Capillary Nylon 6 polymer material produced by femtosecond laser processing

A wicking Nylon 6 polymer material was produced through surface structuring by a direct femtosecond laser nano/microstructuring approach. The produced wicking structure is an array of parallel microgrooves, the surface of which is textured with irregular nanostructures and fine microstructures. High-speed imaging of water spreading vertically uphill against the gravity discloses a series of capillary flow regimes with h proportional to t, h proportional to t(1/2) , and h proportional to t(1/3) scaling laws, where It is the height of capillary rise and t is the time. In the initial stage, the capillary flow occurs with a single front, from which at a certain time a precursor front forms and advances ahead of the main one. Our study shows that the onset of the precursor front occurs in h proportional to t flow regime. The created material exhibits excellent wicking properties and may find applications in various technologically important areas. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement