Metal-Organic Frameworks (MOFs) for Carbon Capture in Green Concrete & Cement Applications

MOFs and the value-add for green cement / concrete:

Metal-Organic Frameworks (MOFs) are a class of materials that consist of metal ions or clusters coordinated to organic ligands to form one-, two-, or three-dimensional structures. MOFs offer immense flexibility in their chemical composition (being synthesized using different metals like Al, Cu, Zn and organic linkers), thereby allowing for the creation of highly specialized sustainable materials with improved characteristics. This chemical versatility exhibited by MOFs make them highly useful for various green concrete and green cement applications, thereby optimizing their CO2 capture, catalytic activity and integration into concrete matrices.

Viva Bio MOFs offer significant value-add for green concrete applications from capturing and utilizing CO2 to enhancing the strength, durability and sustainability of the concrete, resulting in minimized carbon emissions and promotion of eco-friendly construction practices due to their characteristic features:

Large surface area: MOFs possess high surface area making them highly efficient in sequestering CO2 during the production of green concrete, which later can be harnessed in processes such as CO2 curing wherein the CO2 gas is incorporated into the concrete matrix in order to improve its strength and minimize carbon footprint.

• High CO2 adsorption capacity: MOFs prove to be suitable candidates over the traditional materials like zeolites or activated carbon for green concrete applications due to their high CO2 adsorption capacity. The captured CO2 by MOFs from various cement manufacturing processes allows for a more sustainable approach in minimizing the greenhouse gas emissions and hence, reducing the material’s carbon footprint.

• Tuneable pore size and selectivity: MOFs being highly porous structures enables for precise control over the molecules that can pass through or be captured. They exhibit the tendency to selectively capture CO2 even in the presence of other gases like N2 or water vapor, making them ideal for various carbon capture applications. This selectivity shown by MOFs results in more efficient utilization of captured CO2 in concrete curing process, thereby resulting in overall efficiency and performance.

• Catalytic Properties: MOFs act as heterogeneous catalysts wherein their catalytic activity can be utilized for accelerating the carbonation process in green concrete production. This facilitates the efficiency of CO2 utilization, which strengthens the concrete while minimizing the net carbon emissions.

• Reusability and regenerability: MOFs can undergo multiple adsorption-desorption cycles without any significant degradation in their performance making them ideal for continuous industrial applications like cement production. This aids in minimizing the need for frequent replacements, thereby improving the economics and sustainability of green concrete production.

• Lightweight and low density: When compared to the traditional carbon capture materials, MOFs being lightweight (having low density) allows to get incorporated into concrete formulations (without any significant increase in the weight of the material) which is essential for maintaining the structural integrity of the green concrete.

• Structural flexibility: MOFs exhibit a degree of structural flexibility which allows them to adapt to varying conditions making them ideal for dynamic environments like cement plants, where fluctuations in temperature, pressure, gas composition etc. are common. Hence, their breathing behaviour makes them suitable for various dynamic industrial processes.

• Long-term stability: MOFs being chemically stable under harsh conditions allows them to withstand the demanding environment of concrete curing and production processes such as exposure to varying pH levels, temperature fluctuations and moisture, thereby making them reliable for continuous use in green concrete production.

• Modularity and scalability: Lastly, the scalable production methods for MOFs make them ideal for large-scale industrial applications like cement plants where carbon capture needs to be efficient and economically viable.

Key Features of MOFs:

Some of the key features exhibited by metal-organic frameworks (MOFs) which aids in enhancing the sustainability, performance and environment friendliness of cement thereby making them suitable for green cement applications are as follows:

Tuneable Structures: The tuneable nature of MOFs allows for the customization of their interactions with the cement matrix to enhance the mechanical properties like compressive strength, flexural strength and toughness. Several adjustments in the pore structure of MOFs also aids in regulating the moisture transport and improve cement curing and hydration processes, resulting in longer-lasting more resilient cement.

Large surface area and porosity: The high surface area of MOFs allows them to absorb CO2 gas during cement production, improve water retention and curing conditions for cement resulting in enhanced durability.

Environmental Sustainability: MOFs designed using sustainable precursors (eco friendly, renewable and cheap materials) contribute in minimizing the carbon footprint of cement.

