Tetragonally Perforated Lamellae of Polybutadiene-block-poly(2-vinylpyridine)-block-poly(tert-butyl methacrylate) (BVT) Triblock Terpolymers in the Bulk: Preparation, Cross-Linking, and Dissolution

We report on the formation of tetragonally perforated lamellae from a polybutadiene- block -poly(2-vinylpyridine)- block -poly( tert- butyl methacrylate) (BVT) triblock terpolymer, PB 22 P2VP 29 P t BMA 49 110, in the bulk state (the subscripts denote the volume fractions of the respective segment and the superscript the overall molecular weight in kg/mol). The perforations are formed by the protrusion of the block with the highest volume fraction, P t BMA, through both the central perforated PB lamella and the two adjacent perforated lamellae of P2VP. The morphological characterization is based on transmission electron microscopy (TEM) and three-dimensional reconstructions using transmission electron microtomography (TEMT) experiments. In addition, SAXS confirmed an overall lamellar pattern. The so generated structures can be used for the fabrication of well-defined porous sheets with tunable size, as demonstrated by cross-linking of the central perforated PB lamella, followed by sonication-assisted dissolution into micrometer-sized lamellar particles with tetragonally arranged pores in nonselective solvents like THF.