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1.
Langmuir ; 39(21): 7444-7455, 2023 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-37189015

RESUMO

The advantages of porosity and stable unpaired electrons of porphyrinic organic polymers (POPs) with free radicals are exclusive and potentially practical functionalities and combining the semiconductor-like characteristics of these materials and metal ions has been an effective way to assemble an efficient photocatalytic system. Herein, a new ruthenium (Ru) ion-encapsulated porphyrinic organic polymer (POP/Ru) is facilely synthesized as a proper photoresponsive nanozyme with unique photo-oxidase properties. Surprisingly, the proposed POP/Ru revealed outstanding photoresponsive oxidase-mimicking activity due to the synergetic effect of the integration of Ru and π-electrons of POP, which boosts charge separation and transport. POP/Ru was applied to the oxidation of o-phenylenediamine (o-PDA) as a chromogenic probe for producing a colorimetric signal. The kinetic study reveals that these photo-oxidase mimics have a significant affinity for the o-PDA chromogenic agent owing to a lower Km and superior Vmax. Further findings demonstrate that the presence of the l-arginine (l-Arg) target causes an inhibition effect on the photo-nanozymatic colorimetry of POP/Ru. This research develops the applications of the comprehensive colorimetric strategy for ultrasensitive l-Arg monitoring with a limit of detection (LOD) of 15.2 nM in the dynamic range of 4.0 nM-340 µM and illuminates that the proposed photo-oxidase nanozyme as a visual strategy is feasible in l-Arg environmentally friendly colorimetric detection in juice samples.


Assuntos
Colorimetria , Cápsulas , Rutênio/química , Polímeros/química , Colorimetria/métodos , Nanoestruturas/ultraestrutura , Oxirredutases/química , Oxirredutases/metabolismo , Porfirinas/química
2.
Heliyon ; 10(12): e32447, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38994068

RESUMO

This paper deals with the preparation of a novel nanocomposite consisted of magnesium-aluminum layered double hydroxide (Mg-Al LDH) and ethylenediaminetetraacetic acid (EDTA) as well as melamine (MA) as an adsorbent. This nanocomposite was utilized to adsorb different dyes such as rhodamine B (RhB) and methylene blue (MB) from water. The prepared adsorbent was characterized using FT-IR, EDS, XRD, TGA, and FE-SEM analyses. The effects of various parameters such as concentration, time, adsorbent dosage, temperature, and pH were tested to investigate their influence on adsorption conditions. Both methylene blue and rhodamine B dyes showed pseudo-second-order adsorption kinetics, and their adsorption followed the Langmuir isotherm. Moreover, the maximum adsorption capacities for methylene blue and rhodamine B were found to be 1111.103 mg/g at 45 °C and 232.558 mg/g at 60 °C, respectively. Additionally, the adsorption processes were found to be spontaneous (ΔG°< 0, for both dyes) and exothermic (ΔH° = -12.42 kJ/mol for methylene blue and ΔH° = -25.84 kJ/mol for rhodamine B) for both dyes. Hydrogen bonding and electrostatic forces are responsible for the interactions occur between the nanocomposite and the functional groups in the dyes. The experimental findings demonstrated a greater adsorption rate of MB than RhB, suggesting the adsorbent's stronger affinity for MB. This preference is likely due to MB's size, specific functional groups, and smaller molecule size, enabling stronger interactions and more efficient access to adsorption sites compared to RhB. Even after recycling 4 times, the dye adsorption percentages of the adsorbent for MB and RhB dyes were 90 % and 87 %, but the desorption percentages of the adsorbate dyes were 85 % and 80 %, respectively. The prepared adsorbent boasts several unique properties, such as the swift and effortless adsorption of MB and RhB dyes, straightforward synthesis, mild adsorption conditions, remarkable efficiency, and the ability to be recycled up to 4 times without a significant decrease in activity.

