Ion/molecule imprinted polymers with double binding sites via twice imprinting strategy for selective and simultaneous removal of λ-cyhalothrin and Cu(II)

Application Prospect of Ion-Imprinted Polymers in Harmless Treatment of Heavy Metal Wastewater

With the rapid development of industry, the discharge of heavy metal-containing wastewater poses a significant threat to aquatic and terrestrial environments as well as human health. This paper provides a brief introduction to the basic principles of ion-imprinted polymer preparation and focuses on the interaction between template ions and functional monomers. We summarized the current research status on typical heavy metal ions, such as Cu(II), Ni(II), Cd(II), Hg(II), Pb(II), and Cr(VI), as well as metalloid metal ions of the As and Sb classes. Furthermore, it discusses recent advances in multi-ion-imprinted polymers. Finally, the paper addresses the challenges faced by ion-imprinted technology and explores its prospects for application.

Thiourea derivatives acting as functional monomers of As(Ш) molecular imprinted polymers: A theoretical and experimental study on binding mechanisms

Thiourea derivatives are expected to be potential monomers of As(Ш) molecular imprinted polymers (MIPs) which are used to specifically recognize As(Ш). However, the specific recognition and binding mechanisms between template and monomers are unclear, which limits the practical applications of MIPs in As(Ш)detection. In this work, density functional theory (DFT) calculations, molecular dynamics (MD) simulations and experimental methods were jointly applied to explore the binding interactions between H₃AsO₃ and thiourea derivatives and environmental factors influences, aiming to find out the best monomer and optimal preparation conditions for H₃AsO₃ MIPs. Among five monomer candidates, (2, 6-difluorophenyl) thiourea (FT) was calculated to be the most potential one, while allyl thiourea (AT) was the second choice. Configurations of the most stable binding complexes were found out. The optimal solvent was found to be toluene and the bindings were more favorable at pH 7.5 in aqueous solution. Besides, EGDMA was proved as the best cross-linker with the optimal ratio of template: monomer: cross-linker= 2:3:20. Moreover, the binding interactions were identified to be hydrogen bonds, and the non-covalent nature was revealed. These findings provide references for efficient design and preparation of good-performance H₃AsO₃ MIPs, which can be used to detect and remove As(Ш) from environment.

Molecular Imprinting: Green Perspectives and Strategies

Advances in revolutionary technologies pose new challenges for human life; in response to them, global responsibility is pushing modern technologies toward greener pathways. Molecular imprinting technology (MIT) is a multidisciplinary mimic technology simulating the specific binding principle of enzymes to substrates or antigens to antibodies; along with its rapid progress and wide applications, MIT faces the challenge of complying with green sustainable development requirements. With the identification of environmental risks associated with unsustainable MIT, a new aspect of MIT, termed green MIT, has emerged and developed. However, so far, no clear definition has been provided to appraise green MIT. Herein, the implementation process of green chemistry in MIT is demonstrated and a mnemonic device in the form of an acronym, GREENIFICATION, is proposed to present the green MIT principles. The entire greenificated imprinting process is surveyed, including element choice, polymerization implementation, energy input, imprinting strategies, waste treatment, and recovery, as well as the impacts of these processes on operator health and the environment. Moreover, assistance of upgraded instrumentation in deploying greener goals is considered. Finally, future perspectives are presented to provide a more complete picture of the greenificated MIT road map and to pave the way for further development.

Adsorption of Cd2+ by an ion-imprinted thiol-functionalized polymer in competition with heavy metal ions and organic acids

The simultaneous presence of heavy metals and organic acids in nature and wastewaters and their competition for adsorption sites determine the migration, transformation and fate of pollutants in the environment. A Cd²⁺-ion-imprinted polymer (Cd²⁺-IIP) with a thiol-functional group was hydrothermally synthesized by a surface imprinting technique combined with ultrasonic heating for selective adsorption of Cd²⁺ from wastewaters. The adsorbent was characterized by SEM, EDS, XPS, BET and FT-IR measurements. The experimental results concerning Cd²⁺ adsorption from single-, binary-, ternary- and quaternary-metal aqueous solutions containing Cu²⁺, Ni²⁺ and Zn²⁺ revealed high selectivity. In binary-metal solutions, relative selectivity coefficients for Cd²⁺ in respect to Cd²⁺/Cu²⁺, Cd²⁺/Ni²⁺, and Cd²⁺/Zn²⁺ were as high as 3.74, 5.73 and 4.15, respectively. In multi-metal solutions, competing heavy metal ions had little effect on the adsorption of Cd²⁺ attributed to the high selectivity of Cd²⁺-IIP towards Cd²⁺ determined by its coordination geometry. The effect of low-molecular weight organic acids on the Cd²⁺ adsorption was also studied and the results showed that the presence of tartaric, citric and oxalic acids as admixtures in Cd²⁺ aqueous solutions noticeably reduced the cation adsorption in a wide range of concentrations with the minor exception of low contents of citric and tartaric acids slightly improving adsorption.

A Cd²⁺-imprinted thiol-functionalized polymer in competition with heavy metal ions and low molecular weight organic acids was investigated.

Molecularly imprinted polymers fabricated using Janus particle-stabilized Pickering emulsions and charged monomer polymerization

Janus particle-stabilized Pickering emulsions and their applications in protein interfacial imprinting.