Pub Date : 2024-11-04DOI: 10.1016/j.memsci.2024.123478
Jennifer Runhong Du , Jingfeng Zheng , Kailai Ma , Dechen Zhou , Chunliang Du
The formation of a mixed matrix membrane by incorporating nanofillers into a polymer matrix is a potential strategy to improve the separation performance of polymer membranes. However, agglomeration and random arrangement of nanofillers in the mixed matrix membrane result in lower permeation flux increase than expected. In this work, mixed matrix membranes composed of cellulose acetate polymer and varying amounts of Molybdenum disulfide (MoS2) nanosheets as nanofillers were prepared, and an electric field was applied to induce the alignment of MoS2 nanosheets in the membrane thickness direction. The effects of solution parameters including solvent type, MoS2 content, and polymer concentration as well as electric field parameters i.e., frequency, strength, and action time on MoS2 orientation were investigated using a stereoscopic microscope. The pervaporation desalination performance of mixed matrix membranes with randomly arranged MoS2 and orientally arranged MoS2 was assessed. At 2 wt% MoS2 content, the mixed matrix membrane with orientally arranged MoS2 exhibited a flux of 5.44 kg/(m2·h), representing a 25.9 % increase over the mixed matrix membrane with randomly arranged MoS2, while maintaining a salt rejection rate of over 99.9 %. The mixed matrix membrane demonstrated good long-term stability with consistent water flux and salt rejection during 120 h of operation.
{"title":"Enhancing permeability of CA/MoS2 pervaporation membrane via electric field-induced orientation of MoS2 nanosheets","authors":"Jennifer Runhong Du , Jingfeng Zheng , Kailai Ma , Dechen Zhou , Chunliang Du","doi":"10.1016/j.memsci.2024.123478","DOIUrl":"10.1016/j.memsci.2024.123478","url":null,"abstract":"<div><div>The formation of a mixed matrix membrane by incorporating nanofillers into a polymer matrix is a potential strategy to improve the separation performance of polymer membranes. However, agglomeration and random arrangement of nanofillers in the mixed matrix membrane result in lower permeation flux increase than expected. In this work, mixed matrix membranes composed of cellulose acetate polymer and varying amounts of Molybdenum disulfide (MoS<sub>2</sub>) nanosheets as nanofillers were prepared, and an electric field was applied to induce the alignment of MoS<sub>2</sub> nanosheets in the membrane thickness direction. The effects of solution parameters including solvent type, MoS<sub>2</sub> content, and polymer concentration as well as electric field parameters i.e., frequency, strength, and action time on MoS<sub>2</sub> orientation were investigated using a stereoscopic microscope. The pervaporation desalination performance of mixed matrix membranes with randomly arranged MoS<sub>2</sub> and orientally arranged MoS<sub>2</sub> was assessed. At 2 wt% MoS<sub>2</sub> content, the mixed matrix membrane with orientally arranged MoS<sub>2</sub> exhibited a flux of 5.44 kg/(m<sup>2</sup>·h), representing a 25.9 % increase over the mixed matrix membrane with randomly arranged MoS<sub>2</sub>, while maintaining a salt rejection rate of over 99.9 %. The mixed matrix membrane demonstrated good long-term stability with consistent water flux and salt rejection during 120 h of operation.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"715 ","pages":"Article 123478"},"PeriodicalIF":8.4,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-04DOI: 10.1016/j.memsci.2024.123479
Huimin Zhao , Bo Pang , Fujun Cui , Wanting Chen , Guihui Xie , Xuemei Wu , Ruishi Du , Chengbo Liu , Gaohong He
Sulfonated covalent organic frameworks (SCOFs) facilitate rapid proton conduction through densely ordered sulfonic acid groups, however, the brittleness of COFs self-supporting membranes often makes potential difficulty in fuel cell assembly and limits their power density. Herein, a highly flexible SCOF proton exchange membrane is developed through in-situ growth of a continuous BD(SO3H)2–COF microphase within porous PTFE networks. The strong hydrogen bonding between PTFE and BD(SO3H)2–COF contributes to the defect-free morphology of the BD(SO3H)2/PTFE membrane. The reinforce of PTFE network makes the membrane extremely high flexibility, achieving an elongation at break of 124.4 % even with a remarkably high SCOF mass proportion of 90 wt% (BD(SO3H)2/PTFE-0.9). This allows the membrane to be folded repeatedly, even in dry state. The swelling ratio in water at 80 °C is effectively restricted to 8.6 %, even with a high ion exchange capacity of 3.6 mmol g−1 and a water uptake of 68.2 %. The densely ordered sulfonic acid groups in continuous BD(SO3H)2–COF microphase contribute to a high proton conductivity up to 249.2 mSꞏcm−1 at 80 °C, approximately 1.5 folds that of Nafion 212. As a result, the BD(SO3H)2/PTFE-0.9 membrane achieves a fuel cell power density of 1195.3 mWꞏcm−2 at 80 °C, along with a high open circuit voltage of 1.01 V, surpassing the-state-of-the-art COF-based proton exchange membranes. This work provides a novel strategy to fabricate COFs into flexible and size scalable membranes, enhancing the performance of fuel cells.
{"title":"Highly flexible SCOF proton exchange membrane reinforced with PTFE to enhance fuel cell power density","authors":"Huimin Zhao , Bo Pang , Fujun Cui , Wanting Chen , Guihui Xie , Xuemei Wu , Ruishi Du , Chengbo Liu , Gaohong He","doi":"10.1016/j.memsci.2024.123479","DOIUrl":"10.1016/j.memsci.2024.123479","url":null,"abstract":"<div><div>Sulfonated covalent organic frameworks (SCOFs) facilitate rapid proton conduction through densely ordered sulfonic acid groups, however, the brittleness of COFs self-supporting membranes often makes potential difficulty in fuel cell assembly and limits their power density. Herein, a highly flexible SCOF proton exchange membrane is developed through in-situ growth of a continuous BD(SO<sub>3</sub>H)<sub>2</sub>–COF microphase within porous PTFE networks. The strong hydrogen bonding between PTFE and BD(SO<sub>3</sub>H)<sub>2</sub>–COF contributes to the defect-free morphology of the BD(SO<sub>3</sub>H)<sub>2</sub>/PTFE membrane. The reinforce of PTFE network makes the membrane extremely high flexibility, achieving an elongation at break of 124.4 % even with a remarkably high SCOF mass proportion of 90 wt% (BD(SO<sub>3</sub>H)<sub>2</sub>/PTFE-0.9). This allows the membrane to be folded repeatedly, even in dry state. The swelling ratio in water at 80 °C is effectively restricted to 8.6 %, even with a high ion exchange capacity of 3.6 mmol g<sup>−1</sup> and a water uptake of 68.2 %. The densely ordered sulfonic acid groups in continuous BD(SO<sub>3</sub>H)<sub>2</sub>–COF microphase contribute to a high proton conductivity up to 249.2 mSꞏcm<sup>−1</sup> at 80 °C, approximately 1.5 folds that of Nafion 212. As a result, the BD(SO<sub>3</sub>H)<sub>2</sub>/PTFE-0.9 membrane achieves a fuel cell power density of 1195.3 mWꞏcm<sup>−2</sup> at 80 °C, along with a high open circuit voltage of 1.01 V, surpassing the-state-of-the-art COF-based proton exchange membranes. This work provides a novel strategy to fabricate COFs into flexible and size scalable membranes, enhancing the performance of fuel cells.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"715 ","pages":"Article 123479"},"PeriodicalIF":8.4,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/j.memsci.2024.123473
Yi Huang , Yu Qiang , Ruobing Yi , Shuai Wang , Shanshan Liang , Liang Chen
Graphene oxide (GO) membranes are considered ideal candidates for efficient water treatment due to their unique two-dimensional structure and excellent sieving properties. However, the swelling of graphene oxide in aqueous solutions makes it still challenging for practical application. Inspired by the spider web, in this work, we developed a “network-trapped engineering” strategy to stabilize the interlayer spacings of GO membranes, which are defined as GS-Sr membranes. The sodium alginate (SA) and Sr2+ were successfully fixed as the “network” and “rivets” in-between the GO nanosheets, respectively. Benefiting from the design of the network structure, the GS-Sr membranes exhibited excellent interlayer spacing stability. Meanwhile, this evenly distributed network structure in the GO laminates can further optimize the stacking of nanosheets, forming more orderly 2D confined nanochannels. As a result, the membranes exhibited superior salt/dye sieving performance, with a separation factor up to 179.13 for Na2SO4/CR, while still maintaining an outstanding water permeance of 70.14 L m−2 h−1 bar−1. Furthermore, the GS-Sr membrane demonstrated stable separation performance in the long-term test, and the mechanical stability has also been enhanced in the mechanical test. Overall, compared with traditional simple cross-linking strategies, this strategy offers a new insight into fine-construction of two-dimensional nanochannels.
