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1.
J Fluoresc ; 2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37665510

RESUMO

Herein, we report the extraction of natural pigment curcumin from curcuma longa and their linear and third-order nonlinear optical (NLO) characteristics. The characterization techniques viz., UV-Visible absorption, FT-IR, Micro Raman and Gas Chromatography Mass Spectrum (GC-MS) are used to study the spectral characteristics of curcumin. Third-order NLO features of curcumin are studied using Z‒scan technique with a semiconductor diode laser working at 405 nm wavelength. The natural pigment exhibits negative nonlinear index of refraction resulting from self-defocusing and positive coefficient of absorption is the consequence of reverse saturable absorption (RSA). The order of nonlinear index of refraction (n2) and nonlinear coefficient of absorption (ß) is measured to be 10-7 cm2/W and 10-2 cm/W, respectively. Third-order NLO susceptibility (χ(3)) and second-order hyperpolarizability (γ) of curcumin is measured to be 2.73 × 10‒7 esu and 1.67 × 10‒31 esu, respectively. A low optical limiting (OL) threshold of 0.71 mW is observed in the extracted pigment. The experimental results are supplemented by quantum mechanical calculations of the NLO parameters. The overall result finding is that curcumin extracted from curcuma longa has the potential to be novel optical candidates for photonics and optoelectronics applications.

2.
Environ Res ; 212(Pt B): 113274, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35461848

RESUMO

The present work reports the synthesis of hydroxyapatite (HAp) via the green chemistry approach by using the leaf extract of copper pod tree and its adsorptive potential to remove Acid blue 113 (AB113) dye. FESEM-EDS characterization of the synthesized HAp confirmed rod-shaped HAp with prominent Ca and P elements. The crystallinity of HAp was ascertained by XRD and thermal stability was analyzed by TGA. The colloidal suspension stability was determined as - 17.7 mV by Zeta potential analyzer. The mesoporous structure was affirmed via BET studies with a high magnitude of specific surface area. TEM studies substantiated the rod-shaped HAp as observed in FESEM. The signals specific to HAp were observed in XPS studies. Adsorption of AB113 on the synthesized HAp was examined by varying the process parameters. Batch experiments resulted in an optimum dye removal of 92.72% at a pH of 8, 1 g/L of CP-HAp nps dosage, 20 ppm AB113 concentration, 120 min contact time, 150 rpm agitation speed and at room temperature. The maximum adsorption capacity reached 120.48 mg/g. Multifarious isotherms characterized the adsorption with Freundlich isotherm (R2 > 0.968) dominating Langmuir indicating multilayer adsorption. The experimental data reasonably matched pseudo-second-order kinetics with R2 exceeding 0.99. Thermodynamic investigations underlined the spontaneity and exothermicity of the processes. Results showed the suitability of the HAp nanoadsorbent to remove AB113 from wastestreams.


Assuntos
Durapatita , Poluentes Químicos da Água , Adsorção , Compostos Azo , Durapatita/química , Concentração de Íons de Hidrogênio , Cinética , Poluentes Químicos da Água/química
3.
Environ Res ; 212(Pt B): 113295, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35452668

RESUMO

Metal nanoparticles furnished by the green synthesis approach have exhibited fascinating attributes owing to their biocompatibility with biomolecules, and their rapid environmentally friendly synthesis. On copper oxide (CuO) nanoparticles, a laser induced bio reduction work has been accomplish using Centella asiatica aqueous extract at room temperature is the pioneer in the field. This synthesis technique is easy, fruitful, eco-friendly, and counterfeit for the size-tunable synthesis of diverse shapes of stable copper nanoparticles. UV-visible spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), Energy - Dispersive X-ray Spectroscopy (EDX), X-ray diffraction (XRD) and photodegradation study have astounding properties of regulating the formation, crystalline nature, and morphology of an integrated specimen. Moreover, the obtained copper oxide nanoparticle has the tendency to decrease the absorbance maximum value of methylene blue because of the catalytic activity posed by these nanoparticles on the reduction of methylene blue by Centella asiatica. It has been studied and confirmed by UV-visible spectrophotometer, and it has been recognised as an electron relay effect.


