本文選題：正滲透 + 復(fù)合膜�。� 參考：《中國(guó)科學(xué)技術(shù)大學(xué)》2015年博士論文

【摘要】：正滲透(forward osmosis, FO)技術(shù)在常壓條件下能利用半透膜兩側(cè)溶液滲透壓差異,可實(shí)現(xiàn)溶液自發(fā)分離,在解決水源與能源間的矛盾方面表現(xiàn)出巨大的潛力。然而,長(zhǎng)期以來(lái)由于高性能FO膜的短缺抑制了該技術(shù)的發(fā)展,在壓力驅(qū)動(dòng)過(guò)程中表現(xiàn)優(yōu)異的滲透膜,卻在FO過(guò)程中出現(xiàn)嚴(yán)重的內(nèi)濃差極化效應(yīng),導(dǎo)致膜的滲透通量遠(yuǎn)低于理論值,極大地影響了生產(chǎn)效率和FO技術(shù)的實(shí)際應(yīng)用。同時(shí),復(fù)合膜皮層粗糙的表面和化學(xué)結(jié)構(gòu)增加了膜污染傾向。因此,針對(duì)以上問(wèn)題,開(kāi)發(fā)新型的高性能復(fù)合膜,在保持高選擇性的同時(shí),減弱內(nèi)濃差極化的負(fù)面影響,提高水的滲透通量,增強(qiáng)膜的抗污性能,成為當(dāng)前正滲透膜開(kāi)發(fā)的研究熱點(diǎn)。 共混改性是提高聚合物膜材料性能、拓寬其應(yīng)用范圍的簡(jiǎn)單、高效的方法。本文通過(guò)在常用的膜材料PES中摻入碳納米管、氮化碳摻雜石墨烯、MMT@SPES等有效地改善了薄膜復(fù)合膜支撐層的結(jié)構(gòu)和性質(zhì),降低了膜的結(jié)構(gòu)參數(shù),提高了膜的滲透通量,另外,我們還用簡(jiǎn)單的二次界面聚合法實(shí)現(xiàn)了聚酰胺層的化學(xué)結(jié)構(gòu)性質(zhì)、表面形貌及其在正滲透過(guò)程中應(yīng)用性能的轉(zhuǎn)變。主要的研究結(jié)果如下： (1)酸化后的多壁碳管在聚吡咯烷酮的輔助下通過(guò)溶液混合法分散于PES基質(zhì)中,經(jīng)相轉(zhuǎn)化獲得多孔膜,以其為基膜制備了復(fù)合膜,并用于鹽水的分離。結(jié)果發(fā)現(xiàn)：適當(dāng)?shù)奶技{米管可增加基膜孔隙率,因碳管貫穿在基質(zhì)中形成更多的孔道結(jié)構(gòu),有助于通量的增加,復(fù)合膜的截鹽率也可達(dá)97%,同時(shí),基膜的力學(xué)強(qiáng)度并不因形成較多的孔隙發(fā)生下降,反隨碳管的添加量增加而升高。 (2)成功合成了一種多孔層狀材料一氮化碳摻雜石墨烯(CN/rGO)并用作復(fù)合膜支撐層的改性劑,在PES基質(zhì)中添加0.5wt.%的CN/rGO,所得復(fù)合膜在2M氯化鈉為提取液,去離子水為進(jìn)料時(shí),可獲得高達(dá)41.4L/m2h的水通量,比空白膜高20%,這一結(jié)果歸因于膜結(jié)構(gòu)的改善和基膜孔壁親水性的增加。 (3)利用無(wú)機(jī)粒子-蒙脫土(MMT)與親水性聚合物-磺化聚醚砜(SPES)間的靜電作用,減少了親水性聚合物在非溶劑相轉(zhuǎn)化過(guò)程中的損失,FT-IR和XPS分析結(jié)果證明,MMT把更多的SPES錨定在PES基質(zhì)中。我們發(fā)現(xiàn)添加了MMT@SPES的多孔膜,由于潤(rùn)濕性能的增加,純水透過(guò)系數(shù)從PES膜的60.9LMH/bar提升到460LMH/bar,而膜孔徑維持在適合形成聚酰胺層的300kDaMWCO以內(nèi)。用以上多孔膜作基膜的正滲透復(fù)合膜,以PES/MMT@SPES(40)為例,其在FO模式下,水通量比基于PES/SPES所得的復(fù)合膜通量提高了4倍,而鹽的反向滲漏通量減小了一半,這一結(jié)果可歸因于混合基質(zhì)的基膜具有更強(qiáng)的潤(rùn)濕性和更窄的孔徑分布。 (4)通過(guò)分別用乙二胺(EDA)和乙二胺乙磺酸鈉(SEA)水溶液浸漬初生的芳香聚酰胺(PA)層,在復(fù)合膜表面發(fā)生原位二次界面聚合(SIP)反應(yīng),我們系統(tǒng)考察了二次界面聚合及所用浸漬單體對(duì)膜的性質(zhì)及應(yīng)用性能的影響,發(fā)現(xiàn)EDA改性可提高膜的抗污性能,SEA則在不影響膜的選擇性的前提下,正滲透水通量增加了2倍,但盡管其表面更加平滑和親水,抗污能力卻發(fā)生了下降。這是因?yàn)檩^高的滲透的初始通量也加劇了膜污染的程度。雖然膜表面性質(zhì)與膜污染存在一定的聯(lián)系,但初始通量卻是影響膜污染的主要因素。
[Abstract]:Forward osmosis (FO) technology can make use of the difference in osmotic pressure on both sides of the semi permeable membrane under normal pressure, which can realize the spontaneous separation of the solution and show great potential in solving the contradiction between water and energy. However, for a long time, the shortage of high performance FO film inhibits the development of this technology, and in the process of pressure driving. The present excellent permeable membrane has serious internal consistency polarization effect in the process of FO, which leads to the permeation flux of the membrane far below the theoretical value, which greatly affects the production efficiency and the practical application of FO technology. At the same time, the rough surface and chemical structure of the composite membrane increase the tendency of membrane fouling. The performance composite membrane, while maintaining high selectivity, reduces the negative influence of the internal consistency polarization, improves the permeation flux of water and enhances the anti fouling performance of the membrane. It has become a hot spot in the current research of the development of the positive permeable membrane.
Blending modification is a simple and efficient method to improve the properties of polymer film materials and broaden its application range. In this paper, the structure and properties of the support layer of the film composite film are effectively improved by adding carbon nanotubes, carbon nitride doped graphene and MMT@SPES in the commonly used membrane material PES, and the structure parameters of the membrane are reduced and the membrane permeability is improved. In addition, we have also realized the chemical structure properties of the polyamide layer, the surface morphology and the transformation of its application performance in the process of positive Osmosis with a simple two interface polymerization method. The main results are as follows:
