摘要
用聚乙烯醇(PVA)、乙酸纤维素(CA)、冰醋酸、金属氯化物、水为制膜原料,用相转化法制备了掺杂金属氯化物的PVA-CA共混超滤膜.金属氯化物包括碱金属氯化物NaCl、KCl和碱土金属氯化物BaCl2.在一定浓度范围内,研究了金属氯化物含量对共混超滤膜性能的影响.结果表明,当膜液中碱金属氯化物NaCl、KCl的质量分数不超过1%时,改性共混膜在截留性能基本不变的情况下,可提高纯水通量;当其质量分数大于1.5%时,膜的纯水通量显著增加,而截留率随之而降低.其适宜的添加量约为1%,而对碱土金属氯化物BaCl2,其较佳的添加量约为1.5%;在相同操作条件下,对同样质量浓度的添加量,添加KCl的共混膜水通量最大.PVA-CA共混膜经NaCl和KCl改性后,其亲水性有所增加,经BaCl2改性后亲水性略有降低.
The modified PVA-CA blend ultrafiltration membranes were prepared by phase inversion from the casting solutions consisting of polyvinyl alcohol(PVA),cellulose acetate(CA),acetic acid,metal chloride and water.Metal chlorides used in this study include alkali metal chloride KCl and NaCl,and alkali earth metal chloride BaCl2.The effects of different concentration of metal chlorides on the properties of membranes were investigated.The results show that when the mass fraction of the alkali metal chloride in the casting solution is less than 1%,the oil rejection of the o/w emulsion for the salt modified ultrafiltration PVA-CA blend membrane has (little) change compared with the unmodified PVA-CA blend membrane,but the permeate flux is much greater than that of unmodified membrane under the same operation.When the mass fraction of the salt is greater than 1.5%,the permeate flux increases much greater than that of unmodified membrane,but the property of rejection of the alkali metal modified ultrafiltration membrane decreases drastically.Thus,the suitable mass fraction of (NaCl) or KCl is about 1%,but the optimal mass fraction of the BaCl2 is about 1.5%.The results also show that KCl modified PVA-CA blend UF membrane,has the greatest water flux under the same operation condition.Both NaCl and KCl modified PVA-CA blend membranes can increase the hydrophilicity of membrane a little,but the BaCl2 modified blend membrane slightly decrease the hydrophilicity.
出处
《膜科学与技术》
CAS
CSCD
北大核心
2004年第2期7-11,共5页
Membrane Science and Technology
