In Situ Observation of Shear-Induced Jamming Front Propagation during Low-Velocity Impact in Polypropylene Glycol/Fumed Silica Shear Thickening Fluids

Kurkin，Anatoli1; Lipik，Vitali1; Zhang，Xin2; Tok，Alfred1

2022-07-01

10.3390/polym14142768

POLYMERS   Impact Factor & Quartile

2073-4360

Shear jamming, a relatively new type of phase transition from discontinuous shear thickening into a solid-like state driven by shear in dense suspensions, has been shown to originate from frictional interactions between particles. However, not all dense suspensions shear jam. Dense fumed silica colloidal systems have wide applications in the industry of smart materials from body armor to dynamic dampers due to extremely low bulk density and high colloid stability. In this paper, we provide new evidence of shear jamming in polypropylene glycol/fumed silica suspensions using optical in situ speed recording during low-velocity impact and explain how it contributes to impact absorption. Flow rheology confirmed the presence of discontinuous shear thickening at all studied concentrations. Calculations of the flow during impact reveal that front propagation speed is 3-5 times higher than the speed of the impactor rod, which rules out jamming by densification, showing that the cause of the drastic impact absorption is the shear jamming. The main impact absorption begins when the jamming front reaches the boundary, creating a solid-like plug under the rod that confronts its movement. These results provide important insights into the impact absorption mechanism in fumed silica suspensions with a focus on shear jamming.

shear thickening fluid impact behavior jamming discontinues shear thickening impact absorption

SCI ; EI

English

Corresponding

Polymer Science

Polymer Science

WOS:000831390600001

MDPI

20223012413159

Glycols ; Jamming ; Polypropylene oxides ; Polypropylenes ; Shear flow ; Suspensions (fluids)

Fluid Flow, General:631.1 ; Electromagnetic Waves:711 ; Chemical Products Generally:804 ; Organic Compounds:804.1 ; Organic Polymers:815.1.1

2-s2.0-85134786260

Web of Science

1.School of Materials Science and Engineering,Nanyang Technological University,639798,Singapore
2.Department of Mechanics and Aerospace Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Kurkin，Anatoli,Lipik，Vitali,Zhang，Xin,et al. In Situ Observation of Shear-Induced Jamming Front Propagation during Low-Velocity Impact in Polypropylene Glycol/Fumed Silica Shear Thickening Fluids[J]. POLYMERS,2022,14(14).

Kurkin，Anatoli,Lipik，Vitali,Zhang，Xin,&Tok，Alfred.(2022).In Situ Observation of Shear-Induced Jamming Front Propagation during Low-Velocity Impact in Polypropylene Glycol/Fumed Silica Shear Thickening Fluids.POLYMERS,14(14).

Kurkin，Anatoli,et al."In Situ Observation of Shear-Induced Jamming Front Propagation during Low-Velocity Impact in Polypropylene Glycol/Fumed Silica Shear Thickening Fluids".POLYMERS 14.14(2022).