Reticular polymers are set to become a game-changer in materials science. They are highly porous, crystalline materials formed by linking molecular building blocks into precise frameworks. Their structure enables them to selectively trap, store, and release specific molecules, making them best for environmental applications. The most notable examples are metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and porous organic polymers (POPs).
With rising CO₂ emissions and global water shortages, there is a pressing need for effective carbon capture and water harvesting solutions. Traditional methods typically suffer from poor selectivity, high energy use, and limited scalability. Reticular polymers offer a more efficient and tunable option. They’re gaining attention in clean-tech fields, powering technologies from industrial CO₂ capture systems to portable water harvesters.
Fundamentals of reticular polymers
Reticular polymers’ well-ordered, crystalline structure gives them predictable performance and tunability. Their porosity is significantly higher than conventional materials like activated carbon or silica gels. MOFs combine metal ions or clusters with organic linkers; COFs are made from lightweight elements such as carbon, hydrogen, nitrogen, and oxygen; and POPs, though amorphous, offer large surface areas and strong chemical resistance.
Several advanced synthesis techniques have been developed. Solvothermal processes, in which reagents react in the presence of a solvent within a closed system at elevated temperatures, are still standard for MOFs and COFs. Microwave-assisted synthesis shortens reaction times, while mechano-chemical methods like ball milling offer solvent-free alternatives, aligning with green chemistry goals. These approaches allow precise control over material properties, matching them to specific functional demands.
MOFs in carbon capture
MOFs can capture CO₂ via physisorption (weak, reversible interactions) or chemisorption (stronger, chemical bonding). Physisorption is energy-efficient and best for direct air capture. Chemisorption is more suitable for flue gas treatment in industrial settings.
Structural tuning permits enhanced CO₂ selectivity by modifying pore dimensions, metal centers, and functional groups.
- ZIF-8 (zinc-based) is highly stable.
- UiO-66 (zirconium-based) offers thermal and chemical robustness.
- Mg-MOF-74 provides strong CO₂ affinity; and HKUST-1 remains a well-researched benchmark.
Post-synthetic modifications by including amine groups, for example, further improve CO₂ adsorption. Commercial applications are advancing: BASF and Svante are making MOF-based filters for heavy industries, and companies like Carbon Clean are piloting similar systems, moving the technology closer to large-scale deployment.
COFs and POPs in atmospheric water harvesting
Capturing water from the air, under low humidity, requires materials that attract and retain moisture. COFs are the best option because of their customizable, hydrophilic pore chemistry. Functional groups like amines and hydroxyls encourage hydrogen bonding with water molecules.
In arid conditions, COFs facilitate water collection through capillary condensation within the pore network. Materials such as COF-TpPa-1 and ACOF-1 show high efficacy even at relative humidity below 20%. POPs, like PAF-1, with huge pore networks also show potential for bulk water vapor uptake.
These materials are being applied in solar-powered harvesters that use ambient heat to regenerate without external power. Companies like Atoco are already testing COF-based water harvesters in military and off-grid scenarios. This also underlines their potential in challenging environments.
Material design considerations
Precision design is important for effectiveness. Pore size must be compatible with the kinetic diameter of the target molecule, 0.5 to 1 nm for CO₂, larger for water. Surface chemistry customization — amines for CO₂ and polar groups for water — enhances selectivity and capture efficiency.
Thermal, hydrolytic, and mechanical stability are important for real-world use. Materials must bear cycles of heating, hydration, and pressure. For water harvesting, resistance to moisture-related degradation is essential.
Efficient regeneration methods, such as pressure swing adsorption, temperature swing desorption, and solar-based approaches, ensure that the materials can be reused with minimal energy input, improving operational sustainability.
Commercial activity
Commercial deployment of reticular polymers is steadily shifting from the lab to real-world environments, especially in carbon capture and atmospheric water harvesting.
In 2024, BASF began implementing MOF-based filters at cement plants, marking a milestone in industrial decarbonization. These systems use custom-designed MOFs to get selective CO₂ adsorption while reducing the energy demands associated with traditional amine scrubbing.
Another notable player, Nuada (formerly MOF Technologies), is commercializing its Vacuum Pressure Swing Adsorption (VPSA) systems that incorporate MOF sorbents specifically engineered for point-source CO₂ capture. These systems are being trialed in industrial settings across the United Kingdom with aid from the UK Department for Energy Security and Net Zero. Nuada’s solution offers a compact footprint, fast regeneration cycles, and lower operating temperatures, all critical for retrofitting in existing plants. Their modular pathway shows how scalable MOF-based capture systems are getting attention in the decarbonization supply chain.
In the direct air capture space, AspiraDAC, an Australian startup, is using solar-powered DAC units equipped with MOF filters. These portable devices are made for small-scale distributed CO₂ removal as well as off-the-grid operation. Also, they use renewable energy for regeneration. The system’s modularity and use of recyclable MOFs make it ideal for use in climate-vulnerable or remote areas, where centralized infrastructure is not feasible.
In the realm of water harvesting, Atoco is advancing COF-integrated devices for military, disaster-relief, and off-grid applications. Their systems are made to pull moisture from low-humidity air and regenerate using solar thermal energy, a viable solution for mobile hydration in extreme conditions.
Reticular polymers are also making headway in gas separation. Evonik and Air Products are integrating PIM-1-based membranes, enhanced with MOF or POP coatings, into filtration systems for biogas upgrading, marine environments, and aerospace air purification. These composite membranes offer higher permeability and selectivity, key for energy-efficient separation in sectors where compact, durable solutions are critical.
Meanwhile, academic-industry platforms like UC Berkeley’s Reticular Chemistry Structure Resource are accelerating innovation by offering access to thousands of experimentally validated MOF and COF structures. These databases are aiding new material discovery as well as aiding commercialization efforts through computational modeling and design.
Combined, these examples show that reticular polymers are evolving beyond lab-scale research into a core enabler of next-generation clean technologies, with clear momentum across CO₂ capture, water sustainability, and advanced filtration markets.
Regulatory and environmental factors
As scale-up moves forward, safety and lifecycle sustainability issues are under scrutiny. Some MOFs use metals that could pose environmental or health risks. Research is underway to develop less toxic alternatives, and full lifecycle assessments are being conducted.
Durability and recyclability are key. While reticular polymers tend to be stable, long-term industrial testing is still very much needed. Closed-loop regeneration processes and recyclable frameworks are emerging as industry priorities.
Energy efficiency must be balanced against the environmental impact of material synthesis and disposal.
Future outlook
Looking ahead, AI and computational modeling are being used to optimize synthesis and predict high-performance structures. Hybrid frameworks that blend MOFs and COFs are being explored to enhance durability and functionality.
Applications are also expanding. Besides CO₂ and water harvesting, reticular polymers are being studied for use in eliminating heavy metals, capturing volatile organic compounds (VOCs), and targeted drug delivery. Their modular structure makes them best for a variety of industrial and healthcare uses.
Reticular polymers are redefining the materials science space with their versatility as well as performance. As scalability and commercial applications come to the fore, they are set to become essential tools for climate resilience, sustainable manufacturing, and global water access. Strategic investments in innovation, integration, and responsible use will be important to access their full potential.
This article was originally published in PlasticsToday
