The tunable surface-wetting properties of photosensitive random copolymer mats were used to spatially control the orientations of thin-film block copolymer (BCP) structures. A photosensitive mat was produced via thermal treatment on spin-coated random copolymers of poly­(styrene-ran-2-nitrobenzyl methacrylate-ran-glycidyl methacrylate), synthesized via reversible-deactivation radical polymerization. The degree of UV-induced deprotection of the nitrobenzyl esters in the mat was precisely controlled through the amount of UV-irradiation energy imparted to the mat. The resulting polarity switching of the constituents collectively altered the interfacial wetting properties of the mat, and the tunability allowed lamellar or cylinder-forming poly­(styrene-b-methyl methacrylate) BCP thin films, applied over the mat, to change the domain orientation from perpendicular to parallel at proper UV exposures. UV irradiation passing through a photomask was capable of generating defined regions of BCP domains with targeted orientations.

The development of reversible nanostructural associations in graft copolymer architecture has enabled the fabrication of tough polymer electrolyte composites that exhibit autonomous self-healing properties at room temperature. Random copolymers comprising docosyl acrylates (A22) were employed to form network structures in ionic liquids. The behavior of the resulting composites was found to be dictated by associative domain formation and subsequent changes in the intermolecular interactions. Remarkable mechanical properties were achieved without undermining the self-healing capability via adjustments in the chemical structure. This feature is recognizably different considering the conventional trade-off relationship between selfhealing and mechanical properties. Thermal and scattering experiments were conducted to elucidate the structural evolution of the composites. The relative changes in the electrical properties upon mechanical deformation were utilized to realize self-healable strain sensors.

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