抗污染聚醚砜超濾膜的制備及其在油水分離中的應(yīng)用
發(fā)布時(shí)間：2018-12-11 17:25
【摘要】：隨著現(xiàn)代工業(yè)的快速發(fā)展,水環(huán)境問題越來越受到人們的重視,尤其是工業(yè)有機(jī)廢水、含油污水的處理問題備受關(guān)注。各種水處理方法、工藝在水質(zhì)調(diào)理過程中得到了廣泛應(yīng)用,而膜分離技術(shù)被認(rèn)為是解決水質(zhì)問題工藝環(huán)節(jié)中的重要措施之一。高分子聚合物聚醚砜(PES)具有耐高溫、強(qiáng)度高、物化性質(zhì)穩(wěn)定等優(yōu)點(diǎn),是理想的膜材料。但在實(shí)際使用中,由于PES本身的疏水性,純PES膜易被污染,導(dǎo)致膜的分離效率下降,操作成本增加,限制其工業(yè)應(yīng)用。本文采用物理共混和化學(xué)接枝并用的方法對(duì)疏水性PES膜進(jìn)行兩步親水化改性,來提高其抗污染性能,增強(qiáng)其實(shí)際應(yīng)用性。文中先采用物理共混法對(duì)PES膜進(jìn)行親水化改性。利用表面引發(fā)的可逆加成斷裂鏈轉(zhuǎn)移聚合法(RAFT),以普蘭尼克F-127(F127)和丙烯酸(AA)為原料,合成親水性嵌段聚合物PAA-F127-PAA,將其作為添加劑以不同比例與PES共混,通過非溶劑致相分離法(NIPS)制備PES/PAA-F127-PAA膜。研究表明,在成膜過程中,親水性的PAA-F127-PAA會(huì)在界面自由能最低化驅(qū)使下自發(fā)地向膜表面遷移,膜的純水通量、親水性、抗污染能力都得到了改善。且隨添加劑含量的增加,純水通量表現(xiàn)為先增大后減小的趨勢(shì)。當(dāng)添加劑相對(duì)PES的添加量為5wt%時(shí),膜的性能最好,與純PES膜相比,純水通量從122.11L/(m2·h)增大到333.72L/(m2.h),接觸角從82.6°減小到64.3°,通量恢復(fù)率從45.75%提高到81.34%。此外,為繼續(xù)提升改性膜的性能,在物理共混改性基礎(chǔ)上對(duì)膜進(jìn)行進(jìn)一步化學(xué)接枝親水化改性。通過控制電子轉(zhuǎn)移活化再生催化劑原子轉(zhuǎn)移自由基聚合法(ARGET ATRP)的聚合時(shí)間,由(2-乙基(2-溴-2-甲基丙酰氨基))叔丁基氨基甲酸(Boc-Br)和甲基丙烯酸二甲氨乙酯(DMAEMA),合成了不同鏈長(zhǎng)的強(qiáng)親水性聚合物NH2-PDMAPS。以上述性能最好的共混改性膜為基膜,利用合成的親水性聚合物NH2-PDMAPS與膜表面PAA鏈段進(jìn)行酰胺化反應(yīng),制備了PES/PAA-F127-PAA/NH2-PDMAPS改性膜。實(shí)驗(yàn)表明,隨著膜表面接枝的NH2-PDMAPS鏈長(zhǎng)的增加,膜的純水通量先增大后減小。當(dāng)聚合時(shí)間為8h時(shí),改性膜的性能最佳,純水通量為280.78L/(m2·h),接觸角為45.3°,通量恢復(fù)率高達(dá)93.45%,相比于純PES膜,純水通量增大了 129.9%,接觸角降低了 47.1%,通量恢復(fù)率提高了 106.6%。膜的抗污染能力得到了顯著提升,油水分離效果得到了明顯增強(qiáng)。
[Abstract]:With the rapid development of modern industry, people pay more and more attention to the problem of water environment, especially the treatment of industrial organic wastewater and oily wastewater. Various water treatment methods have been widely used in the process of water quality conditioning, and membrane separation technology is considered as one of the most important measures to solve water quality problems. Polymer polyethersulfone (PES) is an ideal membrane material because of its high temperature resistance, high strength and stable physicochemical properties. However, due to the hydrophobicity of PES, the membrane of pure PES is liable to be contaminated, which leads to the decrease of membrane separation efficiency and the increase of operation cost, which limits its industrial application. In this paper, the hydrophilic modification of hydrophobic PES membrane was carried out by means of physical blending and chemical grafting in order to improve its anti-pollution performance and enhance its practical application. In this paper, the hydrophilic modification of PES membrane was carried out by physical blending method. The hydrophilic block polymer PAA-F127-PAA, was synthesized by surface-initiated reversible addition-breaking chain transfer polymerization (RAFT),) with (AA) and F-127 (F127) as raw materials. The PES/PAA-F127-PAA membrane was prepared by non-solvent induced phase separation (NIPS) method by blending it with PES in different proportion as additive. The results show that the hydrophilic PAA-F127-PAA can migrate spontaneously to the membrane surface under the lowest free energy at the interface. The pure water flux, hydrophilicity and antifouling ability of the membrane are improved. With the increase of additive content, the pure water flux increased first and then decreased. When the content of additive relative to PES is 5 wt%, the performance of the membrane is the best. Compared with the pure PES membrane, the pure water flux increases from 122.11L/ (m 2 h) to 333.72L/ (m 2 h), and the contact angle decreases from 82.6 擄to 64.3 擄. The flux recovery rate increased from 45.75% to 81.34%. In addition, in order to improve the properties of the modified membrane, further chemical grafted hydrophilic modification was carried out on the basis of physical blending modification. The polymerization time of (ARGET ATRP) by atom transfer radical polymerization with electron transfer activated regeneration catalyst was controlled. A strong hydrophilic polymer NH2-PDMAPS. with different chain lengths was synthesized from (2-ethyl (2-bromo-2-methylpropionyl) tert-Ding Ji carbamate (Boc-Br) and dimethylaminoethyl methacrylate (DMAEMA),). The PES/PAA-F127-PAA/NH2-PDMAPS modified membrane was prepared by amidation of the hydrophilic polymer NH2-PDMAPS with the PAA segment of the membrane surface. The experimental results show that the pure water flux of the membrane increases first and then decreases with the increase of the NH2-PDMAPS chain length on the surface of the membrane. When the polymerization time is 8 h, the performance of the modified membrane is the best. The pure water flux is 280.78L/ (m ~ 2 h), contact angle is 45.3 擄, and the flux recovery rate is 93.45 擄). Compared with the pure PES membrane, the pure water flux increases 129.9%. The contact angle decreased by 47.1 and the flux recovery rate increased by 106.6. The antifouling ability of the membrane was improved significantly, and the separation effect of oil and water was obviously enhanced.
