Scalable crystalline porous membranes: current state and perspectives

Abstract

This review summarizes the scalable preparation strategies and performance of crystalline porous membranes.

Ultralarge Free‐Standing Imine‐Based Covalent Organic Framework Membranes Fabricated via Compression

“…[ 3 ] Alternatively, other porous materials such as classical inorganic‐based materials (e.g., zeolites, silicas, or carbon) [ 4 ] and more novel organic‐based materials (e.g., conjugated microporous polymers (CMPs), [ 5 ] metal–organic frameworks (MOFs), [ 6 ] and polymers of intrinsic microporosity (PIMs) [ 7 ] ) have been incorporated in the fabrication of membranes because of their advantages (i.e., simultaneous high permeability and high selectivity) over traditional organic polymeric membranes. [ 8 ]…”

Controllable Synthesis and Performance Modulation of 2D Covalent–Organic Frameworks

“…These sp 2 -carbon linked COFs equip with extremely stable molecular structures. Nonetheless, only very few examples have been reported, which may attribute to the low reversibility of sp 2 -carbon linkage and the ambiguous reaction mechanism. In this point, Feng and co-workers proposed that catalysts played a vital role in arranging the precursors along the x and y-directions in a Knoevenagel polymerization.…”

“…Currently, designing well-ordered porous materials has drawn great attentions as such configuration is beneficial to the transport of substances, electrons, and excitons throughout the whole backbone. [1][2][3][4] Apart from the natural products, numerous artificial porous materials such as porous silica, [5] metalorganic frameworks (MOFs), [6] covalent-organic frameworks Covalent-organic frameworks (COFs) are especially interesting and unique as their highly ordered topological structures entirely built from plentiful π-conjugated units through covalent bonds. Arranging tailorable organic building blocks into periodically reticular skeleton bestows predictable lattices and various properties upon COFs in respect of topology diagrams, pore size, properties of channel wall interfaces, etc.…”

Photo-tailored heterocrystalline covalent organic framework membranes for organics separation

“…Moreover, the COF material features an ordered porous structure that has up to 100 times higher surface area than most network polymers 15 . Theoretically, high-crystalline COF membranes (COMs) formed totally by rigid crystallites can harvest high solute selectivity and possible high solvent permeability, however, the defect-free membranes are quite difficult to fabricate [16][17][18] . Low crystalline COMs are much easier to fabricate, but often accompany with much less ordered structure and a dramatic sacrifice in solute selectivity as well as possible solvent permeability 19,20 .…”