本文主要研究内容
作者罗大军（2019）在《双微孔亲水聚丙烯中空纤维膜的微结构构筑、调控及机理研究》一文中研究指出：聚丙烯中空纤维膜(PPHFM)具有抗冲击、耐腐蚀、单位膜面积大和分离效率高等优点被广泛应用在水处理、膜蒸馏、气体分离及生物医药等领域。但熔融纺丝-拉伸法(MS-S)制备的PPHFM由于孔结构单一、片晶簇叠加和PP疏水性导致膜孔隙率较低和亲水性差,使膜在水处理领域或水溶液分离时存在水通量低和抗污染性能差等问题。为了有效地解决这两个问题,本论文基于片晶分离致孔与相分离致孔理论设计一种具有两种不同等级且独立孔径分布的新型双微孔膜结构,用于改善PPHFM的孔隙率和亲水性,提高膜纯水通量和抗污染性,保留膜良好截留性能。同时通过改善共混物体系相容性调控双微孔结构,建立双微孔构筑机理和调控机理模型,探索制膜工艺对膜双微孔结构的影响规律。本论文的研究内容主要如下:1.PP基体中加入不同含量亲水乙烯-乙烯醇共聚物(EVOH)及定量相容剂PP接枝马来酸酐(PP-g-MAH)制备PP/MAH/EVOH共混物,通过MS-S法制备具有双微孔结构的亲水PPHFM。研究共混物中两相形貌、结晶行为、流变行为、中空纤维晶体结构与膜结构性能之间的关系,建立了双微孔结构的构筑机理模型,截留模型与抗污染模型。结果表明:具有双微孔结构的亲水PPHFM孔隙率提高至83.7%,膜表面含氧量最高达5.93%;膜纯水通量提升至322.0±8.8L/m~2·h,相对于PPHFM提高了117.56%;膜抗污染性能有效提高,通量回复率最高增加了25%;对0.1%碳素溶液的截留率最高达99.88%,表现出良好的截留性能。通过双微孔结构构筑机理分析,取向的PP片晶分离形成了小微孔,PP和EVOH的相界面分离形成了大微孔,相互作用的相界面分离形成大微孔中的微纤维;FESEM和流变结果表明,随EVOH含量增加,PP/MAH/EVOH共混物中EVOH岛结构尺寸增大,两相界面相互作用减弱,由两相界面分离形成的大微孔孔径增大;结合共混物结晶行为与中空纤维微观晶体结构的分析,EVOH作为PP基体的有效成核剂,增加了PP/MAH/EVOH共混物中PP球晶成核密度和总结晶速率,减小了PP晶粒尺寸,使PP/MAH/EVOH中空纤维微结构中的片晶厚度均低于PP中空纤维。因此在PP/MAH/EVOH中空纤维膜(PMEVOH-HFMs)中小微孔孔径均小于PPHFM。当PP/EVOH质量比为90/10时膜具有最佳双微孔结构,同时也表现出最佳的性能。2.基于两相界面分离原理,通过添加不同含量PP-g-MAH改善体系相容性实现双微孔结构的调控,建立了双微孔结构调控机理模型。结果表明:随PP-g-MAH含量增加,PP/EVOH/MAH体系相容性逐渐改善,EVOH岛结构尺寸逐渐减小,两相间形成了相互作用逐渐增强的界面,形成的大微孔孔径逐渐增大;随着PP/EVOH/MAH体系相容性逐渐改善,阻碍了PP相的结晶过程,导致PP/EVOH/MAH中空纤维微结构中片晶厚度逐渐减小,片晶取向度先升高后降低。尽管更厚的片晶对应着更大孔径的小微孔,但是在PP-g-MAH含量低于5 wt%时,由于中空纤维中片晶取向度大幅度降低,小微孔孔径均在183 nm左右。因此改变PP/EVOH/MAH体系相容性主要是通过界面相互作用来调控大微孔结构。当加入5 wt%PP-g-MAH时,膜双微孔结构最完善,孔隙率最大,表现出最佳的膜性能。3.考察了MS-S法生产工艺条件因素,对膜双微孔结构的影响,揭示了制膜工艺对膜双微孔结构的影响规律。结果表明:牵引速率和热处理温度均存在极值现象,当牵引速率为395 m/min时,PMEVOH-10(PP/PP-g-MAH/EVOH质量比为90/5/10)中空纤维和PMEVOH-10-HFMs结构与性能表现最佳;当热处理温度为150℃时,PMEVOH-10中空纤维和PMEVOH-10-HFMs结构与性能表现最佳。中空纤维拉伸过程中,同时形成了双微孔结构中的大小微孔,并且孔径随着拉伸比例增加先增大后减小。当拉伸比例为200%时,双微孔孔径和孔隙率达最大值,对应膜的纯水通量也达最大值。通过拉伸不同比例既能实现双微孔的孔径和孔隙率调控,又对PMEVOH-10-HFMs的截留性能没有产生明显影响,但拉伸比例过高时,膜双微孔孔径增大,孔结构变得更狭长,导致膜抗污染性能稍有降低。
Abstract
ju bing xi zhong kong qian wei mo (PPHFM)ju you kang chong ji 、nai fu shi 、chan wei mo mian ji da he fen li xiao lv gao deng you dian bei an fan ying yong zai shui chu li 、mo zheng liu 、qi ti fen li ji sheng wu yi yao deng ling yu 。dan rong rong fang si -la shen fa (MS-S)zhi bei de PPHFMyou yu kong jie gou chan yi 、pian jing cu die jia he PPshu shui xing dao zhi mo kong xi lv jiao di he qin shui xing cha ,shi mo zai shui chu li ling yu huo shui rong ye fen li shi cun zai shui tong liang di he kang wu ran xing neng cha deng wen ti 。wei le you xiao de jie jue zhe liang ge wen ti ,ben lun wen ji yu pian jing fen li zhi kong yu xiang fen li zhi kong li lun she ji yi chong ju you liang chong bu tong deng ji ju du li kong jing fen bu de xin xing shuang wei kong mo jie gou ,yong yu gai shan PPHFMde kong xi lv he qin shui xing ,di gao mo chun shui tong liang he kang wu ran xing ,bao liu mo liang hao jie liu xing neng 。