Assuntos
Cobre , Nanopartículas Metálicas , Cobre/química , Lasers , Nanopartículas Metálicas/química , Azul de Metileno/química , Extratos Vegetais/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
4.
Environ Res ; 211: 112970, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35219632

RESUMO

Recently, researchers are concentrating on the synthesis of composite materials to enhance the efficiency of the materials in various applications. In this work, nickel vanadium oxide (NiV2O6) nanocomposite material is prepared via two methods and the prepared samples have been characterized with basic studies to analyse the effect of preparation method and the reaction time. The XRD studies reveal a polycrystalline growth in both the methods. The broad XRD peaks obtained for samples prepared via hydrothermal method suggests the size reduction and 1D nanostructure formation. The SEM analysis shows the formation of 1D structures in hydrothermal and 3D microsphere structures in solvothermal methods. The possible formation mechanism behind this formation has been discussed in this manuscript. The FTIR peaks in the fingerprint region confirm the formation and vibration of metal-oxygen bonds. The large optical bandgap values obtained from Tauc plot again confirms the formation of nanostructures of the synthesized samples. The photocatalytic activity of nickel vanadium oxide on methylene blue dye under halogen light were performed and, the recyclability of the sample is investigated. It was found from the photocatalytic spectrum that, the samples prepared from both the methods shows a degradation efficiency of more than 80% within 150 min. It was confirmed that the prepared NiV2O6 photocatalyst samples does not lose their degradation ability even after five cycles of repeated usage.


Assuntos
Nanocompostos , Níquel , Catálise , Nanocompostos/química , Óxidos , Solventes , Vanádio , Águas Residuárias
5.
Environ Res ; 214(Pt 1): 113804, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35830910

RESUMO

Photocatalysis is found to be one of the best suited processes that respond to the purification of water systems and the semiconductor nanomaterials are learned to be incredible materials which carry out the photocatalytic process as they readily decompose the pollutants effectively. In this present work, CdSe nanoparticles belonging to II-VI group semiconductor compounds were synthesized using a facile hydrothermal process with different precursor concentrations and were analysed for various characterization studies such as X-ray diffraction (XRD), Transmission electron microscopy (TEM), UV-vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR) and Photoluminescence (PL) studies. The XRD study of the synthesized CdSe nanostructures revealed that the average crystallite size was ranging from 18.5 nm to 24 nm pointing out the increase in size with increase in molar concentrations. The morphological structure of synthesized CdSe samples exhibited urchin-like structure for a lower concentration with several rod-like projections appearing in diverse directions. These CdSe nano-urchins synthesized with lower concentrations are found suitable to carry out the process of photocatalytic activity. The process was carried out under visible light radiation for 180 min with aqueous solution of methylene blue (MB) as the ideal toxin to be degraded. The attained degradation efficiency was nearly 80% clearly displaying that the synthesized samples are good photocatalysts. By tuning the bandgap, through the optimization of the precursor concentrations, greater efficiency can be achieved in future.


Assuntos
Compostos de Cádmio , Compostos de Selênio , Catálise , Luz , Azul de Metileno
6.
Environ Res ; 209: 112821, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35092741

RESUMO

Surfactant -treated tin oxide (SnO2) hierarchical nanorods were successfully synthesized through hydrothermal technique. The X-ray diffraction analysis showed the prepared SnO2 possesses tetragonal rutile structure having appreciable crystallinity with crystallite sizes in the range of 110 nm-120 nm. UV-visible diffuse reflectance absorption spectra confirm that the better visible light absorption band of SnO2 hierarchical nanorods have red shift compared to the pure SnO2. Fourier transform infrared spectroscopy (FTIR) study evident that the as-prepared SnO2 nanorods encompass the characteristic bands of SnO2 nanostructures. The morphological analyses of prepared materials were performed by FESEM, which shows that hierarchal nanorods and complex nanostructures. EDX analyses disclose all the samples are composed of Sn and O elements. The photocatalytic performance of the prepared surfactant treated SnO2 hierarchical nanorods was evaluated using methylene blue (MB) dye removal under direct natural sunlight. Recycling experiment results of CTAB - SnO2 nanorods and photocatalytic reaction mechanism also discussed in detail.


