Fabrication of Chemically Tunable, Hierarchically Branched Polymeric Nanostructures by Multi-branched Anodic Aluminum Oxide Templates.

In this paper, a template-assisted replication method is demonstrated for the fabrication of hierarchically branched polymeric nanostructures composed of post-modifiable poly(pentafluorophenyl acrylate). Anodic aluminum oxide templates with various shapes of hierarchically branched pores are fabricated by an asymmetric two-step anodization process. The hierarchical polymeric nanostructures are obtained by infiltration of pentafluorophenyl acrylate with a cross-linker and photoinitiator, followed by polymerization and selective removal of the template. Furthermore, the nanostructures containing reactive pentafluorophenyl ester are modified with spiropyran amine via post-polymerization modification to fabricate ultraviolet-responsive nanostructures. This method can be readily extended to other amines and offers a generalized strategy for controlling functionality and wettability of surfaces.

Organic nonvolatile resistive switching memory based on molecularly entrapped fullerene derivative within a diblock copolymer nanostructure.

Organic nonvolatile resistive switching memory is developed via selective incorporation of fullerene derivatives, [6,6]-phenyl-C61 butyric acid methyl ester (PCBM), into the nanostructure of self-assembled poly(styrene-b-methyl methacrylate) (PS10 -b-PMMA130) diblock copolymer. PS10 -b-PMMA130 diblock copolymer provides a spatially ordered nanotemplate with a 10-nm PS nanosphere domain surrounded by a PMMA matrix. Spin casting of the blend solution of PS10 -b-PMMA130 and PCBM spontaneously forms smooth films without PCBM aggregation in which PCBM molecules are incorporated within a PS nanosphere domain of PS10 -b-PMMA130 nanostructure by preferential intermixing propensity of PCBM and PS. Based on the well-defined PS10-b-PMMA 130/PCBM nanostructure, resistive random access memory (ReRAM) exhibits significantly improved bipolar-switching behavior with stable and reproducible properties at low operating voltages (RESET at 1.3 V and SET at -1.5 V) under ambient conditions. Finally, flexible memory devices are achieved using a nanostructured PS10 -b-PMMA130 /PCBM composite in which no significant degradation of electrical properties is observed before and after bending.