纳米纤维素晶接枝丙烯酸钠共混改性聚醚砜超滤膜的研究

Study on CNCs-g-AANananocrystal/polyether sulfoneblended ultrafiltration membranes

通过ATRP法在纳米纤维素晶(CNCs)上接枝丙烯酸钠(AANa)制备具有pH响应性的晶体粒子,利用红外光谱(FT-IR),X射线光电子能谱(XPS)对接枝前后的CNCs进行分析表征。接枝后的CNCs与聚醚砜(PES)进行共混,通过相转化法制得共混膜,利用扫描电镜(SEM),水通量测试对共混膜进行分析。结果表明,当CNCs-g-AANa添加量为1%时,CNCs-g-AANa/PES共混膜水通量有明显提高;且共混膜具有pH响应性,当pH值>7.2时,共混膜水通量为137.47L/(m2·h),相比纯PES膜提高了41%;当pH值下降为3.3时,共混膜的水通量达到218.54L/(m2·h),相比纯PES膜提高124%。

In this study,PAA was grafted onto the surface of CNCs by using ATRP conditions to prepare nanocrystals with pH-sensitivity.The CNCs particlesand the modified CNCs were characterized by infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS)andparticle size analyzer.The pure PES membrane and blended CNCs-g-PAA/PES membranes were prepared by aphase inversion process,and the structure of the membranes were analyzed and characterized byscanning electron microscopy(SEM),water flux test and contact angle test.The results show that the pore size of the porous support layer of the membrane is larger than that of the pure PES film,and the pore size becomes larger and thetop layer becomes thinner.When the CNCs-gAANaloading is 1 wt%,the water flux of the CNCs-g-AANa/PESblend film is obviously improved.And the blend film has pH sensitivity.When the pH value is more than 7.2,the water flux of the blend film tends to be constant at 137.47 L/(m2·h),which is 41% higher than that of pure PES membrane.When the pH value decrease to 3.3,the water flux of the blend film reaches 218.54 L/(m2·h)by an increase about 124% as compared with pure PES membrane.