氧化石墨烯（GO）膜因其独特的二维结构和优异的筛分性能，被认为是高效水处理的理想候选材料。然而，氧化石墨烯在水溶液中的膨胀性使其在实际应用中仍面临挑战。受蜘蛛网的启发，在这项工作中，我们开发了一种 "网络陷阱工程 "策略来稳定 GO 膜的层间间距，并将其定义为 GS-Sr 膜。海藻酸钠（SA）和 Sr2+ 分别作为 "网络 "和 "铆钉 "被成功固定在 GO 纳米片之间。得益于网络结构的设计，GS-Sr 膜表现出优异的层间间距稳定性。同时，GO 薄片中这种均匀分布的网络结构可以进一步优化纳米片的堆叠，形成更有序的二维封闭纳米通道。因此，这种膜具有优异的盐分/染料筛分性能，Na2SO4/CR 的分离因子高达 179.13，同时还能保持 70.14 L m-2 h-1 bar-1 的出色透水性。此外，GS-Sr 膜在长期测试中表现出稳定的分离性能，在机械测试中的机械稳定性也有所提高。总之，与传统的简单交联策略相比，这种策略为二维纳米通道的精细构建提供了新的视角。
{"title":"“Network-trapped engineering” of graphene oxide membrane with stable structure","authors":"Yi Huang , Yu Qiang , Ruobing Yi , Shuai Wang , Shanshan Liang , Liang Chen","doi":"10.1016/j.memsci.2024.123473","DOIUrl":"10.1016/j.memsci.2024.123473","url":null,"abstract":"<div><div>Graphene oxide (GO) membranes are considered ideal candidates for efficient water treatment due to their unique two-dimensional structure and excellent sieving properties. However, the swelling of graphene oxide in aqueous solutions makes it still challenging for practical application. Inspired by the spider web, in this work, we developed a “network-trapped engineering” strategy to stabilize the interlayer spacings of GO membranes, which are defined as GS-Sr membranes. The sodium alginate (SA) and Sr<sup>2+</sup> were successfully fixed as the “network” and “rivets” in-between the GO nanosheets, respectively. Benefiting from the design of the network structure, the GS-Sr membranes exhibited excellent interlayer spacing stability. Meanwhile, this evenly distributed network structure in the GO laminates can further optimize the stacking of nanosheets, forming more orderly 2D confined nanochannels. As a result, the membranes exhibited superior salt/dye sieving performance, with a separation factor up to 179.13 for Na<sub>2</sub>SO<sub>4</sub>/CR, while still maintaining an outstanding water permeance of 70.14 L m<sup>−2</sup> h<sup>−1</sup> bar<sup>−1</sup>. Furthermore, the GS-Sr membrane demonstrated stable separation performance in the long-term test, and the mechanical stability has also been enhanced in the mechanical test. Overall, compared with traditional simple cross-linking strategies, this strategy offers a new insight into fine-construction of two-dimensional nanochannels.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"715 ","pages":"Article 123473"},"PeriodicalIF":8.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/j.memsci.2024.123475
Langhui Wu , Ye Liang , Bo Zhang , Shenzhen Cong , Shenyi Tang , Kangkang Jiang , Liping Luan , Zhi Wang , Xinlei Liu
The separation of MeOH/organic mixtures poses a significant challenge in the chemical industry. In this study, metal-organic framework UiO-66-NH2 membranes prepared by a secondary solvothermal method were employed for MeOH/DMC, MeOH/Tol and MeOH/MTBE separation. The membrane performance was significantly boosted by post-synthetic modification with oxalyl chloride (OC), succinyl chloride (SC), and salicylaldehyde (SA). The modified UiO-66-NH2-OC and UiO-66-NH2-SC membranes displayed simultaneous improvement of the separation factors and MeOH fluxes. The modified UiO-66-NH2-SA membranes exhibited an order of magnitude enhancement of separation factors, with comparable MeOH fluxes. Specifically, separation factors of 3220 and 28,000 with MeOH fluxes of 1.18 kg m−2 h−1and 1.03 kg m−2 h−1 for 5/95 wt% MeOH/Tol and 5/95 wt% MeOH/MTBE separation at 40 °C, respectively, were delivered by UiO-66-NH2-SA membranes. Moreover, the UiO-66-NH2-SA membranes demonstrated good stability over 120 h's evaluation. This study offers a promising post-synthetic approach and a class of membrane materials for efficient MeOH/organic separation.
{"title":"Post-synthetic modification of MOF UiO-66-NH₂ membranes for efficient methanol/organic separation","authors":"Langhui Wu , Ye Liang , Bo Zhang , Shenzhen Cong , Shenyi Tang , Kangkang Jiang , Liping Luan , Zhi Wang , Xinlei Liu","doi":"10.1016/j.memsci.2024.123475","DOIUrl":"10.1016/j.memsci.2024.123475","url":null,"abstract":"<div><div>The separation of MeOH/organic mixtures poses a significant challenge in the chemical industry. In this study, metal-organic framework UiO-66-NH<sub>2</sub> membranes prepared by a secondary solvothermal method were employed for MeOH/DMC, MeOH/Tol and MeOH/MTBE separation. The membrane performance was significantly boosted by post-synthetic modification with oxalyl chloride (OC), succinyl chloride (SC), and salicylaldehyde (SA). The modified UiO-66-NH<sub>2</sub>-OC and UiO-66-NH<sub>2</sub>-SC membranes displayed simultaneous improvement of the separation factors and MeOH fluxes. The modified UiO-66-NH<sub>2</sub>-SA membranes exhibited an order of magnitude enhancement of separation factors, with comparable MeOH fluxes. Specifically, separation factors of 3220 and 28,000 with MeOH fluxes of 1.18 kg m<sup>−2</sup> h<sup>−1</sup>and 1.03 kg m<sup>−2</sup> h<sup>−1</sup> for 5/95 wt% MeOH/Tol and 5/95 wt% MeOH/MTBE separation at 40 °C, respectively, were delivered by UiO-66-NH<sub>2</sub>-SA membranes. Moreover, the UiO-66-NH<sub>2</sub>-SA membranes demonstrated good stability over 120 h's evaluation. This study offers a promising post-synthetic approach and a class of membrane materials for efficient MeOH/organic separation.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"715 ","pages":"Article 123475"},"PeriodicalIF":8.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/j.memsci.2024.123474
Xiao Kong , Qi-Zheng Wang , Ye-Fei Wang , Hao-Ming Huo , Fang-Qi Kou , Shu-Bo Zhang , Jun Zhao , Dan Zhang , Liang Hao , Yan-Jiao Chang , Dong-En Zhang
Improving the content of polar crystal phase and the hydrophilicity of PVDF membranes are proved the efficient ways to improve the enduringly anti-fouling ability of PVDF membranes. But synergistic manipulating the polymorphic structure and hydrophilicity of PVDF membranes is rarely reported so far. In this paper, the in-situ esterification reaction between styrene-maleic anhydride (SMA) and meglumine (MG) during nonsolvent induced phase separation (NIPS) process is found to simultaneously manipulate the polymorphic structure and hydrophilicity of PVDF membranes. The water contact angle of membranes is largely reduced from 95.8° to 31.2° with the increase in the MG adding amounts, proving that the hydrophilicity of PVDF membranes is notably improved. Moreover, the β-phase content is improved as the MG adding amounts increase due to the enhanced interactions between the –OH groups and the –CF2 groups of PVDF through hydrogen bonds. As a result, a highly hydrophilic PVDF membrane with >90 % β-phase content is obtained. The durable antifouling testing reveals that the PVDF blend membranes possess lower flow decline ratio and higher flux recovery ratio compared with the virgin PVDF membranes, thus exhibiting better antifouling ability. The synergistic manipulation of hydrophilicity and crystalline phase of PVDF membranes might offer a paradigm shift in the design of high-performance separation membranes.
