Metal-organic frameworks (MOFs) represent the largest known class of porous crystalline materials ever synthesized Their narrow pore windows and nearly unlimited structural and chemical features have made these materials of significant interest for membrane-based gas separations In this comprehensive review, we discuss opportunities and challenges related to the formation of pure MOF films and mixed-matrix membranes (MMMs) Common and emerging separation applications are identified, and membrane transport theory for MOFs is described and contextualized relative to the governing principles that describe transport in polymers Additionally, cross-cutting research opportunities using advanced metrologies and computational techniques are reviewed To quantify membrane performance, we introduce a simple membrane performance score that has been tabulated for all of the literature data compiled in this review These data are reported on upper bound plots, revealing classes of MOF materials that consistently demonstrate promising separation performance Recommendations are provided with the intent of identifying the most promising materials and directions for the field in terms of fundamental science and eventual deployment of MOF materials for commercial membrane-based gas separations

MOF-Based Membranes for Gas Separations.

Metal/covalent–organic framework (MOF/COF) membranes have attracted increasing research interest and have been considered as state-of-the-art platforms applied in various environment- and energy-related separation/transportation processes. To break the trade-off between permeability and selectivity to achieve ultimate separation, recent studies have been oriented towards how to design and exploit ultrathin MOF/COF membranes (i.e. sub-1 μm-thick). Given great advances made in the past five years, it is valuable to timely and systematically summarize the recent development and shed light on the future trend in this multidisciplinary field. In this review, we first present the advanced strategies in fabricating ultrathin defect-free MOF/COF membranes such as in situ growth, contra-diffusion method, layer-by-layer (LBL) assembly, metal-based precursor as the pre-functionalized layer, interface-assisted strategy, and laminated assembly of MOF/COF nanosheets. Then, the recent progress in some emerging applications of ultrathin MOF/COF membranes beyond gas separation is highlighted, including water treatment and seawater desalination, organic solvent nanofiltration, and energy-related separation/transportation (i.e. lithium ion separation and proton conductivity). Finally, some unsolved scientific and technical challenges associated with future perspectives in this field are discussed, inspiring the development of next-generation separation membranes.

Ultrathin metal/covalent-organic framework membranes towards ultimate separation.

The field of metal–organic frameworks (MOFs) has been incorrectly believed to be purely crystalline. However, non-crystalline MOFs (amorphous MOFs, MOF liquids, and MOF glasses) are starting to emerge as alternative materials, beyond the dictatorial domain of crystalline MOFs. Non-crystalline MOFs present many opportunities, either as novel functional materials themselves, or as vehicles to create other materials. In this extensive Review, we describe the two approaches to preparing amorphous MOFs: (1) the amorphization of crystalline MOFs and (2) the direct synthesis. Special attention is paid to the relationship between preparation method, properties and applications of amorphous MOFs. We also explore the field of MOF liquids and their applications, centering our attention to the phenomenon of melting. Finally, MOF glasses are explained. We highlight the properties and applications of the MOF glasses that are not usually found in crystalline MOFs. New related glass materials such as MOF-blends, flux melted MOFs, MOF crystal-glass composites, MOF and inorganic glass composites, and MOF glass membranes are also reviewed. We conclude the fields of amorphous MOFs, MOF liquids, and MOF glasses by presenting our thoughts on the possible future research directions.

Metal–organic frameworks (MOFs) beyond crystallinity: amorphous MOFs, MOF liquids and MOF glasses

In this Review, we showcase the upsurge in the development and fundamental photophysical studies of more than 100 metal-organic frameworks (MOFs) as versatile stimuli-responsive platforms. The goal is to provide a comprehensive analysis of the field of photoresponsive MOFs while delving into the underlying photophysical properties of various classes of photochromic molecules including diarylethene, azobenzene, and spiropyran as well as naphthalenediimide and viologen derivatives integrated inside a MOF matrix as part of a framework backbone, as a ligand side group, or as a guest. In particular, the geometrical constraints, photoisomerization rates, and electronic structures of photochromic molecules integrated inside a rigid MOF scaffold are discussed. Thus, this Review reflects on the challenges and opportunities of using photoswitchable MOFs in next-generation multifunctional stimuli-responsive materials while highlighting their use in optoelectronics, erasable inks, or as the next generation of sensing devices.

Photophysics Modulation in Photoswitchable Metal–Organic Frameworks

Metal–organic frameworks and covalent organic frameworks as disruptive membrane materials for energy-efficient gas separation

The combination of well-defined molecular cavities and chemical functionality makes crystalline porous solids attractive for a great number of technological applications, from catalysis to gas separation. However, in contrast to other widely applied synthetic solids such as polymers, the lack of processability of crystalline extended solids hampers their application. In this work, we demonstrate that metal–organic frameworks, a type of highly crystalline porous solid, can be made solution processable via outer surface functionalization using N-heterocyclic carbene ligands. Selective outer surface functionalization of relatively large nanoparticles (250 nm) of the well-known zeolitic imidazolate framework ZIF-67 allows for the stabilization of processable dispersions exhibiting permanent porosity. The resulting type III porous liquids can either be directly deployed as liquid adsorbents or be co-processed with state-of-the-art polymers to yield highly loaded mixed matrix membranes with excellent mechanical properties and an outstanding performance in the challenging separation of propylene from propane. We anticipate that this approach can be extended to other metal–organic frameworks and other applications. Solution processability is required for many industrial processes, but metal–organic frameworks are in general not dispersible, hindering their application. Here, a surface modification is reported that allows porous liquid formation and so synthesis of highly loaded and mechanically robust mixed matrix membranes.

/pdf/solution-processable-metal-organic-frameworks-for-mixed-3k2onks6af.pdf

Solution processable metal-organic frameworks for mixed matrix membranes using porous liquids.

Metal–organic frameworks (MOFs) with an exceptionally large pore volume and inner surface area are perfect materials for loading with intelligent guest molecules. First, an ultrathin 200 nm high-flux UiO-67 layer deposited on a porous α-Al2O3 support by solvothermal growth has been developed. This neat UiO-67 membrane is then used as a host material for light-responsive guest molecules. Azobenzene (AZB) is loaded in the pores of the UiO-67 membrane. From adsorption measurements, we determined that the pores of UiO-67 are completely filled with AZB and, thereby, steric hindrance inhibits any optical switching. After in situ thermally controlled desorption of AZB from the membrane, AZB can be switched and gas permeation changes are observed, yielding an uncomplicated and effective smart material with remote controllable gas permeation. The switching of AZB in solution and inside the host could be demonstrated by ultraviolet–visible spectroscopy. Tracking the completely reversible control over the permeance ...

Azobenzene Guest Molecules as Light-Switchable CO2 Valves in an Ultrathin UiO-67 Membrane

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Lion Sundermann

Author Tools

Chat about Author

Papers

Solution processable metal-organic frameworks for mixed matrix membranes using porous liquids.

Azobenzene Guest Molecules as Light-Switchable CO2 Valves in an Ultrathin UiO-67 Membrane