Zeolitic imidazolate frameworks have stimulated great attention due to their potential applications in energy storage, catalysis, gas sensing, drug delivery etc. In this paper, the three-dimensional porous nanomaterial Co3O4/ZnCo2O4/CuO with hollow polyhedral nanocage structures and highly enhanced electrochemical performances was synthesized successfully by a zeolitic imidazolate framework-67 route. The composites hold the shape of the ZIF-67 templates well and the shell has multiple compositions. In the process, we first synthesized the nanostructure hydroxide precursors and then transformed them into the corresponding metal oxide composites by thermal annealing in air. In addition, the mass ratio of Zn to Cu in this material is discussed and optimized. We found that when the mass ratio is 3, the composite material has better electrochemical properties. When applied as an electrode material, Co3O4/ZnCo2O4/CuO-1 shows enhanced pseudocapacitive properties and good cycling stability compared with Co3O4/ZnCo2O4, Co3O4/CuO and Co3O4/ZnCo2O4/CuO-2, and Co3O4/ZnCo2O4/CuO-3. The assembled Co3O4/ZnCo2O4/CuO-1//AC hybrid device can be reversibly cycled in a large potential range of 0-1.6 V and can deliver a high energy density of 35.82 W h kg-1 as well as the maximum power density of 4799.25 W kg-1.

No abstract

No abstract

The general lack of knowledge on the dynamics of polymer vesicles under flow field has confounded their applications in drug delivery and other fields. Therefore, dissipative particle dynamics (DPD) simulations on the dynamic behavior of diblock copolymer vesicles in a nanochannel under Poiseuille flow are conducted. The simulation results show that the block copolymer vesicles with hydrophobic blocks of different rigidities exhibit significantly different mechanical stabilities under the flow fields. With increasing the Reynolds number, the coil–coil block copolymer vesicles undergo a shape transition from spherical to bullet‐like to asymmetric and eventually split into two parts. In contrast, the rod–coil block copolymer vesicles deform from spherical to bullet‐like to parachute‐like structures and ultimately ruptured. The flow‐induced distortion and reorganization of copolymers mainly cause the deformation of vesicles. The distinguished motions of the block copolymers with different rigid blocks lead to the distinct performance of the vesicles. The findings could help understand the flow behavior of polymer vesicles in a nanochannel or a blood vessel and assist the design of bio‐functional polymersomes.

Side-chain liquid crystalline copolymers are able to self-assemble into various aggregates in selective solvents, in particular, deformed structures.