{"title":"Synergistic manipulation of the polymorphic structure and hydrophilicity of PVDF membranes based on the in-situ esterification reaction to prepare anti-fouling PVDF membranes","authors":"Xiao Kong , Qi-Zheng Wang , Ye-Fei Wang , Hao-Ming Huo , Fang-Qi Kou , Shu-Bo Zhang , Jun Zhao , Dan Zhang , Liang Hao , Yan-Jiao Chang , Dong-En Zhang","doi":"10.1016/j.memsci.2024.123474","DOIUrl":"10.1016/j.memsci.2024.123474","url":null,"abstract":"<div><div>Improving the content of polar crystal phase and the hydrophilicity of PVDF membranes are proved the efficient ways to improve the enduringly anti-fouling ability of PVDF membranes. But synergistic manipulating the polymorphic structure and hydrophilicity of PVDF membranes is rarely reported so far. In this paper, the in-situ esterification reaction between styrene-maleic anhydride (SMA) and meglumine (MG) during nonsolvent induced phase separation (NIPS) process is found to simultaneously manipulate the polymorphic structure and hydrophilicity of PVDF membranes. The water contact angle of membranes is largely reduced from 95.8° to 31.2° with the increase in the MG adding amounts, proving that the hydrophilicity of PVDF membranes is notably improved. Moreover, the β-phase content is improved as the MG adding amounts increase due to the enhanced interactions between the –OH groups and the –CF<sub>2</sub> groups of PVDF through hydrogen bonds. As a result, a highly hydrophilic PVDF membrane with >90 % β-phase content is obtained. The durable antifouling testing reveals that the PVDF blend membranes possess lower flow decline ratio and higher flux recovery ratio compared with the virgin PVDF membranes, thus exhibiting better antifouling ability. The synergistic manipulation of hydrophilicity and crystalline phase of PVDF membranes might offer a paradigm shift in the design of high-performance separation membranes.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"715 ","pages":"Article 123474"},"PeriodicalIF":8.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-31DOI: 10.1016/j.memsci.2024.123455
Xiaomeng Chu , Haoxi Zhang , Cuizhi Zhang , Runan Shao , Zitong Huang , Hongfu Lv , Shaojie Liu , Lei Liu , Nanwen Li , Song Zhao
Selecting appropriate polymer backbones is crucial for the advancement of anion exchange membranes (AEMs) that exhibit both high ionic conductivity and robust chemical stability. In this study, we synthesized rigid and chemically inert aryl-ether-free polyphenylene-based polymer backbones containing alkaline-resistant N-cyclic cations, i.e. dimethyl piperidinium (DMP) or 6-azonia-spiro[5.5]undecane (ASU), as high-performance AEMs. The procedure encompassed several key steps: superacid-catalyzed Friedel-Crafts polycondensation, bromomethylation, azidation, and Cu(I)-mediated azide-alkyne cycloaddition. The synthesized BP-ASU(DMP)-x copolymers demonstrated excellent film-forming capabilities to afford robust AEMs as compared to polyolefin-based counterparts. Owing to the significant incompatibility between the hydrophobic backbones and the hydrophilic cations, the BP-ASU(DMP)-x membranes exhibited a well-defined microphase-separated morphology, resulting in exceptionally high hydroxide conductivity, up to 157.2 mS cm−1 at 80 °C in water. More importantly, BP-ASU-150 membrane exhibited no chemical degradation and a conductivity retention of >97 % when immersed in 1 M NaOH solution at 80 °C for 4000 h. Compared to the poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and polyolefin-based counterparts, the achieved outstanding alkaline stability is related to aryl-ether-free polyphenylene and alkali-stable N-cyclic cations, highlighting the importance of polymer backbones for AEM materials. Finally, all the polyphenylene-based AEMs with incorporated N-cyclic cations were assembled in single H2/O2 AEMFCs, with the BP-ASU-150 membrane demonstrating a peak power density (PPD) of 860.4 mW cm−2 at a current density of 1363 mA cm−2. We concluded that the BP-ASU(DMP) AEMs demonstrated superior performance across various metrics due to exceptional stability and robustness of polyphenylene polymers, highlighting their potential as backbones for high-performance AEM materials.
选择合适的聚合物骨架对于开发具有高离子传导性和强大化学稳定性的阴离子交换膜（AEM）至关重要。在本研究中，我们合成了含有耐碱 N 环阳离子（即二甲基哌啶鎓（DMP）或 6-氮杂螺[5.5]十一烷（ASU））的刚性和化学惰性无芳基聚苯乙烯基聚合物骨架，作为高性能 AEM。该过程包括几个关键步骤：超酸催化弗里德尔-卡夫斯缩聚、溴甲基化、叠氮化和 Cu(I)-mediated 叠氮-炔环化。与基于聚烯烃的共聚物相比，合成的 BP-ASU(DMP)-x 共聚物具有出色的成膜能力，可提供坚固耐用的 AEM。由于疏水性骨架与亲水性阳离子之间存在明显的不相容性，BP-ASU(DMP)-x 膜呈现出清晰的微相分离形态，因此具有极高的氢氧化物电导率，在 80 °C 的水中可达 157.2 mS cm-1。更重要的是，BP-ASU-150 膜在 80 °C 的 1 M NaOH 溶液中浸泡 4000 小时后，没有发生化学降解，电导率保持率高达 97%。与聚(2,6-二甲基-1,4-苯基氧化物)（PPO）和聚烯烃基同类产品相比，BP-ASU-150 所具有的出色碱性稳定性与不含芳基醚的聚亚苯基和碱性稳定的 N-环阳离子有关，凸显了聚合物骨架对 AEM 材料的重要性。最后，在单个 H2/O2 AEMFC 中组装了所有含有 N 环阳离子的聚苯基 AEM，其中 BP-ASU-150 膜在电流密度为 1363 mA cm-2 时的峰值功率密度（PPD）为 860.4 mW cm-2。我们得出的结论是，BP-ASU(DMP) AEM 在各种指标上都表现出了卓越的性能，这归功于聚苯聚合物卓越的稳定性和坚固性，凸显了它们作为高性能 AEM 材料骨架的潜力。
{"title":"Aryl-ether-free polyphenylene-based anion exchange membranes incorporating N-cyclic quaternary ammoniums for enhanced alkaline fuel cell performance","authors":"Xiaomeng Chu , Haoxi Zhang , Cuizhi Zhang , Runan Shao , Zitong Huang , Hongfu Lv , Shaojie Liu , Lei Liu , Nanwen Li , Song Zhao","doi":"10.1016/j.memsci.2024.123455","DOIUrl":"10.1016/j.memsci.2024.123455","url":null,"abstract":"<div><div>Selecting appropriate polymer backbones is crucial for the advancement of anion exchange membranes (AEMs) that exhibit both high ionic conductivity and robust chemical stability. In this study, we synthesized rigid and chemically inert aryl-ether-free polyphenylene-based polymer backbones containing alkaline-resistant N-cyclic cations, i.e. dimethyl piperidinium (DMP) or 6-azonia-spiro[5.5]undecane (ASU), as high-performance AEMs. The procedure encompassed several key steps: superacid-catalyzed Friedel-Crafts polycondensation, bromomethylation, azidation, and Cu(I)-mediated azide-alkyne cycloaddition. The synthesized BP-ASU(DMP)-x copolymers demonstrated excellent film-forming capabilities to afford robust AEMs as compared to polyolefin-based counterparts. Owing to the significant incompatibility between the hydrophobic backbones and the hydrophilic cations, the BP-ASU(DMP)-x membranes exhibited a well-defined microphase-separated morphology, resulting in exceptionally high hydroxide conductivity, up to 157.2 mS cm<sup>−1</sup> at 80 °C in water. More importantly, BP-ASU-150 membrane exhibited no chemical degradation and a conductivity retention of >97 % when immersed in 1 M NaOH solution at 80 °C for 4000 h. Compared to the poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and polyolefin-based counterparts, the achieved outstanding alkaline stability is related to aryl-ether-free polyphenylene and alkali-stable N-cyclic cations, highlighting the importance of polymer backbones for AEM materials. Finally, all the polyphenylene-based AEMs with incorporated N-cyclic cations were assembled in single H<sub>2</sub>/O<sub>2</sub> AEMFCs, with the BP-ASU-150 membrane demonstrating a peak power density (PPD) of 860.4 mW cm<sup>−2</sup> at a current density of 1363 mA cm<sup>−2</sup>. We concluded that the BP-ASU(DMP) AEMs demonstrated superior performance across various metrics due to exceptional stability and robustness of polyphenylene polymers, highlighting their potential as backbones for high-performance AEM materials.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"715 ","pages":"Article 123455"},"PeriodicalIF":8.4,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-29DOI: 10.1016/j.memsci.2024.123456
Yumei Zhao , Qingwei Gao , Xiaofei Xu , Chunyan Ma , Qikuan He , Yulin Min , Shuangliang Zhao
Proton exchange membrane fuel cells (PEMFCs) have emerged as a key research area due to their ability to convert various gaseous energy sources (such as hydrogen and methanol) into electrical energy with high efficiency and zero pollution. The design of the proton exchange membrane (PEM), which is the site for proton transfer, is critical. To explore the influence of characteristic functional groups on proton transfer mechanism in biomimetic proton exchange membranes, the crown ether structure was introduced into polymer backbone chains to mimic biological ion channels. The motion behaviors of proton were qualitatively characterized through molecular dynamics simulation. It was found that protons are strongest complexed in the best matching 18CO6-PEM case based on the analysis of RDF, residence time, interaction energy, and number of hydrogen bonds. The characteristic groups of biological proton channels with smaller or larger pores can help protons detach from the complexation under the action of an electric field. The proton transfer in crown-ether biomimetic proton exchange membranes is not just a single mechanism, but a compromise between two mechanisms in parallel. This work provides a new perspective on designing proton conduction membranes by embedding large ring motifs with intrinsic cavities and the key parameters required for establishing the proton transfer model.
{"title":"Compromise mechanism of proton transfer in crown ether-based biomimetic proton exchange membranes: Insights from molecular dynamics simulations","authors":"Yumei Zhao , Qingwei Gao , Xiaofei Xu , Chunyan Ma , Qikuan He , Yulin Min , Shuangliang Zhao","doi":"10.1016/j.memsci.2024.123456","DOIUrl":"10.1016/j.memsci.2024.123456","url":null,"abstract":"<div><div>Proton exchange membrane fuel cells (PEMFCs) have emerged as a key research area due to their ability to convert various gaseous energy sources (such as hydrogen and methanol) into electrical energy with high efficiency and zero pollution. The design of the proton exchange membrane (PEM), which is the site for proton transfer, is critical. To explore the influence of characteristic functional groups on proton transfer mechanism in biomimetic proton exchange membranes, the crown ether structure was introduced into polymer backbone chains to mimic biological ion channels. The motion behaviors of proton were qualitatively characterized through molecular dynamics simulation. It was found that protons are strongest complexed in the best matching 18CO6-PEM case based on the analysis of RDF, residence time, interaction energy, and number of hydrogen bonds. The characteristic groups of biological proton channels with smaller or larger pores can help protons detach from the complexation under the action of an electric field. The proton transfer in crown-ether biomimetic proton exchange membranes is not just a single mechanism, but a compromise between two mechanisms in parallel. This work provides a new perspective on designing proton conduction membranes by embedding large ring motifs with intrinsic cavities and the key parameters required for establishing the proton transfer model.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"715 ","pages":"Article 123456"},"PeriodicalIF":8.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1016/j.memsci.2024.123461
Song Song , Tianwen Wang , Jiaxiang Xia , Shiwen Bao , Xuexiao Hu , Wenjing Han , Yingzhuo Ma , Kunyan Sui , Jun Gao , Xueli Liu , Lei Jiang
Smart membranes with stimuli-modulated liquid-selective permeation hold promise for on-demand separation of oil/water mixtures, yet the facile preparation of membranes with sensitive and easily implemented responsiveness still remains a challenge. Herein, we present the sensitive manipulation of water-selective permeation using a weak electric field with ultra-low voltages and the resulting on-demand separation of oil-in-water emulsions on a facilely prepared laminar membrane. Fabricated via simple vacuum filtration, the MXene membrane possesses high conductivity and molecule-scaled transport channels, both of which facilitate the sensitive modulation. A voltage of just several negative volts (−4 V) can significantly switch the wetting and permeation of water on the membrane, which is distinctly lower than that previously reported (hundreds of volts and even several kV). In addition, the negatively charged membrane, under the applied bias, enhances the rejection of surfactant-wrapped oil droplets, preventing the fouling of material surfaces. Consequently, the separation of oil-in-water emulsions was achieved with high oil rejection rate (99 %) and considerable flux for a variety of oil types and percentages. Particularly for the crude oil/water mixtures, the rejection rate reached 99 % and the flux achieved 69.72 L m−2 h−1. This study presents a novel example for achieving easy and economical smart separation of oil/water mixtures using highly conductive materials, and should also spark research in areas such as water purification, drug delivery, microfluidic valves, etc.
具有刺激调制液体选择渗透性的智能膜有望实现油水混合物的按需分离，但如何轻松制备灵敏且易于实现响应的膜仍是一项挑战。在本文中，我们介绍了利用超低电压的弱电场灵敏操纵水选择性渗透，并由此在简易制备的层状膜上实现了水包油乳液的按需分离。MXene 膜通过简单的真空过滤制成，具有高导电性和分子尺度的传输通道，这两点都有助于实现灵敏的调制。仅几负伏（-4 V）的电压就能显著改变水在膜上的润湿和渗透，这明显低于之前报道的电压（几百伏甚至几千伏）。此外，带负电荷的膜在外加偏压的作用下，能增强对表面活性剂包裹的油滴的排斥，防止材料表面结垢。因此，在分离水包油型乳状液时，对各种油的类型和比例都能达到很高的油排斥率（99%）和相当大的通量。特别是对于原油/水混合物，其排油率达到 99%，通量达到 69.72 L m-2 h-1。这项研究为利用高导电性材料实现油/水混合物的简便、经济的智能分离提供了一个新的范例，也将为水净化、药物输送、微流体阀门等领域的研究带来启发。
{"title":"Ultra-low voltage modulated water-selective permeation for on-demand separation of oil/water emulsions based on the facilely prepared laminar membranes with high conductivity","authors":"Song Song , Tianwen Wang , Jiaxiang Xia , Shiwen Bao , Xuexiao Hu , Wenjing Han , Yingzhuo Ma , Kunyan Sui , Jun Gao , Xueli Liu , Lei Jiang","doi":"10.1016/j.memsci.2024.123461","DOIUrl":"10.1016/j.memsci.2024.123461","url":null,"abstract":"<div><div>Smart membranes with stimuli-modulated liquid-selective permeation hold promise for on-demand separation of oil/water mixtures, yet the facile preparation of membranes with sensitive and easily implemented responsiveness still remains a challenge. Herein, we present the sensitive manipulation of water-selective permeation using a weak electric field with ultra-low voltages and the resulting on-demand separation of oil-in-water emulsions on a facilely prepared laminar membrane. Fabricated <em>via</em> simple vacuum filtration, the MXene membrane possesses high conductivity and molecule-scaled transport channels, both of which facilitate the sensitive modulation. A voltage of just several negative volts (−4 V) can significantly switch the wetting and permeation of water on the membrane, which is distinctly lower than that previously reported (hundreds of volts and even several kV). In addition, the negatively charged membrane, under the applied bias, enhances the rejection of surfactant-wrapped oil droplets, preventing the fouling of material surfaces. Consequently, the separation of oil-in-water emulsions was achieved with high oil rejection rate (99 %) and considerable flux for a variety of oil types and percentages. Particularly for the crude oil/water mixtures, the rejection rate reached 99 % and the flux achieved 69.72 L m<sup>−2</sup> h<sup>−1</sup>. This study presents a novel example for achieving easy and economical smart separation of oil/water mixtures using highly conductive materials, and should also spark research in areas such as water purification, drug delivery, microfluidic valves, <em>etc</em>.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"715 ","pages":"Article 123461"},"PeriodicalIF":8.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1016/j.memsci.2024.123450
Xinglin Li , Qian Wang , Shasha Guo , Cheng He , Hengyang Mao , Xiaoshan Meng , Zhengzhong Zhou , Tao Zheng
Animal carcasses can be harmlessly treated through high-temperature and high-pressure hydrolysis, resulting in the production of bioactive polypeptides. The polypeptides can be effectively separated from other impurities by ultrafiltration (UF) membranes technology. However, membrane fouling is inevitable during filtrating process, which significantly impacts their lifespan and economic efficiency. In this study, the photocatalyst ZnO nanoparticles on the PVDF membrane surface (PVDF/Zn) were fabricated to degrade foulant. Firstly, tannic acid (TA) was blended into the membrane to provide coordination sites to fix Zn2⁺. Then, ZnO nanoparticles was synthesized exclusively on the membrane surface under ultrasonic assistance, where the ultrasonic energy generated by the cavitation bubbles was excluded by the pore size. Chemical composition and morphology characterization were conducted to prove the successful synthesis of ZnO on the membrane surface. The PVDF/Zn membrane demonstrated a flux of 42 L m−2h−1 and a rejection of 97 % when filtering BSA solution, with a flux recovery rate (FRR) of 80 % after photocatalytic degradation. During the treatment of high-temperature and high-pressure hydrolyzed animal carcass solution (HHAS), the FRR exceeded 90 %, effectively separating impurities from polypeptides. This work provides a novel approach to enhancing the efficiency of treating HHAS and offers new insights into the preparation of photocatalytic membranes.
{"title":"Ultrasonic assisted in-situ synthesis of photocatalytic ZnO on PVDF membrane surface for fouling degradation","authors":"Xinglin Li , Qian Wang , Shasha Guo , Cheng He , Hengyang Mao , Xiaoshan Meng , Zhengzhong Zhou , Tao Zheng","doi":"10.1016/j.memsci.2024.123450","DOIUrl":"10.1016/j.memsci.2024.123450","url":null,"abstract":"<div><div>Animal carcasses can be harmlessly treated through high-temperature and high-pressure hydrolysis, resulting in the production of bioactive polypeptides. The polypeptides can be effectively separated from other impurities by ultrafiltration (UF) membranes technology. However, membrane fouling is inevitable during filtrating process, which significantly impacts their lifespan and economic efficiency. In this study, the photocatalyst ZnO nanoparticles on the PVDF membrane surface (PVDF/Zn) were fabricated to degrade foulant. Firstly, tannic acid (TA) was blended into the membrane to provide coordination sites to fix Zn<sup>2</sup>⁺. Then, ZnO nanoparticles was synthesized