L-S相轉(zhuǎn)化法與化學(xué)反應(yīng)結(jié)合在醋酸纖維素膜制備過程中的應(yīng)用
發(fā)布時(shí)間：2018-12-31 18:30
【摘要】：抗污染膜的制備是解決膜污染問題的根本途徑。本論文以醋酸纖維素(CA)為膜材料,采用L-S相轉(zhuǎn)化與化學(xué)反應(yīng)相結(jié)合的制膜方法制備醋酸纖維素膜,并通過純水通量、腐殖酸(HA)截留率等來考察醋酸纖維素膜的性能。首先,以CA為膜材料,富馬酸為添加劑,用L-S相轉(zhuǎn)化法與化學(xué)反應(yīng)結(jié)合制備膜時(shí),研究了不同溶劑(N,N-二甲基甲酰胺(DMF),N,N-二甲基乙酰胺(DMAc),N甲基吡咯烷酮(NMP),二甲基亞砜(DMSO))對(duì)膜性能的影響。實(shí)驗(yàn)結(jié)果表明:存在化學(xué)反應(yīng)時(shí),化學(xué)反應(yīng)可以增加膜的凝膠速度,膜的斷面結(jié)構(gòu)為典型的非對(duì)稱型,孔隙率增加;當(dāng)使用NMP作為溶劑時(shí),制備得到的膜的純水通量高(162.7 L/(m2·h)),膜的孔徑分布較狹窄,用L-S相轉(zhuǎn)化與化學(xué)反應(yīng)結(jié)合的方法法制備的膜用來過濾活性污泥后,去離子水清洗污染的膜,通量恢復(fù)率最高的是NMP為溶劑制備的膜(90.6%),并顯示了其優(yōu)越的抗污染性能。其次,通過在CA鑄膜液中加入氧化石墨烯(GO)和納米SiO2顆粒,用L-S相轉(zhuǎn)化法與化學(xué)反應(yīng)結(jié)合來制備膜GO-SiO2/CA,以期利用GO和SiO2的獨(dú)特性能來改善CA膜的抗污染性能和機(jī)械性能。本文還比較了加入不同質(zhì)量比的GO和SiO2所制備得到的膜的孔徑分布曲線和環(huán)境掃描電鏡圖片。此外,還使用研究級(jí)萬能顯微鏡,分別觀察了不同制膜液組成在不同凝膠浴中的凝膠成膜動(dòng)力學(xué)過程。實(shí)驗(yàn)結(jié)果表明:GO-SiO2/CA共混膜的孔隙率比CA膜的孔隙率更高,其孔隙增加到78.6%,并且GO-SiO2/CA共混膜的孔徑分布更狹窄。此外,在鑄膜液中添加了SiO2與GO后,膜的親水性增強(qiáng),GO-SiO2/CA共混膜的純水通量比純CA膜的提高了57.4%;當(dāng)GO和SiO2的比例為50/50時(shí),純水通量最大達(dá)到255.7 L/(m2·h),該膜被腐殖酸污染后使用去離子水清洗的通量恢復(fù)率(FRR)達(dá)到89.9%。當(dāng)GO為0.05 wt.%時(shí),楊氏模量可達(dá)到220.2 MPa。由此可見,使用L-S相轉(zhuǎn)化與化學(xué)反應(yīng)相結(jié)合的制膜方法制備的GO-SiO2/CA共混膜具有較高的水通量,較優(yōu)的抗污染能力,較強(qiáng)的機(jī)械性能和較好的長(zhǎng)期運(yùn)行穩(wěn)定性。
[Abstract]:The preparation of anti-fouling membrane is the fundamental way to solve the problem of membrane fouling. In this paper, cellulose acetate membrane was prepared by L-S phase transformation and chemical reaction with cellulose acetate (CA) as the membrane material, and the pure water flux was used to prepare the cellulose acetate membrane. The (HA) retention rate of humic acid was used to study the properties of cellulose acetate membrane. Firstly, when CA was used as membrane material and fumaric acid was used as additive, when L-S phase inversion method was combined with chemical reaction to prepare the membrane, different solvents (N- N-dimethylformamide, (DMF), N-dimethylacetamide (DMAc),) were studied. Effect of N methyl pyrrolidone (NMP), dimethyl sulfoxide (DMSO) on the properties of the membrane. The experimental results show that chemical reaction can increase the gel velocity of the membrane, and the cross section structure of the membrane is a typical asymmetric type, and the porosity of the membrane increases. When NMP was used as solvent, the membrane with high pure water flux (162.7 L / (m2) h), membrane had narrow pore size distribution. The membrane prepared by the method of L-S phase transformation and chemical reaction was used to filter activated sludge. The membrane prepared with NMP as solvent has the highest flux recovery rate (90.6%), and its excellent antifouling performance is shown. Secondly, the membrane GO-SiO2/CA, was prepared by adding graphene oxide (GO) and nanometer SiO2 particles into CA casting solution and combining L-S phase inversion method with chemical reaction. In order to improve the antifouling and mechanical properties of CA membrane by using the unique properties of GO and SiO2. The pore size distribution curves and environmental scanning electron microscopy (SEM) images of the membranes prepared by adding different mass ratios of GO and SiO2 were also compared. In addition, the kinetic process of film formation was observed by using a universal microscope with different composition of membrane preparation solution in different gel bath. The experimental results show that the porosity of GO-SiO2/CA blend membrane is higher than that of CA membrane, the porosity of GO-SiO2/CA blend membrane increases to 78.6, and the pore size distribution of GO-SiO2/CA blend membrane is narrower. In addition, when SiO2 and GO were added into the casting solution, the hydrophilicity of the membrane was enhanced, and the pure water flux of the GO-SiO2/CA blend membrane increased 57.4% than that of the pure CA membrane. When the ratio of GO to SiO2 is 50 / 50, the maximum pure water flux is 255.7 L / (m ~ 2 h),). The recovery rate of pure water flux is up to 89. 9% after the membrane is polluted by humic acid and washed with deionized water. When GO is 0. 05 wt.%, Young's modulus can reach 220.2 MPa.. It can be seen that the GO-SiO2/CA blend membrane prepared by combining L-S phase conversion with chemical reaction has higher water flux, better anti-pollution ability, stronger mechanical properties and better long-term operation stability.
