聚醚砜納濾膜的制備、結(jié)構(gòu)調(diào)控與性能研究
發(fā)布時(shí)間：2019-01-03 14:49
【摘要】：本文采用相轉(zhuǎn)化法制備了磺化聚砜(SPSF)/聚醚砜(PES)/苯乙烯-馬來(lái)酸酐共聚物(SMA)共混新型納濾膜,以磺化聚砜(SPSF)和聚醚砜(PES)作為制備基膜的原材料,以聚乙烯吡咯烷酮(PVP)和苯乙烯-馬來(lái)酸酐共聚物(SMA)作為添加劑,以N,N-二甲基乙酰胺(DMAc)作為溶劑,通過(guò)研究不同的SPSF與PES固含量值,不同的PVP添加量,不同的SMA添加量來(lái)探討這些物質(zhì)配比對(duì)膜結(jié)構(gòu)性能的影響;同時(shí)還討論了制膜工藝條件中的預(yù)蒸發(fā)時(shí)間,預(yù)蒸發(fā)溫度,凝固浴溫度和鑄膜液溫度對(duì)SPSF/PES/SMA共混納濾基膜結(jié)構(gòu)性能的影響;為進(jìn)一步對(duì)制備的膜進(jìn)行優(yōu)化改性,最后對(duì)膜表面進(jìn)行改性處理,其中以甲醛為交聯(lián)劑,使其與馬來(lái)酸酐(MA)官能團(tuán)發(fā)生交聯(lián)反應(yīng)形成納濾脫鹽層,考察了交聯(lián)劑濃度、交聯(lián)溫度、交聯(lián)時(shí)間對(duì)脫鹽層結(jié)構(gòu)和脫鹽率的影響規(guī)律,并初步解釋了納濾脫鹽層的形成過(guò)程。研究結(jié)果表明,隨著SPSF與PES固含量的增加,膜水通量整體上呈現(xiàn)遞減趨勢(shì),膜對(duì)Na2SO4的脫鹽率上升。隨著PVP含量的增加,鑄膜液粘度變大,膜指狀孔得到抑制。隨著SMA的加入消除了膜的指狀孔,使膜內(nèi)部結(jié)構(gòu)變得致密。當(dāng)選取SPSF與PES固含量為25%、添加劑PVP固含量為5%、添加劑SMA固含量為6%時(shí)制備出的SPSF/PES/SMA共混納濾基膜綜合性能較好。在SPSF/PES/SMA體系中,隨著預(yù)蒸發(fā)時(shí)間增加,水通量下降,脫鹽率上升。固定其它條件不變,隨著預(yù)蒸發(fā)溫度的升高,膜水通量降低,脫鹽率上升。隨著凝固浴溫度升高,膜水通量上升,且在此過(guò)程中膜對(duì)Na2SO4的截留率上升。最后考察鑄膜液溶解溫度對(duì)膜性能的影響,隨著鑄膜液溫度的上升,膜水通量先升后降,脫鹽率則是先降后升。綜合考慮預(yù)蒸發(fā)時(shí)間為90s,預(yù)蒸發(fā)溫度為70℃,凝固浴溫度為25℃,鑄膜液溫度為60℃時(shí)為最優(yōu)制膜工藝條件,此時(shí)的膜對(duì)二價(jià)鹽Na2SO4的截留率為56.70%,水通量為39.96L/m~2·h。為進(jìn)一步對(duì)制備的膜進(jìn)行優(yōu)化改性,最后對(duì)膜表面進(jìn)行改性處理。隨著交聯(lián)劑濃度從4%增加到12%,膜對(duì)Na2SO4的截留率從57.84%提高到75.89%,總體上對(duì)比基膜56.70%的脫鹽率,改性過(guò)后的膜明顯優(yōu)于基膜。固定其他條件不變,升高交聯(lián)溫度不利于得到高水通量的膜。此外隨著交聯(lián)時(shí)間增加,膜皮層厚度增加,膜水通量下降。綜合考慮,當(dāng)交聯(lián)條件中交聯(lián)劑濃度為10%,交聯(lián)溫度為90℃,交聯(lián)時(shí)間為3h時(shí)改性的膜綜合性能較優(yōu),此時(shí)測(cè)得的脫鹽率為77.25%,對(duì)應(yīng)的水通量也能達(dá)到13.75L/m~2·h。
[Abstract]:A novel sulfonated polysulfone (SPSF) / polyethersulfone (PES) / styrene-maleic anhydride copolymer (SMA) nanofiltration membrane was prepared by phase inversion method. Sulfonated polysulfone (SPSF) and polyethersulfone (PES) were used as the raw materials for the preparation of the membranes. Polyvinylpyrrolidone (PVP) and styrene-maleic anhydride copolymer (SMA) were used as additives and NN-dimethyl acetamide (DMAc) as solvent. The solid contents of SPSF and PES were studied. The effects of different SMA ratios on the structure and properties of the membranes were investigated. At the same time, the effects of pre-evaporation time, pre-evaporation temperature, coagulation bath temperature and casting liquid temperature on the structure and properties of SPSF/PES/SMA blend nanofiltration membrane were also discussed. In order to optimize the membrane, the surface of the membrane was modified. Formaldehyde was used as crosslinking agent to form a nanofiltration desalination layer with maleic anhydride (MA) functional group. The concentration of crosslinking agent was investigated. The effects of crosslinking temperature and crosslinking time on the structure and desalination rate of desalination layer were studied. The formation process of nanofiltration desalination layer was also explained. The results show that with the increase of solid content of SPSF and PES, the water flux of the membrane decreases as a whole, and the desalination rate of the membrane to Na2SO4 increases. With the increase of PVP content, the viscosity of casting solution increased and the finger pore was inhibited. With the addition of SMA, the finger-like pores of the membrane were eliminated, and the internal structure of the membrane became compact. When the solid content of SPSF and PES is 25, the solid content of additive PVP is 5 and the solid content of additive SMA is 6, the composite properties of SPSF/PES/SMA blend nanofiltration base membrane