Super anti‐impact silicone elastomer with shell‐less shear thickening fluid droplets in matrix

Abstract A soft and stretchable safeguarding silicone rubber is obtained by embedding large amount of shell‐less shear thickening fluid (STF) droplets into polydimethylsiloxane (PDMS) matrix through the synergistic process of emulsification and polymerization. Feeding time and temperature are optimized to generate the efficient STFs with 72.2 wt% SiO 2 and high thickening viscosity of 6340 Pa·s. The embedding process and the evolution of the shell‐less STF droplets in PDMS matrix are explored by both optical and scanning electronic microscopes. The influence of the STF content on the mechanical and anti‐impact performance of the composites is explored through tensile tests and drop hammer tests. The STF content could be as much as 75 wt%, which enhances not only the softness and stretchability (elongation at break >200%) but also the impact‐protective performance of the silicone rubber. The STF/PDMS composites covering on planar and nonplanar glass substrates demonstrate self‐adaptive protection effect by reducing the force impact peak by 35%, due to the shear thickening and energy absorption of STF in the composites. This study develops a facile and scalable method for the implantation of the STF into polymer matrix, extending the applications of STF/PDMS composites in varied fields.