本文選題：聚砜類超濾膜 + 兩性離子��； 參考：《浙江大學(xué)》2015年博士論文

【摘要】：芳香族聚砜有著優(yōu)異的化學(xué)穩(wěn)定性、熱穩(wěn)定性、機(jī)械強(qiáng)度以及良好的可加工性,是超／微濾膜的主流材質(zhì)之一。事實(shí)上,聚砜類超濾膜已被廣泛應(yīng)用于水處理、食品飲料純化、蛋白質(zhì)分離、血液透析、生物醫(yī)藥分離等領(lǐng)域。然而,在液體過濾中,聚砜膜自身較強(qiáng)的疏水性,容易引發(fā)天然有機(jī)物、蛋白質(zhì)、膠體等污染質(zhì)在膜表面和膜孔內(nèi)吸附和積聚,造成膜污染,劣化膜性能,縮短膜的使用壽命。在生物醫(yī)用領(lǐng)域,疏水性聚砜膜會(huì)激發(fā)蛋白質(zhì)吸附和血小板粘附,可能引發(fā)凝血／血栓、免疫排斥等嚴(yán)重問題。因此,聚砜膜在使用之前常常需要進(jìn)行改性,以滿足膜材料的多方面性能需求。為克服已有改性方法的不足,本論文從分子結(jié)構(gòu)設(shè)計(jì)出發(fā),合成出一系列適宜用于聚砜類超濾膜改性的反應(yīng)性兩親共聚物,綜合采用溶液共混和膜表面反應(yīng)的方法,將具有極強(qiáng)水合能力的兩性離子聚合物鏈引入膜表面,以改善聚砜類超濾膜的親水性／透水性、抗污染能力和血液相容性。首先通過縮聚反應(yīng)合成羥基封端的聚砜遙爪聚合物,通過端羥基的反應(yīng)特性,采用原子轉(zhuǎn)移自由基聚合和可逆加成-斷裂鏈轉(zhuǎn)移自由基聚合,分別合成兩親性嵌段共聚物PSF-b-PDMAEMA和PES-b-PDMAEMA。通過非溶劑誘導(dǎo)相轉(zhuǎn)化法(NIPS)制備聚砜類共混膜PSF/PSF-b-PDMAEMA和PES/PES-b-PDMAEMA,兩親性共聚物自發(fā)向膜表面遷移／富集,共混膜的親水性和滲透性能都得到提高,并表現(xiàn)出一定的刺激響應(yīng)性。同時(shí),表面富集的PDMAEMA為膜表面改性提供了二次修飾的平臺(tái),分別采用3-溴丙酸、1,3-丙磺酸內(nèi)酯和溴癸烷與PDMAEMA進(jìn)行季銨化反應(yīng),得到聚羧酸型兩性離子、聚磺酸型兩性離子和聚陽離子修飾的聚砜類膜。研究結(jié)果表明,兩性離子化的聚砜類超濾膜表現(xiàn)出優(yōu)良的抗污染性和血液相容性,陽離子化膜表現(xiàn)出優(yōu)異的抗菌性。以末端帶羥基的PES遙爪聚合物為前體,通過RAFT反應(yīng)成功合成兩親嵌段共聚物PES-b-PHEMA,通過調(diào)節(jié)聚合時(shí)間可有效調(diào)節(jié)嵌段聚合物的分子量。與PES共混得到PES/PES-b-PHEMA共混膜,PES-b-PHEMA在成膜過程中向表面富集,利用表面富集的PHEMA將含溴基團(tuán)的引發(fā)劑固定在膜表面,而后將聚磺酸基甜菜堿(PSBMA)通過ATRP反應(yīng)接枝到PES共混膜表面。該接枝反應(yīng)具有活性可控的特征,接枝量與反應(yīng)時(shí)間呈現(xiàn)線性增長關(guān)系。表面接枝PSBMA后,PES膜表面化學(xué)組成和形貌發(fā)生較大改變,親水性有明顯提高。改性膜對(duì)蛋白質(zhì)和油的分離能力明顯提高,并可有效減弱蛋白質(zhì)或油污因吸附造成的不可逆污染,顯著提高了PES膜的抗污染性能。改性膜具有明顯的電解質(zhì)響應(yīng)性,隨著溶液中電解質(zhì)濃度提高,通量逐漸減小,同時(shí)該響應(yīng)性是可逆的。此夕,PSBMA接枝層能夠抑制血小板在膜表面的粘附與變性,延長血漿復(fù)鈣化時(shí)間,改善了PES膜的血液相容性。合成含雙鍵官能團(tuán)的聚醚砜共聚物PES-b-PHEDMA,通過NIPS法制備PES/PES-b-PHEDMA共混膜。在相轉(zhuǎn)化過程中,兩親性共聚物向表面富集,共混膜表面含有活性雙鍵官能團(tuán)。再以PEGDA為交聯(lián)劑,通過膜表面雙鍵和兩性離子單體SBMA的自由基交聯(lián)反應(yīng),在PES膜表面生成兩性離子凝膠層。膜表面的孔徑及孔隙率略有下降,對(duì)BSA的截留率明顯提高,有效提高了PES膜對(duì)BSA的分離效率。由于兩性離子凝膠層較強(qiáng)的水合能力,表面固定凝膠層之后PES膜的親水性和保水性都得到顯著提高,同時(shí)表現(xiàn)出優(yōu)異的抗污染性和血液相容性。由于共混的兩親性共聚物與膜本體材料相互纏結(jié),后續(xù)交聯(lián)反應(yīng)引入的凝膠層也通過共價(jià)鍵連接,凝膠層在PES膜表面保持持久穩(wěn)定的改性效果。為了進(jìn)一步提高兩親性共聚物的改性效率,提高聚砜膜的蛋白質(zhì)分離性能,首先合成聚醚砜兩性離子共聚物PES-b-PSBMA,其在水溶液中發(fā)生自組裝形成具有核殼結(jié)構(gòu)的球形膠束。將PES-b-PSBMA膠束通過過濾沉積的方法均勻地沉積在聚砜膜表面,制備PSF/PES-b-PSBMA復(fù)合膜。通過ATR-FTIR、XPS和SEM分析復(fù)合膜的表面化學(xué)組成和形貌,并證明該膠柬成功沉積在膜表面。PSF/PES-b-PSBMA復(fù)合膜的親水性比PSF基膜有所提高,水通量略有降低。蛋白質(zhì)分離性能得到大幅度提升,對(duì)BSA的截留率從42%提高到96%以上,對(duì)LYZ和BSA的分離因子從1.8提高到29。該方法制備的膜在蛋白質(zhì)分離提純領(lǐng)域有著廣闊的應(yīng)用前景,并為聚合物分離膜的功能化改性開辟了新的思路。綜上所述,通過聚砜基兩親性共聚物的分子設(shè)計(jì),結(jié)合共混改性和后續(xù)表面反應(yīng),可實(shí)現(xiàn)聚砜類超濾膜的表面兩性離子化,顯著提高聚砜膜的抗生物污染性、血液相容性和分離性能,為實(shí)現(xiàn)聚砜類超濾膜的高性能化提供了理論和技術(shù)支撐。
[Abstract]:Aromatic polysulfone has excellent chemical stability, thermal stability, mechanical strength and good machinability. It is one of the main materials of ultrafiltration membrane. In fact, polysulfone ultrafiltration membrane has been widely used in the fields of water treatment, food and beverage purification, protein separation, hemodialysis, biological medicine separation and so on. However, in liquid filtration, the membrane is used in liquid filtration. The polysulfone membrane has strong hydrophobicity, which can easily lead to the adsorption and accumulation of natural organic, protein, colloid and other contaminants in the surface and pore of the membrane, causing membrane fouling, deterioration membrane performance and shortening the service life of the membrane. In the biomedical