Lei Jiao,Lida Meng,Kangkang Yan,Jing Wang,Ge Li,Zhikan Yao,Zhilin Sun,Lin Zhang
Membrane wetting is a crucial issue in the desalination process by vacuum membrane distillation (VMD). However, the micromechanism of the wetting behavior is far from clear. Here, electrospun nanofiber membranes (ENMs) had been utilized to clarify the pore variations inside the membrane for desalination from NaCl aqueous solution, where the distinct open pore structure of ENMs could address the characterizing limitations for the change occurring in the membrane pores. A wetting formation model had been depicted on the basis of characterized results, illustrating that the basic reason for wetting was the initial NaCl crystallization caused by supersaturation, which was different from the membrane pores blocking or the structure damage caused by scaling. Moreover, membrane regeneration experiments also showed that the wetting caused by the crystallization of NaCl was reversible. By a reasonable regeneration strategy, VMD used for desalination was expected to achieve continuous operation with rejection over 99.9%.
Xiaobin Jiang,Mingguang Han,Zeqiu Xia,Jin Li,Xuehua Ruan,Xiaoming Yan,Wu Xiao,Gaohong He
Droplet evaporative crystallization on microscale heterogeneous surface is a vivid topic in chemical engineering, bioengineering, nanomaterials, and so on. Here, 3D printed interfacial matrix platform with regular pillar convexity and tunnel structure is fabricated to reveal the mechanism of the interfacial micro droplet crystallization. Element-based rotation volume model is established to simulate the concentration and nucleation barrier distribution during the microscale process. Sodium urate monohydrate and NaCl crystallization on the pillar convex structure both confirm that confined capillary flow in the micro droplet and initial nucleation condition dominate the nucleation, growth control and particle distribution. Droplet crystallization stretches over the tunnel structure reveal an interesting phenomenon that two regions possessing distinct-different nucleation barriers can isolated obtain the crystal particles from nanoscale to even millimeter scale. The fabricated platform and the capillary circulation transfer theory unfold a potential approach to harvest high value-added crystals with specific morphology and desire sizes distribution.
危险品化学品经营许可证（带存储）