π-π stack driven competitive /complementary adsorption of aromatic compounds on MIL-53(Al)

Eco-Friendly and Low-Cost Synthesis of Transparent Antiviral- and Antibacterial-Coated Films Based on Cu2O and MIL-53(Al)

This research presents the development of an innovative antimicrobial coating consisting of cuprous oxide (Cu2O) integrated with the metal-organic framework MIL-53(Al) through an eco-friendly and low-cost synthesis method that employs glucose as a reducing agent under mild conditions. The microstructural properties of the composite materials were characterized by using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The antibacterial efficacy of the Cu2O-MIL-53(Al) (CuM) composite was assessed against Escherichia coli and Staphylococcus aureus, achieving a reduction efficacy of 99.99% with 5% copper incorporated into the MIL-53(Al) framework within a contact time of 24 h. The incorporation of CuM into a macromolecular host matrix of polyurethane-carboxymethylcellulose (CuM/PUD-CMC), applied as a coating on a low-cost plastic film, produced a transparent film with 87.10% transparency. This coating demonstrated a 99.99% reduction in E. coli and S. aureus populations within a contact time of 24 h. The CuM/PUD-CMC coating demonstrated substantial antiviral efficacy, achieving inactivation rates of 99.35% for Human Coronavirus 229E, 99.40% for Influenza A virus, and 97.76% for Enterovirus 71 within a contact time of 5 min. The CuM nanoparticles exhibited low toxicity toward zebrafish while effectively eradicating bacteria and inactivating viruses. The proposed low-cost material and coating method demonstrate significant potential as a broad-spectrum antimicrobial and antiviral agent, highlighting its suitability for various applications in biomedical and healthcare formulations.

Green synthesis of magnetic azo-linked porous organic polymers with recyclable properties for enhanced Bisphenol-A adsorption from aqueous solutions

Porous organic polymers (POPs) present superior adsorption performance to steroid endocrine disruptors. However, the effective recovery and high cost have been a big limitation for their large-scale applications. Herein, magnetic azo-linked porous polymers (Fe3O4@SiO2/ALP-p) were designed and prepared in a green synthesis approach using low-price materials from phloroglucinol and pararosaniline via a diazo-coupling reaction under standard temperature and pressure conditions, which embedded with Fe3O4@SiO2 nanoparticles to form three-dimensional interlayer network structure with flexible-rigid interweaving. The saturated adsorption capacity to bisphenol-A (BPA) was 485.09 mg/g at 298 K, which increased by 1.4 times compared with ALP-p of relatively smaller mass density. This enhanced adsorption was ascribed to increment from surface adsorption and pore filling with 2.3 times of specific surface area and 2.6 times of pore volume, although the total organic functional groups decreased with Fe3O4@SiO2 amendment. Also, the adsorption rate increased by about 1.1 and 1.5-fold due to enhancement in the initial stage of surface adsorption and subsequent stage pore diffusion, respectively. Moreover, this adsorbent could be used in broad pH (3.0-7.0) and salinity adaptability (<0.5 mol/L). The loss of adsorption capacity and magnetic recovery were lower than 1.1% and 0.8% in each operation cycle because of the flexible-rigid interweave. This excellent performance was contributed by synergistic effects from physisorption and chemisorption, such as pore filling, electrostatic attraction, π-π stacking, hydrogen bonding, and hydrophobic interaction. This study offered a cost-effective, high-performing, and ecologically friendly material along with a green preparation method.

Characterization of an Iron-Copper Bimetallic Metal-Organic Framework for Adsorption of Methyl Orange in Aqueous Solution

Iron-based organic frame material MIL-53 (Fe) was synthesized by the hydrothermal method with Cu2+ incorporated to obtain bimetallic composite MIL-53 (Fe, Cu). The structure and morphology of the material were characterized by SEM, XRD, BET, FTIR, XPS, and zeta potential. The adsorption performance of MIL-53 (Fe, Cu) on methyl orange was tested under a variety of conditions, including the effects of pH and material dosage, by the static adsorption test. The results show that under the condition of pH = 7, a temperature of 30°C, and an adsorbent dosage of 20 mg, the removal rate of MIL-53 (Fe, Cu) for methyl orange can reach more than 96% within 4 h, and the maximum adsorption capacity after fitting by the thermodynamic model can reach 294.43 mg/g, showing the excellent adsorption performance of MIL-53 (Fe, Cu) on methyl orange. In addition, by exploring the adsorption mechanism of MIL-53 (Fe, Cu) on methyl orange, it is found that the adsorption of MIL-53 (Fe, Cu) on methyl orange depends on chemical adsorption, as evidenced by combining Fe3+ and Cu2+ in the material with methyl orange molecules to form complexes to achieve adsorption. While the specific surface area of the material had no obvious effect on adsorption, the effects of pH, temperature, and concentration were explored. At a pH of 6.5, greater adsorption occurred at higher temperatures, as determined by thermodynamic model fitting, as well as with higher initial methyl orange molecule concentration.