3.
Sci Rep ; 14(1): 8655, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622185

RESUMO

In this research, a new and eco-friendly heterogeneous catalyst (ND@Tannicacid-Cu) was synthesized based on nanodiamond and copper tannic acid via esterification process. The as-prepared catalyst was characterized by Fourier transforms infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD) methods. The catalytic efficacy of the intended catalyst was examined by one-step three-component reaction of 1,4-benzodiazepine derivatives from a mixture of ortho-phenylenediamine, aromatic aldehydes, and dimedone under mild conditions. In all instances, corresponding 2,4-benzodiazepines derivatives were synthesized with high efficiency, short reaction time, straightforward work up procedure, no requirement for column-chromatography, and cost-effective catalyst. The heterogeneous catalyst was easily recycled using fillers, and it can be reused for eight cycles without significantly diminishing its performance.

4.
Int J Biol Macromol ; 273(Pt 1): 132953, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38944566

RESUMO

This study investigates the potential applications of incorporating 2D bacterial cellulose microfibers (BCM) biochar into chitosan/polyethyleneimine beads as a semi-natural sorbent for the efficient removal of tetracycline (TET) and metronidazole (MET) antibiotics. Batch adsorption experiments and characterization techniques evaluate removal performance and synthesized adsorbent properties. The adsorbent eliminated 99.13 % and 90 % of TET and MET at a 10 mg.L-1 concentration with optimal pH values of 8 and 6, respectively, for 90 min. Under optimum conditions and a 400 mg.L-1 concentration, MET and TET have possessed the maximum adsorption capacities of 691.325 and 960.778 mg.g-1, respectively. According to the isothermal analysis, the adsorption of TET fundamentally follows the Temkin (R2 = 0.997), Redlich-Peterson (R2 = 0.996), and Langmuir (R2 = 0.996) models. In contrast, the MET adsorption can be described by the Langmuir (R2 = 0.997), and Toth (R2 = 0.991) models. The pseudo-second-order (R2 = 0.998, 0.992) and Avrami (R2 = 0.999, 0.999) kinetic models were well-fitted with the kinetic results for MET and TET respectively. Diffusion models recommend that pore, liquid-film, and intraparticle diffusion govern the rate of the adsorption process. The developed semi-natural sorbent demonstrated exceptional adsorption capacity over eleven cycles due to its porous bead structure, making it a potential candidate for wastewater remediation.


Assuntos
Celulose , Carvão Vegetal , Quitosana , Metronidazol , Polietilenoimina , Tetraciclina , Poluentes Químicos da Água , Tetraciclina/química , Tetraciclina/isolamento & purificação , Quitosana/química , Adsorção , Carvão Vegetal/química , Celulose/química , Metronidazol/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Cinética , Polietilenoimina/química , Concentração de Íons de Hidrogênio , Purificação da Água/métodos , Antibacterianos/química
5.
Artigo em Inglês | MEDLINE | ID: mdl-38884856

RESUMO

In the present study, we present a pyranopyrazole-TiO2 which is encapsulated with a niosome as nanocarrier for delivery of curcumin into breast cancer cells. Nanocarrier porous TiO2 is biocompatible and with a high specific surface area and a large pore volume and was used to carry pyranopyrazole, which has been reported as an anti-cancer. Niosome in the outer layer, helpful for loading curcumin into the niosomal layer, demonstrates a pH-dependent release and can be effective for cancer treatment. Entrapment efficiency of curcumin was found at 81.02% in carriers. The results of MTT and flow cytometry revealed that apoptosis is notably enhanced by loading curcumin on pyranopyrazole-TiO2@niosome. Also, there was high biocompatibility with MCF-10A, while exhibiting significant anti-cancer and anti-metastatic effects on MCF-7, whose cell viability was 38.79% in the loaded curcumin on carrier and was more than other samples even, than free curcumin (42.82%). Furthermore, the regulation of gene expression in cancer cells decreased the regulation of MMP-2 and MMP-9 genes and increased the expression of caspase-3 and caspase-9 genes. Finally, fluorescence activity in MCF-7 significantly increased after treatment with samples.

