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- Shi, Tianhui, et al.
(författare)
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Postsynthetic amine modification of porous organic polymers for CO2 capture and separation
- 2024
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Ingår i: Journal of Polymer Science. - : John Wiley & Sons. - 2642-4150 .- 2642-4169. ; 62:8, s. 1554-1568
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Tidskriftsartikel (refereegranskat)abstract
- Porous organic polymers (POPs) constitute an important class of sorbents studied in various adsorption and separation processes. Their unique properties, including high surface areas, adjustable pore sizes, and surface chemistries make them ideal candidates for CO2 capture. To achieve a high CO2 adsorption capacity and selectivity, particularly at the low partition pressures required for post-combustion CO2 capture or direct capture of CO2 from the atmosphere, incorporating amines onto the polymer frameworks or within the pores has shown much promise. This review provides a comprehensive summary of recent studies on the synthesis and CO2 capture performance of amine-functionalized POPs. The review also provides a detailed discussion of structure-performance relationships, focusing on how the loading amount and amine type influence CO2 capture capacity, CO2/N2 selectivity, heat of adsorption, sorption kinetics, and recyclability of POPs. Additionally, the authors offer their perspective on the challenges associated with the practical implementation of amine-modified POPs for CO2 capture.
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| 2. |
- Kong, Xueying, et al.
(författare)
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Ambient Aqueous Synthesis of Imine-Linked Covalent Organic Frameworks (COFs) and Fabrication of Freestanding Cellulose Nanofiber@COF Nanopapers
- 2023
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 146:1, s. 742-751
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Tidskriftsartikel (refereegranskat)abstract
- Covalent organic frameworks (COFs) are usually synthesized under solvothermal conditions that require the use of toxic organic solvents, high reaction temperatures, and complicated procedures. Additionally, their insolubility and infusibility present substantial challenges in the processing of COFs. Herein, we report a facile, green approach for the synthesis of imine-linked COFs in an aqueous solution at room temperature. The key behind the synthesis is the regulation of the reaction rate. The preactivation of aldehyde monomers using acetic acid significantly enhances their reactivity in aqueous solutions. Meanwhile, the still somewhat lower imine formation rate and higher imine breaking rates in aqueous solution, in contrast to conventional solvothermal synthesis, allow for the modulation of the reaction equilibrium and the crystallization of the products. As a result, highly crystalline COFs with large surface areas can be formed in relatively high yields in a few minutes. In total, 16 COFs are successfully synthesized from monomers with different molecular sizes, geometries, pendant groups, and core structures, demonstrating the versatility of this approach. Notably, this method works well on the gram scale synthesis of COFs. Furthermore, the aqueous synthesis facilitates the interfacial growth of COF nanolayers on the surface of cellulose nanofibers (CNFs). The resulting CNF@COF hybrid nanofibers can be easily processed into freestanding nanopapers, demonstrating high efficiency in removing trace amounts of antibiotics from wastewater. This study provides a route to the green synthesis and processing of various COFs, paving the way for practical applications in diverse fields.
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| 3. |
- Kong, Xueying, et al.
(författare)
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Aqueous synthesis and engineering of imine-linked covalent organic frameworks
- 2023
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Ingår i: One-day symposium: Sorption, Transport and Catalysis in Metal-Organic Frameworks. Uppsala 18/9 2023. - Uppsala.
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Konferensbidrag (refereegranskat)abstract
- Covalent organic frameworks (COFs) are typically synthesized through solvothermal methods, which necessitate the use of hazardous organic solvents, elevated reaction temperatures, and intricate procedures. Additionally, their insolubility and inability to melt present substantial challenges in the processing of COFs. In this study, we present an eco-friendly method for synthesizing imine-linked COFs by simply stirring the initial materials in an aqueous solution at room temperature. A key element of this approach involves the pre-activation of aldehyde monomers using acetic acid, significantly enhancing their reactivity in aqueous solutions. This innovative strategy results in the rapid formation of highly crystalline COFs formed at relatively high yields, with substantial surface areas, within minutes. Remarkably, this method performs exceptionally well on a gram-scale, producing highly crystalline and porous COFs in scaled-up reactions.We successfully synthesized a total of 15 COFs using monomers with diverse molecular sizes, geometries, pendant groups, and core structures, underscoring the versatility of this approach. Furthermore, our use of cellulose nanofibers (CNFs) as a substrate during the syntheses allows for the growth of COF nanolayers on the CNF surface. These CNF@COF hybrid nanofibers can be effortlessly transformed into freestanding nanopapers.Significantly, both COF powders and CNF@COF nanopapers exhibit remarkable efficiency in removing trace amounts of antibiotics from wastewater. This research offers a promising avenue for the green synthesis and processing of various COFs, paving the way for practical applications in diverse fields.
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