Fabrication of metal-organic framework-mixed matrix membranes with abundant open metal sites through dual-induction mechanism

Confinement Effects and Manipulation Strategies of Nanocomposite Membranes towards Molecular Separation

Materials featuring well-defined nanoscale channels offer inherent advantages in the selective transport of gases, liquids, and ions, making them pivotal in applications such as molecular separation, catalysis and energy storage. A crucial challenge lies in assembling ordered nanochannel structures and translating these microscopic architectures into macroscopic regular distributions to enhance performance. Nanocomposites provide a promising solution by incorporating nanoscale material (e.g., filler) that significantly enhances macroscale properties of matrix (e.g., polymer). In this review, we spotlight nanocomposite membranes nanocomposite membranes that utilize confinement effects between filler and matrix to precisely control nanochannel apertures, surface properties, and channel distribution for efficient separation of target systems. We discussed the underlying design principles, channel architectures, and strategies for optimizing polymer-filler interfaces and nanochannel manipulation within functional membranes. Emphasis is placed on the fundamental mechanisms of mass transport, and the structure-property-performance relationships within the nanocomposite membranes towards molecular separation. This work aims to provide a comprehensive understanding of how these nanocomposite membranes can be further developed to meet the demands of industrial and environmental applications.

Color and functionality construction of cellulose towels with biological Monascus pigment based on a nano-suspension system

As a sanitary textile that directly contacts sensitive parts of the human body, such as mouth, nose and eyes, towel is very important for our daily life and health. However, the colored cellulose towels we use daily are dyed with synthetic dyes. This can be a problem for people with sensitive skin, particularly babies. In this research, cellulose towel fabric was dyed using a nano-level Monascus pigment dyeing solution, which eliminated the need for organic solvent to dissolve the pigment, making it an environmentally friendly dyeing scheme. After 90 °C pre-mordanting treatment and 80 °C dyeing for 30 min respectively, the K/S value of towel fabric could reach 9. In addition, the washing fastness of dyed towel fabric was 3-4, the dry/wet friction fastness was 4-5 and 3-4, and the K/S value remained high even after 20 washing times, and also demonstrated a certain level of UV resistance and antibacterial properties. In conclusion, the application of the dyeing method for cellulose towel fabric with biological Monascus pigment based on a nano-suspension system was found to be both efficient and environmentally friendly, which was anticipated to replace certain traditional synthetic dyes in the future.

Defect engineering improves CO2/N2 and CH4/N2 separation performance of MOF-801

A defect engineering modification method is reported to improve the CO2/N2 and CH4/N2 separation performance of MOF-801, owing to skeleton shrinkage caused by defect modification, Zr-FA0.5 shows excellent gas separation performance compared with the prototype MOF.

Non-CO2 greenhouse gas separation using advanced porous materials

Global warming has become a growing concern over decades, prompting numerous research endeavours to reduce the carbon dioxide (CO2) emission, the major greenhouse gas (GHG). However, the contribution of other non-CO2 GHGs including methane (CH4), nitrous oxide (N2O), fluorocarbons, perfluorinated gases, etc. should not be overlooked, due to their high global warming potential and environmental hazards. In order to reduce the emission of non-CO2 GHGs, advanced separation technologies with high efficiency and low energy consumption such as adsorptive separation or membrane separation are highly desirable. Advanced porous materials (APMs) including metal-organic frameworks (MOFs), covalent organic frameworks (COFs), hydrogen-bonded organic frameworks (HOFs), porous organic polymers (POPs), etc. have been developed to boost the adsorptive and membrane separation, due to their tunable pore structure and surface functionality. This review summarizes the progress of APM adsorbents and membranes for non-CO2 GHG separation. The material design and fabrication strategies, along with the molecular-level separation mechanisms are discussed. Besides, the state-of-the-art separation performance and challenges of various APM materials towards each type of non-CO2 GHG are analyzed, offering insightful guidance for future research. Moreover, practical industrial challenges and opportunities from the aspect of engineering are also discussed, to facilitate the industrial implementation of APMs for non-CO2 GHG separation.

Balancing the Crystallinity and Film Formation of Metal-Organic Framework Membranes through In Situ Modulation for Efficient Gas Separation

Polycrystalline metal-organic framework (MOF) layers hold great promise as molecular sieve membranes for efficient gas separation. Nevertheless, the high crystallinity tends to cause inter-crystalline defects/cracks in the nearby crystals, which makes crystalline porous materials face a great challenge in the fabrication of defect-free membranes. Herein, for the first time, we demonstrate the balance between crystallinity and film formation of MOF membrane through a facile in situ modulation strategy. Monocarboxylic acid was introduced as a modulator to regulate the crystallinity via competitive complexation and thus concomitantly control the film-forming state during membrane growth. Through adjusting the ratio of modulator acid/linker acid, an appropriate balance between this structural "trade-off" was achieved. The resulting MOF membrane with moderate crystallinity and coherent morphology exhibits molecular sieving for H2 /CO2 separation with selectivity up to 82.5.

Bimetallic Metal-Organic Frameworks (BMOF) and BMOF- Incorporated Membranes for Energy and Environmental Applications

Bimetallic metal organic frameworks (BMOFs) are a class of crystalline solids and their structure comprises two metal ions in the lattice. BMOFs show a synergistic effect of two metal centres and enhanced properties compared to MOFs. By controlling the composition and relative distribution of two metal ions in the lattice the structure, morphology, and topology of BMOFs could be regulated resulting in an improvement in the tunability of pore structure, activity, and selectivity. Thus, developing BMOFs and BMOF incorporated membranes for applications such as adsorption, separation, catalysis, and sensing is a promising strategy to mitigate environmental pollution and address the looming energy crisis. Herein we present an overview of recent advancements in the area of BMOFs and a comprehensive review of BMOF incorporated membranes reported to date. The scope, challenges as well as future perspectives for BMOFs and BMOF incorporated membranes are presented.