(1) the multi wall carbon tube after acidification is dispersed in the PES matrix by solution mixing under the aid of Polypyrrolidone ketone, and the porous membrane is obtained by phase transformation. The composite membrane is prepared as the base film and used in the separation of salt water. The results show that the proper carbon nanotubes can increase the pore rate of the base film, and the carbon tube can form more Kong Daojie in the matrix. With the increase of flux, the salt cutting rate of the composite membrane is also up to 97%. At the same time, the mechanical strength of the base film does not decrease with the formation of more pores, but increases with the increase of the amount of carbon nanotubes.
(2) a porous layered material, carbon nitride doped graphene (CN/rGO) was successfully synthesized and used as a modifier for the composite membrane support layer. The CN/rGO of 0.5wt.% was added to the matrix of PES. The composite membrane was extracted from 2M sodium chloride and the deionized water was used as the feed. The water flux of up to 41.4L/m2h was obtained, which was higher than that of the blank film. The result was attributed to the result of this result. Improvement of membrane structure and increase of hydrophilicity of basement membrane.
(3) using the electrostatic action between the inorganic particle montmorillonite (MMT) and the hydrophilic polymer sulfonated polyethersulfone (SPES), the loss of the hydrophilic polymer during the non solvent phase transformation is reduced. The results of FT-IR and XPS analysis show that MMT has anchored more SPES in the PES matrix. We found the porous membrane added to the MMT@SPES, due to the wettability. The permeability of pure water is increased from the 60.9LMH/bar of the PES film to 460LMH/bar, and the membrane pore size is maintained within the 300kDaMWCO suitable for forming the polyamide layer. The positive permeable composite membrane with the above porous membrane as the basement membrane, for example, in PES/MMT@SPES (40), is 4 times higher than the flux of the composite membrane based on PES/SPES in the FO mode, while the salt flux is higher than that of the PES/SPES. The reverse leakage flux is reduced by half. This result can be attributed to the stronger wettability and narrower pore size distribution of the substrate.
(4) by impregnating the primary aromatic polyamide (PA) layer with ethylenediamine (EDA) and ethylenediamine sodium sulfonate (SEA) aqueous solution respectively, the in-situ two interfacial polymerization (SIP) reaction occurred on the surface of the composite membrane. The effects of two interfacial polymerization and the impregnated monomers on the properties and application properties of the membrane were systematically investigated. It was found that the EDA modification could improve the membrane. The flux of positive permeable water increased by 2 times without affecting the selectivity of the membrane, but in spite of the smooth and hydrophilic surface of the SEA, the anti fouling ability decreased. This is because the initial flux of high permeability also aggravates the degree of membrane fouling. Although the membrane surface properties are related to the membrane pollution, the initial flux has a certain relationship with the membrane fouling. Flux is the main factor affecting membrane fouling.

