Xun Xu; Fangwang Ming; Jinqing Hong; Zhoucheng Wang
Abstract
The flexible and freestanding graphene oxide (GO) film was fabricated for drug delivery and antibacterial. The film was synthesized by covalently attaching cefalexin onto graphene oxide sheets and then made by filtration of the colloidal suspension. SEM and optical images show that the Cefalexin-grafted ...
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The flexible and freestanding graphene oxide (GO) film was fabricated for drug delivery and antibacterial. The film was synthesized by covalently attaching cefalexin onto graphene oxide sheets and then made by filtration of the colloidal suspension. SEM and optical images show that the Cefalexin-grafted graphene oxide (GO-CE) film possesses the unique 2D layer-by-layer structure and it could form channels for drug release when immersed in water. The drug loading and release tests certify that the GO-CE film is a promising drug delivery membrane with high load capacity (0.621 mg mg -1 ) and long-acting release properties (72 h), and can effectively inhibit the growth of E. coli and S. aureus bacteria while showing minimal cytotoxicity for a long time. The cellular culture results of the HeLa Cells indicate that the GO-CE film exhibits excellent biocompatibility. Based on these advantages, the GO-CE film is expected to be used in the environmental and medical applications.
Alpana Thakur; Sunil Kumar; Manjula Sharma; V. S. Rangra
Abstract
Graphite oxide (GO) and reduced graphene oxide (RGO) have been synthesized using chemical methods. Prepared graphite oxide and reduced graphene oxide were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. ...
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Graphite oxide (GO) and reduced graphene oxide (RGO) have been synthesized using chemical methods. Prepared graphite oxide and reduced graphene oxide were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. XRD patterns, Raman spectra and FTIR spectroscopy confirms significant structural changes while reducing GO to RGO. The obtained products were further analyzed for their optical and electrical properties using UV-Vis spectroscopy, photoluminescence spectroscopy and four-point probe. RGO has shown excellent electrical conductivity of 1.363×10 4 S/m. The bactericidal action of prepared GO and RGO was also studied against Escherichia coli and Staphylococcus aureus bacteria.
K.C. Anjaneya; J. Manjanna; V.M. Ashwin Kumar; H.S. Jayanna; C.S. Naveen
Abstract
We report the nature of rare earth ion doped ceria (REC), Ce0.8Ln0.2O2−δ, (Ln = Y 3+ , Gd 3+ , Sm 3+ , Nd 3+ and La 3+ ) as oxide ion conductors for their plausible application as electrolytes in intermediate temperature solid oxide fuel cell (SOFC). The samples were prepared by citrate-complexation ...
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We report the nature of rare earth ion doped ceria (REC), Ce0.8Ln0.2O2−δ, (Ln = Y 3+ , Gd 3+ , Sm 3+ , Nd 3+ and La 3+ ) as oxide ion conductors for their plausible application as electrolytes in intermediate temperature solid oxide fuel cell (SOFC). The samples were prepared by citrate-complexation method and characterized by XRD, SEM/ EDX and UV-Visible spectra. The cubic fluorite-type crystal structure is confirmed from XRD patterns, and the observed lattice parameters are in agreement with calculated values. The UV-Vis spectra of the particles dispersed in aqueous medium showed absorption in the UV region which is ascribed to charge-transfer transition. The dc conductivities at 673 K are in the order of Ce0.8Sm0.2O2−δ > Ce0.8Gd0.2O2−δ > Ce0.8Y0.2O2−δ > Ce0.8Nd0.2O2−δ > Ce0.8La0.2O2−δ and their corresponding activation energies are 0.85, 0.87, 0.87, 0.88 and 0.95 eV. Based on ionic and electronic transference numbers, electrical conductivity obtained here is purely ionic, i.e., oxide ion conductors.
Prasanta Dhak; A. Kundu; K. Pramanik; P. Pramanik; D. Dhak
Abstract
Small amounts of Cu and Al-K substitution on the A and B site of BaTiO3, respectively resulting a solid solution of the type Ba1-xCuxTi1-x(AlK)xO3 (BCTAK) [x = 0.05, 0.10, 0.15, 0.20] have been investigated. The compositions have been prepared in the nanocrystalline range by chemical route. X-ray diffraction ...
