Dynamic Nanoparticle Networks (DNNs) as Tunable Platforms for Regenerable Water Purification Systems

The global availability of clean drinking water has reached crisis levels especially in under-developed parts of the world with an estimated 844 million people lacking access to safe drinking water. Novel, sustainable approaches to water purification are now critical to combat this global issue. Traditionally, natural raw water is processed to decrease the concentration of natural and man-made pollutants to legal limits at centralized municipal plants, at private well sources and/or by the users at the point-of-use. Both centralized and point-of-use treatment rely on same physicochemical principles to remove suspended and soluble constituents of the pollutants. One of the main premises of water treatment is concentrating pollutants on highly charged, high surface area solid surfaces (e.g., activated carbon, membrane, ion exchange resin). Since these sorptive materials have a certain removal capacity, they exhaust their treatment ability in time. However, regeneration and reuse can provide a green approach to minimize the cost and environmental impact of water treatment. The overarching objective of this project is to develop dynamically crosslinked, polymer nanoparticle networks for applications as water purification adsorbent materials that can be effectively regenerated using network dissociation and reformation.

The described synthetic approach combines photo-controlled atom transfer radical polymerization induced self-assembly (PhotoATR-PISA) with alkyne functional initiators and copper-catalyzed “click” chemistry with dynamic covalent (DC), bis-azide crosslinkers to form Dynamic Nanoparticle Networks (DNNs). Furthermore, PhotoATR-PISA with disulfide functional initiators results in in situ fabrication of DNNs with multi-responsive disulfide crosslinks between nanoparticles. These DNN adsorbent materials are inherently tunable in nanostructured morphologies (via altering molecular weight in PISA synthesis), chemical composition (through core modification of nanoparticles) and dynamicity (through utilization of different DC bonds) providing a divergent synthetic approach for forming regenerable adsorbent materials. These various factors will be studied systematically to not only investigate the overall regeneration capabilities of the described adsorbent materials but also the potential for chemically-targeted adsorption of high-priority pollutants through targeted intermolecular interactions. Furthermore, we plan to investigate different types of regeneration mechanisms via installation of different DC bonding groups for low temperature thermal regeneration in boiling water (via dynamic Diels-Alder reactions of furans and maleimides and disulfide exchange) and UV-regeneration (via dynamic coumarin dimerization reactions).


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For questions or to get more information please contact: James Reuther by email: james_reuther@uml.edu.

Schematic of point-of-use water filter concept: Dynamic Nanoparticle Networks that undergo reversable crosslinking to trap pollutants can be regenerated for repeated use. Scanning Electron Microscopy images of the nanoparticles in three forms: spheres, worms, and vesicles.

Schematic of point-of-use water filter concept: Dynamic Nanoparticle Networks that undergo reversable crosslinking to trap pollutants can be regenerated for repeated use. Scanning Electron Microscopy images of the nanoparticles in three forms: spheres, worms, and vesicles.