No abstract

A series of poly(n-butyl acrylate) (PnBA, 5 to 32 kg mol-1) homopolymers and diblock copolymers with poly(ethylene glycol) (PEG, constant molecular weight of 0.3 kg mol-1) is synthesized for the purpose of the investigation of quasi-2D polymer films at the air-water interface. The presented compression isotherms show a transition from θ solvent behavior for PnBA homopolymers to good solvent conditions when the volume fraction of the PEG in the block copolymers is increased by decreasing the molecular weight of PnBA. A transition from a semi-dilute regime to a densely packed layer is observed in the pressure isotherms for all the polymers. In the densely packed films we found first evidence for thin film breakup of a thin polymer film directly at the air-water interface. Combination of results from Brewster-Angle-Microscopy and Surface X-ray scattering provide a consistent picture of the film breakup. Our results suggest a preferred length scale of 2.5 μm. This scenario is analogous to a spinodal mechanism driven by thermal fluctuations of the film height.

Binary mesocrystals offer the combination of nanocrystal properties in an ordered superstructure.H ere,w e demonstrate the simultaneous self-assembly of platinum and iron oxide nanocubes into micrometer-sized 3D mesocrystals using the gas-phase diffusion technique.B yt he addition of minor amounts of as econdary particle type tailored to nearly identical size, shape and surface chemistry,w ew ere able to promote ar andom incorporation of foreign particles into as elf-assembling host lattice.T he random distribution of the binary particle types on the surface and within its bulk has been visualizedusing advanced transmission and scanning electron microscopyt echniques.T he 20-40 mms ized binary mesocrystals have been further characterized through wide and small angle scattering techniques to reveal along-range orderingo n the atomic scale throughout the crystal while showing clear evidence that the material consists of individual building blocks.T hrough careful adjustments of the crystallization parameters,w ec ould further obtain ar everse superstructure, where incorporated particles and host lattice switch roles.

Stimuli-responsive mesoporous silica films were prepared by evaporation-induced self-assembly through the physical entrapment of a functional block copolymer structuring agent, which simultaneously serves to functionalise the mesopore.