Periodic Reporting for period 2 - INDESMOF (International Network on Ionic Liquid Deep Eutectic Solvent Based Metal Organic Frameworks Mixed Matrix Membranes.)
Reporting period: 2020-03-01 to 2023-12-31
The remediation of water pollution, as specially of heavy metal water pollution, is one of the main issues to solve during the XXI century. Heavy metals can enter into the water-ecosystems either natural sources or because of anthropogenic activities as mining, leathering or platting. For example, many places around the world show an acute but natural arsenic contamination of surface and underground waters, as is the case of the north of Chile. In parallel, many industrial or mining activities give rise to a controlled, but continuous, release of heavy metals substances to the environment. (Fig.1).
In a green and circular economy model: i) heavy metals need to be carefully monitored during their extraction and, ii) separated and safely disposed during their use in industry. Also, iii) preventive measurements need to put in place to avoid their entrance into the environment, and finally, iv) if this occurs, remediation actions must be applied to recover them.
Current water treatment technologies fail to retain highly soluble and mobile heavy metals. For that, the development of new membranes able to over-perform the current technology will open the perspective to improve not just the quality of the water used for human consumption, but also the one linked to industries and mines. Thus, the main objective of INDESMOF-RISE action is to improve and exchange interdisciplinary knowledge on membranes and filters based on Metal-Organic Frameworks and Deep Eutectic Solvents. The composite membrane and filtering devices will be applied for the selective capture of heavy metals from different water sources. If INDESMOF action achieves the assembly of tailorable membrane technology, the direct benefits for the society would be evident. First by generating clean drinkable water, and second, by reducing the toxicity and increasing the quality of the surrounding natural environment.
A consortium with such expertise is put together to undertake an integrative and concerted effort to provide the fundamental innovations and breakthroughs that are needed to fabricate and understand the underpinning processes occurring in new sorbent materials, and in the membranes and filters designed from them. In addition, a key goal will be to assemble and shape the active sorbents as filters and membranes able to function efficiently for heavy metals recovery and separation. All these scientific efforts have been complemented with training, communication and dissemination plans that assure the training of young researches, the sharing of knowledge and technology to the scientific community and society, as well as the possibility to translate the project results in patentable technologies.
In a green and circular economy model: i) heavy metals need to be carefully monitored during their extraction and, ii) separated and safely disposed during their use in industry. Also, iii) preventive measurements need to put in place to avoid their entrance into the environment, and finally, iv) if this occurs, remediation actions must be applied to recover them.
Current water treatment technologies fail to retain highly soluble and mobile heavy metals. For that, the development of new membranes able to over-perform the current technology will open the perspective to improve not just the quality of the water used for human consumption, but also the one linked to industries and mines. Thus, the main objective of INDESMOF-RISE action is to improve and exchange interdisciplinary knowledge on membranes and filters based on Metal-Organic Frameworks and Deep Eutectic Solvents. The composite membrane and filtering devices will be applied for the selective capture of heavy metals from different water sources. If INDESMOF action achieves the assembly of tailorable membrane technology, the direct benefits for the society would be evident. First by generating clean drinkable water, and second, by reducing the toxicity and increasing the quality of the surrounding natural environment.
A consortium with such expertise is put together to undertake an integrative and concerted effort to provide the fundamental innovations and breakthroughs that are needed to fabricate and understand the underpinning processes occurring in new sorbent materials, and in the membranes and filters designed from them. In addition, a key goal will be to assemble and shape the active sorbents as filters and membranes able to function efficiently for heavy metals recovery and separation. All these scientific efforts have been complemented with training, communication and dissemination plans that assure the training of young researches, the sharing of knowledge and technology to the scientific community and society, as well as the possibility to translate the project results in patentable technologies.
During INDESMOF, a wide and comprehensive experimental screening for (A) the chemical encoding of already known Metal-Organic Frameworks (MOFs), and (B) the design and synthesis of new MOFs has been carried out. Although the initial INDESMOF proposal intended to explore the chemical modification of MOFs with Ionic Liquids and Deep Eutectic Solvents (DES), we realized that the water stability of these systems preclude their application for water remediation. As a mitigation measure, benchmark MOF sorbents and photocatalysts have been tested for heavy metal selective adsorption and separation and photo-catalysis. In addition, the performance of new MOFs and their multivariate combinations have been tested for adsorption of heavy metals from multi-metallic mixtures.
The active sorbents have been immobilized and shaped as filters and membranes employing natural and synthetic polymers as mechanical and active scaffolds. A myriad of processing techniques has been employed to endow the membranes and filters with different interconnected pore structures. Their assembly as macro, meso and micro porous composites has allowed developing a broad scope filters able to retain efficiently heavy metals, organic dyes, enzymes, proteins and nanoparticles in the same device (Fig. 3). Even more, the photocatalytic performance of the composite systems overperform the light driven oxidative and adsorption of the individual components for arsenic species. Overall, some of the active materials developed within INDESMOF rival and even overperform the capacities to retain arsenic, chromium and mercury of known materials, even when tested in real water matrixes. In addition to this, the consortium has identified dual photoactive-sorbent MOF and MOF/polymer filters/membranes able to oxidize As(III) to As(V), reduce Cr(VI) to Cr(III), and in parallel immobilize them preventing their release to the environment.
