Preparation and characterization of shear thickening fluid/carbon nanotubes/Kevlar composite materials

Shear thickening fluid (STF), carbon nanotubes (CNTs) are both promising in body protection and anti-impact for the drastic viscosity change of STF and the extremely high tensile strength and elongation of CNTs. The excellent performance of the above two combined with traditional Kevlar fabrics can significantly improve the mechanical properties and reduce the number of layers used for body protection. This work reports a new method to prepare STF/CNTs/Kevlar with excellent tensile properties and anti-impact performance by spraying method with 1 wt% polyvinyl alcohol (PVA) solution as a binder for better integration between CNTs and Kevlar. Surface morphology changes in the preparation process indicate the combined structure of PVA binder, CNTs, and STF, presenting a uniform macroscopic and nonuniform microscopic surface of STF/CNTs/Kevlar composite. The tensile strength and anti-impact properties including punch residual velocity and energy absorbed were studied and results for STF/CNTs/Kevlar composite are 669.8 +/- 18.1 MPa, 1.602 +/- 0.045 m/s, and 21.683 +/- 1.182 J in 12 ms, increased by 46.4%, 23.0%, and 240.2%, respectively, compared with neat Kevlar, owing to the improved tight bonding and friction between fabrics yarns caused by PVA adhesive and tangled CNTs, accompanied with the enhanced viscosity of STF under forces.HighlightsComposites were made by spraying PVA, CNTs, and STF onto Kevlar fabrics;The tensile strength of the composite was 46.4% higher than Kevlar;The energy absorbed in 12 ms in anti-impact tests was improved by 240.2%;Tight bonding and friction between yarns are reasons to improve properties;The raised viscosity of STF under forces is useful for mechanical properties. Illustration of the procedures and samples for preparing CNT/STF/Kevlar composite: (A) procedures and (B) samples.image

Automated summary

Combining shear thickening fluid (STF) and carbon nanotubes (CNTs) with traditional Kevlar fabrics shows promise in improving mechanical properties and reducing thickness in body protection. This research introduces a new method for producing STF/CNTs/Kevlar composites with enhanced tensile properties and anti-impact performance using a polyvinyl alcohol (PVA) solution as a binder. The composites exhibit increased tensile strength and improved anti-impact properties due to better bonding and friction between yarns, as well as the increased viscosity of STF under forces.