6.
Adv Colloid Interface Sci ; 328: 103158, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38718629

RESUMO

The preparation/application of heterogeneous (nano)materials from natural resources has currently become increasingly fascinating for researchers. Cellulose is the most abundant renewable polysaccharide on earth. The unique physicochemical, structural, biological, and environmental properties of this natural biopolymer have led to its increased application in many fields. The more desirable features of cellulose-based (nano)materials such as biodegradability, renewability, biocompatibility, cost-effectiveness, simplicity of preparation, environmentally friendly nature, and widespread range of applications have converted them into promising compounds in medicine, catalysis, biofuel cells, and water/wastewater treatment processes. Functionalized cellulose-based (nano)materials containing sulfonic acid groups may prove to be one of the most promising sustainable bio(nano)materials of modern times in the field of cellulose science and (nano)technology owing to their intrinsic features, high crystallinity, high specific surface area, abundance, reactivity, and recyclability. In this review, the developments in the application of sulfonated cellulose-based (nano)materials containing sulfonic acid (-SO3H) groups in catalysis, water purification, biological/biomedical, environmental, and fuel cell applications have been reported. This review provides an overview of the methods used to chemically modify cellulose and/or cellulose derivatives in different forms, including nanocrystals, hydrogels, films/membranes, and (nano)composites/blends by introducing sulfonate groups on the cellulose backbone, focusing on diverse sulfonating agents utilized and substitution regioselectivity, and highlights their potential applications in different industries for the generation of alternative energies and products.

7.
Heliyon ; 10(8): e29674, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38681630

RESUMO

In this study, a biodegradable and eco-friendly biocatalyst (eggshell/Fe3O4) was synthesized utilizing eggshell impregnated with Fe3O4 nanoparticles. The characterization of prepared catalyst was carried out by Fourier transform infrared radiation (FT-IR), scanning electron microscopy (SEM), X-ray Diffraction (XRD), energy-dispersive X-ray (EDX), thermal gravimetric analysis-differential thermogravimetry (TGA-DTG), vibrating sample magnometer (VSM), and atomic force microscopy (AFM). The eggshell/Fe3O4 biocatalyst was served in multi-component reactions (MCRs) for the synthesis of 2-amino thiophene derivatives from variety aromatic aldehydes, malononitrile, ethyl acetoacetate, and sulfur (S8). To achieve optimal reaction conditions, a thorough examination was conducted on key factors, such as the solvent type, reaction time and temperature, and the ratio of eggshell to Fe3O4. The findings suggest that high yield product can be obtained at microwave temperature (MW) in EtOH solvent within 10 min. Additionally, the eggshell/Fe3O4 biocatalyst exhibited high catalytic activity, which was sustained over the five cycles, without any significant decline in its performance.

8.
Int J Biol Macromol ; 254(Pt 2): 127794, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37923035

RESUMO

In this epoch, the disposal of multipollutant wastewater inevitably compromises life on Earth. In this study, the inclusion of Bacterial cellulose microfilaments reinforced chitosan adorned with melamine 2D plates creates a unique 3D bead structure for anionic dye removal. The establishment of an imine network between melamine and chitosan, along with the quantity of inter- and intra­hydrogen bonds, boosts the specific surface area to 106.68 m2.g-1. Removal efficiency and in-depth comprehension of synthesized adsorbent characteristics were assessed using batch adsorption experiments and characterization methods. Additionally, pH, adsorbent quantity, time, beginning concentration of solution, and temperature were analyzed and optimized as adsorption essential factors. Owing to the profusion of hydroxyl, amine, imine functional groups and aromatic rings, the synthesized adsorbent intimated an astonishing maximum adsorption capacity of 3168 mg.g-1 in Congo red dye removal at pH 5.5. Based on the kinetic evaluation, pseudo-second-order (R2 = 0.999), pseudo-first-order (R2 = 0.964), and Avrami (R2 = 0.986) models were well-fitted with the kinetic results among the seven investigated models. The isothermal study reveals that the adsorption mechanism predominantly follows the Redlich-Peterson (R2 = 0.996), Koble-Carrigan, and Hill isotherm models (R2 = 0.994). The developed semi-natural sorbent suggests high adsorption capacity, which results from its exceptional structure, presenting promising implications for wastewater treatment.