The consortium has put in place great efforts to unravel the underpinning mechanisms leading to the MOF structure functionalization, and the posterior adsorption of the heavy metals (Fig. 2). A combined experimental approach has been developed to visualize the chromium and copper speciation within the materials after operation. In addition, small angle and inelastic neutron scattering experiments have been performed to definitively unravel the nanostructure of the composites and the local-structure of adsorption sites. These findings have given us key clues to further improve the initial materials performance.
Today, we still keep testing the best MOF-biopolymer system in continuous flow adsorption conditions with the aim of developing and patenting a water remediation portable cartridge in the coming future.
The active sorbents have been immobilized and shaped as filters and membranes employing natural and synthetic polymers as mechanical and active scaffolds. A myriad of processing techniques has been employed to endow the membranes and filters with different interconnected pore structures. Their assembly as macro, meso and micro porous composites has allowed developing a broad scope filters able to retain efficiently heavy metals, organic dyes, enzymes, proteins and nanoparticles in the same device (Fig. 3). Even more, the photocatalytic performance of the composite systems overperform the light driven oxidative and adsorption of the individual components for arsenic species. Overall, some of the active materials developed within INDESMOF rival and even overperform the capacities to retain arsenic, chromium and mercury of known materials, even when tested in real water matrixes. In addition to this, the consortium has identified dual photoactive-sorbent MOF and MOF/polymer filters/membranes able to oxidize As(III) to As(V), reduce Cr(VI) to Cr(III), and in parallel immobilize them preventing their release to the environment.
The consortium has put in place great efforts to unravel the underpinning mechanisms leading to the MOF structure functionalization, and the posterior adsorption of the heavy metals (Fig. 2). A combined experimental approach has been developed to visualize the chromium and copper speciation within the materials after operation. In addition, small angle and inelastic neutron scattering experiments have been performed to definitively unravel the nanostructure of the composites and the local-structure of adsorption sites. These findings have given us key clues to further improve the initial materials performance.
Today, we still keep testing the best MOF-biopolymer system in continuous flow adsorption conditions with the aim of developing and patenting a water remediation portable cartridge in the coming future.
The straightforward methodologies applied to create and modify MOF materials with metal chelator molecules as dimercaptossucinic acid (i.e. defined by WHO as an essential drug for metal poisoning) have given rise to sorbent materials that rival and even overperform the adsorption capacity previously reported sorbents. Indeed, the toxicity and ecotoxicity of some of the new-MOF materials developed within the action has been already tested confirming a very low to negligible-toxicity. In addition, INDESMOF action has discovered the potentiality of photoactive MOFs to drive the photo-oxidation and posterior immobilization of As(III) to As(V). In that respect, the consortium has proven this technology in real polluted water streams at geographically isolated areas at the north of Chile.
Straightforward methodologies have been implemented to immobilize the sorbents in polymeric supports, confirming that no loss on the properties of the active MOFs occurs during the process. Indeed, the combination of biopolymers and MOFs gives rise to a system that over-perform the adsorption capacity of the average sum of its components.
The consortium has already developed multivariate MOF systems decorated with multiple metal chelator molecules. Applying this concept, we have further tuned the affinity of the active materials to separate efficiently single metal ions from complex multicomponent solutions. In parallel, great efforts have been put in place to unravel the adsorption mechanisms of the developed systems, proposing accurate local structural models. Further, the integration of the MOF into membranes and filters has allowed to obtain portable water-remediation systems. We have already developed in-situ modification protocols of these membranes/filters to dote them of specific adsorptive properties. Today, some partners of the consortium are developing a portable water cartridge system based on the best performing Biopolymer/MOF membranes.
Straightforward methodologies have been implemented to immobilize the sorbents in polymeric supports, confirming that no loss on the properties of the active MOFs occurs during the process. Indeed, the combination of biopolymers and MOFs gives rise to a system that over-perform the adsorption capacity of the average sum of its components.
The consortium has already developed multivariate MOF systems decorated with multiple metal chelator molecules. Applying this concept, we have further tuned the affinity of the active materials to separate efficiently single metal ions from complex multicomponent solutions. In parallel, great efforts have been put in place to unravel the adsorption mechanisms of the developed systems, proposing accurate local structural models. Further, the integration of the MOF into membranes and filters has allowed to obtain portable water-remediation systems. We have already developed in-situ modification protocols of these membranes/filters to dote them of specific adsorptive properties. Today, some partners of the consortium are developing a portable water cartridge system based on the best performing Biopolymer/MOF membranes.