Ultra-high molecular weight polyethylene(UHMWPE)membranes were prepared by 5 wt%UHMWPE/parafn oil gels via thermally induced phase separation method and dried in air without signifcant collapse.The UHMWPE membranes we...Ultra-high molecular weight polyethylene(UHMWPE)membranes were prepared by 5 wt%UHMWPE/parafn oil gels via thermally induced phase separation method and dried in air without signifcant collapse.The UHMWPE membranes were annealed at 110℃ for increasing the pores size in order to decrease the capillary forces.Furthermore,a new multiple stage extractant exchange drying(MSEED)technique was adopted to decrease the shrinkage of the UHMWPE membranes.Specifcally,the parafn oil was extracted by dichloromethane,then dichloromethane was replaced by ethanol,next ethanol could be exchanged to other liquid which is non-afnity with UHMWPE,for example water.UHMWPE membranes(annealing for 25 min)dried by dichloromethane-ethanol-water-air process have the lowest volume shrinkage of 16.5%and the porosity is as high as 88.29%.Moreover,compared with supercritical CO_(2)(SC-CO_(2))drying,atmospheric drying UHMWPE membranes have a lower pure water permeance,but a higher carbon particles rejection.展开更多
基金This research is supported by Shanghai International S&T Cooperation Fund(No.16160731302)the Natural Science Foundation of China(No.51473031).
文摘Ultra-high molecular weight polyethylene(UHMWPE)membranes were prepared by 5 wt%UHMWPE/parafn oil gels via thermally induced phase separation method and dried in air without signifcant collapse.The UHMWPE membranes were annealed at 110℃ for increasing the pores size in order to decrease the capillary forces.Furthermore,a new multiple stage extractant exchange drying(MSEED)technique was adopted to decrease the shrinkage of the UHMWPE membranes.Specifcally,the parafn oil was extracted by dichloromethane,then dichloromethane was replaced by ethanol,next ethanol could be exchanged to other liquid which is non-afnity with UHMWPE,for example water.UHMWPE membranes(annealing for 25 min)dried by dichloromethane-ethanol-water-air process have the lowest volume shrinkage of 16.5%and the porosity is as high as 88.29%.Moreover,compared with supercritical CO_(2)(SC-CO_(2))drying,atmospheric drying UHMWPE membranes have a lower pure water permeance,but a higher carbon particles rejection.
