Synthesis and characterization of ZnS/CuFe2O4 Magnetic hybrid nanocatalyst and its application in the synthesis of 2-amino-3-cyano-4H-pyran derivatives

The ZnS/CuFe2O4 magnetic hybrid nanocatalyst was synthesized for the first time by a simple procedure. Investigation and characterization of this catalyst were carried out using energy-dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) analyses. Synthetic nanoparticles were used as a magnetic and heterogeneous catalyst for the one-pot synthesis of 2-amino-3-cyano-4H-pyran derivatives with condensation of dimedone, aromatic aldehydes and malononitrile in ethanol at room temperature. The reported method has advantages such as mild conditions, good yields, simple separation of products from the reaction mixture and the use of biocompatible solvent and inexpensive catalyst. Nanocatalyst ZnS/CuFe2O4 was easily separated from the reaction using an external magnetic field and reused several times in reactions without appreciable reduction in catalytic activity

Molecularly Imprinted Magnetic Nanocomposite Based on Carboxymethyl Dextrin for Removal of Ciprofloxacin Antibiotic from Contaminated Water

Broad-spectrum antibiotics from the fluoroquinolone family have emerged as prominent water contaminants, among other pharmaceutical pollutants. In the present study, an antibacterial magnetic molecularly imprinted polymer (MMIP) composite was successfully fabricated using carboxy methyl dextrin grafted to poly(aniline-co-meta-phenylenediamine) in the presence of Fe3O4/CuO nanoparticles and ciprofloxacin antibiotic. The characteristics of obtained materials were investigated using FTIR, XRD, VSM, TGA, EDX, FE-SEM, zeta potential, and BETanalyses. Afterward, the MMIP’s antibacterial activity and adsorption effectiveness for removing ciprofloxacin from aqueous solutions were explored. The results of the antibacterial tests showed that MMIP had an antibacterial effect against Escherichia coli, a Gram-negative pathogen (16 mm), and Staphylococcus aureus, a Gram-positive pathogen (22 mm). Adsorption efficacy was evaluated under a variety of experimental conditions, including solution pH, adsorbent dosage, contact time, and initial concentration. The maximum adsorption capacity (Qmax) of the MMIP for ciprofloxacin was determined to be 1111.1 mg/g using 3 mg of MMIP, with an initial concentration of 400 mg/L of ciprofloxacin at pH 7, within 15 min, and agitated at 25 °C, and the experimental adsorption results were well-described by the Freundlich isotherm model. The adsorption kinetic data were well represented by the pseudo-second-order model. Electrostatic interaction, cation exchange, π-π interactions, and hydrogen bonding were mostly able to adsorb the majority of the ciprofloxacin onto the MMIP. Adsorption–desorption experiments revealed that the MMIP could be retrieved and reused with no noticeable reduction in adsorption efficacy after three consecutive cycles

Neomycin antibiotic removal by antimicrobial nanobiosorbent based on sodium alginate-grafted-poly(3-aminophenol)/silver-decorated metal-organic frameworks

Antibiotics, widely used in human and animal medicine, pose a significant threat to water quality due to their persistent presence even after use. Their insolubility in water and resistance to conventional removal methods exacerbate their environmental impact. This study aimed to develop an antimicrobial composite, alginate-grafted-poly(3-aminophenol)/silver-decorated metal-organic framework (SA-g-P3AP@MOF(Fe)/Ag) via an in-situ copolymerization technique. This composite proved effective in removing neomycin from contaminated water. Characterization via FTIR, XRD, BET, and TGA analyses confirmed the composite's structure and properties. Under optimized conditions (pH = 7, 30-minute contact time, 5 mg adsorbent amount, 25 °C temperature, and 700 mg/L pollutant concentration), the composite removed 87 % of neomycin from water samples. The interaction between neomycin and the composite aligned with the Freundlich isotherm, exhibiting a maximum adsorption capacity (Qmax) of 625 mg/g, and adhered to the pseudo-second-order kinetic. Thermodynamic analysis indicated the exothermic and spontaneous nature of neomycin adsorption onto the synthesized composite. The proposed adsorption mechanism centered on intermolecular interactions between amine, alcohol, and imine functional groups of the SA-g-P3AP@MOF(Fe)/Ag and neomycin antibiotic. The incorporation of MOF(Fe)/Ag with its highly porous structure significantly bolstered neomycin adsorption, enhancing the antibacterial effectiveness of SA-g-P3AP@MOF(Fe)/Ag

Preparation of antimicrobial composite from Arabic gum-grafted-poly(p-phenylene diamine)/MOF(Fe) decorated with Cu nanoparticles as a unique nanobiosorbent for removal of cloxacillin antibiotic

The growth of the world population has led to an increase in the demand for fresh water. Water pollution is often caused by hasty urbanization without proper management of hazardous waste. Therefore, it is vital to implement new methods to remove pollutants from water. In the current study, an antimicrobial nanocomposite adsorbent composed of Arabic gum-grafted-poly(para phenylene diamine) (AG-g-PpPA) decorated with metal-organic framework and copper nanoparticles (AG-g-PpPA@MOF(Fe)/Cu) was synthesized via in-situ copolymerization. The nanocomposite was utilized for eliminating the antibiotic cloxacillin from water solutions. The effects of different factors were analyzed, including pH, the quantity of adsorbent, contact time, and preliminary cloxacillin concentrations. Ideal parameters were pH 7, 5 mg adsorbent dosage, 10 min contact time, and an initial 500 mg/L cloxacillin concentration. The adsorption process followed the Freundlich isotherm equation, with a maximum adsorption ability of 400 mg/g. The kinetics information appropriately fits a pseudo-second-order model. Thermodynamic calculation showed the adsorption occurred spontaneously. The nanocomposite also displayed antibacterial action in contradiction to Escherichia coli and Staphylococcus aureus. Additionally, the adsorbent could be recovered and reused effectively. The excellent adsorption ability highlights the potential of AG-g-PpPA@MOF(Fe)/Cu adsorbent for eliminating pharmaceutical pollutants from wastewater

Enhancement of adsorption efficiency of crystal violet and chlorpyrifos onto pectin hydrogel@Fe3O4-bentonite as a versatile nanoadsorbent

Abstract The magnetic mesoporous hydrogel-based nanoadsornet was prepared by adding the ex situ prepared Fe3O4 magnetic nanoparticles (MNPs) and bentonite clay into the three-dimentional (3D) cross-linked pectin hydrogel substrate for the adsorption of organophosphorus chlorpyrifos (CPF) pesticide and crystal violet (CV) organic dye. Different analytical methods were utilized to confirm the structural features. Based on the obtained data, the zeta potential of the nanoadsorbent in deionized water with a pH of 7 was − 34.1 mV, and the surface area was measured to be 68.90 m2/g. The prepared hydrogel nanoadsorbent novelty owes to possessing a reactive functional group containing a heteroatom, a porous and cross-linked structure that aids convenient contaminants molecules diffusion and interactions between the nanoadsorbent and contaminants, viz., CPF and CV. The main driving forces in the adsorption by the Pectin hydrogel@Fe3O4-bentonite adsorbent are electrostatic and hydrogen-bond interactions, which resulted in a great adsorption capacity. To determine optimum adsorption conditions, effective factors on the adsorption capacity of the CV and CPF, including solution pH, adsorbent dosage, contact time, and initial concentration of pollutants, have been experimentally investigated. Thus, in optimum conditions, i.e., contact time (20 and 15 min), pH 7 and 8, adsorbent dosage (0.005 g), initial concentration (50 mg/L), T (298 K) for CPF and CV, respectively, the CPF and CV adsorption capacity were 833.333 mg/g and 909.091 mg/g. The prepared pectin hydrogel@Fe3O4-bentonite magnetic nanoadsorbent presented high porosity, enhanced surface area, and numerous reactive sites and was prepared using inexpensive and available materials. Moreover, the Freundlich isotherm has described the adsorption procedure, and the pseudo-second-order model explained the adsorption kinetics. The prepared novel nanoadsorbent was magnetically isolated and reused for three successive adsorption–desorption runs without a specific reduction in the adsorption efficiency. Therefore, the pectin hydrogel@Fe3O4-bentonite magnetic nanoadsorbent is a promising adsorption system for eliminating organophosphorus pesticides and organic dyes due to its remarkable adsorption capacity amounts

Highly efficient remediation of chlorpyrifos and malachite green by an SBA-15 incorporated guar gum-grafted-poly (acrylic acid)/cobalt ferrite matrix for water purification

The Santa Barbara Amorphous-15-guar gum-grafted-poly (acrylic acid)/cobalt ferrite (SBA-15-GG-g-PAA/CoFe2O4) mesoporous adsorbent was prepared by graft copolymerization of acrylic acid (AA) onto guar gum (GG) in the Santa Barbara Amorphous-15 (SBA-15) substrate presence, followed by incorporating CoFe2O4 magnetic nanoparticles (MNPs). Diverse analyses were conducted to identify the prepared mesoporous adsorbent’s chemical and morphological properties, thermal resistance, magnetic characteristics, surface area, and porosity. Based on the magnetic hysteresis loops, the mesoporous adsorbent rendered ferromagnetic behavior. According to TGA, it has char yields of 72 wt% at 800 °C and superparamagnetic behavior (Ms of 3.22 emu.g−1). The crystalline structure and cubic phases of CoFe2O4 MNPs in the GG-g-PAA amorphous matrix were demonstrated by XRD. The CoFe2O4 MNP formation with partial aggregations onto smooth, nonporous, and regular surfaces of the GG was depicted by FESEM images. Also, the precisely-arranged hexagonal structure with cylindrical pores of SBA-15 was authenticated by FESEM images. Additionally, the SBA-15 substrate has increased the BET surface area of the prepared mesoporous adsorbent to 40.55 m2/g, which is higher than the composite without SBA-15 mesoporous silica. Several experimental setups were used to evaluate the effectiveness of adsorption, including pH of the medium (4–9), Adsorbent dosage (0.003–0.02 g), Interaction time (1–25 min), and Initial pollutant concentration (50–400 mg/L). Using 0.003 g of mesoporous adsorbent at 25 °C, chlorpyrifos (CPF) and malachite green (MG) had maximum adsorption capacities (Qmax) of 909.1 mg/g and 1000.0 mg/g, respectively. In this study, the Langmuir isotherm model fitted the adsorption data perfectly withRMG2 = 0.9987 andRCPF2 = 0.9994, and the pseudo-second-order model explained the adsorption kinetics with RMG2 = 0.9644 and RCPF2 = 0.9923. MG and CPF adsorption to the SBA-15-GG-g-PAA/CoFe2O4 mesoporous adsorbent was successful due to hydrogen bonds, exchange interactions, diffusion, and entrapment in the hydrogel network. In addition to the three-dimensional structure, the mesoporous adsorbent has available adsorption sites for reactive molecules. The reusability of the SBA-15-GG-g-PAA/CoFe2O4 was perused and showed that the mesoporous adsorbent can be separated efficiently and retrieved in three sequential cycles without considerable diminution in the adsorption efficiency

Carrageenan-grafted-poly(acrylamide) magnetic nanocomposite modified with graphene oxide for ciprofloxacin removal from polluted water

The κ-carrageenan-grafted-poly(acrylamide)/Fe3O4-GO (κ-car-g-PAAm@Fe3O4-GO) adsorbent was attained in three stages, utilizing grafted poly(acrylamide) (PAAm) onto κ-carrageenan (κ-car) in Fe3O4 and graphene oxide (GO) presence. Various characteristic analyses were carried out to peruse the chemical properties, morphological features, thermal stability, magnetic behavior, and porosity of the prepared nanoadsorbent. According to the results obtained from the analyses, the prepared nanoadsorbent showed superparamagnetic behavior. It rendered a semicrystalline structure by Fe3O4 presence in the amorphous matrix of the κ-car-g-PAAm. The SEM images exhibit well dispersion of the Fe3O4 magnetic nanoparticles (MNPs) and lamellar GO sheets throughout the hydrogel context. Besides, along with the GO incorporation into the structure, the BET surface area (2.361 m2/g), pore volume (0.008 cm3/g), and pore size (137.49 nm) of the κ-car-g-PAAm@Fe3O4-GO nanoadsorbent were higher than κ-car-g-PAAm@Fe3O4. The maximum adsorption capacity (Qmax) at an ambient temperature for CPFX adsorption was 1146.467 mg/g. These adsorption experiments’ data were described by the Freundlich isotherm, and the pseudo-second-order explains the adsorption kinetics well. The retrievability of the prepared nanoadsorbent was studied and indicated that it could be isolated effectively and reused in three consecutive cycles without remarkable adsorption efficiency loss