Optimizing magnetic, dielectric, and antimicrobial performance in chitosan-PEG-Fe2O3@NiO nanomagnetic composites

There is a growing interest in eco-friendly and cost-effective organic-inorganic nanocomposites due to their alignment with the principles of "green" chemistry, as well as their biocompatibility and non-toxicity. This study focused on producing Chitosan-PEG-Fe2O3@NiO nanomagnetic composites to improve the stability, dielectric properties, and antimicrobial effectiveness of these nanocomposite materials. The process involved synthesizing Fe2O3@NiO via sol-gel and polymerizing chitosan-PEG. The nanocomposites were characterized by XRD, TEM, FTIR, optical, dielectric, and VSM. Incorporating Fe2O3@NiO significantly improved stability, and the interaction with Fe2O3 during the sol-gel process facilitated the formation of NiFe2O4 with an increase in the crystallinity within the chitosan-PEG matrix. The study examined optical and dielectric properties, highlighting that the 3 NiO-doped chitosan-PEG-Fe2O3 composites had high electrical conductivity (1.8 ∗ 10-3 S/cm) and a significant dielectric constant (106 at low frequencies). As the ratio of NiO NPs within the chitosan-PEG-Fe2O3 increases, the energy band gap of chitosan-PEG-Fe2O3 films decreases up to 3.7 eV. This decrease is owing to the quantum confinement effect. These composites also demonstrated improved antimicrobial activity against E. coli and S. aureus and higher activity in the presence of nanomagnetic particles. The minimum inhibitory concentrations of CS-PEG-Fe2O3/NiO NPs against (Bacillus cereus, M. luteus, S. aureus and (S. enterica, H. pylori, E. coli) were (22-35 mm) and (21-34 mm), respectively.

Exploring nanoarchitectonics and optical properties of PAA-ZnO@BCP wide-band-gap organic semiconductors

This work reports the formation of polyacrylic acid (PAA)-zinc oxide (ZnO)-bromocresol purple (BCP), (PAA-ZnO@ (0.00-0.01) BCP wide-bandgap organic semiconductors deposited onto glass substrates via a sol-gel polymerization process. These semiconductor films were deposited on glass substrates using a spin coating and then dried at 60 °C. The PAA-ZnO film appeared to be of amorphous phase, and films loaded with BCP revealed semicrystalline behavior. The surface of the films exhibited adherence and extended grains. The hydrogen bonds formed between PAA-ZnO and the BCP dye within the PAA-ZnO@BCP films was performed using FTIR-spectroscopy. The prepared nanocomposites demonstrate an indirect band transition which is affected slightly by adding ZnO and BCP dye. Optical parameters such as the absorption coefficient, the refractive index, the dielectric constant, optical conductivity, optical depth, and optical electronegativity of the prepared nanocomposites were studied as functions of incident light energy (wavelength). The PAA carbonyl group n-π* transition and BCP aromatic ring π-π* transitions were detected at about 285 (for all samples) and 432 nm (for BCP loaded samples), respectively. The superior photoluminescence characteristics observed in the BCP/PAA-Zn films excited with a wavelength of 250 nm indicated the successful loading of the BCP dye during the self-aggregation of the PAA-Zn film.

Advancing energy storage and supercapacitor applications through the development of Li+-doped MgTiO3 perovskite nano-ceramics

Perovskite oxide materials, specifically MgTiO3 (MT) and Li-doped MgTiO3 (MTxLi), were synthesized via a sol-gel method and calcination at 800 °C. This study explores the impact of varying Li doping levels (x = 0, 0.01, 0.05, and 0.1) on the crystalline structure and properties of MgTiO3. X-ray diffraction analysis revealed a well-defined rhombohedral MgTiO3 phase. Optical diffuse reflectance measurements provided insights into energy gap values, refractive index, and dielectric constant. Li+ doping enhanced the electrical properties of MgTiO3, with a notable phase transition observed at 50 °C. The study investigated impedance and AC conductivity under varying temperature and frequency conditions (25-120 °C, 4 Hz to 8 MHz). Electrochemical analysis through cyclic voltammetry and electrochemical impedance spectroscopy confirmed highly electrocatalytic properties for MTxLi, particularly when modified onto screen-printed electrodes. This work not only advances the understanding of Li-doped MgTiO3 nanostructures but also highlights their significant potential for direct electrochemical applications, particularly in the realm of energy storage.

