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Hou et al. Microstructures 2023;3:2023039 https://dx.doi.org/10.20517/microstructures.2023.37 Page 7 of 17

relatively low cost, making it possible for industries to incorporate graphene into their products.
Furthermore, collaborations between academia and industry have facilitated the transfer of graphene
research from the lab to the factory floor. Companies, including Samsung, Nokia, and IBM, have invested in
graphene research and development, leading to the creation of new graphene-based products such as
flexible displays, sensors, and batteries . In addition, the EU-funded Graphene Flagship project has played
[57]
[58]
a crucial role in the industrialization of graphene . The project, launched in 2013, aims to accelerate the
commercialization of graphene by bringing together over 150 academic and industrial partners from across
Europe to develop new graphene-based technologies. Overall, the combination of advancements in
research, scalable production methods, industry-academia collaborations, and funding initiatives has paved
the way for the industrialization of graphene. Consequently, MOF-based products are increasingly prevalent
across various industries, with expectations that MOFs will continue to play a significant role in future
technology development.

MULTIFUNCTION OF MOF-BASED FLAME RETARDANTS
Due to the exorbitant cost of MOF-based flame retardants, their industrialization is still in its infancy.
However, as a versatile material, it can also serve other purposes, such as wastewater adsorption, while
retaining its flame-retardant properties [Figure 3]. This design has become a focal point of scholarly
attention. Zhou et al. utilized MOF-derived layered double hydroxide (LDH) and 3-amino-propyl
triethoxy-silane to modify hydroxylated boron nitride, resulting in polyurethane foam (PUF) composites
with exceptional thermal stability, fire safety, and high absorption capacity. The incorporation of flame
retardants significantly decreased the amount of combustible gas and toxic CO gas generated during PUF
pyrolysis. The inhibition of smoke release was evidenced by a significant decrease in the emission of
aromatic compounds. Moreover, the incorporation of 1 wt.% additive resulted in PUF composites with
excellent pump oil adsorption capacity, achieving a removal rate of as high as 95%, which outperformed
[59]
other PUF-based materials for oil and water separation . Piao et al. provided a growth site for ZIF-67 by
in-situ polymerization of a polydopamine film on the surface of a polyurethane sponge. Then, ZIF-67 was
etched with copper nitrate to form CuCo-LDH, and a high-performance oil-water separation flame
retardant polyurethane sponge was obtained. The polyurethane composites demonstrate exceptional
superhydrophobicity and superlipophilicity while also enhancing thermal stability, exhibiting excellent
flame retardancy, and inhibiting the generation of toxic smoke. As such, they represent a highly efficient,
sustainable, and safe material for emergency treatment of oil/organic solvent spills .
[60]

Under the influence of this trend, we believe MOFs can be designed as a “one-pack” material with specific
functionalities that allow them to serve multiple roles simultaneously. In the latest reports, MOFs can be
functionalized with antimicrobial agents, ultraviolet (UV) stabilizers, or other additives to provide
additional properties to the material. This can be particularly useful in applications where multiple
properties are required, such as in the construction of buildings or in the aerospace industry. MOFs can
exhibit antimicrobial activity through the release of metal ions. Besides, their high surface area and porous
nature can facilitate contact between the MOFs and microorganisms, allowing for efficient antimicrobial
action.

One example is the report by Zhao et al. on the synthesis of a novel antibacterial material based on silver
nanoparticle-modified 2D MOF nanosheets. The authors first synthesized the MOF nanosheets using a
solvothermal method and then modified them with silver nanoparticles using a simple deposition-reduction
process. The resulting hybrid nanosheets exhibited excellent stability and could be easily dispersed in water.
Then, they investigated the antibacterial properties of the hybrid nanosheets against Escherichia coli and
Staphylococcus aureus and found that the nanosheets exhibited excellent antibacterial activity, which was