tong shi tong guo gai shan gong hun wu ti ji xiang rong xing diao kong shuang wei kong jie gou ,jian li shuang wei kong gou zhu ji li he diao kong ji li mo xing ,tan suo zhi mo gong yi dui mo shuang wei kong jie gou de ying xiang gui lv 。ben lun wen de yan jiu nei rong zhu yao ru xia :1.PPji ti zhong jia ru bu tong han liang qin shui yi xi -yi xi chun gong ju wu (EVOH)ji ding liang xiang rong ji PPjie zhi ma lai suan gan (PP-g-MAH)zhi bei PP/MAH/EVOHgong hun wu ,tong guo MS-Sfa zhi bei ju you shuang wei kong jie gou de qin shui PPHFM。yan jiu gong hun wu zhong liang xiang xing mao 、jie jing hang wei 、liu bian hang wei 、zhong kong qian wei jing ti jie gou yu mo jie gou xing neng zhi jian de guan ji ,jian li le shuang wei kong jie gou de gou zhu ji li mo xing ,jie liu mo xing yu kang wu ran mo xing 。jie guo biao ming :ju you shuang wei kong jie gou de qin shui PPHFMkong xi lv di gao zhi 83.7%,mo biao mian han yang liang zui gao da 5.93%;mo chun shui tong liang di sheng zhi 322.0±8.8L/m~2·h,xiang dui yu PPHFMdi gao le 117.56%;mo kang wu ran xing neng you xiao di gao ,tong liang hui fu lv zui gao zeng jia le 25%;dui 0.1%tan su rong ye de jie liu lv zui gao da 99.88%,biao xian chu liang hao de jie liu xing neng 。tong guo shuang wei kong jie gou gou zhu ji li fen xi ,qu xiang de PPpian jing fen li xing cheng le xiao wei kong ,PPhe EVOHde xiang jie mian fen li xing cheng le da wei kong ,xiang hu zuo yong de xiang jie mian fen li xing cheng da wei kong zhong de wei qian wei ;FESEMhe liu bian jie guo biao ming ,sui EVOHhan liang zeng jia ,PP/MAH/EVOHgong hun wu zhong EVOHdao jie gou che cun zeng da ,liang xiang jie mian xiang hu zuo yong jian ruo ,you liang xiang jie mian fen li xing cheng de da wei kong kong jing zeng da ;jie ge gong hun wu jie jing hang wei yu zhong kong qian wei wei guan jing ti jie gou de fen xi ,EVOHzuo wei PPji ti de you xiao cheng he ji ,zeng jia le PP/MAH/EVOHgong hun wu zhong PPqiu jing cheng he mi du he zong jie jing su lv ,jian xiao le PPjing li che cun ,shi PP/MAH/EVOHzhong kong qian wei wei jie gou zhong de pian jing hou du jun di yu PPzhong kong qian wei 。yin ci zai PP/MAH/EVOHzhong kong qian wei mo (PMEVOH-HFMs)zhong xiao wei kong kong jing jun xiao yu PPHFM。dang PP/EVOHzhi liang bi wei 90/10shi mo ju you zui jia shuang wei kong jie gou ,tong shi ye biao xian chu zui jia de xing neng 。2.ji yu liang xiang jie mian fen li yuan li ,tong guo tian jia bu tong han liang PP-g-MAHgai shan ti ji xiang rong xing shi xian shuang wei kong jie gou de diao kong ,jian li le shuang wei kong jie gou diao kong ji li mo xing 。