Sector spin coating for fast preparation of polymer libraries

The feasibility of sector spin coating (or combinatorial spin-coating) is demonstrated (i.e., spin coating of various samples onto one single substrate using a metal template to divide the substrate into sectors). Film thickness increases in an angular direction against the sense of rotation. In the radial direction, the film thickness is constant within 2%. A library of 8 poly(methyl methacrylate)/polystyrene-blends with varying composition was spin coated and subsequently analyzed using automated atomic force microscopy: 24 measurements could be performed within 72 min. The contact angles of a library of 16 polyoxazoline diblock copolymers were measured using one substrate with 16 spin-coated sectors. Forty-eight measurements could be performed within 50 min. On the basis of the surface energies calculated using the Owens-Wendt-Rath-Kaeble method, the library can be divided into three groups of polymers: those containing a dispersive nonyloxazoline block, those containing a polar phenyloxazoline block, and those containing neither.