Structuring of polymer surfaces for micro- and biotechnical applications by hybrid UV-Laser-Fluoration

• Applicants: Dr. Arnd Schimanski; Professor Dr.-Ing. Frank Vollertsen
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2011 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 174919320

Surface fluorinations have been used for some time, for example to inhibit diffusion of hydrocarbons through a polymer or change the wettability of a polymer surface. Typically, the component to be fluorinated is subjected to elemental fluorine in a reactor, wherein the component is fluorinated everywhere, where it is accessible by the fluorine. A specific method for the fluorination, in which a non-reactive fluorine-containing precursors and two UV sources are used also has been presented, but has hardly been used. If the fluorination has to be localized, always more process steps are required, regardless of the method. Often, a time- and cost-intensive masking is carried out on the areas not to be fluorinated. The minimum size of the producible areas is inherently limited.To avoid the time-consuming and labor-intensive masking for the localized fluorination, a hybrid fluorination method will be examined here, where the localized fluorination is carried out in a single process step.The aim of the project is the development of the fundamentals of a new hybrid method for localized fluorination of polymer surfaces. The new hybrid fluorination technique combines two established technologies, the process of gas-phase fluorination and the surface modification of polymers by UV irradiation. Both processes take place at the same time, whereby synergistic effects are utilized. By this, structures can be produced which cannot be generated in other ways, such as localized hydrophilic structures within a hydrophobic surface.In the first funding period, the main focus of the research was the proof of feasibility of a local UV laser-based fluorination of polymer surfaces. The originally proposed funding period was amounted to 3 years, of which at first only 1.5 years were approved and were associated with a milestone: The proof of feasibility of the UV-laser based local fluorination had to be provided.The proof of feasibility of localized fluorination a polymeric surface could now be provided with the investigated method. In the second funding period is it planned to continue in accordance with the original proposal. Especially the boundaries of the local fluorination will be determined. During the first funding period, besides gas-phase fluorination the idea of a liquid phase fluorination arose. This promises a far more sharp-edged local fluorination. These investigations will also be carried out in the second phase applied here.

• DFG Programme: Research Grants