Jian Dai,Gaohong He,Xuehua Ruan,Wenji Zheng,Yu Pan,Xiaoming Yan
A series of novel bis-imidazolium crosslinked polysulfone membranes (CL-PSf-ImOHs) membranes were prepared through simultaneous quaternization and crosslinking reactions of 4,4′-bis(2-methylimidazole-1-ylmethyl)diphenyl (bis-Im-diPh) and chloromethyl groups on the polymer during the membrane formation. The novel bis-Im-diPh crosslinker possesses a rigid bis-phenyl structure, which creates large free volume and leads to the formation of continuous hydroxide conducting channels in the membrane as demonstrated by TEM . The properties of the crosslinked membrane were controlled by varying the molar ratio ( R d/c ) of bis-Im-diPh and chloromethyl groups from 0.18 to 0.33. With increasing R d/c , the swelling ratio decreases, and the hydroxide conductivity increases. The CL-PSf-ImOH membrane with R d/c of 0.33 exhibits the conductivity of 112 mS cm −1 at 60 °C, much higher than that of non-crosslinked membrane (83 mS cm −1 , losing its morphology at 60 °C) and those of other crosslinked membranes (17–68 mS cm −1 ) prepared with the similar methods. In addition, the CL-PSf-ImOH membranes show good dimensional stability at elevated temperatures.
RbBr nanocubes were transformed from solid to hollow nanostructure under e-beam irradiation while maintaining the size, exterior shape, and crystalline structure. The process of the morphological evolution was studied by in situ TEM characterization at atomic resolution. The transformation was attributed to combination of the radiolysis and surface ligand bonding (stabilization). The radiolysis occurred at the surface resulted in evaporation or sputtering of the constituent atoms at the unpassivated sites, leaving vacancies at the surface which facilitate the outward diffusion of atoms from inside. The atoms near the surface were stabilized by the bonding of the ligands and remained in the crystalline configuration, leading to the formation of hollow nanocubes.
危险品化学品经营许可证（带存储）