Assuntos
Nanoestruturas , Nanotubos , Catálise , Luz , Azul de Metileno/química , Nanoestruturas/química
7.
Environ Res ; 213: 113595, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35688219

RESUMO

Semiconductor nanoparticles and nanocrystals have a great impact due to its contribution in the diverse fields including electronics, solar energy, biological imaging, and photonics. Among these semiconductor nanoparticles, cadmium selenide of II-VI group binary semiconductor nanoparticles were synthesized using solvothermal process for the different reaction temperatures. The XRD pattern of the synthesized samples confirms the crystalline nature of the samples and showed increase in its crystallite size with rise in temperature. The morphology of the samples was analysed with TEM images and found that the nanoparticles synthesized at different temperatures were varied in size and shape indicating the increase in the size of the particles with the raise in temperature. The optical properties of the samples pointed out that they exhibit a blue shift owing to quantum confinement. Photocatalytic activity was carried out for the synthesized samples under visible light radiation using methylene blue (MB) as a model pollutant and it proved to be a good photocatalyst achieving the efficiency of 75% which is promising for future application with good optimization. The efficiency could be increased when these semiconductor CdSe nanoparticles are doped with metal particles due to an increase in the absorption edge wavelength and a decrease in bandgap energy were reported in detail.


Assuntos
Compostos de Cádmio , Nanopartículas , Compostos de Selênio , Compostos de Cádmio/química , Catálise , Nanopartículas/química , Têxteis , Águas Residuárias
8.
Environ Res ; 203: 111814, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34352234

RESUMO

The adsorption behavior of biomaterial activated Sawdust-Chitosan nanocomposite beads (SDNCB) powder was investigated along with synthesis and experimental techniques approaches to study the removal efficiency of some heavy metal ions including Ni (II) and Cu (II) ions from aqueous solutions by assessing the surface-modified activated carbon by the cost-effective non-conventional method. Structural analysis of the entitled compound was evaluated by the PXRD techniques and its surface morphology was inferred by the following techniques: TEM, EDAX. The behavior of the functional group presents in the compound was discussed using the FTIR technique. Such parameters like dosage, pH, time, temperature, and initial concentration of copper and nickel were associated with this to examine the effect of adsorption of heavy elements that exist in the portable solution. Further, the cellulose and chitosan beads complex material have an appropriate surface area, it demonstrated metal ions removal efficiency was more appreciable due to the action of activated carbon, where this showed fast rate sorption kinetics due to strong involvement of Cu+ & Ni+ towards cellulose and chitosan's functional groups in the bio composite. The isotherm model so-called Langmuir, Freundlich, and Temkin model was utilized to plot the experimental adsorption dataset to infer the maximum adsorption capacity. Based on this model, the adsorption properties of the beads treated compound was determined by plotting the graphs in which sorption intensity (n) which implies expected sorption, and the correlation value are 1.989, 0.998, and 0,981 respectively.


Assuntos
Quitosana , Nanocompostos , Poluentes Químicos da Água , Adsorção , Cobre , Concentração de Íons de Hidrogênio , Cinética , Níquel , Termodinâmica
9.
Environ Res ; 203: 111880, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34400161

RESUMO

The present research work focuses on preparing 3D transition metal doped copper oxide nanostructures through sonication method and to investigate the effect of doping different transition metal into copper oxide (CuO) on the basic properties of CuO nanoparticles and, to study the photocatalytic behaviour of the doped CuO samples. The morphological studies performed with the help of SEM revealed the formation of flower like CuO 3D nanostructures for all the doped samples. The slight shift in the position of peaks in the x-ray diffraction (XRD) pattern confirms that doping has been successfully done into CuO. Also, the sharp diffraction peaks suggest the polycrystalline nature of the sample with monoclinic structure. The UV-vis absorption analysis reveals a bandgap of 2.26, 2.12 and 2.15 eV for the CuO samples doped with nickel, zinc, and iron respectively via Tauc plot. The photocatalytic performance of the samples tested through the degradation of methylene blue (MB) dye suggests that samples doped with Zn shows better degradation. Thus, it is evident that the morphology and the optical properties of the CuO can be tailored by doping transition metal into it.