Assuntos
Quitosana , Poluentes Químicos da Água , Vermelho Congo/química , Quitosana/química , Celulose/química , Adsorção , Cinética , Iminas , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio
9.
Sci Rep ; 13(1): 10215, 2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37353547

RESUMO

In this work, a new and efficient composite LDH with high adsorption power using layered double hydroxide (LDH), 2,4-toluene diisocyanate (TDI), and tris (hydroxymethyl) aminomethane (THAM) was designed and prepared, which was used as an adsorbent to adsorb diazinon from contaminated water. The chemical composition and morphology of the adsorbent were evaluated using Fourier transform infrared (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), Energy dispersive X-ray (EDX) and Field emission scanning electron microscopy (FESEM) techniques. Also, the optimal conditions for adsorption of diazinon from water were determined by LDH@TDI@THAM composite. Various parameters like the effect of adsorbent dosage, pH, concentration and contact time of diazinon were studied to determine the optimal adsorption conditions. Then, different isotherm models and kinetic adsorption were used to describe the equilibrium data and kinetic. Also, the maximum adsorption capacity is obtained when the pH of the solution is 7. The maximum adsorption capacity for LDH@TDI@THAM composite was 1000 mg/g at 65 °C and the negative values of ΔG indicate that the adsorption process is spontaneous. After that, studying the reusability of LDH@TDI@THAM composite showed that the removal of diazinon by LDH@TDI@THAM was possible for up to four periods without a significant decrease in performance.


Assuntos
Inseticidas , Poluentes Químicos da Água , Água/química , Diazinon , Compostos Organofosforados , Hidróxidos/química , Adsorção , Zinco , Poluentes Químicos da Água/química , Cinética , Concentração de Íons de Hidrogênio , Espectroscopia de Infravermelho com Transformada de Fourier
10.
Heliyon ; 9(11): e20978, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37928013

RESUMO

In this work, using layered double hydroxide (LDH) inorganic substrate, melamine as binding agent and dendrimer G1 and also pyromellitic acid (PMA) organic catalytic agent a heterogeneous acid catalyst was designed and prepared. After that, the prepared organic-inorganic catalyst was evaluated by various identification techniques such as FTIR, EDX, XRD, TGA, FESEM, and BET, and the results showed that the desired structure was successfully prepared. Also, in order to investigate the efficiency of the LDH@Me-PMA nanocatalyst as an efficient and heterogeneous catalyst, it was used for green and one-pot synthesis of 2,3-dihydro quinazoline and 3,4-dihydropyrimidinone-2-(1H)-ones derivatives. The use of LDH@Me-PMA catalyst led to the synthesis of the desired derivatives with higher efficiency and shorter reaction time than previously reported works. In addition, the prepared LDH@Me-PMA acid catalyst has the ability to be recycled and reused for 5 consecutive periods and has high stability, which is well consistent with the principles of green chemistry.

11.
RSC Adv ; 13(32): 22205-22215, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37492511

RESUMO

Microwave absorbing architectures have gained a great deal of attention due to their widespread application in diverse fields, especially in refining electromagnetic pollution. The aim of this study is to investigate the metamaterial characteristics of porphyrin derivatives as conjugated rings in the microwave region and evaluate the influence of electron-withdrawing and donating groups on microwave attenuating performance. Initially, an innovative microwave curing procedure was applied to synthesize the derivates; following that, the phenyl, aniline, and nitrophenyl-coupled structures were identified by XRD, FTIR, FESEM, and DRS analyses. The optical features illustrated that the characteristic band gap of the conjugated loops is obtained and that the optical performance can be manipulated by coupling the functional groups. Eventually, the achieved results demonstrated that the best microwave absorbing performance is related to aniline-coupled porphyrin with a maximum reflection loss (RL) value of -104.93 dB at 10.09 GHz with 2.80 mm in thickness attaining an efficient bandwidth (EB) (RL ≤ 10 dB) higher than the X-band. Noticeably, polyethylene (PE) was applied as an absorbing matrix presenting a meaningful idea for the development of practical microwave absorbers as a new generation of electromagnetic refining and stealth materials. The presented research provides precious inspiration to tailor novel microwave absorbing materials with metamaterial capability to promote their microwave absorbing performance.