【學(xué)位授予單位】：北京工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TQ051.893
本文編號(hào)：2396953
[Abstract]:The preparation of anti-fouling membrane is the fundamental way to solve the problem of membrane fouling. In this paper, cellulose acetate membrane was prepared by L-S phase transformation and chemical reaction with cellulose acetate (CA) as the membrane material, and the pure water flux was used to prepare the cellulose acetate membrane. The (HA) retention rate of humic acid was used to study the properties of cellulose acetate membrane. Firstly, when CA was used as membrane material and fumaric acid was used as additive, when L-S phase inversion method was combined with chemical reaction to prepare the membrane, different solvents (N- N-dimethylformamide, (DMF), N-dimethylacetamide (DMAc),) were studied. Effect of N methyl pyrrolidone (NMP), dimethyl sulfoxide (DMSO) on the properties of the membrane. The experimental results show that chemical reaction can increase the gel velocity of the membrane, and the cross section structure of the membrane is a typical asymmetric type, and the porosity of the membrane increases. When NMP was used as solvent, the membrane with high pure water flux (162.7 L / (m2) h), membrane had narrow pore size distribution. The membrane prepared by the method of L-S phase transformation and chemical reaction was used to filter activated sludge. The membrane prepared with NMP as solvent has the highest flux recovery rate (90.6%), and its excellent antifouling performance is shown. Secondly, the membrane GO-SiO2/CA, was prepared by adding graphene oxide (GO) and nanometer SiO2 particles into CA casting solution and combining L-S phase inversion method with chemical reaction. In order to improve the antifouling and mechanical properties of CA membrane by using the unique properties of GO and SiO2. The pore size distribution curves and environmental scanning electron microscopy (SEM) images of the membranes prepared by adding different mass ratios of GO and SiO2 were also compared. In addition, the kinetic process of film formation was observed by using a universal microscope with different composition of membrane preparation solution in different gel bath. The experimental results show that the porosity of GO-SiO2/CA blend membrane is higher than that of CA membrane, the porosity of GO-SiO2/CA blend membrane increases to 78.6, and the pore size distribution of GO-SiO2/CA blend membrane is narrower. In addition, when SiO2 and GO were added into the casting solution, the hydrophilicity of the membrane was enhanced, and the pure water flux of the GO-SiO2/CA blend membrane increased 57.4% than that of the pure CA membrane. When the ratio of GO to SiO2 is 50 / 50, the maximum pure water flux is 255.7 L / (m ~ 2 h),). The recovery rate of pure water flux is up to 89. 9% after the membrane is polluted by humic acid and washed with deionized water. When GO is 0. 05 wt.%, Young's modulus can reach 220.2 MPa.. It can be seen that the GO-SiO2/CA blend membrane prepared by combining L-S phase conversion with chemical reaction has higher water flux, better anti-pollution ability, stronger mechanical properties and better long-term operation stability.
【學(xué)位授予單位】：北京工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TQ051.893
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相關(guān)期刊論文 前4條
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