field, the hydrophobic polysulfone membrane will stimulate protein adsorption and platelet adhesion, and may lead to coagulation / thrombus. Therefore, the polysulfone membrane often needs to be modified before it is used to meet the multifaceted performance requirements of the membrane material. In order to overcome the shortcomings of the existing modified methods, a series of reactive two Pro copolymer suitable for polysulfone ultrafiltration membrane modification has been synthesized in order to overcome the shortcomings of the existing modified methods. In order to improve the hydrophilic / permeable property, pollution resistance and blood compatibility of polysulfone ultrafiltration membrane, the hydrophilic / permeable property, pollution resistance and blood compatibility of polysulfone ultrafiltration membrane have been introduced into the membrane surface by the method of liquid mixing and membrane surface reaction. First, polysulfone teleclaws polymer with hydroxyl terminated terminated by polycondensation is synthesized by condensation reaction. Two amphiphilic block copolymers, PSF-b-PDMAEMA and PES-b-PDMAEMA., were synthesized by atom transfer radical polymerization and reversible addition - fracture chain transfer free radical polymerization, respectively, to prepare polysulfone blend membranes PSF/PSF-b-PDMAEMA and PES/PES-b-PDMAEMA by non solvent induced phase transformation (NIPS). The two amphiphilic copolymers migrate to the surface of the membrane spontaneously and blend. The hydrophilic and permeable properties of the membrane were improved and showed a certain stimulus responsiveness. At the same time, the surface enriched PDMAEMA provided two modified platforms for the surface modification of the membrane. 3- bromopropionic acid, 1,3- propionic acid lactone and bromo decane were used for quaternylation, and polycarboxylic amphoteric ions, polysulfonic amphoteric sexes were obtained. The polysulfone membrane modified by ions and polycation shows that the amphoteric polysulfone ultrafiltration membrane has excellent antifouling and blood compatibility, and the cationic membrane exhibits excellent antibacterial properties. The PES tele polymer with the hydroxyl group at the end is used as the precursor, and the two parent block copolymer PES-b-PHEMA is successfully synthesized through the RAFT reaction. The molecular weight of the block polymer can be adjusted effectively by adjusting the polymerization time. PES/PES-b-PHEMA blend membrane is blended with PES. PES-b-PHEMA is enriched in the film forming process. The brominated group initiator is immobilized on the membrane surface by the surface enriched PHEMA, and then the polysulfonyl betaine (PSBMA) is grafted to PES by ATRP reaction. On the surface of the membrane, the graft reaction has the characteristics of active and controllable activity, the grafting amount and the reaction time show a linear growth relationship. After the surface grafting of PSBMA, the surface chemical composition and morphology of the PES film are greatly changed, the hydrophilic property is obviously improved. The separation ability of the modified membrane to protein and oil is obviously improved, and the protein or oil pollution can be effectively weakened. The irreversible pollution caused by the attached membrane significantly improves the anti pollution performance of the PES membrane. The modified membrane has an