聚碳酸酯和聚酯核孔膜的性能研究

Characteristics of polycarbonate and polyester nuclear track membranes

聚碳酸酯(Polycarbonate,PC)和聚对苯二甲酸乙二酯(Polyethylene Terephthalate,PET)薄膜因其可被碱性溶液有效刻蚀而被用于核孔膜材料。采用11.4 MeV·u-1的Au离子和20 MeV·u^(-1)的Kr离子分别辐照PC及PET薄膜,然后经NaOH溶液蚀刻,制得膜孔径分别为20-400 nm和100-700 nm的PC和PET核孔膜。扫描电子显微镜(Scan Electron Microscope,SEM)和气-液排除法等表征和测试结果显示孔密度与辐照剂量有关;蚀刻时间越长,膜孔径越大,实验制备的核孔膜孔分布越均匀。被辐照后的PET膜亲水性比PC膜高。在0.15 MPa和室温下,水溶液中的牛血清白蛋白(Bovine Serum Albumin,BSA)可被不同孔径的PET核孔膜有效截留;膜孔径越小,截留率越高,过滤所需压力越大,膜越易被污染。

Background： Polycarbonate （PC） and polyethylene terephthalate （PET） films were widely used as the materials for nuclear track membranes because both of them could be etched effectively with alkaline solutions. Purpose： This paper aims to research the characteristics of polycarbonate and polyester nuclear track membranes. Methods： The PC and PET foils were irradiated with Au ions （11.4 MeV＇u1） and Kr ions （20 MeV＇u-1） respectively. Then the irradiated foils were etched with the NaOH aqueous solution. The pore sizes of PC and PET nuclear track membranes were in the range of 20 nm to 400 nm and 100 nm to 700 nm, respectively. Results： The pore sizes and their distributions of these membranes were characterized with scanning electron microscopy （SEM） and the methodof gas-liquid displacement, respectively. It suggested that the irradiation fluence determined the membrane pore density; the longer the etching time, the larger the membrane pore size, and the evener the distribution of membrane pore sizes. The surfaces of the irradiated PET membranes were more hydrophilic than those of the irradiated PC membranes. Conclusion： The experimental results suggest that bovine serum albumin （BSA） in aqueous solution could be rejected effectively by PET nuclear track membranes with different membrane pore sizes at 0.15 MPa and ambient temperature. The smaller the membrane pore size, the higher the rejection to BSA, and the higher the operating pressure required, resulting in more serious membrane fouling.