Search

Fabricating mechanically responsive actuators that can efficiently convert external stimuli into mechanical work is of great significance for real‐world applications. Herein, we rationally design a class of rigid–flexible coupling crystalline crosslinked polymers (CCPs) to fabricate vapomechanically responsive actuators. Interfacial condensation reactions of flexible macromers with rigid monomers afford a series of freestanding CCP membranes. Notably, it is the first example where crosslinked polymers show high crystallinity and porosity. Moreover, the CCP membranes exhibit good mechanical properties and interesting vapor‐triggered actuation performance, which is reversible and repeatable. We find that the unusual polymer structures, high vapor sorption, and anisotropic membranes contribute to the directional deformation performance of the CCP actuators. The synthesis approach in this work provides new insights into the design and fabrication of smart materials for advanced applications. [ABSTRACT FROM AUTHOR]

Fabricating mechanically responsive actuators that can efficiently convert external stimuli into mechanical work is of great significance for real‐world applications. Herein, we rationally design a class of rigid–flexible coupling crystalline crosslinked polymers (CCPs) to fabricate vapomechanically responsive actuators. Interfacial condensation reactions of flexible macromers with rigid monomers afford a series of freestanding CCP membranes. Notably, it is the first example where crosslinked polymers show high crystallinity and porosity. Moreover, the CCP membranes exhibit good mechanical properties and interesting vapor‐triggered actuation performance, which is reversible and repeatable. We find that the unusual polymer structures, high vapor sorption, and anisotropic membranes contribute to the directional deformation performance of the CCP actuators. The synthesis approach in this work provides new insights into the design and fabrication of smart materials for advanced applications. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are an emerging class of crystalline porous polymers with highly tuneable structures and functionalities. COFs have been proposed as ideal materials for applications in the energy-intensive field of molecular separation due to their notable intrinsic features such as low density, exceptional stability, high surface area, and readily adjustable pore size and chemical environment. This review attempts to highlight the key advancements made in the synthesis of COFs for diverse separation applications such as water treatment or the separation of gas mixtures and organic molecules, including chiral and isomeric compounds. Methods proposed for the fabrication of COF-based columns and continuous membranes for practical applications are also discussed in detail. Finally, a perspective regarding the remaining challenges and future directions for COF research in the field of separation has also been presented. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) with high specific porosity, easy functionalization, and tailored structure are an emerging class of crystalline porous polymers that have been extensively exploited as ideal materials in various fields. Among them, sp2-carbon linked COFs with high chemical stability, porous backbone, and unique π-electron conjugated architectures structure have raised widespread attention. Specifically, the porous channels of olefin-linked COFs could be packed with active sites for catalysis and guest molecules, while π–π stacking interactions and conjugation systems pave the way for electron transfer. In recent years, many efforts have been devoted to the development of sp2-carbon linked COFs for applications in catalysis, energy storage, gas adsorption, and separation. In this review, we highlight the design principles, synthesis strategies, and impactful applications of olefin-linked COFs. We are looking forward to this review to deepen the understanding of the synthesis of olefin-linked COFs and motivate the further development of these novel conjugated organic materials with distinctive physicochemical properties, as well as their applications in a variety of fields. [ABSTRACT FROM AUTHOR]

This review exhibits a pioneering systematic introduction to the design, classification and application of an emerging material, ionic Covalent Organic Frameworks, and elucidates the current problems and future directions. [Display omitted] • Summarized the classification and construction methodology of iCOFs (ionic covalent organic frameworks). • Summarized the current progress of the application of iCOFs. • Commented the advantages and disadvantages of iCOFs. • Provided a guide for future research into creating new iCOFs. Ionic covalent organic frameworks (iCOFs) are an emerging type of crystalline organic polymers that consist of the ionic skeleton and corresponding counterions. As a joint subgroup of porous ionic polymers (PiPs) and COFs, iCOFs can combine the benefits of both PiPs and COFs. Thus, iCOFs demonstrate great potential in many application fields such as ion conduction, life science, adsorption, separation, catalysis, and sensing. In this context, this review straightens the thread of thought toward this seductive material. A comprehensive introduction was expanded in all kinds of synthesis methods, classification features, and application potential. Finally, the opportunities and challenges of iCOFs were analyzed in detail to understand the future developing prospects deeply. [ABSTRACT FROM AUTHOR]