Assuntos
Nanopartículas , Nanoestruturas , Catálise , Cobre , Luz , Azul de Metileno
10.
Environ Res ; 205: 112560, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34915030

RESUMO

A modest sol-gel method has been employed to prepare the pure and Ag doped MnO2 nanoparticles and methodologically studied their physical, morphological, and photosensitive properties through XRD, TEM, EDAX, Raman, UV, PL and N2 adsorption - desorption study. Tetragonal crystalline arrangement with spherical nanoparticles was found out through XRD and TEM studies. The EDAX studies further supported that formation Ag in the MnO2 crystal matrix. The bandgap energy of Ag doped MnO2 was absorbed through UV spectra. Photo -generated recombination process and surface related defects were further recognized by PL spectra. Through visible light irradiation, the photo - degradation of methyl orange (MO) and phenol dye solutions were observed. The optimum condition of (10 wt% of Ag) Ag doped MnO2 catalyst showed tremendous photocatalytic efficiency towards MO than phenol under same experimental study.


Assuntos
Poluentes Ambientais , Nanoestruturas , Purificação da Água , Catálise , Luz , Compostos de Manganês , Nanoestruturas/química , Óxidos , Titânio/química
11.
Environ Res ; 202: 111627, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34246640

RESUMO

In this present research, we succeeded in synthesizing nanostructured silver particles (NS-AgPs) using bio active agent present in the leaf extracts of Cleome gynandra (CG) under green synthesis. While adding silver nitrate (AgNO3) solution in green extracts of CG leaf containing bio compound, the mixture turns from yellow to reddish brown, as a consequence of existence of nanostructured silver particles (NS-AgPs) and later UV instrument is used to obtain the Ultraviolet visible spectroscopy (UV-vis) spectra to confirm existing nanostructured silver particles (NS-AgPs) in aqueous solutions (synthesized sample). To confirm existing functional groups in NS-AgPs, the fourier transform infrared spectroscopy (FTIR) study is carried throughout this research. The scanning and tunneling of wave like nature of electrons passing through powdered NS-AgPs sample gives Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) images respectively, which are carried out to find out the 2-dimensional size and shape distribution of NS-AgPs. Further dynamic light scattering (DLS) and zeta potential studies are used to confirm the size and good stability of NS-AgPs respectively. It is evident that NS-AgPs exhibits a strong toxic activity against microorganism and to confirm this mechanism the antibacterial (against Escherichia coli and Staphylococcus aureus) study is carried out.


Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Antibacterianos/toxicidade , Nanopartículas Metálicas/toxicidade , Testes de Sensibilidade Microbiana , Óxidos , Extratos Vegetais , Compostos de Prata , Espectroscopia de Infravermelho com Transformada de Fourier
12.
Environ Res ; 199: 111274, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34000268

RESUMO

In this present investigation, an aqueous Basella alba leaves extract was used to synthesize AgNPs. The green synthesis approach is carried out in our work due to non-toxic, less cost, and ecofriendly methods. FTIR spectra are used to confirm the biomolecules present in B.alba leaves extract along with AgNPs and these compounds are responsible for Ag particle from micro to nanostructure. The FCC structure and crystalline nature of the AgNPs are analyzed with the help of XRD and TEM techniques respectively. DLS and Zeta potential techniques are carried out to find the size and stability of AgNPs respectively and UV is used to verify the presence of AgNPs in synthesized samples employing SPR peaks around 435 nm. The antioxidant studies expose eminent scavenging activity which ranges from 13.71% to maximum 67.88%. Green synthesized AgNPs possess well organized biological activities concerning antioxidant and antibacterial, which can be used in some biologically applications.


