A new synthesis method for organic-inorganic hybrid Poly(vinylidene fluoride)-SiO2 cation-change membranes (CEMs) is proposed. This method involves mixing tetraethyl orthosilicate (TEOS) and 3-mercapto-propyl-triethoxy-silane (MPTES) into a polyvinylidene fluoride (PVDF) sol-gel solution. The resulting slurry was used to prepare films, which were immersed in 0.01 M HCl, which caused hydrolysis and polycondensation between the MPTES and TEOS. The resulting Si-O-Si polymers chains intertwined and/or penetrated the PVDF skeleton, significantly improving the mechanical strength of the resulting hybrid PVDF-SiO2 CEMs. The -SH functional groups of MPTES oxidized to-SO3H, which contributed to the excellent permeability of these CEMs. The surface morphology, hybrid structure, oxidative stability, and physicochemical properties (IEC, water uptake, membrane resistance, membrane potential, transport number, and selective permittivity) of the CEMs obtained in this work were characterized using scanning electron microscope and Fourier transform infrared spectroscopy, as well as electrochemical testing. Tests to analyze the oxidative stability, water uptake, membrane potential, and selective permeability were also performed. Our organic-inorganic hybrid PVDF-SiO2 CEMs demonstrated higher oxidative stability and lower resistance than commercial Ionsep-HC-C membranes with a hydrocarbon structure. Thus, the synthesis method described in this work is very promising for the production of very efficient CEMs. In addition, the physical and electrochemical properties of the PVDF-SiO2 CEMs are comparable to the Ionsep-HC-C membranes. The electrolysis of the concentrated CoCl2 solution performed using PVDF-SiO2-6 and Ionsep-HC-C CEMs showed that at the same current density, Co2+ production, and current efficiency of the PVDF-SiO2-6 CEM membrane were slightly higher than those obtained using the Ionsep-HC-C membrane. Therefore, our novel membrane might be suitable for the recovery of cobalt from concentrated CoCl2 solutions.
Abstract Room temperature phosphorescent (RTP) materials have triggered wide interests because of their excellent performance and various promising applications. However, conventional RTP materials possessing color‐tunable and ultralong afterglow often suffer from low phosphorescent emission efficiency. Herein, a long lifetime and high‐efficiency RTP emission system composed of boric acid as the host matrix and organic phosphors as guest molecules is constructed by suppressing the non‐radiative transition process and promoting the triplet exciton of the phosphors. The synergistic effect of the physically limited domain and supramolecular anchoring also contributes to the ultralong lifetime (up to 1.85 s) and high phosphorescence quantum yield (up to 53%). The afterglow can be visually observed for 30 s. With a large overlap of π ‐conjugated chromophores, the emission peak of RTP redshifted, realizing cyan, green, and red afterglow in the monochromatic domain. In addition, the emission of colorful afterglow and white afterglow is adjustable with the different co‐doping ratios. Finally, the application of RTP materials to anti‐counterfeiting encryption is demonstrated.
The BA@Fluo can achieve dual-mode emission of RTP and TADF, and colorful afterglow can be achieved under temperature regulation. Particularly, BA@Fluo was characterized by fluorescence discoloration, and increased quantum yield caused by grinding.
The citric acid (CA) cross-linked polyvinyl alcohol (PVA) adsorbent, PVA–CA, was efficiently synthesized and its application to the removal of dyes in water, particularly the cationic dye, methylene blue (MB), was thoroughly investigated. The morphologies and physiochemical characteristics of PVA–CA were fully characterized by SEM, FT-IR, XRD, TGA, BET, and XPS. The effects of contact time, adsorbent dosage, MB concentration, solution pH, and temperature on the adsorption performance were compared using controllable methods. The maximum adsorption capacity of PVA–CA was 709.86 mg g−1 and the removal rate remained high through several adsorption–desorption cycles, demonstrating that such a composite absorbent has a good adsorption performance and recoverability. Further analysis by the density functional theory (DFT) showed that van der Waals interactions, electrostatic interactions and hydrogen bonding interactions between PVA–CA and MB played significant roles in the adsorption mechanism.
A new Cs-γ-CD-MOF material obtained in colourless large crystals and with a three-dimensional porous structure containing coordinated by cesium ions and γ-cyclodextrin was synthesised by an improved vapour diffusion method. The chemical formula of the Cs-γ-CD-MOF material was C24H34CsO20, with the I4 space group. Compared with the traditional solvent vapour diffusion method (7 days), this method is advantageous for rapid crystal formation (1 day). Simultaneously, the drug adsortion capacity of γ-CD and Cs-γ-CD-MOFs for myricetin was compared and the results indicated that Cs-γ-CD-MOFs (280.05 mg g−1) have a higher drug adsorption capacity than γ-CD (142.92 mg g−1). Finally, the energy and conformation of the Cs-γ-CD-MOF material for adsorbing the drug myricetin were obtained through molecular docking.
The investigation of ferroelectric materials is an important aspect of condensed matter physics. Compared to the traditional inorganic ferroelectric ones, organic ferroelectric materials possess unique advantages, including light weight, scalability, flexibility, and solvent treatability. However, the study of organic ferroelectric materials is still in its infancy, especially from the view of supramolecular chemistry; various mechanisms of forming self-assembly and thus diverse building blocks employed are not yet to be further developed. Herein, a pillararene-based charge transfer (CT) self-assembly was produced by utilizing pillar[5]quinone (P5Q) as the electron acceptor and phenothiazine (PTZ) as the electron donor. Compared to the intrinsic P5Q, our fabricated donor–acceptor complex displays particular intriguing features, such as the enhanced second-harmonic generation and ferroelectric responses, benefiting from the CT interaction between P5Q and PTZ. The current work provides a unique strategy for the successful construction of supramolecular ferroelectrics.
Citric acid (CA)-based polymeric adsorbent materials were fully characterized and analyzed for the adsorption treatment of methylene blue (MB). Also, the effects of various factors on their performance were thoroughly examined.
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