Evaluation of cyclohexane pretreatment effect on the transfer of laser-textured surface from Ti-6Al-4V to UV-sensitive resin via UV-molding technique

Abstract

UV-sensitive resin is a versatile and cost-effective polymer widely employed across various industrial sectors. Nevertheless, numerous applications necessitate micro-patterned surfaces exhibiting low wettability. Therefore, the development of straightforward surface modification techniques applicable to a broad range of polymers holds significant practical value. However, such approaches often face challenges, including undesirable polymer adhesion to the template and inaccuracies in transferring surface textures from the template to the polymer. In this study, a nanosecond laser was utilized to generate laser-textured surface on a Ti-6Al-4V (Ti) template prior to UV molding. The Ti template underwent cyclohexane treatment at either 70 °C or 140 °C for 2 h before the molding process. UV molding was subsequently performed using dual UV light sources for 15 min. The influence of these temperature treatments on the fidelity of microstructure replication and the wettability of the resulting UV-sensitive resin surfaces was evaluated using Confocal Laser Scanning Microscopy and water contact angle measurements. The findings demonstrated that UV molding, when assisted by cyclohexane pretreatment at 140 °C, yielded micro-protrusions with the best replication accuracy, exhibiting widths of 18.4 ± 6 μm and heights of 5.5 ± 0.9 μm—closely matching the dimensions of the micro-hole array cavities on the Ti template (width: 18 ± 2.3 μm; height: 6.4 ± 0.3 μm). The distribution of micro-protrusions on the UV-sensitive resin surface was more uniform compared to other samples. Furthermore, the wettability of the UV-sensitive resin surface decreased, with the water contact angle increasing from 68.7° to 101.7° on the replicated micro-patterned surface.