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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 151: 760-72, 2015 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-26172463

RESUMO

In this research, a chemical precipitation method was used to synthesize undoped and doped cadmium oxide nanoparticles and studied by TG-DTA, XRD, FT-IR, SEM, with EDX and antibacterial activities, respectively. The melting points, thermal stability and the kinetic parameters like entropy (ΔS), enthalpy (ΔH), Gibb's energy (ΔG), activation energy (E), frequency factor (A) were evaluated from TG-DTA measurements. X-ray diffraction analysis (XRD) brought out the information about the synthesized products exist in spherical in shape with cubic structure. The functional groups and band area of the samples were established by Fourier transform infrared (FT-IR) spectroscopy. The direct and indirect band gap energy of pure and doped samples were determined by UV-Vis-DRS. The surface morphological, elemental compositions and particles sizes were evaluated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Finally, antibacterial activities indicated the Gram-positive and Gram-negative bacteria are more active in transporter, dehydrogenize and periplasmic enzymatic activities of pure and doped samples.


Assuntos
Antibacterianos/química , Bário/química , Compostos de Cádmio/química , Nanopartículas Metálicas/química , Óxidos/química , Antibacterianos/farmacologia , Compostos de Cádmio/farmacologia , Precipitação Química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Magnetismo , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Varredura , Nanopartículas/química , Nanopartículas/ultraestrutura , Óxidos/farmacologia , Espectrometria por Raios X , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 151: 895-907, 2015 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-26184475

RESUMO

The present study was made to design the pure and various levels of Cu doped (0.025 M, 0.05 M and 0.075 M) BaSO4 NPs synthesized by chemical precipitation method. The synthesized products have been characterised by X-ray Diffractometer (XRD), Fourier transform infrared (FT-IR) spectrometer, thermogravimetric and differential thermal analysis (TG-DTA), UV-Vis-diffused reflectance spectroscopy (UV-Vis-DRS), field emission-scanning electron microscopy with energy dispersive spectroscopy (FE-SEM with EDS), transmission electron microscopy (TEM) and application oriented study like antibacterial activity also reported. The result determined from XRD was affirmed by the results obtained from electron microscopic measurements. XRD study revealed that the synthesized products were composed of orthorhombic structure and highly crystalline in nature. Furthermore, flaky like morphology of pure and Cu-BaSO4 nanoparticles have been observed from the images obtained from these studies. The existence of Cu(2+) was confirmed by EDS analysis. The functional groups of the synthesized samples were analysed by FT-IR study. The band gap energies of pure and doped samples were accomplished using UV-Vis-DRS analysis. Also, the kinetic parameters were evaluated and reported from the thermal stability of nanoparticles. Eventually, gram-negative bacteria shows the less antibacterial activities compared to gram-positive bacteria due to adsorption of BaSO4 nanoparticles on the surface of the used bacteria.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Sulfato de Bário/química , Cobre/química , Nanopartículas/química , Precipitação Química , Análise Diferencial Térmica , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Espectrometria por Raios X , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios X
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 136 Pt C: 1751-9, 2015 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-25467666

RESUMO

In the present study, synthesized pure and Ag (1%, 2%, and 3%) doped Cadmium Oxide (CdO) nanoparticles by chemical precipitation method. Then, the synthesized products were characterized by thermo gravimetric-differential thermal analysis (TG-DTA), X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR) spectroscopy, Ultra violet-Vis diffused reflectance spectroscopy (UV-Vis-DRS), Scanning electron microscopy (SEM), Energy dispersive X-rays (EDX) spectroscopy, and anti-bacterial activities, respectively. The transition temperatures and phase transitions of Cd(OH)2 to CdO at 400°C was confirmed by TG-DTA analysis. The XRD patterns show the cubic shape and average particle sizes are 21, 40, 34, and 37nm, respectively for pure and Ag doped samples. FT-IR study confirmed the presence of CdO and Ag at 677 and 459cm(-1), respectively. UV-Vis-DRS study shows the variation on direct and indirect band gaps. The surface morphologies and elemental analysis have been confirmed from SEM and with EDX. In addition, the synthesized products have been characterized by antibacterial activities against Gram-positive and negative bacteria. Further, the present investigation suggests that CdO nanoparticles have the great potential applications on various industrial and medical fields of research.


