological Behaviors ◽

Shear Thickening Fluids

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Effect of addition of silicone oil on the rheology of fumed silica and polyethylene glycol shear thickening suspension

Journal of Polymer Engineering ◽

10.1515/polyeng-2018-0054 ◽

2018 ◽

Vol 39 (1) ◽

pp. 48-57 ◽

Cited By ~ 4

Author(s):

Mansi Singh ◽

Sanjeev Kumar Verma ◽

Ipsita Biswas ◽

Rajeev Mehta

Keyword(s):

Polyethylene Glycol ◽

Liquid Medium ◽

Fumed Silica ◽

Silicone Oil ◽

Shear Thickening ◽

Colloidal Suspensions ◽

Nano Particles ◽

Dynamic State ◽

Elastic Behavior ◽

Wide Range

Abstract Shear thickening fluids (STF) are stabilized and concentrated colloidal suspensions of hard nano-particles in a liquid medium (polymer) that, under the influence of impact forces, show non-Newtonian fluid behavior (shear thickening) dissipating the energy of impact. The viscosity of the dispersion medium should be optimum to lead to an increase in shear thickening, and at the same time, should also allow proper dispersion of the particles. Herein, an STF based on 20 wt% fractal nano-fumed silica particles of 11 nm suspended in a liquid medium of polyethylene glycol (PEG 200) with different concentrations of silicone oil was prepared. These systems were studied in terms of steady-state and dynamic-state rheological behavior under a wide range of temperature, shear rate, strain rate and frequency. The STF with replacement of up to only 20% of PEG with silicone oil as the liquid medium shows a large increase (about four times) in shear thickening parameters when compared with STF containing only PEG under the same processing conditions. It also shows more elastic behavior at high frequencies which are due to the high cross-linking property of silicone oil, contributing to much-improved properties, which are highly desirable from the view point of many applications.

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