Synergy between Ionic Capacity and Intrinsic Porosity in Imidazolium-Based Cationic Organic Polymers and Its Effect on Anionic Dye Adsorption

Abstract

A series of novel imidazolium-based cationic organic polymers (COPs) with various ionic capacities (ICs) and porosities were synthesized by adjusting the structure of the building units and applied to the adsorption of organic dyes from aqueous solutions. The charge-incorporated polymer without pores was almost incapable of adsorbing dyes. Among polymers with similar porosities, COPs with higher IC values exhibited higher adsorption capacities, and the polymer with the largest IC but only a surface area of 74.2 m2 g–1 exhibited the best adsorption performance toward Acid Orange 7 (559.4 mg g–1, 21 times that of the uncharged polymer). The results demonstrated the synergistic effect between IC and intrinsic porosity: high porosity was necessary for adsorption, whereas electrostatic interactions between charges and dyes dominate removal efficiency; increasing the charge content is more effective than increasing the surface area in this polymer system. This work provides in-depth insight into the organic-dye adsorption process and a path toward the rational molecular design of high-performance COPs.

Ultrathin Polymer Nanotubes Assembled from Side-Chain Amphiphilic Alternating Azocopolymers for the Potential of Highly-Efficient and Photo-Controllable Dye Removal

“…Organic pollutants, such as highly water-soluble, nondegradable, potentially toxic, and carcinogenic organic dyes, are the primary contaminants in wastewater from industrial production and manufacturing, posing a serious threat to ecosystems and human health. − To address this issue, an effective strategy was to develop desirable absorbents with high adsorption rates and excellent adsorption capacity, requiring unique structural merits of large specific surface areas and abundant functional groups . Hence, numerous substances, including carbon, , zeolites, metal–organic frameworks, covalent organic frameworks, , polymer-based nanocomposites, − ultrathin organic nanomaterials (UTONMs), − etc., have been rationally designed and fabricated to remove organic pollutants from wastewater. Among them, synthetic UTONMs have emerged attractive attention due to their architectural versatility, facile synthesis, low density, and abundant functional groups on the surface. − The introduction of hollow nanostructures and a decrease in the dimension and size of UTONMs are necessary to increase the specific surface area, pollutant binding sites, and subsequent adsorption performance. , Therefore, the development of ultrathin organic nanotube-based absorbents with high absorption rates and controllable adsorption capacity is inevitable, which has rarely been studied so far.…”

Natural Ellagic Acid-Derived Nanoporous Organic Polymers for CO2 and Organic Dye Adsorption

“…Porous organic polymers (POPs) are an emerging class of lightweight robust nanoporous materials constructed from organic monomers via strong covalent bonds. − The tunable pore structure, designable skeletons, and tailored functionality have offered POPs great potential in diverse applications including adsorption/separation, − catalysis, − sensing, − and energy storage. − Over the past few decades, great efforts have been devoted to exploring new functional organic monomers to construct functional POPs for task-specific applications. − However, the functional organic monomers derived from fossil feedstocks are still few and usually expensive because of the complex synthesis routes. Therefore, the exploration of new organic monomers with high functionality and low cost is still highly desirable in the field of POPs.…”