Assuntos
Nanopartículas Metálicas , Prata , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Extratos Vegetais , Folhas de Planta , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Environ Res ; 198: 111199, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33932479

RESUMO

In the present study, Allium cepa leaf extract was utilized to reduce the silver nitrate into the nanoscale range of silver ions (Ag NPs). The biosynthesized Ag NPs were extensively characterized by X-ray diffraction analysis (XRD), Dynamic light scattering analysis (DLS), UV-Visible spectroscopy (UV-vis), Transmission electron microscopy (TEM), Energy dispersive X-ray analysis (EDX) and Fourier transform infrared spectroscopy (FTIR). The antioxidant activity of synthesized Ag NPs was verified by DPPH assay. From the results obtained from XRD and DLS studies, the size of Ag NPs was determined to be around 54.3 nm. The measured zeta potential value of -19.1 mV confirms the excellent stability of biosynthesized Ag NPs. TEM analyses reveal that the biosynthesized Ag NPs have a spherical structure of 13 nm in size. The presence of various functional groups was confirmed through FTIR studies and EDAX verifies the weight percentage of silver content in biosynthesized nanoparticles to be 30.33%. In the present study, anti-cancer activity was carried out by using breast cancer cell line MCF-7. Further, silver nanoparticles exhibited antimicrobial effectiveness against gram-positive Bacillus cereus and gram-negative Escherichia coli. The MTT assay also showed better cytotoxic activity against the MCF- 7 cell line.


Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Humanos , Células MCF-7 , Nanopartículas Metálicas/toxicidade , Testes de Sensibilidade Microbiana , Cebolas , Extratos Vegetais/farmacologia , Prata , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
14.
Photochem Photobiol Sci ; 18(2): 592, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30675604

RESUMO

Correction for 'Synthesis and antimicrobial photodynamic effect of methylene blue conjugated carbon nanotubes on E. coli and S. aureus' by Paramanantham Parasuraman et al., Photochem. Photobiol. Sci., 2019, DOI: 10.1039/c8pp00369f.

15.
Photochem Photobiol Sci ; 18(2): 563-576, 2019 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-30601523

RESUMO

Catheter-related bloodstream infections (CRBSIs) are one of the leading causes of high morbidity and mortality in hospitalized patients. The proper management, prevention and treatment of CRBSIs rely on the understanding of these highly resistant bacterial infections. The emergence of such a challenge to public health has resulted in the development of an alternative antimicrobial strategy called antimicrobial photodynamic therapy (aPDT). In the presence of a photosensitizer (PS), light of the appropriate wavelength, and molecular oxygen, aPDT generates reactive oxygen species (ROS) which lead to microbial cell death and cell damage. We investigated the enhanced antibacterial and antibiofilm activities of methylene blue conjugated carbon nanotubes (MBCNTs) on biofilms of E. coli and S. aureus using a laser light source at 670 nm with radiant exposure of 58.49 J cm-2. Photodynamic inactivation in test cultures showed 4.86 and 5.55 log10 reductions in E. coli and S. aureus, respectively. Biofilm inhibition assays, cell viability assays and EPS reduction assays showed higher inhibition in S. aureus than in E. coli, suggesting that pronounced ROS generation occurred due to photodynamic therapy in S. aureus. Results from a study into the mechanism of action proved that the cell membrane is the main target for photodynamic inactivation. Comparatively higher photodynamic inactivation was observed in Gram positive bacteria due to the increased production of free radicals inside these cells. From this study, we conclude that MBCNT can be used as a promising nanocomposite for the eradication of dangerous pathogens on medical devices.