【學(xué)位授予單位】：東南大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TQ051.893;X703
本文編號(hào)：2372939
[Abstract]:With the rapid development of modern industry, people pay more and more attention to the problem of water environment, especially the treatment of industrial organic wastewater and oily wastewater. Various water treatment methods have been widely used in the process of water quality conditioning, and membrane separation technology is considered as one of the most important measures to solve water quality problems. Polymer polyethersulfone (PES) is an ideal membrane material because of its high temperature resistance, high strength and stable physicochemical properties. However, due to the hydrophobicity of PES, the membrane of pure PES is liable to be contaminated, which leads to the decrease of membrane separation efficiency and the increase of operation cost, which limits its industrial application. In this paper, the hydrophilic modification of hydrophobic PES membrane was carried out by means of physical blending and chemical grafting in order to improve its anti-pollution performance and enhance its practical application. In this paper, the hydrophilic modification of PES membrane was carried out by physical blending method. The hydrophilic block polymer PAA-F127-PAA, was synthesized by surface-initiated reversible addition-breaking chain transfer polymerization (RAFT),) with (AA) and F-127 (F127) as raw materials. The PES/PAA-F127-PAA membrane was prepared by non-solvent induced phase separation (NIPS) method by blending it with PES in different proportion as additive. The results show that the hydrophilic PAA-F127-PAA can migrate spontaneously to the membrane surface under the lowest free energy at the interface. The pure water flux, hydrophilicity and antifouling ability of the membrane are improved. With the increase of additive content, the pure water flux increased first and then decreased. When the content of additive relative to PES is 5 wt%, the performance of the membrane is the best. Compared with the pure PES membrane, the pure water flux increases from 122.11L/ (m 2 h) to 333.72L/ (m 2 h), and the contact angle decreases from 82.6 擄to 64.3 擄. The flux recovery rate increased from 45.75% to 81.34%. In addition, in order to improve the properties of the modified membrane, further chemical grafted hydrophilic modification was carried out on the basis of physical blending modification. The polymerization time of (ARGET ATRP) by atom transfer radical polymerization with electron transfer activated regeneration catalyst was controlled. A strong hydrophilic polymer NH2-PDMAPS. with different chain lengths was synthesized from (2-ethyl (2-bromo-2-methylpropionyl) tert-Ding Ji carbamate (Boc-Br) and dimethylaminoethyl methacrylate (DMAEMA),). The PES/PAA-F127-PAA/NH2-PDMAPS modified membrane was prepared by amidation of the hydrophilic polymer NH2-PDMAPS with the PAA segment of the membrane surface. The experimental results show that the pure water flux of the membrane increases first and then decreases with the increase of the NH2-PDMAPS chain length on the surface of the membrane. When the polymerization time is 8 h, the performance of the modified membrane is the best. The pure water flux is 280.78L/ (m ~ 2 h), contact angle is 45.3 擄, and the flux recovery rate is 93.45 擄). Compared with the pure PES membrane, the pure water flux increases 129.9%. The contact angle decreased by 47.1 and the flux recovery rate increased by 106.6. The antifouling ability of the membrane was improved significantly, and the separation effect of oil and water was obviously enhanced.
【學(xué)位授予單位】：東南大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TQ051.893;X703
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 唐龍祥;范保林;劉春華;張奎;王平華;;ATRP法在納米SiO_2表面接枝PS及其對(duì)HDPE的改性[J];高分子材料科學(xué)與工程;2011年05期
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