Assuntos
Antibacterianos , Compostos de Cádmio/química , Precipitação Química , Nanopartículas Metálicas/química , Óxidos/química , Prata/química , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Compostos de Cádmio/síntese química , Compostos de Cádmio/farmacologia , Análise Diferencial Térmica , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Nanocompostos/química , Óxidos/síntese química , Óxidos/farmacologia , Tamanho da Partícula , Prata/farmacologia , Compostos de Prata/síntese química , Compostos de Prata/química , Compostos de Prata/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 137: 137-47, 2015 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-25218222

RESUMO

In the present study, we reported that the synthesis and characterization of pure and diverse mole Co-doped BaSO4 nanoparticles have been synthesized by chemical precipitation technique. X-ray diffraction analysis (XRD) brought out the information about the synthesized products is orthorhombic structure and highly crystalline in nature. The average grain size of the samples was determined by using the Debye-Scherer's equation. The existence of functional groups and band area of the samples were confirmed by Fourier transform infrared (FTIR) spectroscopy. The direct and indirect band gap energy of pure and doped samples was carried out using UV-VIS-DRS. The surface micrograph, morphological distribution and elemental compositions of the synthesized products were assessed by scanning electron microscopy (SEM) and Energy dispersive X-ray (EDS). Thermo gravimetric and differential thermal analysis (TG-DTA) techniques were analyzed thermal behaviour of pure and Co-doped samples. Finally, antibacterial activities found the Gram-positive and Gram-negative bacteria are more active in transporter, dehydrogenize and periplasmic enzymatic activities of pure and doped samples.


Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Sulfato de Bário/síntese química , Sulfato de Bário/farmacologia , Precipitação Química , Cobalto/química , Nanopartículas/química , Antibacterianos/química , Bactérias/efeitos dos fármacos , Sulfato de Bário/química , Análise Diferencial Térmica , Humanos , Luz , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Nanopartículas/ultraestrutura , Espalhamento de Radiação , Espectrometria por Raios X , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Termogravimetria , Difração de Raios X
5.
Artigo em Inglês | MEDLINE | ID: mdl-24681311

RESUMO

In the present study, an attempt has been made for characterization and synthesis of pure and Ni-doped α-Fe2O3 (hematite) nanoparticles by chemical precipitation method. The synthesized products have been studied by X-ray diffraction (X-RD), Fourier transform infrared (FTIR) spectroscopy, UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), vibrating sample magnetometer (VSM) and scanning electron microscopy (SEM) techniques. The estimated average diameter of α-Fe2O3 nanoparticles were calculated by using the Debye-Scherrer equation and established as 31 nm. SEM micrographs showed the surface morphology as well as structures and particles distributions of synthesized samples. The UV-Vis DRS showed the indirect and direct band gap energies of pure and Ni-doped α-Fe2O3, these were reduced from 1.9847 to 1.52 eV and 2.0503 to 1.76 eV respectively. This result suggested the dopant enhanced the semiconducting behavior of iron oxide nanoparticles to an extent proportional to its nickel doped in the α-Fe2O3. Further, the magnetic properties of the pure and doped samples were investigated by vibrating sample magnetometer (VSM) and evaluated the information of pure and doped samples exhibited saturated hysteresis loop at room temperature, which is indicating that the weak ferromagnetism in nature of our synthesized samples. In addition, it has been found from the magnetization hysteresis curves of Ni-doping, resulting from increased the saturation of magnetization and reduced the coercivity of used samples. Therefore, the present study showed the reduction in band gap energies and coercive field for α-Fe2O3 nanoparticles due to nickel doped.


Assuntos
Compostos Férricos/química , Nanopartículas/química , Nanopartículas/ultraestrutura , Níquel/química , Tamanho da Partícula
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