Search

A MXene-based SA-imprinted membrane using cooperative dual-imprinting strategy has been rationally developed to obtain high-selectivity double-layer-based SA-imprinted sites for selective recognition and separation of SA. [Display omitted] Ti 3 C 2 T x (MXene) has attracted extensive attention from scholars at home and abroad due to its rich surface termination functional groups and two-dimensional multilayer structure. In this work, MXene was introduced to the membrane by vacuum-assisted filtration processes, and the formed interlayer channel facilitated the construction of recognition sites and molecular transmission. In this paper, PDA@MXene@PDA@SiO 2 -PVDF dual-imprinted mixed matrix membrane (PMS-DIMs) were developed by the cooperative dual-imprinting strategy, which was used for the adsorption of shikimic acid (SA). Firstly, SiO 2 -PVDF nanofiber basement membrane were prepared by electrospinning method and the first Polydopamine (PDA)-based imprinted layer was constructed on the membrane. PDA not only realized the imprinting process, PDA modification was used to give MXene nanosheets better antioxidant properties and to confer the SiO 2 -PVDF nanofiber membrane the interface stability. After that, the second-imprinted sites were constructed on the stacked MXene nanosheets surface as well as between the layers. The SA dual-imprinted sites significantly increased the efficiency of the selective adsorption efficiency, when the template molecule passed through the membrane, the cooperative dual-imprinting strategy enabled multiplex recognition and adsorption of template molecules. As a consequence, which greatly improving the rebinding ability(262.17 g m−2), and mselectivity factors (β Catechol/SA , β P-HB/SA , β P-NP/SA were 2.34, 4.50 and 5.68). High stability proved the potentials of the PMS-DIMs for practical application. Precise SA-recognition sites were constructed on the PMS-DIMs, PMS-DIMs not only exhibit excellent selective rebinding properties but also have high permeability. [ABSTRACT FROM AUTHOR]

Dual-imprinted GO/TiO 2 -loaded nanocomposite membranes based on polydopamine-based and sol–gel imprinting methods were prepared for selective separation of tetracycline. [Display omitted] Molecularly imprinted membranes (MIMs) with sufficient and even-distributed recognition sites that can break the permeability-selectivity trade-off phenomenon are desirable in chemical field of selective separation. Herein graphene oxide (GO)/TiO 2 -loaded nanocomposite fibrous membranes were prepared by developing two kinds of tetracycline (TC)-imprinted systems in the same MIMs-based material. Thereinto, polydopamine-based and sol–gel-based imprinting processes were applied to the synthesis of GO/TiO 2 -loaded dual-imprinted mixed matrix membranes (GT-DIMs). The as-prepared GT-DIMs encompassed innovative GO/TiO 2 -based nanocomposite fibrous channels and two kinds of TC-imprinted systems, and critical comparisons regarding the fluxes, rebinding capacities and permselectivity were provided and studied. Importantly, dual-imprinted system of GT-DIMs could not only allow for largely enhanced rebinding result (70.63 mg/g) and fast adsorption equilibrium rate within 30 min, but also facilitate the high permselectivity of TC in complex separation systems and lab-simulated wastewater samples. The permselectivity factors were all around 5.0, which strongly demonstrated the efficiently selective recognition and separation performance of GT-DIMs. Overall, based on testing results of practical separation and scalability, excellent structural stability and separation continuity had been successfully obtained for selective separation applications of pollutants. [ABSTRACT FROM AUTHOR]

[Display omitted] • The high-performance MXene nanosheets with stable and tunable lamellar nanochannels were introduced to the polymeric membrane matrix. • As a multifunction hybrid coating, PDA enhances the antioxidant properties and hydrophilicity of the original MXene. • A discontinuous cooperative imprinting strategy is developed to achieve high selectivity. • A lasting adsorption stability was realized. Ti 3 C 2 T x (MXene) has attracted wide research interest for application in various fields due to its rich surface chemistry and 2D multilayer structure. However, its application remains challenging due to its oxidative fragility. Here, Polydopamine (PDA) act as both the functional monomer and crosslinker, could self-polymerize to form a stable multifunction hybrid coating on MXene surfaces, which enhances the antioxidant properties of the MXene while form the first SA-imprinted sites. During the second imprinting process, the PDA-based first SA-imprinted recognition layer acted as the "anchor" to trigger the second SA-imprinted layer (sol–gel boronate affinity imprinting layer). Benefiting from the above mentioned discontinuous cooperative imprinting strategy, an efficient SA dual-imprinted sites was constructed on the surface of MXene-based molecularly imprinted membrane(P-MBMs). Such cooperative imprinting strategy could generate highly specific and strong binding sites for the template molecule. Adsorption isotherm and dynamics, permeation selectivity, and stability were studied, with ideal rebinding ability for SA (363.29 g m−2) and permselectivity factors (β Catechol/SA = 2.40, β P-HB/SA = 5.50, β P-NP/SA = 7.54), respectively. In-situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) analysis revealed that the high selectivity of P-MBMs for SA was mainly realized by the SA dual-imprinted sites constructed on the membrane. In addition, dynamic penetration test was first used to to verify the stability of the P-MBMs to specifically recognize the target molecule in this work. Compared to one-step imprinting approaches, the proposed discontinuous cooperative imprinting strategy would offer precise recognition sites, multiple strengthening of SA-imprinted sites could improve the selective separation performance of P-MBMs. [ABSTRACT FROM AUTHOR]

We present the design and fabrication of high-performance molecularly imprinted membranes (MIMs) using a UiO-66@PDA framework with densely imprinted sites for the targeted adsorption of artemisinin (ATSN). UiO-66@PDA was synthesized by modifying polydopamine with metal-organic frame (MOF) that contain Zr(IV) ions. The unique UiO-66@PDA structure exhibits an excellent specific surface area and strong binding abilities towards ATSN due to the abundant phenolic, quinone, and amino functional groups. The addition of SiO 2 nanoparticles further enhanced the stability of the hybrid membrane during the adsorption process, and the preparation of inorganic-organic hybrid membranes (k-SUPCP-IMs) involves the use of a click chemistry-based imprinted polymer that takes advantage of the heterogeneous structure of the material. This process highlights the importance of different building blocks and functional reactions in controlling the morphology and porosity of porous organic polymers. The results showed satisfactory rebinding ability (40.07 mg g−1) and superselective (β ATMT/ATSN = 7.87, β DDTM/ATSN = 8.26, β ATST/ATSN = 6.40). It was noteworthy that the unique electrostatic interaction between SiO 2 and the imprinted molecules provides optimal conditions for the formation of high-affinity binding sites, thereinto, the creation of additional active sites played a critical role in improving the sensitivity of MIMs. The close combination of porous MOF-based heterojunctions and abundant adsorption sites realizes the synergistic promotion of selectivity and efficient separation of artemisinin. [Display omitted] • The preparation of porous MOF-based heterojunction can improve the solute transport rate and obtain sufficient anchor points. • SiO 2 nanoparticles with a large amount of active -OH ensure the "survival" of the membrane in complex environments. • Excellent light absorbent material provides guarantee for the formation of imprinting sites. • Porous structure and adsorption sites gives advantages in achieving enhanced permeation flux and selectivity. [ABSTRACT FROM AUTHOR]