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Small amounts of Cu and Al-K substitution on the A and B site of BaTiO3, respectively resulting a solid solution of the type Ba1-xCuxTi1-x(AlK)xO3 (BCTAK) [x = 0.05, 0.10, 0.15, 0.20] have been investigated. The compositions have been prepared in the nanocrystalline range by chemical route. X-ray diffraction revealed the tetragonal (P4/mmm) phase. Average crystallite size and particle size were found to be in the range between 25 nm and 35 nm which were analyzed through X-ray diffraction and transmission electron microscopy respectively. A dielectric study of these compounds as a function of temperature suggested that with increasing substitution concentration the dielectric constant decreased and the Curie temperature shifted towards the lower temperature side. Discontinuous grain growth accompanied with excellent dielectric diffuseness was found with increasing concentration of substitution. The dielectric diffuseness γ was found to be maximum to 1.91 at the substitution of BCTAK x = 0.20. The activation energy, Ea was found to decrease along with an increase in conductivity with increasing substitution concentration in BCTAK.
D. M. Pimpalshende; S. J. Dhoble
Abstract
Nowadays the research on synthesis of inorganic luminescent material with proper dimensions and morphologies has attracted great attention. Inorganic luminescent materials like LaPO4 have found many practical applications in the field of electroluminescent devices, integrated optics, biological labels, ...
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Nowadays the research on synthesis of inorganic luminescent material with proper dimensions and morphologies has attracted great attention. Inorganic luminescent materials like LaPO4 have found many practical applications in the field of electroluminescent devices, integrated optics, biological labels, modern lighting and display fields. We have prepared Dysprosium (Dy) doped LaPO4 nanoparticles at relatively low temperature in polyethylene glycol (PEG) medium by wet chemical method. Dy 3+ is doped in LaPO4 at various atomic concentrations (1, 2, 5 and 10 at %). All the samples have been characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) and thermoluminescence (TL) techniques. XRD study reveals the monoclinic structure of prepared nanoparticles. Unit cell volume is found to be decrease linearly with increasing Dy 3+ concentration indicating homogeneous substitution of La 3+ ions in LaPO4 by Dy 3+ . From the FTIR study it is found that the band at 1044 cm -1 assigned to the phosphate group PO4 3- in the region of υ3 anti-symmetric stretching of P-O band. The PL spectrum shows emission band at about 435 nm is observed due to the transision of Dy 3+ ions corresponding to wavelength in the blue color region. The glow curve of LaPO4: Dy phosphor obeys second order kinetics.
Punita Srivastava;Kedar Singh
Abstract
We have developed successfully the synthesis of highly yielded CdSe nanoparticles (NPs) at 60 0C by solvothermal route in which the cadmium and selenium precursors have been dissolved in deionized water, ethylene glycol and hydrazine hydrate. This route is very facile, inexpensive and less hazardous ...
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We have developed successfully the synthesis of highly yielded CdSe nanoparticles (NPs) at 60 0C by solvothermal route in which the cadmium and selenium precursors have been dissolved in deionized water, ethylene glycol and hydrazine hydrate. This route is very facile, inexpensive and less hazardous and ensures almost complete yield of the precursors. The powder product was well characterized by powder X- ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), UV-Vis spectroscopy, Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR) .It is investigated that as synthesized powder has a hexagonal (Wurtzite) structure of CdSe with diameters of the particles are in the range of 10-15 nm. The formation mechanism is also discussed.
Javed Ijaz Hussain; Sunil Kumar; Athar Adil Hashmi; Zaheer Khan
Abstract
In this paper we report the effect of aniline concentrations on the growth and size of silver nanocrystals using aniline and silver nitrate as reductant and oxidant, respectively. UV-Vis spectroscopy, transmission electron microscopy (TEM) and selected areas electron diffraction (SAED) have been employed ...
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In this paper we report the effect of aniline concentrations on the growth and size of silver nanocrystals using aniline and silver nitrate as reductant and oxidant, respectively. UV-Vis spectroscopy, transmission electron microscopy (TEM) and selected areas electron diffraction (SAED) have been employed to characterize silver nanoparticles. The TEM images show that silver nanocrystals are roughly spherical and of uniform particle size, and the average particle size is ca. 25 nm. A broad surface plasmon resonance band appears at 400 nm. The rings patterns are in good agreement with the standard values of the face-centered-cubic form of silver nanocrystals. This is attributed to the adsorption of aniline and /or interparticle interaction onto the surface of Ag-nanocrystals through electrostatic interactions between the lone-pairs electrons of –NH2 and positive surface of Ag- nanoparticles.