TY - JOUR A1 - Weh, Lothar A1 - Venthur, Astrid T1 - Evolution of fractal-like surface structures in layers of polycrylonitrile solutions by interfacial dynamic processes JF - Journal of colloid and interface science N2 - Solvent evaporation causes concentration and temperature gradients at the free surface of a coating polymer solution. Thereby surface-tension-driven flows can result in a surface instability with regular structures within the layer. Different types of surface structures can occur at spots with thickness differences. One can find fractal-like structures especially in the edge zone of a layer. The evolution of such fractal-like structures at the surfaces of coating solutions of polyacrylonitrile (PAN) in dimethylformamide (DMF) during layer hardening is examined. Condensation of water on the surface of the fluid layer exerts a strong influence on the formation of these structures. Solutions of PAN in DMF are important for the production of ultrafiltration membranes. Such membranes are produced by precipitation in a water bath after a short open time. KW - Surface flow KW - Coatings KW - Surface tension KW - Spreading motions KW - Planar membranes PY - 2004 DO - https://doi.org/10.1016/j.jcis.2003.11.033 SN - 0021-9797 SN - 1095-7103 VL - 271 IS - 2 SP - 407 EP - 415 PB - Elsevier CY - Orlando, Fla. AN - OPUS4-3426 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -