Article
Engineering, Chemical
Menno Houben, Romy van Geijn, Machiel van Essen, Zandrie Borneman, Kitty Nijmeijer
Summary: The high-pressure behavior of supercritical carbon dioxide in glassy Matrimid (R) 5218 polymer membranes was investigated, with emphasis on the impact of CO2 fluid density and plasticization phenomena on CO2 permeability.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Xiaochen Xu, Jie Dong, Xian Xiao, Xin Zhao, Qinghua Zhang
Summary: The newly developed thin film composite membranes (TFC) can enhance CO2 permeation by minimizing gas trans-membrane resistance and defects, with a thickness range of 103-485 nm that can be optimized through adjusting interfacial polymerization parameters. The TFC membrane exhibits an optimum CO2 permeance of 330 GPU with high CO2/N-2 and CO2/CH4 ideal selectivities of 30 and 32, respectively, showing improved CO2 separation performance compared to conventional PI flat membranes. Additionally, these membranes demonstrate excellent plasticizing resistance and long-term stability, contributing to the development of thin glassy polymeric membranes for CO2 separation.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Engineering, Environmental
Xianbo Hou, Yiqi Mao, Rubing Zhang, Daining Fang
Summary: The study developed a polyimide (PI) nanofiber cross-linked polyimide aerogel membrane with high flexibility, strong mechanical properties, and efficient heat insulation. Addition of nanofibers significantly enhanced the performance of aerogel, making it a potential material for applications in modern technology, military, and aerospace.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Polymer Science
Yangfeng Gao, Chao Dong, Fan Zhang, Hongwei Ma, Yang Li
Summary: In this study, low cross-linked mesoporous polyimide aerogels with imidazole were synthesized successfully. The obtained aerogels exhibited outstanding thermal stability and high CO2 adsorption capacity. The specific surface area and adsorption performance of the aerogels can be controlled by adjusting the monomer ratio.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Polymer Science
Shogo Tachibana, Kei Hashimoto, Haruna Mizuno, Kazuhide Ueno, Masayoshi Watanabe
Summary: The effects of polymer structure on CO2 separation and mechanical properties of ion gel membranes composed of ionic liquids and sulfonated polyimides were investigated. It was found that polymers with multiblock structure exhibited higher IL uptake and CO2 permeability, while those with fluorinated non-ionic part showed improved mechanical properties without sacrificing CO2 permeability. These results suggest that polyimide sequence and non-ionic structure play important roles in the performance of the composite membranes.
Article
Engineering, Chemical
Menno Houben, Machiel van Essen, Kitty Nijmeijer, Zandrie Borneman
Summary: Research has shown that the plasticization behavior of Matrimid (R) 5218 polymer membranes induced by CO2 varies under different conditions. In the liquid-like sc-CO2 region, the CO2 concentration remains stable with no hysteresis, while the CO2 permeability displays more pronounced time-dependent behavior. The presence of a concentration gradient during permeation experiments results in different time-dependent behaviors between CO2 sorption and permeation.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Polymer Science
Weixin Li, Longfei Peng, Yinhui Li, Zan Chen, Cuijia Duan, Shuo Yan, Biao Yuan
Summary: The design and synthesis of porous materials with novel structures and functional groups for the preparation of mixed matrix membranes (MMMs) is an effective approach to overcome the trade-off effect in membrane technology. In this study, hyper cross-linked polymers containing amino groups (HCPs-NH2) with a hydrophilic CO2 frame were successfully prepared and used to fabricate polyimide (PI)/HCPs-NH2 MMMs. The results showed that the PI/HCPs-NH2 MMMs exhibited higher permeability and selectivity compared to pure PI film, indicating the breakthrough of the trade-off effect. The presence of HCPs-NH2 with a hydrophilic CO2 frame played a crucial role in enhancing CO2 permeability.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
William Guzman, Ian Johnson, Jeffrey S. Wiggins
Summary: High-temperature polymers, such as phenylethynyl-terminated ortho-hydroxy imide oligomers (oHIOs), exhibit excellent thermal stability and solubility, making them suitable for aerospace applications. Through thermal rearrangements, oHIOs can be converted into polybenzoxazole networks with high thermal stability. This work highlights the importance of preparing imide oligomer networks with outstanding thermal stability and processability for carbon/carbon composites.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Engineering, Chemical
Wei Xie, Yang Jiao, Zhili Cai, Hongyan Liu, Lili Gong, Wei Lai, Linglong Shan, Shuangjiang Luo
Summary: This study developed benzimidazole functionalized polyimides and ionic polyimides with high CO2/CH4 selectivity for natural gas sweetening, demonstrating improved gas separation properties by tightening microporous structures and restricting polymer chain mobility. High performance was observed under high-pressure mixed-gas conditions.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Sunghwan Park, Hae-Kwon Jeong
Summary: The permeability reduction in the polymer-modification-enabled in-situ metal-organic framework formation (PMMOF) process can be addressed by using a cross-linked polyimide. The degree of cross-linking affects both the properties of the polymer and the formation of filler particles. The swelling of the polymer and the structural rigidity are critical in mitigating the permeability reduction.
Article
Engineering, Chemical
Menno Houben, Zandrie Borneman, Kitty Nijmeijer
Summary: This study investigates the impact of crown-ether ring size and rigidity on the gas separation performance and plasticization behavior of Matrimid (R) 5218 polyimide membranes. The crown-ether containing membranes exhibit enhanced solubility selectivity for CO2 but reduced solubility and permeability for both CO2 and N-2. The variation in crown-ether size and rigidity does not significantly affect the plasticization resistance of the membranes.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Engineering, Chemical
Ki Jung Kim, Yunmi Chae, Seong Jin An, Jin Hui Jo, Sungmin Park, Won Seok Chi
Summary: This study investigates microphase-separated structured PI-POEM graft copolymer membranes, which have controllable POEM concentrations and the ability to modify material properties. The results show that PI-POEM graft copolymer membranes exhibit high CO2 affinity and separation performance, making them promising for CO2 separation processes.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Engineering, Chemical
Fangxu Fan, Yongchao Sun, Qizheng Zhao, Jingfa Zhang, Jianyu Guan, Gaohong He, Canghai Ma
Summary: The application of fluorinated polyimides in gas separation membranes is expanding due to their strong thermal and chemical stability. To overcome the trade-off between gas permeability and selectivity, a series of polyimides containing rigid cardo groups with C-F bonds (FFDA) were synthesized. Copolymerizing DAM segments with FFDA resulted in 6FDA-FFDA/DAM copolyimide, which showed enhanced gas separation performance. The design principles in this work pave the way for fabricating desirable polymeric membranes for selective CO2 separation.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Chemistry, Physical
Zhiqiang Wu, Yiwen Peng, Ying Song, Haoyu Liang, Lei Gong, Zhenguo Liu, Qiuyu Zhang, Yanhui Chen
Summary: A series of cross-linked polyimide films with outstanding dielectric properties and high temperature energy storage property were prepared by introducing the end-capping agent, norbornene dioic anhydride. The cross-linked structure greatly reduces the dielectric loss and improves the electrical insulation properties of the films. The films exhibit a maximum energy storage density of 9.4 J/cm3 and maintain high energy storage density and efficiency at elevated temperatures.
MATERIALS TODAY ENERGY
(2023)
Article
Materials Science, Ceramics
Ze Zhang, Xiaodong Wang, Ting Liu, Lin Liu, Shuang Xi, Xiaoxue Zhang, Guoqing Zu, Jun Shen
Summary: The properties of linear polyimide aerogels were enhanced by introducing the network structure of polyvinylpolymethylsiloxane, resulting in doubly cross-linked polyimide-PVPMS structure with resilience and fire-retardant properties. The introduced PVPMS network structure weakened the effect of PI rigidity on LPAs, and played a significant role in the physical properties of PPCAs, allowing for the use of lower cost monomers in large-scale production.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)