exclusively on the membrane surface under ultrasonic assistance, where the ultrasonic energy generated by the cavitation bubbles was excluded by the pore size. Chemical composition and morphology characterization were conducted to prove the successful synthesis of ZnO on the membrane surface. The PVDF/Zn membrane demonstrated a flux of 42 L m<sup>−2</sup>h<sup>−1</sup> and a rejection of 97 % when filtering BSA solution, with a flux recovery rate (FRR) of 80 % after photocatalytic degradation. During the treatment of high-temperature and high-pressure hydrolyzed animal carcass solution (HHAS), the FRR exceeded 90 %, effectively separating impurities from polypeptides. This work provides a novel approach to enhancing the efficiency of treating HHAS and offers new insights into the preparation of photocatalytic membranes.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"715 ","pages":"Article 123450"},"PeriodicalIF":8.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1016/j.memsci.2024.123454
Yongfan Zhu , Meng Wu , Wanglin Zhou , Jinkun Tan , Zhicheng Zhang , Guangru Zhang , Zhengkun Liu , Gongping Liu , Wanqin Jin
In membrane reactors, the thermo-mechanical stability of the membrane determines the operability of the reaction, while the permeability and catalytic performance dictate the reaction process. A high chemical expansion coefficient can exacerbate the mismatch in the thermal expansion behaviour between the two sides of the membrane, potentially resulting in fracture. The low permeability and slow catalytic activity can slow the reaction process and result in an unsatisfactory product composition. Here, a Ba0.5Sr0.5Co0.7Fe0.2Ni0.1O3-δ (BSCFN) four-channel hollow fibre membrane with a low chemical-expansion and high oxygen permeation flux has been successfully fabricated by phase inversion and a one-step thermal process (OSTP). Reaction sintering during the OSTP forms an NiO in-situ exsolution phase on the membrane surface, and A-site stoichiometry excess occurs, improves the oxygen permeation flux, and provides the membrane with self-catalytic ability during the partial oxidation of methane (POM) reactions. Consequently, the BSCFN membrane shows excellent performance; exhibiting an oxygen flux of 11.75 mL cm−2·min−1 at 900 °C. Furthermore, the self-catalytic BSCFN membrane has a good hydrogen production of 10.1 mL cm−2·min−1 during the POM process, which is 7.5 times higher than that of Ba0.5Sr0.5Co0.8Fe0.2O3-δ membranes (1.87 mL cm−2·min−1). This offers a viable strategy for the development of membrane reactor applications.
在膜反应器中，膜的热机械稳定性决定了反应的可操作性，而渗透性和催化性能则决定了反应过程。高化学膨胀系数会加剧膜两侧热膨胀行为的不匹配，可能导致断裂。低渗透性和缓慢的催化活性会减缓反应过程，导致产品成分不理想。在这里，通过相反转和一步热处理（OSTP），成功地制造出了具有低化学膨胀和高氧气渗透通量的 Ba0.5Sr0.5Co0.7Fe0.2Ni0.1O3-δ（BSCFN）四通道中空纤维膜。OSTP 过程中的反应烧结在膜表面形成了 NiO 原位外溶解相，A 位化学计量过剩，提高了透氧通量，并使膜在甲烷部分氧化（POM）反应中具有自催化能力。因此，BSCFN 膜表现出卓越的性能；在 900 °C 时，氧气通量达到 11.75 mL cm-2-min-1。此外，自催化 BSCFN 膜在 POM 过程中的产氢量高达 10.1 mL cm-2-min-1，是 Ba0.5Sr0.5Co0.8Fe0.2O3-δ 膜（1.87 mL cm-2-min-1）的 7.5 倍。这为开发膜反应器应用提供了可行的策略。
{"title":"Low chemical-expansion and self-catalytic nickel-substituted strontium cobaltite perovskite four-channel hollow fibre membrane for partial oxidation of methane","authors":"Yongfan Zhu , Meng Wu , Wanglin Zhou , Jinkun Tan , Zhicheng Zhang , Guangru Zhang , Zhengkun Liu , Gongping Liu , Wanqin Jin","doi":"10.1016/j.memsci.2024.123454","DOIUrl":"10.1016/j.memsci.2024.123454","url":null,"abstract":"<div><div>In membrane reactors, the thermo-mechanical stability of the membrane determines the operability of the reaction, while the permeability and catalytic performance dictate the reaction process. A high chemical expansion coefficient can exacerbate the mismatch in the thermal expansion behaviour between the two sides of the membrane, potentially resulting in fracture. The low permeability and slow catalytic activity can slow the reaction process and result in an unsatisfactory product composition. Here, a Ba<sub>0.5</sub>Sr<sub>0.5</sub>Co<sub>0.7</sub>Fe<sub>0.2</sub>Ni<sub>0.1</sub>O<sub>3-δ</sub> (BSCFN) four-channel hollow fibre membrane with a low chemical-expansion and high oxygen permeation flux has been successfully fabricated by phase inversion and a one-step thermal process (OSTP). Reaction sintering during the OSTP forms an NiO <em>in-situ</em> exsolution phase on the membrane surface, and A-site stoichiometry excess occurs, improves the oxygen permeation flux, and provides the membrane with self-catalytic ability during the partial oxidation of methane (POM) reactions. Consequently, the BSCFN membrane shows excellent performance; exhibiting an oxygen flux of 11.75 mL cm<sup>−2</sup>·min<sup>−1</sup> at 900 °C. Furthermore, the self-catalytic BSCFN membrane has a good hydrogen production of 10.1 mL cm<sup>−2</sup>·min<sup>−1</sup> during the POM process, which is 7.5 times higher than that of Ba<sub>0.5</sub>Sr<sub>0.5</sub>Co<sub>0.8</sub>Fe<sub>0.2</sub>O<sub>3-δ</sub> membranes (1.87 mL cm<sup>−2</sup>·min<sup>−1</sup>). This offers a viable strategy for the development of membrane reactor applications.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"715 ","pages":"Article 123454"},"PeriodicalIF":8.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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