A facile method has been developed for synthesizing polymer nanocapsules and thin films using multiple in‐plane stitching of monomers by the formation of reversible disulfide linkages. Owing to the reversibility of the disulfide linkages, the nanostructured materials readily transform their structures in response to environmental changes at room temperature. For example, in reducing environments, the polymer nanocapsules release loaded cargo molecules. Moreover, reversible morphological transformations between these structures can be achieved by simple solvent exchanges. This work is a novel approach for the formation of robust nano/microstructured materials that dynamically respond to environmental stimuli. 相似文献
The self‐assembly of nanostructured globular protein arrays in thin films is demonstrated using protein–polymer block copolymers based on a model protein mCherry and the polymer poly(oligoethylene glycol acrylate) (POEGA). Conjugates are flow coated into thin films on a poly(ethylene oxide) grafted Si surface, forming self‐assembled cylindrical nanostructures with POEGA domains selectively segregating to the air–film interface. Long‐range order and preferential arrangement of parallel cylinders templated by selective surfaces are demonstrated by controlling relative humidity. Long‐range order increases with coating speed when the film thicknesses are kept constant, due to reduced nucleation per unit area of drying film. Fluorescence emission spectra of mCherry in films prepared at <25% relative humidity shows a small shift suggesting that proteins are more perturbed at low humidity than high humidity or the solution state.
Nowadays, the microscopic mechanism controlling the distribution of local glass transition temperatures (Tgs) across thin polymer films is still unclear and thus large‐scale applications of polymer films are restricted. Dynamic Monte Carlo simulations are performed to investigate the key factors dominating the distribution of layer Tgs in two kinds of capped ultrathin films with and without attractive polymer–substrate interactions, respectively. For the film without polymer–substrate interaction, the interfacial layer Tg is lower than the middle layer Tg. Additionally, the layer Tgs and the layer segment densities below Tg are linearly correlated, indicating that polymer density determines the distribution of layer Tgs. However, for the films with polymer–substrate interactions, the interfacial layer Tg increases dramatically with the raise of interfacial interactions, while the middle layer Tg decreases slightly. The interfacial layer Tg is proportional to the strength of interfacial interaction, while the middle layer Tg is linearly correlated with the segment density of the middle layer below Tg. Namely, interfacial interaction is the main factor dominating the interfacial layer Tg, while segment density controls the middle layer Tg.