Enhancing the hydroxide conductivity of imidazolium-functionalized polysulfone by incorporating organic microsphere with ionic brushes

Cross-linked quaternized polyethersulfone-amino crystalline nanocellulose composite membrane for enhanced phosphate removal from wastewater

Cross-linked quaternized polyethersulfone (QPES) hybrid mixed polymer membranes (MPMs) loading amino crystalline nanocellulose (ACNC) were successfully fabricated and applied for phosphate removal. The successful production of novel materials was validated by microscopic, spectral, and microanalytical methods. When compared to the native QPES membrane, the primary qualities of QPES hybrid membranes (hydrophilicity, porosity, permeability, antifouling) have been greatly improved overall. In addition, the surface zeta potential (SZP) and ion exchange capacity (IEC) measurements demonstrated the high positive surface charge densities of MPMs, which is beneficial for phosphate uptake. Phosphate adsorption by these membranes was studied at different temperatures, contact times, and initial phosphate concentrations using batch experiments, to investigate the optimal conditions for phosphate uptake. The MPMs showed excellent adsorption capacities with maximal removal capacities in the range of 68.8-87.95 %. Phosphate adsorption on MPMs was regulated primarily by the Sips isotherm model with multilayer adsorption capabilities and exhibited pseudo-second order kinetics (R² = 0.9951-0.9976). The positive ΔH° and ΔS° values are indicative of the endothermic nature of phosphate adsorption and randomness increase. The negative ΔG° value indicates the spontaneousity of phosphate adsorption. Phosphate removal effectiveness of the membranes was maintained following recovery and regeneration with NaOH.

Research Progress in Energy Based on Polyphosphazene Materials in the Past Ten Years

With the rapid development of electronic devices, the corresponding energy storage equipment has also been continuously developed. As important components, including electrodes and diaphragms, in energy storage device and energy storage and conversion devices, they all face huge challenges. Polyphosphazene polymers are widely used in various fields, such as biomedicine, energy storage, etc., due to their unique properties. Due to its unique design variability, adjustable characteristics and high chemical stability, they can solve many related problems of energy storage equipment. They are expected to become a new generation of energy materials. This article briefly introduces the research progress in energy based on polyphosphazene materials in the past ten years, on topics such as fuel cells, solar cells, lithium batteries and supercapacitors, etc. The main focus of this work is on the defects of different types of batteries. Scholars have introduced different functional group modification that solves the corresponding problem, thus increasing the battery performance.

A novel porous hollow carboxyl-polysulfone microsphere for selective removal of cationic dyes

Herein, we obtained porous hollow carboxyl-polysulfone (PH-CPSF) microspheres through non-solvent-induced phase separation (NIPS) method and simple modification, used as highly efficient adsorbents for removing cationic dyes from sewage. The resulting PH-CPSF microspheres possess a hollow core and sponge-like shell structure, with high surface area, durable chemical inertness and structural stability. The as-synthesized PH-CPSF microspheres deliver a desirable adsorption effect after deprotonation treatment, with an adsorption capacity reaching up to 154.5 mg g^-1 at 25 °C (pH = 7) of methylene blue (MB). The inter-molecular interactions between MB and the surface of the PH-CPSF, including π-π interaction, hydrogen bonding, strong charge attraction and weak charge attraction endow the adsorption ability of the PH-CPSF. The pseudo-second-order kinetic model pronounces in the adsorption behavior, and the adsorption equilibrium data is fitted to the Langmuir model. Moreover, PH-CPSF microspheres can also be used as adsorption fillers for large-scale water purification, and a removal rate of 94.0% for MB can be achieved under a flow rate of 8000 L m^-3 h^-1. The reusability of 95.3% removal effect for PH-CPSF microspheres after 20 consecutive cycles can be attained by a simple regeneration treatment. The adsorption efficiency of the PH-CPSF microspheres was evaluated by variety of cationic and anionic dyes, with high adsorption capacity toward cationic dyes (100%) and less than 10% toward anionic dyes. These results manifest that PH-CPSF microspheres are a potential adsorbent with long-term purification capabilities, which are expected to be used in small and large-scale sewage treatment.

Surface-Grafted Polymeric Ionic Liquids with Tunable Morphology via In/Ex Situ Cross-linking Methods

Surface-grafted poly(ionic liquid) (PIL) films were prepared by both in and ex situ cross-linking methods with reversible addition-fragmentation chain transfer (RAFT) polymerization. Cross-linked brushes are more stable than linear brushes without sacrificing the surface functionality and, therefore, have increased potential for applications in biomedicine and materials chemistry. The two methods, in situ via a bifunctional cross-linker and ex situ via thermal cross-linking, were systematically compared on silicon-wafer substrates. Films obtained through in situ cross-linking were superior to films derived from our ex situ cross-linking technique with respect to responsive behavior and controlling the formation of polymer brushes on the surface. Alternatively, more stable layers were obtained by the ex situ cross-linking method using a cross-linker based on Meldrum's acid, where the film structure could be changed from a brush to collapsed film morphologies with an increasing cross-linker ratio.

Quaternized cellulose and graphene oxide crosslinked polyphenylene oxide based anion exchange membrane

Anion exchange membrane fuel cells (AEMFCs) have captivated vast interest due to non-platinum group metal catalysts and fuel flexibility. One of the major shortcomings of AEMFCs, however, is the lack of a stable and high anion conducting membrane. This study introduces a new strategy for fabrication of high conducting anion exchange membrane (AEM) using a hybrid nanocomposite of graphene oxide (GO), cellulose, and poly(phenylene oxide) (PPO), which are functionalized with 1,4-diazabicyclo[2.2.2]octane. The compositional ratio of GO/cellulose/PPO was optimized with respect to ionic conductivity, water uptake, swelling ratio, and mechanical properties. The membrane at GO/cellulose/PPO weight ratio of 1/1/100 displayed an impressive hydroxyl conductivity of ∼114 mS/cm at 25 °C and ∼215 mS/cm at 80 °C, which is considerably higher than the highest value reported. Further, the hybrid composite membranes were mechanically stable even when operating at high temperature (80 °C). The result indicates that the introduction of quaternized GO and cellulose into a polymer matrix is a promising approach for designing high performance AEMs.