obvious electrolyte response. With the increase of the electrolyte concentration, the flux gradually decreases and the response is reversible. On this night, the PSBMA graft layer can inhibit the adhesion and denaturation of the platelets on the membrane surface and prolong the time of the plasma calcification. The blood compatibility of the PES membrane was improved. The Polyethersulfone copolymer PES-b-PHEDMA containing the double bond functional group was synthesized and the PES/PES-b-PHEDMA blend membrane was prepared by the NIPS method. In the phase transformation, the two amphiphilic copolymers were enriched to the surface, and the surface of the blend membrane contained active double bond functional groups. And then PEGDA was used as the crosslinker, through the double bond surface and the amphoteric ion single. The free radical crosslinking reaction of the body SBMA produces an amphoteric ion gel layer on the surface of the PES membrane. The pore size and porosity of the membrane surface decreases slightly, the interception rate of the BSA is obviously improved, and the separation efficiency of the PES film to BSA is effectively improved. The hydrophilic property and water retention of the PES film after the gel layer is fixed on the surface of the gels with the strong hydration ability of the gels. Both of the two amphiphilic copolymers were entangled with the bulk of the membrane, the gel layer introduced by the subsequent crosslinking reaction was also linked through the covalent bond, and the gel layer maintained a lasting and stable modification effect on the surface of the PES membrane. In order to further improve the two amphiphilic copolymers. In order to improve the protein separation performance of polysulfone membrane, the Polyethersulfone amphoteric ion copolymer PES-b-PSBMA was first synthesized, and a spherical micelle with nuclear shell structure was formed by self assembly in aqueous solution. The PES-b-PSBMA micelle was deposited evenly on the surface of polysulfone membrane by filtering and deposition, and the PSF/PES-b-PSBMA composite membrane was prepared. ATR-FTIR, XPS and SEM were used to analyze the surface chemical composition and morphology of the composite membrane. It was proved that the hydrophilic property of the.PSF/PES-b-PSBMA composite film deposited on the membrane surface was higher than that of the PSF film, and the water flux decreased slightly. The separation performance of the protein was greatly improved, the interception rate of BSA was increased from 42% to over 96%, and the separation of LYZ and BSA was found. The separation factor from 1.8 to 29. has a wide application prospect in the field of protein separation and purification, and opens a new idea for the functional modification of the polymer separation membrane. In summary, the polysulfone ultrafiltration membrane can be realized by the molecular design of the polysulfone based two parent copolymer, the blending modification and the subsequent surface reaction. The surface amphoteric ionization significantly improves the biopollution resistance, blood compatibility and separation performance of polysulfone membrane, which provides theoretical and technical support for the high performance of polysulfone ultrafiltration membrane.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2015
【分類號(hào)】：TQ051.893
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本文編號(hào)：1958935