發(fā)布時間：2018-01-16 13:11

  本文關鍵詞：改性聚丙烯腈超濾膜性能研究　出處：《華東理工大學》2017年碩士論文　論文類型：學位論文

  更多相關文章： 聚丙烯腈超濾膜 反應改性 共混改性 表面接枝

【摘要】：超濾膜分離技術作為溫和、節(jié)能、高效率的分離技術,被廣泛的應用于污水處理、家庭應用水等領域。聚丙烯腈(PAN)作為易得的化工原料,有著耐候性、耐化學試劑等優(yōu)良特性,但較差的機械性能和抗污染性能限制了其在水處理技術中的應用。本文主要采用PAN原料,利用非溶劑致相分離的方法制備平板超濾膜,通過反應、共混以及表面改性等方法,調控PAN膜的結構以及表面特性。通過SEM、AFM以及FTIR等方法進行微觀分析,同時利用純水通量、截留率以及接觸角等對平板膜進行性能表征。采用乙醇胺(ETA)與PAN反應,制備PAN-ETA平板膜。研究反應溫度和PAN濃度對平板膜結構以及性能的影響。結果表明,隨著反應溫度的提高以及PAN濃度的提高,鑄膜液黏度逐漸增加,在凝膠浴中從瞬時分相變?yōu)檠訒r分相,平板膜斷面結構相應的從不規(guī)整的指狀孔變?yōu)楹＞d狀孔結構。通過與ETA的反應反應,PAN的平板膜的親水性能、機械性能以及抗污染性能得到提高。當反應溫度為80℃,PAN的濃度為18%時,模擬計算得到平板膜的平均孔徑為4.44 nm;平板膜的純水通量為52.72 L·m~(-2)·h~(-1),對PEG2w的截留率達到96.04%;靜態(tài)接觸角為49°,在0.3 g/L的BSA溶液中運行衰減率為15%,通量恢復達到90%以上;抗拉強度達到5.40 MPa,斷裂伸長率為87.65%,而在PAN18T25對PEG2w的截留幾乎為0;靜態(tài)接觸角為60°,在0.3g/L的BSA溶液中運行衰減率為37%,通量恢復僅為66%;膜抗拉強度為4.56 MPa,斷裂伸長率僅為26.53%,其次通過納米二氧化鈦(Tio_2)和制備的氧化石墨烯(GO)共混改性PAN平板膜。無機粒子的共混改性能夠有效的提高膜的表面孔隙率和粗糙度,提高膜的親水性能抗污染性能。GO和納米Tio_2都具有較強的親水性能,能夠在分相時逃逸富集在膜的分離層,使得膜形成含有不規(guī)則指狀的斷面和親水性良好的表面。當GO的添加量達到0.06 g,共混溫度為80℃時,斷面出現(xiàn)指狀孔,通量為63.69L·m~(-2)·h~(-1),對PEG2w的截留保持90%以上。在0.3g/L的BSA溶液中運行衰減率為11%。當Tio_2添加量為0.30g時,斷面出現(xiàn)倒三角型的指狀孔,通量提高到94.48 L.m·2·h~(-1),但是截留能力大幅下降;在BSA水溶液中運行通量衰減率為13%。最后通過聚酰胺胺(PAMAM)對PAN平板膜表面接枝,在表面形成親水性良好的致密符合層,得到小孔徑超濾膜,極大的提高膜的親水性能和截留能力。實驗結果顯示在60℃環(huán)境下接枝反應4h,此時純水通量為14.86L·m·2·h~(-1),瞬間接觸角為70.5°,比M-pure降低了 10°;對PEG2k的截留率達到91.37%。
[Abstract]:As a mild, energy saving and high efficiency separation technology, ultrafiltration membrane separation technology has been widely used in sewage treatment, domestic application of water and other fields. Polyacrylonitrile (PAN) as a readily available chemical raw materials, has weathering resistance. Chemical reagents and other excellent properties, but poor mechanical properties and anti-pollution performance limits its application in water treatment technology. This paper mainly uses PAN raw materials. The flat plate ultrafiltration membrane was prepared by non-solvent phase separation method. The structure and surface properties of PAN membrane were regulated by reaction, blending and surface modification. SEM was used to prepare the membrane. The AFM and FTIR methods were used to analyze the properties of the membrane, and the pure water flux, retention rate and contact angle were used to characterize the properties of the membrane. The ethanolamine ETA-ETA was used to react with PAN. The effects of reaction temperature and PAN concentration on the structure and properties of PAN-ETA flat membrane were studied. The results showed that with the increase of reaction temperature and PAN concentration. The viscosity of casting liquid increased gradually, from instantaneous phase separation to delayed phase separation in gel bath, and the irregular finger pore into sponge pore structure corresponding to the cross-section structure of flat membrane. The reaction with ETA was carried out. The hydrophilicity, mechanical properties and antifouling properties of PAN flat membrane were improved when the reaction temperature was 80 鈩，

本文編號：1433257