本文選題：反滲透復合膜 + 耐氧化�。� 參考：《浙江工業(yè)大學》2017年碩士論文

【摘要】：芳香聚酰胺復合反滲透(RO)膜中起分離作用的聚酰胺皮層易受活性氯的攻擊發(fā)生結構降解,使膜性能下降,壽命衰減。為解決這一問題,本文將探究過硫酸鹽改性商品芳香聚酰胺RO膜的方法,提高膜的分離性能和耐氧化性能,并對改性機理做出初步探討。用過硫酸鉀(K2S2O8)水溶液浸泡改性商品RO膜,控制以下五個影響因素:浸泡溶液的溫度、K2S2O8濃度、浸泡時間以及熱處理溫度和熱處理時間。對NaCl水溶液的分離性能結果表明,最佳的改性條件是浸泡溫度為60℃,K2S2O8濃度為5 wt%,浸泡時間為100 min,熱處理時間為5 min,熱處理溫度為120℃。此時通量提高43.2%,截留率提高0.2%。對小分子醇(乙醇、異丙醇,正丁醇)的分離實驗表明在5 wt%,100 min下改性膜的截留性能最好。靜態(tài)氧化實驗表明改性膜具有更好的耐氧化性,其中耐氧化性能最佳的改性條件是5 wt%,100min。SEM、AFM結果表明,適當?shù)母男詶l件不會破壞膜表面的“峰-谷結構”,只會降低膜表面粗糙度,而高強度的處理則破壞膜的表面形貌。由ATR-FTIR和XPS得出,改性膜的紅外譜圖變化不大,而O元素含量增加,這說明改性膜表面的羧基增多;Zeta電位表征得出改性膜表面負電荷相對含量增加,這與膜表面羧基增多的結果一致。改性后接觸角降低,即親水性增加�；谏鲜鼋Y果,提出“界面層交聯(lián)-皮層表面氧化”機理,即商品RO膜經K2S2O8改性后,一方面,底膜的聚砜與皮層的聚酰胺分子交聯(lián),形成致密的界面層;另一方面,皮層受過硫酸鹽的氧化作用,結構變得疏松、厚度變薄,失去對溶質的截留作用,此時界面層起截留作用。由于界面層結構更加致密,對溶質的截留能力更強,因此膜的截留率提高;同時,疏松、變薄的皮層將減小溶劑的透膜阻力,使通量增加。界面處交聯(lián)之后穩(wěn)定性增加,能夠耐受更高強度的氧化,從而提高膜的耐氧化性能。
[Abstract]:The polyamide polyamide composite reverse osmosis (RO) membrane is separated from the polyamide cortex, which is vulnerable to the structural degradation of the active chlorine, which reduces the membrane performance and attenuates the life. In order to solve this problem, this paper will explore the method of sulphate modified aromatic polyamide RO film, the separation performance and oxidation resistance of the high film, and the modification machine. A preliminary discussion was made. The modified RO film was soaked with potassium persulfate (K2S2O8) water solution to control the following five factors: the temperature of the soaking solution, the concentration of K2S2O8, the soaking time, the heat treatment temperature and the heat treatment time. The results of the separation performance of the NaCl solution showed that the optimum modification condition was that the soaking temperature was 60, K2S2O8 concentration. For 5 wt%, the soaking time was 100 min, the heat treatment time was 5 min and the heat treatment temperature was 120 C. The flux increased by 43.2%. The separation rate of the retention rate increased by 0.2%. to the small molecular alcohols (ethanol, isopropanol and n-butanol). The experiment showed that the modified film was best retained under 5 wt% and 100 min. The static oxidation experiment showed that the modified membrane had better oxidation resistance. The best modification conditions of the oxidation resistance are 5 wt%, 100min.SEM, and AFM results show that the proper modification conditions will not destroy the "peak valley structure" on the surface of the membrane, only reduce the surface roughness of the membrane, while the high strength treatment destroys the surface morphology of the membrane. The infrared spectrum of the modified membrane is not changed little by the ATR-FTIR and XPS, and the O element contains the elements. The increase of the quantity indicates that the carboxyl group on the surface of the modified membrane increases, and the Zeta potential indicates that the relative content of the negative charge on the surface of the modified membrane increases, which is in accordance with the increase of the carboxyl group on the surface of the membrane. After the modification, the contact angle is reduced, that is, the hydrophilicity is increased. Based on the above results, the mechanism of "interface layer cross-linking - cortical surface oxidation" is proposed, that is, the commodity RO film via K2S2O8 After modification, on the one hand, the polysulfone of the base membrane is crosslinked with the polyamide molecules of the cortex to form a dense interface layer; on the other hand, the cortex has been oxidized by sulfate, the structure becomes loose, the thickness becomes thinner, and the intercepting action of the solute is lost. At this time the interface layer is intercepted. Because the structure of the interface layer is more compact, the ability to intercept the solute is more important. As a result, the retention rate of the membrane is improved; at the same time, the loose, thinner cortex will reduce the permeation resistance of the solvent and increase the flux. The stability increases after the crosslinking at the interface, and can withstand the oxidation of higher strength, thus improving the oxidation resistance of the membrane.

【學位授予單位】：浙江工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TQ051.893

【參考文獻】

相關期刊論文 前7條

1 蔡志奇;梁松苗;;抗氧化復合反滲透膜的制備及其在強氧化環(huán)境下的結構與性能研究[J];水處理技術;2015年01期

2 黃海;張林;侯立安;;海水淡化反滲透耐氯膜材料的研究與制備進展[J];中國工程科學;2014年07期

3 漆春一;楊萍;錢曉明;;有效氯含量測試方法探討[J];上海紡織科技;2010年12期

4 方林;黃紅海;;ATR-FTIR光譜技術在高聚物研究中的應用[J];化學工程師;2008年03期

5 錢欣,程蓉;原子力顯微鏡在合成膜表征中的應用[J];膜科學與技術;2004年02期

6 董曉靜,岳紅,管萍,張新麗;復合反滲透膜研究進展[J];材料導報;2002年03期

7 呂曉龍,杜啟云;新型反滲透復合膜[J];水處理技術;1989年05期

相關博士學位論文 前1條

1 魏新渝;高耐氯性復合反滲透膜的制備研究[D];天津大學;2010年

相關碩士學位論文 前3條

1 王展;Fe(Ⅲ)/過硫酸鹽體系降解有機污染物及其機理研究[D];上海大學;2015年

2 許曉熊;界面聚合法制備PAMAM復合納濾膜及其結構與性能研究[D];廈門大學;2009年

3 范芳慧;聚酰胺膜氯化降解機理及用ADMH接枝改性的研究[D];天津大學;2009年

，

本文編號：1846876