jie guo biao ming :sui PP-g-MAHhan liang zeng jia ,PP/EVOH/MAHti ji xiang rong xing zhu jian gai shan ,EVOHdao jie gou che cun zhu jian jian xiao ,liang xiang jian xing cheng le xiang hu zuo yong zhu jian zeng jiang de jie mian ,xing cheng de da wei kong kong jing zhu jian zeng da ;sui zhao PP/EVOH/MAHti ji xiang rong xing zhu jian gai shan ,zu ai le PPxiang de jie jing guo cheng ,dao zhi PP/EVOH/MAHzhong kong qian wei wei jie gou zhong pian jing hou du zhu jian jian xiao ,pian jing qu xiang du xian sheng gao hou jiang di 。jin guan geng hou de pian jing dui ying zhao geng da kong jing de xiao wei kong ,dan shi zai PP-g-MAHhan liang di yu 5 wt%shi ,you yu zhong kong qian wei zhong pian jing qu xiang du da fu du jiang di ,xiao wei kong kong jing jun zai 183 nmzuo you 。yin ci gai bian PP/EVOH/MAHti ji xiang rong xing zhu yao shi tong guo jie mian xiang hu zuo yong lai diao kong da wei kong jie gou 。dang jia ru 5 wt%PP-g-MAHshi ,mo shuang wei kong jie gou zui wan shan ,kong xi lv zui da ,biao xian chu zui jia de mo xing neng 。3.kao cha le MS-Sfa sheng chan gong yi tiao jian yin su ,dui mo shuang wei kong jie gou de ying xiang ,jie shi le zhi mo gong yi dui mo shuang wei kong jie gou de ying xiang gui lv 。jie guo biao ming :qian yin su lv he re chu li wen du jun cun zai ji zhi xian xiang ,dang qian yin su lv wei 395 m/minshi ,PMEVOH-10(PP/PP-g-MAH/EVOHzhi liang bi wei 90/5/10)zhong kong qian wei he PMEVOH-10-HFMsjie gou yu xing neng biao xian zui jia ;dang re chu li wen du wei 150℃shi ,PMEVOH-10zhong kong qian wei he PMEVOH-10-HFMsjie gou yu xing neng biao xian zui jia 。zhong kong qian wei la shen guo cheng zhong ,tong shi xing cheng le shuang wei kong jie gou zhong de da xiao wei kong ,bing ju kong jing sui zhao la shen bi li zeng jia xian zeng da hou jian xiao 。dang la shen bi li wei 200%shi ,shuang wei kong kong jing he kong xi lv da zui da zhi ,dui ying mo de chun shui tong liang ye da zui da zhi 。tong guo la shen bu tong bi li ji neng shi xian shuang wei kong de kong jing he kong xi lv diao kong ,you dui PMEVOH-10-HFMsde jie liu xing neng mei you chan sheng ming xian ying xiang ,dan la shen bi li guo gao shi ,mo shuang wei kong kong jing zeng da ,kong jie gou bian de geng xia chang ,dao zhi mo kang wu ran xing neng shao you jiang di 。
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论文详细介绍
论文作者分别是来自贵州大学的罗大军，发表于刊物贵州大学2019-07-16论文，是一篇关于双微孔结构论文,亲水改性论文,聚丙烯中空纤维膜论文,熔融纺丝拉伸论文,结晶动力学论文,贵州大学2019-07-16论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自贵州大学2019-07-16论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。
标签：双微孔结构论文; 亲水改性论文; 聚丙烯中空纤维膜论文; 熔融纺丝拉伸论文; 结晶动力学论文; 贵州大学2019-07-16论文;