12.
Int J Biol Macromol ; 227: 685-697, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36535355

RESUMO

In this work, a novel and efficient magnetic biocatalyst was designed, prepared and identified using cherry tree gum as a biopolymer functionalized with 1,3,5-benzenetricarboxylic acid (gum@Fe3O4@BTA). The obtained biocatalyst was prepared using available and cheap materials in an easy process. This biocatalyst was used as an efficient catalyst with high catalytic activity for the synthesis of a three-component one-pot protocol and four-component one-pot protocol of tetrahydro-4H-chromene derivatives and polyhydroquinoline derivatives in EtOH green solvent under reflux conditions, respectively. The synthesized heterogeneous biocatalysts were identified and analyzed by FT-IR, EDS, FESEM, TGA and XRD techniques. The synthesis of tetrahydro-4H-chromene and polyhydroquinoline derivatives by using this biocatalyst has advantages such as high efficiency, short reaction time, simple work method, absence of dangerous solvents, environmentally friendly conditions, easy separation of the biocatalyst by an external magnet, and the ability reuse for five periods without significant decrease in catalytic activity.


Assuntos
Benzopiranos , Ácidos Tricarboxílicos , Espectroscopia de Infravermelho com Transformada de Fourier , Solventes , Fenômenos Magnéticos
13.
Heliyon ; 9(11): e22185, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38053897

RESUMO

In this study, a new and recyclable biocatalyst (MgAl CO3-LDH@Asn) was synthesized by immobilizing l-asparagine amino acid (Asn) on the surface of 3-(chloropropyl)-trimethoxysilane modified MgAl CO3-layered double hydroxide (LDH). The physicochemical properties of the samples were identified by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and thermogravimetric analysis (TGA) techniques. The MgAl CO3-LDH@Asn was employed in the multi-component assembly process for the synthesis of tri-substituted derivatives of 2,4,5-(H1)-imidazoles from benzyl, various benzaldehyde derivatives, and ammonium acetate. For optimizing the reaction, the main factors, including the amount of MgAl CO3-LDH@Asn, type of solvent, reaction time, and temperature were evaluated. The optimum conditions of the model reaction were achieved using 20 mg of MgAl CO3-LDH@Asn biocatalyst in ethanol solvent after 20 min at reflux temperature. According to the findings above, the results indicated that high-yield products are achieved within a short time frame. Moreover, the high catalytic activity of the MgAl CO3-LDH@Asn was maintained for four cycles without significantly diminishing its performance.

14.
Sci Rep ; 13(1): 10133, 2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37349381

RESUMO

In this research, mesoporous carbon (MC) with high efficiency (0.65 g yield from 1.0 g MCM-41 and 1.25 g sucrose) was successfully prepared by adding carbon precursor (sucrose) in a single step with ultrasonic waves, which reduces time and energy cost. Then, the Cu2+/Mesoporous carbon nanocatalyst (Cu2+/MC) was synthesized by adding Cu(NO3)2 in a single step and applied as a catalyst in amidation reactions of alcohols. Also, Cu2+/MC was characterized using different spectroscopic methods and techniques, including Fourier transform infrared spectroscopy (FT-IR), Field Emission Scanning Electron Microscopy (FE-SEM), N2 adsorption analysis (BET), X-ray diffraction analysis (XRD), Energy Dispersive X-ray (EDX), and Thermogravimetric Analysis (TGA). Moreover, to show the catalytic merits of Cu2+/MC, various primary and secondary amines and ammonium salts were applied in the amidation of alcohols. Easy synthesis method, recyclability, excellent yields (80-93%), and simple work-up are some noticeable strengths of using Cu2+/MC as a catalyst in this reaction.