Assuntos
Escherichia coli/efeitos dos fármacos , Escherichia coli/efeitos da radiação , Azul de Metileno/química , Azul de Metileno/farmacologia , Nanotubos de Carbono/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/efeitos da radiação , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Técnicas de Química Sintética , Escherichia coli/metabolismo , Escherichia coli/fisiologia , Luz , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos da radiação , Azul de Metileno/síntese química , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/metabolismo , Staphylococcus aureus/fisiologia
16.
J Nanosci Nanotechnol ; 19(8): 4447-4457, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30913735

RESUMO

The present work reports low cost, green synthesis of Zinc oxide (ZnO) nanoparticles. The biosynthesized nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (ATR-FTIR). The synthesized ZnO nanoparticles were pure, predominantly spherical in shape with size ranging from 25 nm. The biosynthesized ZnO nanoparticles have been used for antibacterial and In Vitro applications. The antibacterial activity of the prepared CS/PVA/MC3-ZnO1, CS/PVA/MC3-ZnO2, and CS/PVA/MC3-ZnO3 nanocomposites samples was tested against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) due to disk diffusion method. When adding the ZnO nanoparticles both bacteria were very good inhibition zone was obtained. The transmission ZnO micrographs depicts spherical with uniform shape and good crystallinity and are composed of nanoparticles with a diameter less than 25 nm the average cube size was 100 nm. The AFM thickness of the CS/PVA/MC3-ZnO scaffold was, estimated from the AFM image, was about 10-20 nm and a roughness-like structure was observed. The FE-SEM film exhibits a scaffold exhibited porous structures. The excellent cell viability of the composite scaffolds was attributed to the good biocompatibility of the CS/PVA/MC3-ZnO3 as well as green fabrication process of the scaffolds. MTT analysis exposed that the samples did not have any toxicity. Since these positive points, these two kinds of scaffolds show appropriate properties for attachment, proliferation, and tendency to form group from L929 cells. In this work, we have prepared zinc oxide by high pressure homogenization process and the resultant zinc oxide was evaluated as fibers in CS/PVA/MC3 films.


Assuntos
Quitosana , Nanocompostos , Óxido de Zinco , Antibacterianos/toxicidade , Quitosana/farmacologia , Escherichia coli , Fibroblastos , Metilcelulose , Nanocompostos/toxicidade , Álcool de Polivinil , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus , Difração de Raios X , Óxido de Zinco/farmacologia
17.
J Nanosci Nanotechnol ; 19(2): 859-866, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30360163

RESUMO

Different mole ratios of (8:2, 6:4, 4:6 and 2:8) iron tungstate-tungsten trioxide (FeWO4-WO3) composite nanoparticles were synthesized by solid state method. The synthesized composite nanoparticles were characterized by powder X-ray diffraction analysis (XRD), field-emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) studies. The crystalline nature and particle size of the samples were characterized by powder X-ray diffraction analysis (XRD). The morphology was confirmed by field-emission scanning electron microscopy (FE-SEM) analysis and transmission electron microscope (TEM). The energy dispersive X-ray spectroscopy (EDX) proved the purity of nanocomposites. Vibrating sample magnetometer reveals that the sample shows paramagnetic property based on the metal present in the prepared nanocomposites at room temperature. The magnetic property is due to the structural defects rather than the impurity phase. Magnetization saturation value (Ms = 398.7 emu/g) of FWWO-46 composite nanoparticles is high enough to be magnetically removed by applying a magnetic field. The composites were subjected to DC conductance measurement as a function of relative humidity in the range of 5-98%, achieved by different water vapour buffers thermostated at room temperature. The sensitivity factor, Sf (R5%/R98%) measured at 25 °C revealed that FWWO-46 shows the highest humidity sensitivity factor Sf = 3956, with a response and recovery time of 45 s and 100 s respectively. Photocatalytic degradation of methylene blue (MB) from aqueous solution has been carried out using FeWO4-WO3 composite nanoparticles as photocatalyst under Ultraviolet radiation.

