Preparation of Superhydrophobic Graphene-Elastomer Composite Films and Monitoring of Their Waterproof Performance for Swimming

Abstract

To meet the synergistic requirements of "waterproofness, elasticity, and durability" for waterproof films in swimming equipment, this study developed a graphene-PDMS composite film and established a multi-dimensional performance evaluation system. By modifying the film with a silane coupling agent to optimize interfacial bonding, a 100 ± 5 μm thick film was prepared using a tape casting process (5 mm/s). The performance advantages of a 3 % graphene addition were specifically simulated: the film achieved a tensile strength of 8.5 MPa (a 40 % increase compared to pure PDMS) and a strength decay of only 8.2 % after 10,000 cycles. After fluor silane modification, the film exhibited a WCA of 158 ± 2° and a SA of 8 ± 1°, a 24-hour water absorption of 0.45 % (an 80 % decrease compared to pure PDMS), and a hydrostatic pressure resistance of 15 kPa (a 50 % increase compared to PTFE). Dynamic simulations indicate that after 4 hours of exposure to a 2 m/s water flow, the water permeability is less than 0.01 g/(h·cm²), and the film remains superhydrophobic (WCA > 140°) after 10,000 cycles of 10 % strain. The strength decay rate after 14 days of seawater immersion is 11.8 %, surpassing all other performance indicators of conventional films. These results demonstrate that composite films with a 3 % graphene addition are suitable for swimming, providing data support for the development of waterproof equipment.