Tailored Porous Organic Polymers for Task-Specific Water Purification

Abstract

Conspectus The Industrial Revolution has resulted in social and economic improvements, but unfortunately, with the development of manufacturing and mining, water sources have been pervaded with contaminants, putting Earth’s freshwater supply in peril. Therefore, the segregation of pollutantssuch as radionuclides, heavy metals, and oil spillsfrom water streams, has become a pertinent problem. Attempts have been made to extract these pollutants through chemical precipitation, sorbents, and membranes. The limitations of the current remediation methods, including the generation of a considerable volume of chemical sludge as well as low uptake capacity and/or selectivity, actuate the need for materials innovation. These insufficiencies have provoked our interest in the exploration of porous organic polymers (POPs) for water treatment. This category of porous material has been at the forefront of materials research due to its modular nature, i.e., its tunable functionality and tailorable porosity. Compared to other materials, the practicality of POPs comes from their purely organic composition, which lends to their stability and ease of synthesis. The potential of using POPs as a design platform for solid extractors is closely associated with the ease with which their pore space can be functionalized with high densities of strong adsorption sites, resulting in a material that retains its robustness while providing specified interactions depending on the contaminant of choice. POPs raise opportunities to improve current or enable new technologies to achieve safer water. In this Account, we describe some of our efforts toward the exploitation of the unique properties of POPs for improving water purification by answering key questions and proposing research opportunities. The design strategies and principles involved for functionalizing POPs include the following: increasing the density and flexibility of the chelator to enhance their cooperation, introducing the secondary sphere modifiers to reinforce the primary binding, and enforcing the orientation of the ligands in the pore channel to increase the accessibility and cooperation of the functionalities. For each strategy, we first describe its chemical basis, followed by presenting examples that convey the underlying concepts, giving rise to functional materials that are beyond the traditional ones, as demonstrated by radionuclide sequestration, heavy metal decontamination, and oil-spill cleanup. Our endeavors to explore the applicability of POPs to deal with these high-priority contaminants are expected to impact personal consumer water purifiers, industrial wastewater management systems, and nuclear waste management. In our view, more exciting will be new applications and new examples of the functionalization strategies made by creatively merging the strategies mentioned above, enabling increasingly selective binding and efficiency and ultimately promoting POPs for practical applications to enhance water security.

De novo synthesis of bifunctional conjugated microporous polymers for synergistic coordination mediated uranium entrapment

“…Moreover, the well-folded skeletons of CMPs are similar to natural protein scaffolds that have evolved over millennia to chelate specific metal ions with high selectivity [22]. These intriguing properties endow CMPs with great potential to be engineered as highefficiency separation materials for entrapment of heavy metal ions [23].…”

Precisely Controlled Multidimensional Covalent Frameworks: Polymerization of Supramolecular Colloids

“…The construction of nano‐ or mesoporous structures with special functionalities and persistent shapes is a major goal for removing pollutants due to economic and environmental concerns [1–7] . Based on the morphological architectures, 2D flat frameworks are favorable for accomplishing this goal since they can provide high accessible surface area [8–11] . However, pollutants with different shapes require the bended architectures for strong surface interactions [12–13] .…”

“…[1][2][3][4][5][6][7] Based on the morphological architectures, 2D flat frameworks are favorable for accomplishing this goal since they can provide high accessible surface area. [8][9][10][11] However, pollutants with different shapes require the bended architectures for strong surface interactions. [12][13] Although well-ordered or disordered porous materials, like porous silica, [14][15] metal-organic frameworks (MOFs), [16][17] and covalent organic frameworks (COFs) [18][19][20] with various shapes such as fibers, sheets, cubes, and spheres have been successfully employed for pollutant extraction and preconcentration, [21] the curved porous structure generated from random crystallization of preconstructed bulky porous mate-rials based on the noncovalent interaction exhibits several deficiencies including lack of long-term stability as well as low recyclability.…”

A neutral porous organic polymer host for the recognition of anionic dyes in water

“…have been used previously for binding a range of molecules and ions in water. [50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67] To test our approach, here we have prepared Urea-POP-1, a urea-functionalized POP host. Urea is commonly used as a neutral hydrogen bond donor that effectively provides parallel hydrogen bonds to cooperatively bind electron rich oxyanions to offset the energetic penalty of desolvation.…”