Assuntos
Álcoois , Carbono , Espectroscopia de Infravermelho com Transformada de Fourier , Microscopia Eletrônica de Varredura
15.
Anal Chim Acta ; 1247: 340924, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36781249

RESUMO

This study reports the development of a vanadium-docked porphyrinic covalent organic framework as a novel class of highly polar photoactive materials. Thanks to its extended π-electron conjugation and high chemical stabilities, this framework can serve as an oxidase-Like photo-nanozyme for photocatalytic oxidation of o-phenylenediamine (o-PDA) and a colorimetric substrate for the production of the yellow-colored oxidized o-PDA (o-PDAox). The physicochemical properties of the as-prepared photo-nanozyme were characterized by several analytical techniques. Its enhanced light harvesting and charge separation and transfer were also verified by electrochemical and spectroscopic analysis. This photo-nonenzymatic colorimetric assay was applied for the sensitive L-Arginine (L-Arg) detection as a typical amino acid in the linear range of 8.1 nM-330 µM with a limit of detection (LOD) of 3.5 nM. The findings of this research confirmed the safety and feasibility of the proposed photo-nonenzymatic colorimetric sensing strategy for the detection of L-Arg and other similar biomolecules in food samples. Kinetic investigation revealed that the photo-responsive oxidase mimic exhibits satisfactory Km (0.47 mM) and Vmax (42.0 µM/s) values. This work broadened our insight into the development of modified porphyrinic-COF-based visible light-responsive oxidase-like photo-nanozyme for environmentally friendly colorimetric biosensing.


Assuntos
Estruturas Metalorgânicas , Oxirredutases , Estruturas Metalorgânicas/química , Colorimetria/métodos , Vanádio , Arginina
16.
RSC Adv ; 13(32): 21873-21881, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37475756

RESUMO

A novel and biologically active nanobiocomposite is synthesized based on carbon nitride nanosheet (g-C3N4) based carboxymethylcellulose hydrogels with embedded zinc ferrite nanoparticles. Physical-chemical aspects, morphological properties, and their multifunctional biological properties have been considered in the process of evaluation of the synthesized structure. The hydrogels' compressive strength and compressive modulus are 1.98 ± 0.03 MPa and 3.46 ± 0.05 MPa, respectively. Regarding the biological response, it is shown that the nanobiocomposite is non-toxic and biocompatible, and hemocompatible (with Hu02 cells). In addition, the developed material offers a suitable antibacterial activity for both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli).

17.
Sci Rep ; 12(1): 11288, 2022 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-35787674

RESUMO

This paper was designed and prepared a new nanoarchitectonics of LDH/polymer composite with specific morphology. For this purpose, CTAB surfactant was used to control the morphology of layered double hydroxide (LDH) and to prepare LDH/polymer nanocomposites (LDH-APS-PEI-DTPA). The polymer was synthesized using diethylenetriaminepentaacetic acid (DTPA), polyethylenimine and used with LDH to form a nanocomposite with high thermal stability. Subsequently, the prepared nanocomposite was identified using FTIR, EDX, TGA, XRD, FESEM, and BET techniques. In addition, the prepared LDH-APS-PEI-DTPA nanocomposite was used as a heterogeneous and recyclable catalyst for the synthesis of imidazole derivatives under green conditions. The results showed that the LDH-APS-PEI-DTPA nanocomposite benefit from suitable morphology, simple preparation, high catalytic activity, and high surface area. Also, the proposed LDH-APS-PEI-DTPA heterogeneous catalyst showed high stability and reusability for five consecutive runs which was consistent with the principles of green chemistry.