【學(xué)位授予單位】：中國(guó)科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2015
【分類號(hào)】：TQ051.893

【共引文獻(xiàn)】

相關(guān)期刊論文 前10條

1 劉建華;于海波;楊海華;李琳;;滲透汽化傳質(zhì)模型的研究進(jìn)展[J];廣州化工;2013年17期

2 馬寧;劉操;李其軍;劉金翰;;膜工藝在水處理行業(yè)中的應(yīng)用及性能分析[J];給水排水動(dòng)態(tài);2013年05期

3 楊建華;王立國(guó);;正滲透膜的原理及應(yīng)用[J];城鎮(zhèn)供水;2013年05期

4 王磊;苗瑞;呂永濤;劉紫文;馮玲;;AFM微顆粒探針及其在膜的有機(jī)物污染機(jī)制解析中的應(yīng)用研究與展望[J];材料導(dǎo)報(bào);2013年13期

5 Yao Gao;Gui-ying Zong;Hong-wei Bai;傅強(qiáng);;Combined Effects of Stretching and Nanofillers on the Crystalline Structure and Mechanical Properties of Polypropylene and Single-walled Carbon Nanotube Composite Fibers[J];Chinese Journal of Polymer Science;2014年02期

6 李海軍;張捍民;楊鳳林;;對(duì)稱正滲透膜制備及膜性能表征[J];環(huán)境科學(xué)與技術(shù);2013年12期

7 杜杰;杜昌文;申亞珍;周健民;;碳納米管/聚合物復(fù)合材料及其在包膜控釋肥料中的應(yīng)用[J];材料保護(hù);2013年S2期

8 盧艷;宋英;孫秋;王福平;;導(dǎo)電聚苯胺納米復(fù)合熱電材料研究進(jìn)展[J];功能材料;2014年02期

9 常蘭;秦偉超;;碳納米管表面改性及其吸附水中污染物的研究進(jìn)展[J];化工技術(shù)與開(kāi)發(fā);2014年03期

10 李魁;朱奇;陳慧英;洪昱斌;丁馬太;何旭敏;藍(lán)偉光;;PEG的分子量和濃度對(duì)PES中空纖維膜結(jié)構(gòu)和性能的影響[J];功能材料;2014年04期

，

本文編號(hào)：1843302