Gas adsorption and CO2 sequestration: MOFs with the ability to selectively adsorb gases particularly CO2 helps in potentially creating cement that not only produces less CO2 but also actively absorbs CO2 from the environment over time, thus playing a significant role in carbon sequestration process.

Self-healing capabilities: MOFs can be designed in such a way that they can act as carriers for self-healing agents like encapsulated water, chemicals, or minerals. This helps in repairing microcracks in cement autonomously, thereby enhancing the lifespan of cement structures and reducing the consumption of resources over the lifecycle of the cement.

Thermal stability: Zr-based MOFs with high thermal stability can be employed for green cement applications as thermal stability is crucial for cement exposed to high temperatures during production requiring fire resistance. Thus, MOFs improve the thermal performance of cement making them suitable for high-temperature environments.

Improved mechanical properties: MOFs can reinforce the cement matrix by filling micro-voids and interacting with cement components at the molecular level, leading to higher durability and load-hearing capacity as well as enhancing the mechanical strength of the cement.

Moisture regulation: MOFs possess the ability to control moisture absorption and release essential for avoiding shrinkage cracks and for enhancing the overall durability as well as long-term stability of the cement.

Lightweight nature: The lightweight nature of the MOFs aids in the development of the lighter cement composites, reducing the material’s weight while enhancing its mechanical properties. This is useful for applications like precast concrete or in areas requiring weight reduction for structural efficiency.

Chemical resistance: MOFs with high resistance towards chemical degradation in acidic or alkaline environments is essential for improving the cement’s performance in harsh conditions like marine environments or in contact with chemicals making them more durable and long-lasting.

Examples of Viva Bio MOFs for green concrete and green cement applications:

Metal-organic frameworks (MOFs) spanning different families with diverse chemical and physical properties can be effectively employed for the enhancement of green concrete as well as green cement in terms of mechanical strength, durability, sustainability and reduced carbon footprint.

Zeolitic Imidazolate Frameworks (e.g. ZIF-8) with high chemical stability and excellent mechanical strength can be efficiently employed to enhance thermal insulation, assist in moisture control and improve the durability of concrete and cement.

The eco-friendly nature of amino acid -based MOFs (e.g. MOFs with 2 aminoterephthalate (BDC-NH2) and other such linkers) are ideal for sustainable construction materials in order to minimize the carbon footprint of concrete production. Bio-MOF-100 (Zn4O(BDC-NH2)3) incorporates amino acids in its structure which enhances its biodegradability and its porosity can be further tuned for CO2 capture. At the same time, such MOFs enhance the sustainability of cement by reducing the carbon footprint and providing controlled gas adsorption.

Carboxylate-based MOFs like UiO-66, UiO-67 etc. can be utilized due to their excellent stability under harsh conditions making them ideal for concrete reinforcement and their water adsorption/desorption capacity aids in controlling moisture which is essential for self-healing concrete as well as contribute to CO2 capture during the curing process making it a suitable candidate for green cement.

Porphyrin-based MOFs such as M-TCPP (where M are different transition metal ions like Zn, Cu, Fe, Co etc. and TCPP is tetra(4-carboxyphenyl)porphyrin) with large surface area and high stability find potential in the development of energy-efficient concrete that effectively interacts with light which aids in self-cleaning or catalytic functions within concrete or the cement thereby minimizing the environmental pollutants and enhancing sustainability.

Phosphonate-based MOFs like MIL-91(Al) etc. with high thermal and chemical stability can be utilized in environments where heat resistance is crucial making them ideal for fire-resistant concrete applications. These MOFs also increase the thermal stability and the chemical resistance of the cement, extending the lifespan of structures and contributing to sustainability.

HKUST-1 (Cu-BTC) with a paddlewheel structure having high porosity can be utilized for capturing CO2 in concrete and cement curing processes, minimizing emissions and enhancing the environmental sustainability of the material.

Who is Viva Bio?

Viva Bio develops biotechnology solutions to solve the high mortality rate problems harming the global population. Our initial developments include a drug-delivery system with uses in targeted cancer drug delivery as well as opioid overdose intervention. Along the way, we have developed hundreds of MOF compounds which can provide substantial value to the Carbon Capture industry. Viva Bio would like to license these compounds to your business and can also develop custom compounds to suite your Carbon Capture needs and help you expand the potential Carbon Capture markets!

Contact Viva Bio: (203)-219-8878 david@vivabiotechnology.com www.vivabiotechnology.com