Assuntos
Fármacos Dermatológicos , Nitroimidazóis , Inibidores de 14-alfa Desmetilase , Antifúngicos , Hidróxidos , Imidazóis , Ácido Pentético , Polímeros
18.
Sci Rep ; 12(1): 4221, 2022 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-35273221

RESUMO

In this research, an efficient heterogeneous catalyst based on graphitic carbon nitride nanosheets (CN) has been reported. The CN was functionalized by 1,3-dibromopropane as a linker (CN-Pr-Br) and subsequently modified with metformin (CN-Pr-Met). Furthermore, the copper(II) was coordinated on modified CN (CN-Pr-Met-Cu(II)) and during this process, 7.94% copper(II) was loaded into the catalyst structure. The synthesized catalyst was evaluated by various techniques including fourier-transform infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and inductively coupled plasma atomic emission spectroscopy (ICP-OES). CN-Pr-Met-Cu(II) was used as a catalyst in the synthesis of amides via the oxidation of benzyl alcohols. The conditions of this reaction were optimized in terms of temperature, time, amount of catalyst, type of base, oxidant, and solvent. Moreover, a variety of amides with an efficiency of 75-95% were synthesized. The reaction was carried out in the presence of benzyl alcohols, amine hydrochloride salts, tert-butyl hydroperoxide (TBHP), CaCO3, and CN-Pr-Met-Cu(II) at 80 °C of acetonitrile solvent. The synthesized catalyst can be easily separated from the reaction medium and reused for 7 consecutive runs without a significant reduction in reaction efficiency.

19.
Sci Rep ; 12(1): 2331, 2022 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-35149698

RESUMO

In this study, an efficient catalyst based on graphitic carbon nitride nanosheets (CN) and copper(II) supported ß-cyclodextrin (ß-CD/Cu(II)) was synthesized and used for tandem oxidative amidation of benzylic alcohols. In this regard, CN was functionalized by ß-CD/Cu(II) via 1,3-dibromopropane linker (CN-Pr-ß-CD/Cu(II)). The prepared catalyst was characterized using FT-IR, XRD, FE-SEM, EDS, TGA, ICP-OES, BET, and TEM analyses. CN-Pr-ß-CD/Cu(II) was subsequently applied in a direct oxidative amidation reaction and it was observed that different benzyl alcohols were converted to desire amides with good to excellent efficiency. This reaction was performed in the presence of amine hydrochloride salts, tert-butyl hydroperoxide (TBHP), and Ca2CO3 in acetonitrile (CH3CN) under nitrogen atmosphere. CN-Pr-ß-CD/Cu(II) can be recycled and reused five times without significant reduction in reaction efficiency.

20.
R Soc Open Sci ; 9(6): 212025, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35706673

RESUMO

In this study, green synthesis of modified Cu(OH)2 nanowires by Fe3O4@SiO2 core-shell nanospheres was easily performed via chemical reduction. In other words, the direct coating of Cu(OH)2 on Fe3O4@SiO2 was successfully realized without the extra complicated procedures. Various concentrations of synthesized nanocomposites were tested on pathogenic and nosocomial bacteria. In this study, the structural information and characterization of Fe3O4@SiO2/Cu(OH)2 nanowires (FSCNWs) were obtained using FE-SEM, FT-IR, EDX and X-ray diffraction. This nanocomposite can effectively kill important infectious bacteria, including Staphylococcus aureus, Escherichia coli, Staphylococcus saprophyticus, Pseudomonas aeruginosa and Klebsiella pneumoniae. Studies have shown that FSCNW nanocomposites affect common antibiotic-resistant bacteria. This result confirms the function of FSCNW as an effective, beneficial and environmentally friendly antibacterial agent that can used in a wide range of applications in medicine. FSCNWs can be separated conveniently from bacteria-containing solutions using a magnet. Compared with nanocomposites based on other metals such as silver and gold, the use of FSCNWs in water treatment has been recommended because of the precursor of copper for its low price and less toxicity. In addition to its special properties such as mild reaction conditions, green synthesis methods, admissible magnetic properties, easy separation, high antibacterial activity and beneficial efficiency.

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