are better. In SPSF/PES/SMA system, with the increase of pre-evaporation time, the water flux decreases and the desalinization rate increases. With the increase of preevaporation temperature, the membrane water flux decreases and the desalinization rate increases. With the increase of coagulation bath temperature, the water flux of the membrane increased, and the rejection rate of membrane to Na2SO4 increased during the process. Finally, the effect of solution temperature on membrane properties was investigated. With the increase of casting temperature, the membrane water flux increased first and then decreased, and the desalinization rate decreased first and then increased. When the pre-evaporation time is 90 s, the pre-evaporation temperature is 70 鈩，
本文編號(hào)：2399532
[Abstract]:A novel sulfonated polysulfone (SPSF) / polyethersulfone (PES) / styrene-maleic anhydride copolymer (SMA) nanofiltration membrane was prepared by phase inversion method. Sulfonated polysulfone (SPSF) and polyethersulfone (PES) were used as the raw materials for the preparation of the membranes. Polyvinylpyrrolidone (PVP) and styrene-maleic anhydride copolymer (SMA) were used as additives and NN-dimethyl acetamide (DMAc) as solvent. The solid contents of SPSF and PES were studied. The effects of different SMA ratios on the structure and properties of the membranes were investigated. At the same time, the effects of pre-evaporation time, pre-evaporation temperature, coagulation bath temperature and casting liquid temperature on the structure and properties of SPSF/PES/SMA blend nanofiltration membrane were also discussed. In order to optimize the membrane, the surface of the membrane was modified. Formaldehyde was used as crosslinking agent to form a nanofiltration desalination layer with maleic anhydride (MA) functional group. The concentration of crosslinking agent was investigated. The effects of crosslinking temperature and crosslinking time on the structure and desalination rate of desalination layer were studied. The formation process of nanofiltration desalination layer was also explained. The results show that with the increase of solid content of SPSF and PES, the water flux of the membrane decreases as a whole, and the desalination rate of the membrane to Na2SO4 increases. With the increase of PVP content, the viscosity of casting solution increased and the finger pore was inhibited. With the addition of SMA, the finger-like pores of the membrane were eliminated, and the internal structure of the membrane became compact. When the solid content of SPSF and PES is 25, the solid content of additive PVP is 5 and the solid content of additive SMA is 6, the composite properties of SPSF/PES/SMA blend nanofiltration base membrane are better. In SPSF/PES/SMA system, with the increase of pre-evaporation time, the water flux decreases and the desalinization rate increases. With the increase of preevaporation temperature, the membrane water flux decreases and the desalinization rate increases. With the increase of coagulation bath temperature, the water flux of the membrane increased, and the rejection rate of membrane to Na2SO4 increased during the process. Finally, the effect of solution temperature on membrane properties was investigated. With the increase of casting temperature, the membrane water flux increased first and then decreased, and the desalinization rate decreased first and then increased. When the pre-evaporation time is 90 s, the pre-evaporation temperature is 70 鈩，
本文編號(hào)：2399532
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