In order to develop high performance composite membranes for alcohol permselective pervaporation(PV),poly(dimethylsiloxane)/ZIF-8(PDMS/ZIF-8)coated polymeric hollow fiber membranes were studied in this research.First,...In order to develop high performance composite membranes for alcohol permselective pervaporation(PV),poly(dimethylsiloxane)/ZIF-8(PDMS/ZIF-8)coated polymeric hollow fiber membranes were studied in this research.First,PDMS was used for the active layer,and Torlon?,PVDF,Ultem?,and Matrimid?with different porosity were used as support layer for fabrication of hollow fiber composite membranes.The performance of the membranes varied with different hollow fiber substrates was investigated.Pure gas permeance of the hollow fiber was tested to investigate the pore size of all fibers.The effect of support layer on the mass transfer in hydrophobic PV composite membrane was investigated.The results show that proper porosity and pore diameter of the support are demanded to minimize the Knudsen effect.Based on the result,ZIF-8 was introduced to prepare more selective separation layer,in order to improve the PV performance.The PDMS/ZIF-8/Torlon?membrane had a separation factor of 8.9 and a total flux of 847 g·m-2·h-1.This hollow fiber PDMS/ZIF-8/Torlon?composite membrane has a great potential in the industrial application.展开更多
针对印染废水难以处理而对环境造成污染问题,以活性黑染料为目标污染物,制备了一种ZIF-8/MCM-48新型复合吸附材料,并采用X射线衍射(X-ray Diffraction,XRD)、扫描电镜(Scanning Electron Microscopy,SEM)、N_(2)的吸脱附曲线对其形貌、...针对印染废水难以处理而对环境造成污染问题,以活性黑染料为目标污染物,制备了一种ZIF-8/MCM-48新型复合吸附材料,并采用X射线衍射(X-ray Diffraction,XRD)、扫描电镜(Scanning Electron Microscopy,SEM)、N_(2)的吸脱附曲线对其形貌、结构、组成进行表征,研究了其对活性黑染料废水的吸附性能,并通过调整ZIF-8/MCM-48复合物比例、活性黑染料废水浓度、染料废水pH值及吸附时间,来确定最大吸附量和最佳吸附条件。结果表明,ZIF-8/MCM-48复合吸附剂的投加量为0.4 g/L、废水pH值为6、吸附时间为50 min时,0.15 g/L活性黑染料废水的脱色率达到了最高,为58.7%。最后对吸附过程进行了动力学分析,发现其符合二级动力学方程。展开更多
An alternative method for SU-8 removal is proposed.Instead of directly using SU-8 microstructure as the electroplating mold,a polydimethysiloxane (PDMS) replica is employed.The metallic micromold insert obtained throu...An alternative method for SU-8 removal is proposed.Instead of directly using SU-8 microstructure as the electroplating mold,a polydimethysiloxane (PDMS) replica is employed.The metallic micromold insert obtained through this method can be easily peeled off from the PDMS replica,meanwhile with high resolution and smooth surfaces.展开更多
基金Supported by the National Natural Science Foundation of China(21706003)the National High Technology Research and Development Program of China(2015AA03A602)+1 种基金the High-Caliber Talents Project of Beijing Municipal Institutions(CIT&TCD20170305)the China Scholarship Council(201406540011).
文摘In order to develop high performance composite membranes for alcohol permselective pervaporation(PV),poly(dimethylsiloxane)/ZIF-8(PDMS/ZIF-8)coated polymeric hollow fiber membranes were studied in this research.First,PDMS was used for the active layer,and Torlon?,PVDF,Ultem?,and Matrimid?with different porosity were used as support layer for fabrication of hollow fiber composite membranes.The performance of the membranes varied with different hollow fiber substrates was investigated.Pure gas permeance of the hollow fiber was tested to investigate the pore size of all fibers.The effect of support layer on the mass transfer in hydrophobic PV composite membrane was investigated.The results show that proper porosity and pore diameter of the support are demanded to minimize the Knudsen effect.Based on the result,ZIF-8 was introduced to prepare more selective separation layer,in order to improve the PV performance.The PDMS/ZIF-8/Torlon?membrane had a separation factor of 8.9 and a total flux of 847 g·m-2·h-1.This hollow fiber PDMS/ZIF-8/Torlon?composite membrane has a great potential in the industrial application.
文摘An alternative method for SU-8 removal is proposed.Instead of directly using SU-8 microstructure as the electroplating mold,a polydimethysiloxane (PDMS) replica is employed.The metallic micromold insert obtained through this method can be easily peeled off from the PDMS replica,meanwhile with high resolution and smooth surfaces.