Humidity sensing using Zn(1.6 - x)Na0.4CuxTiO4 spinel nanostructures

In this paper, we present a humidity sensing material based on nanostructured Zn(1.6 - x)Na0.4CuxTiO4 spinel to enhance optical and sensitivity performance. Nano-porous of Zn (1.6 - x) Na0.4CuxTiO4 spinel were synthesized using sol gel reactions and calcined at 700 °C. The nanostructures of Zn(1.6 - x)Na0.4CuxTiO4 spinel underwent thorough characterization through multiple techniques. X-ray diffractometry (XRD) coupled with Rietveld refinement using FullProf software, transmission electron microscopy (TEM), Raman Spectroscopy, and optical analysis were employed to assess various aspects of the nanostructures. These techniques were utilized to determine the phase composition, particle size distribution, chemical bonding, and the tunable band gap of the nanostructures. The X-ray diffraction (XRD) analysis of Zn(1.6 - x)Na0.4CuxTiO4 samples revealed well-defined and prominent peaks, indicating a highly crystalline cubic spinel structure. The lattice parameter was decreased from 8.4401 to 8.4212 Å with increasing Cu content from 0 to 1.2 mol%. UV-visible diffuse reflectance spectra were employed to investigate the optical characteristics of copper-doped Zn1.6Na0.4TiO4. The applicability of Cu@NaZT spinel nanostructures in humidity sensors was evaluated at ambient conditions. The fabricated sensor was investigated in a wide span of humidity (11-97%). The examined sensor demonstrates a low hysteresis, excellent repeatability, fast response and recovery. The response and recovery times were estimated to be 20 s and 6 s respectively. The highest sensitivity was achieved at 200 Hz. The proposed sensor can be coupled easily with electronic devices as the humidity-impedance relationship is linear.

Synthesis and characterization of chitosan-corn starch-SiO2/silver eco-nanocomposites: Exploring optoelectronic and antibacterial potential

This work discusses the physicochemical and antimicrobial characteristics of chitosan-corn starch eco-nanocomposites integrated with silica@Ag nano-spheres. These composites were synthesized through sol-gel polymerization and subsequently exposed to simulated body fluid (SBF). The incorporation of Ag into the eco-nanocomposites led to a decrease in diffuse reflectance across the entire wavelength range. The dielectric permittivity exhibited an increase up to 52.1 at a frequency of 100 kHz, while the ac conductivity reached a value of 5.2 ∗ 10-6 (S cm-1) at the same frequency for the sample with the highest Ag content. The study utilized XRD and FTIR techniques to examine the materials before and after in vitro testing and evaluated the antibacterial properties of the eco-nanocomposites against several pathogenic microorganisms, including Staphylococcus haemolyticus, Staphylococcus aureus, Klebsiella pneumoniae, and Escherichia coli, using the agar diffusion method. The eco-nanocomposites demonstrated bioactivity by forming a hydroxy appetite layer on their surfaces and were capable of releasing silver (Ag) at concentrations of 1.3, 1.9, and 2.5 mol%. This study suggests that chitosan-corn starch-SiO2-based doped with Ag eco-nanocomposite has the potential for various applications, including biomedical and environmental fields, where their antibacterial properties can be utilized to combat harmful microorganisms.

Construction and characterization of nano-oval BaTi0.7Fe0.3O3@NiFe2O4 nanocomposites as an effective platform for the determination of H2O2

Talented di-phase ferrite/ferroelectric BaTi₀.₇Fe₀.₃O₃@NiFe₂O₄ (BFT@NFO) in oval nano-morphology was chemically synthesized using controlled sol-gel processes and calcined at 600 °C. The effects of shielding using NiFe₂O₄ (NFO) nanoparticles on the microstructure, phase transition, thermal, and relative permittivity of BaTi₀.₇Fe₀.₃O₃ (BTF) nano-perovskite were systematically explored. X-ray diffraction patterns and Full-Prof software exhibited the forming of the BaTi₂Fe₄O₁₁ hexagonal phase. TEM and SEM images demonstrated that the coating of BaTi0.₇Fe₀.₃O₃ has been successfully controlled with exquisite nano-oval NiFe₂O₄ shapes. The NFO shielding can significantly promote the thermal stability and the relative permittivity of BFT@NFO pero-magnetic nanocomposites and lowers the Curie temperature. Thermogravimetric and optical analysis were used to test the thermal stability and estimate the effective optical parameters. Magnetic studies showed a decrease in saturation magnetization of NiFe₂O₄ NPs compared to their bulk system, which is attributed to surface spin disorder. Herein, characterization and the sensitive electrochemical sensor were constructed for the evaluation of peroxide oxidation detection using the chemically adjusted nano-ovals barium titanate-iron@nickel ferrite nanocomposites. Finally, The BFT@NFO exhibited excellent electrochemical properties which can be ascribed to this compound possessing two electrochemical active components and/or the nano-ovals structure of the particles which can further improve the electrochemistry through the possible oxidation states and the synergistic effect. The result advocates that when the BTF is shielded with NFO nanoparticles the thermal, dielectric, and electrochemical properties of nano-oval BaTi_0.7Fe_0.3O₃@NiFe₂O₄ nanocomposites can be synchronously developed. Thus, the production of ultrasensitive electrochemical nano-systems for the determination of hydrogen peroxide is of extensive significance.

Facile synthesis and potential application of Ni0.6Zn0.4Fe2O4 and Ni0.6Zn0.2Ce0.2Fe2O4 magnetic nanocubes as a new strategy in sewage treatment

Disinfection using chlorine has paramount importance in the treatment of either drinking water or sewage since it can kill and inhibit all waterborne pathogens, but it may result in carcinogenic substances when interacting with organic matter. An eco-friendly sol-gel process with citrate was used to prepare the nano-cubic activated nickel-zinc ferrite magnetic nanostructures (Ni_0.6Zn_0.4Fe₂O₄ and Ni_0.6Zn_0.2Ce_0.2Fe₂O₄). The activated nanomagnetic samples were characterized using XRD, HR-TEM, HR-SEM, FTIR, and VSM techniques. The structural and magnetic results showed that the nano-cubes magnetic-structures exhibited higher crystalline degrees and an increase in the total magnetization, enabling spinel nano-ferrite to possess potentials for excellent industry various applications. Likewise, the VSM results reveal that Ce₂O₃ had a significant influence on the magnetic behavior such as the coercivity (Hc; 69.226-133.15) saturation and magnetization (Ms; 24.562-52.174). The results revealed that all Magnetic nanoparticles (MNPs) had an outstanding inhibitory effect on microbes tested. The manufactured particles showed a remarkable ability to eliminate pathogenic bacteria in real sewage samples. The results obtained endorsed that the manufactured magnetic nanoparticles (MNPs) are powerful nano-weapons with an excellent anticipated output for the deactivation of pathogenic microbes during sewage treatment, with, nickel-zinc-cerium ferrite being more effective in inhibiting microbial growth than nickel-zinc-cerium ferrite.

Correction to: Nanoceramics and novel functionalized silicate-based magnetic nanocomposites as substitutional disinfectants for water and wastewater purification

The correct name of the 2nd Author is presented in this paper.

Nanoceramics and novel functionalized silicate-based magnetic nanocomposites as substitutional disinfectants for water and wastewater purification

Herein, we successfully synthesized nano-porous Co₂O₃/Cu₂O₃: Al₂O₃: SiO₂ ((0, 5, 7, 9) Co-CAS) using the acidic sol-gel approach and calcined at 800 °C for 4 h. The crystallization behavior and spectroscopic properties were investigated using X-ray diffraction, field emission-scanning electron microscopy, and Fourier-transform infrared absorption spectra analysis. The antibiotic properties of the nano-porous CAS, 5Co-CAS, and 9Co-CAS magnetic nanocomposites was studied against some potentially pathogenic bacteria in water and wastewater samples. The bacteria tested included Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, and Bacillus subtilis. Incorporating Co₂O₃ resulted in the identification of three peaks at 2θ = 10.2°, 13.4°, and 15°. The introduction of cobalt nanoparticles created a ferromagnetic behavior in the CAS nanoceramic, with the magnetic moment and saturation values increasing with increased Co₂O₃ doping. 9Co-CAS was most potent against all the tested pathogens with minimum inhibitory concentrations of 25 mg/L within 40 min for E. coli and P. aeruginosa and 50 mg/L within 10 min for S. enterica; the lowest antibacterial activity was observed with the unmodified CAS. The findings revealed that the manufactured nanocomposite materials were potent disinfectants with a promising application for water and wastewater treatment.

Detection of 3,4-diaminotoluene based on Sr0.3Pb0.7TiO3/CoFe2O4 core/shell nanocomposite via an electrochemical approach

We reported a scalable sol–gel method for the preparation of Sr_0.3Pb_0.7TiO₃/CoFe₂O₄ core–shell magnetic nanocomposite with a finely controlled shell and evaluated its efficiency as an electrochemical sensor for the selective detection of 3,4-diaminotoluene.

Sol gel synthesis of hybrid chitosan/calcium aluminosilicate nanocomposite membranes and its application as support for CO2 sensor

Modification of chitosan with cross-linkers, blends with various kinds of polymers, nanoparticles and new organic-inorganic hybrid composites in order to obtain some improved properties attached more attention nowadays due to their good sensitivity in changing electrical and optical properties. In the current work modified hybrid chitosan/calcium aluminosilicate (CH/CAS) nanocomposite membranes and doped with (3, 5 & 7 mol%) Al₂O₃ nanoparticles were synthesized via sol-gel process in acidic conditions, which can be efficiently employed to capture CO₂ gas at lower and moderate temperatures. Furthermore, the fabricated CH/CAS nanocomposite membrane loading with (3, 5 & 7 mol%) Al₂O₃ were investigated using XRD, SEM, FTIR and dielectric measurements. The results indicated that the incorporation of Al₂O₃ in CH/CAS matrix significantly affected on the structural, dielectric and appeared good reliability for sensing CO₂ at atmospheric pressure. The dielectric behaviour for the prepared CH/CAS indicates that the dielectric constant (ε') decreases. According to XRD the introducing of Al₂O₃ leads to increase the crystallinity of the system and thus the dipoles of the system orient hardly with the applied field and results in lesser dielectric constant (ε'). Correspondingly, the CH/CAS nanocomposite membranes were characterized and its performance as CO₂ gas sensor was evaluated.