18.
J Nanosci Nanotechnol ; 19(5): 2493-2500, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30501745

RESUMO

Sodium Alginate/Poly(vinyl alcohol) (SA/PVA) blend scaffolds were successfully prepared via solution casting method for controlled release of ciprofloxacin (CPF). The structures of the films were evaluated by ATR-FTIR, XRD and SEM. A wide variety of material characteristics for the SA/PVA blend scaffolds were investigated, including the swelling behaviour, liquid displacement method, mechanical property and antibacterial activity. ATR-FTIR studies evaluated the chemical interaction between the biopolymeric scaffolds and the drug. XRD studies proved the amorphous behaviour of the prepared scaffolds. SEM images revealed good cohesivity and compatibility between the biopolymers and the cargos. SA/PVA loaded with ciprofloxacin showed maximum swelling percentage, porosity and tensile strength. The formulated ciprofloxacin loaded SA/PVA scaffold showed strong antibacterial activity. The results of CPF release from biopolymeric scaffolds at pH 1.2, 5.3 and 7.4 indicated strong pH dependence. In vitro drug-controlled release studies showed a slower and more continuous release for the SA/PVA in comparison with plain SA and PVA and the drug-delivery cumulative release was proportional to the amount and the interlayer distance of SA/PVA blend scaffolds. A sustained drug release pattern was observed with a non fickian diffusion mechanism.


Assuntos
Alginatos , Álcool de Polivinil , Ciprofloxacina/farmacologia , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos
19.
J Nanosci Nanotechnol ; 19(6): 3511-3518, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30744779

RESUMO

Unadulterated and scorch stage In2SnO3 nanopowder is effectively arranged with the doping proportion of 80-20% (In2O3-Sn) by simple sol-gel combustion direction. The material is characterized by XRD measurements and their geometrical parameters are compared with calculated values. The FT-IR and NMR spectra are recorded in both bulk and nanophase and FT-Raman spectrum is recorded in bulk phase and the fundamental frequencies are assigned. The optimized parameters and the frequencies are calculated using HF and DFT (B3LYP, B3PW91 and MPW1PW91) theory in bulk phase of In2SnO3 and are compared with its nanophase. The vibrational frequency pattern in nanophase gets realigned and the frequencies are shifted up and down little bit to the region of spectra when compared with bulk phase. The UV-visible spectrum is simulated and analyzed. The frontier molecular orbital analysis has been carried out and the values of the HOMO-LUMO bandgap (Kubo gap) explore the optical and electronic characteristics of the In2SnO3. Structural studies by XRD showed the crystallite sizes of the particles. The atomic arrangement in the grain boundary seems to be somewhat different from regular periodic arrangement whereas inside the grain there is a good periodic arrangement of atoms. Above 10 mol% Sn ions, 15 mol% Sn ions, 20 mol% Sn ions to 50 mol% Sn ions form correlated clusters, 20 mol% Sn ions which lead to broadening. These EPR spectra were formed to contain two different components, one from the single isolated ions and the other from the clusters. The transition is observed for different composition increase with decreasing grain size.

20.
J Nanosci Nanotechnol ; 19(5): 2590-2598, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30501755

RESUMO

Cobalt oxide nanorods were successfully synthesized by a hot plate combustion method using the plant extract of Vitis vinifera. The plant extract as an alternative to toxic chemicals can be used generally as reducing and capping agents. The obtained nanorods were characterized by XRD, FT-IR, Raman, TEM, SAED, EDX, DRS, PL and VSM techniques for the structural, morphological, optical and magnetic properties. The XRD, FT-IR, Raman, EDX analysis confirmed the high purity of the sample. The TEM and SAED results showed the rod shape morphology of the sample. DRS and PL showed the band gap energy and emission at visible region. VSM showed the antiferromagnetic nature of the sample. The photocatalytic activities of the as-prepared cobalt oxide nanorods were investigated for the degradation of textile dying waste water. As per the standards of Indian pollution control board for industrial waste water let out into river bodies, the degradation reactions of waste water was found to be 250 mg/L at 150 min. Also, the same catalyst is used for the reduction of 4-nitrophenol and 4-nitroaniline using sodium borohydride as a reducing agent and it exhibits excellent reduction reaction, because of the high active surface sites. The time taken for the reduction reaction was 300 sec and 210 sec for 4-nitrophenol and 4-nitroaniline respectively. Also, the antibacterial activities towards the bacterial strains were studied and reported.


Assuntos
Antibacterianos , Nanotubos , Antibacterianos/farmacologia , Catálise , Cobalto , Óxidos , Espectroscopia de Infravermelho com Transformada de Fourier
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