Flexible, Mechanically Stable, Porous Self‐Standing Microfiber Network Membranes of Covalent Organic Frameworks: Preparation Method and Characterization

Abstract

Covalent organic frameworks (COFs) show advantageous characteristics, such as an ordered pore structure and a large surface area for gas storage and separation, energy storage, catalysis, and molecular separation. However, COFs usually exist as difficult-to-process powders, and preparing continuous, robust, flexible, foldable, and rollable COF membranes is still a challenge. Herein, such COF membranes with fiber morphology for the first time prepared via a newly introduced template-assisted framework process are reported. This method uses electrospun porous polymer membranes as a sacrificial large dimension template for making self-standing COF membranes. The porous COF fiber membranes, besides having high crystallinity, also show a large surface area (1153 m 2 g −1 ), good mechanical stability, excellent thermal stability, and flexibility. This study opens up the possibility of preparation of large dimension COF membranes and their derivatives in a simple way and hence shows promise in technical applications in separation, catalysis, and energy in the future.

Monolithic Covalent Organic Frameworks with Hierarchical Architecture: Attractive Platform for Contaminant Remediation

“…A deep understanding of the design principles is critical to develop reliable and robust monolithic COFs for environmental applications. Various strategies have been adopted to fabricate monolithic COFs, such as post-cross-linking , and 3D printing, ,,− as well as template-assisted ,, and substrate-assisted in situ growth methods. ,− Generally, there are three strategies for preparing monolithic COFs with hierarchical structures (Figure ). The post-cross-linking method.…”

Amorphous-to-Crystalline Transformation: General Synthesis of Hollow Structured Covalent Organic Frameworks with High Crystallinity

“…Because the properties of COF materials are highly dependent on their morphologies, controlling morphologies is very promising for improving the performances of COFs. In this regard, COFs with various shapes including nanospheres, − nanofibers, , and nanosheets , have been prepared and exhibited outstanding performances in catalysis, gas storage/separation, and DNA detection. Among different morphologies, hollow nanostructures are particularly interesting due to their advantages in manipulating the loading of guest molecules and in imparting multifunctionality. − Therefore, the controllable fabrication of hollow structured COFs (HCOFs) with intrinsic periodic network structures is of utmost significance for further exploring their applications.…”

Facile Preparation of PET/PA6 Bicomponent Microfilament Fabrics with Tunable Porosity for Comfortable Medical Protective Clothing

“…Medical protective clothing is a vital medical component utilized to treat patients and safeguard medical personnel in medical places. − Various microfiber fabrics are now being considered for use in medical protective gear due to their desirable properties of a high specific surface area − and high flexibility. , In public health emergencies of worldwide importance, medical protective equipment successfully minimizes the risk of infection through liquid proofing and particle filtration. − However, restriction of comfort performance in poor ventilation and unpleasant contact is difficult to avoid for long-term usage of medical protective garments.…”