We report on a novel wrinkle formation process of water absorbing hydrogel particles. When the hydrogel particles called Super Absorbent Polymer (SAP) are dropped onto water which is held in a cylindrical container, the particles rapidly swell at the air-water interface to form a sheet-like structure. Once the sheet-like structure reaches the wall of the container by its continuous in-plane expansion, it starts to buckle with a characteristic pattern of wrinkles. We applied a simple model to estimate the wavelength of the wrinkle, which was in agreement with experimental values. We also discussed the effect of buoyant force on the wrinkle formation.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering