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1.
Sci Rep ; 14(1): 3060, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38321100

RESUMO

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.

2.
Int J Biol Macromol ; 260(Pt 2): 129545, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38272427

RESUMO

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.


Assuntos
Anti-Infecciosos , Quitosana , Nanocompostos , Quitosana/química , Staphylococcus aureus , Escherichia coli , Compostos Férricos/farmacologia , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Fenômenos Magnéticos , Nanocompostos/química , Antibacterianos/farmacologia , Antibacterianos/química
3.
Sci Rep ; 14(1): 562, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38177355

RESUMO

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.

4.
Int J Biol Macromol ; 249: 126077, 2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37532191

RESUMO

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.


Assuntos
Quitosana , Nanopartículas Metálicas , Nanocompostos , Quitosana/farmacologia , Quitosana/química , Dióxido de Silício/química , Prata/química , Zea mays , Antibacterianos/farmacologia , Antibacterianos/química , Nanocompostos/química , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana
5.
Sci Rep ; 12(1): 9855, 2022 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-35701523

RESUMO

This article investigates the effect of Ni2+ content on structural (XRD, XPS), morphological (TEM), and magnetic behaviors of silica magnesium zirconium copper nanoceramics calcined at 800 °C. The sol-gel route is followed for the silica magnesium zirconium copper/(0.0-0.7) Ni2+ samples preparation. X-ray photoelectron spectroscopy is employed to analyze the chemical states of elements for the samples. The three representative binding energy magnitudes for O, Ni, and Cu reside at 534, 857, and 979 eV, consecutively. The saturation magnetization constricts with the elevation of Ni2+ content, while the magnetic hysteresis loop resembles the superparamagnetic attitude. The optical spectra present the possibility of direct and indirect transitions in the prepared nanoceramics. Energy gap (value and type), refractive index, and real and imaginary dielectric constant were extracted. The energy gap approaches 3.75 eV and 3.71 eV for direct and indirect transitions correspondingly with (0.7) Ni2+. The antimicrobial and the toxicity performance of all inspected nanocomposites were conducted against pathogenic microbes. The attained results evidenced that SMZC-0.7Ni possesses energetic antimicrobial potential against all targeted microbes. The investigated SMZC-0.7Ni nanocomposite functioned to eradicate frequent waterborne pathogens in wastewater at an appropriate dose (100 mg/L), demonstrating that SMZC can be utilized as a competent disinfectant in the municipal wastewater decontamination process. Inherently, SMZC-0.7Ni can be employed as an excellent nano-weapon against multiple dangerous microorganisms.


Assuntos
Anti-Infecciosos , Purificação da Água , Antibacterianos , Cobre/química , Magnésio , Dióxido de Silício/química , Águas Residuárias , Zircônio/química
6.
Carbohydr Polym ; 291: 119656, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35698357

RESUMO

We study the microstructure, optical, thermal, dielectric, and mechanical properties of flexible oxidized cellulose (OC) films loaded with different mass fractions of cubic structure Bi0.5Na0.25K0.25TiO3 by blending solution technique and casting method. The films were characterized using infrared, X-ray diffraction, scanning electron microscopy, and UV-visible spectroscopy. The optical results confirmed the formation of crystalline bismuth sodium titanate/OC semiconductor films with a direct energy bandgap (3.002-3.276 eV) and have the ability for optoelectronic applications. The dielectric constant and dielectric loss of OC /BNKT film decreased obviously with increasing frequency. However, the ferroelectric state of the BNKT and its correlation with structure verified the existence of a relaxer behavior to this ratio. OC film with 20% dopped BNKT displayed energetic bactericidal activity against Gram-positive and Gram-negative bacteria. The presented study suggested that this film can be used as an antibacterial packaging material to diminish packaging's adverse environmental impacts with non-cytotoxicity.


Assuntos
Celulose Oxidada , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Difração de Raios X
8.
J Environ Manage ; 270: 110816, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32501235

RESUMO

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 (Ni0.6Zn0.4Fe2O4 and Ni0.6Zn0.2Ce0.2Fe2O4). 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.


Assuntos
Nanopartículas , Nanoestruturas , Fenômenos Magnéticos , Magnetismo , Esgotos
9.
Environ Sci Pollut Res Int ; 27(21): 26668-26680, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32378108

RESUMO

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.


Assuntos
Desinfetantes , Nanocompostos , Antibacterianos , Escherichia coli , Fenômenos Magnéticos , Testes de Sensibilidade Microbiana , Silicatos , Dióxido de Silício , Espectroscopia de Infravermelho com Transformada de Fourier , Águas Residuárias , Água , Difração de Raios X
10.
Int J Biol Macromol ; 125: 503-509, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30537501

RESUMO

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.


Assuntos
Aluminossilicato de Cálcio/química , Dióxido de Carbono/química , Quitosana/química , Géis/química , Membranas/química , Nanocompostos/química , Nanopartículas/química , Polímeros/química , Temperatura
11.
Int J Biol Macromol ; 97: 561-567, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28108409

RESUMO

Hybrid Chitosan/Poly ethylene glycol/calcium silicate (CS/PEG/calcium silicate) nanocomposite modified with different two types, zinc oxide nanoparticles (ZnO-NPs) and tartrazine dye (E102) were prepared by sol gel method and the characterization of their structure and biological properties were carried out in order to evaluate the possible use in optical and biomedical fields. The hybrid CS/PEG/calcium silicate complex formations have been established by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic analysis. The spheres-like chitosan-PEG/calcium silicate and modified with both ZnO-NPs and (E102) were obtained with optimum concentration of 11% ZnO-NPs and 0.3gm (E102) dyes. Spheres-like particle shape of these nanocomposites from SEM images, higher UV absorption in the region of 200-300nm by UV-vis absorption spectrophotometer are recorded. The fabricate CS/PEG/calcium silicate nanocomposites and doped with ZnO-NPs and tetrazine were studied contrary to gram positive (Staphylococcus aureus), gram negative (Pseudomonas aeruginosa) bacteria, fungi (Candidia albicans) and Aspargillus niger via the agar plate method. The obtained results indicated that the prepared CS-PEG/calcium silicate nanocomposites have good antibacterial properties agnist G+ve, G-ve bacteria and fungi, so that it could be a promised candidate in various optical and in biological applications as well as packaging application.


Assuntos
Compostos de Cálcio/química , Quitosana/química , Nanocompostos/química , Nanopartículas/química , Polietilenoglicóis/química , Silicatos/química , Tartrazina/química , Óxido de Zinco/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Técnicas de Química Sintética , Corantes/química , Nanotecnologia , Fenômenos Ópticos
12.
Int J Biol Macromol ; 93(Pt A): 267-275, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27543348

RESUMO

Chitosan (CS)/calcium silicate nanocomposites pure and doped with Ag ions (1, 2mol%) were prepared via sol-gel method. The prepared CS/calcium silicate nanocomposites were investigated through X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The XRD results, indicating that after increasing the Ag ions in the CS/calcium silicate nanocomposite the crystallinity degree increased regularly in the prepared nanocomposites accompanying to the continuously rearrangement in the internal structure of nanocomposite under the effect of inorganic nanoparticles. Correspondingly, the optical properties of the prepared nanocomposites films were measured using UV/vis spectroscopy. The reflectance increased while the energy band gap decreased from 3.96eV to 2.43eV with Ag-ions concentration. More over the transition type changed from direct into indirect by adding Ag-ions, indicate that new band between valence and conduction band were formed. In addition, the optical parameters showed an increase in refractive indices and decrease in the surface and volume energies losses with increasing Ag-ions. Correspondingly, the prepared nanocomposites exhibited good antibacterial activity against gram positive (Staphylococcus aureus), gram negative (Pseudomonas aeruginosa) bacteria and fungi (Candidia albicans). The results suggested that the prepared CS/calcium silicate nanocomposites can be a promised candidate for optical sensors applications and smart packaging materials.


Assuntos
Compostos de Cálcio/química , Quitosana/química , Quitosana/farmacologia , Nanopartículas Metálicas/química , Nanocompostos/química , Fenômenos Ópticos , Silicatos/química , Prata/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Relação Estrutura-Atividade
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