Studies on Characterization, Optical Absorption, and Photoluminescence of Yttrium Doped ZnS Nanoparticles

Pure ZnS and ZnS:Y nanoparticles were synthesized by a chemical coprecipitation route using EDTA-ethylenediamine as a stabilizing agent. X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectrometry (FTIR), thermogravimetric-differential scanning calorimetry (TG-DSC), and UV-visible and photoluminescence (PL) spectroscopy were employed to characterize the as-synthesized ZnS and ZnS:Y nanoparticles, respectively. XRD and TEM studies show the formation of cubic ZnS:Y particles with an average size of ~4.5 nm. The doping did not alter the phase of the zinc sulphide, as a result the sample showed cubic zincblende structure. The UV-visible spectra of ZnS and ZnS:Y nanoparticles showed a band gap energy value, 3.85 eV and 3.73 eV, which corresponds to a semiconductor material. A luminescence characteristics such as strong and stable visible-light emissions in the orange region alone with the blue emission peaks were observed for doped ZnS nanoparticles at room temperature. The PL intensity of orange emission peak was found to be increased with an increase in yttrium ions concentration by suppressing blue emission peaks. These results strongly propose that yttrium doped zinc sulphide nanoparticles form a new class of luminescent material.

Download Full-text

Study on Structure, Thermal Behavior, and Viscoelastic Properties of Nanodiamond-Reinforced Poly (vinyl alcohol) Nanocomposites

Polymers ◽

10.3390/polym13091426 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1426

Author(s):

Tomáš Remiš ◽

Petr Bělský ◽

Tomáš Kovářík ◽

Jaroslav Kadlec ◽

Mina Ghafouri Azar ◽

...

Keyword(s):

Electron Microscopy ◽

Mechanical Analysis ◽

Single Step ◽

Poly Vinyl Alcohol ◽

Scanning Calorimetry ◽

X Ray Scattering ◽

Transmission Electron ◽

Primary Particles ◽

Solution Casting Method ◽

Average Size

In this work, advanced polymer nanocomposites comprising of polyvinyl alcohol (PVA) and nanodiamonds (NDs) were developed using a single-step solution-casting method. The properties of the prepared PVA/NDs nanocomposites were investigated using Raman spectroscopy, small- and wide-angle X-ray scattering (SAXS/WAXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It was revealed that the tensile strength improved dramatically with increasing ND content in the PVA matrix, suggesting a strong interaction between the NDs and the PVA. SEM, TEM, and SAXS showed that NDs were present in the form of agglomerates with an average size of ~60 nm with primary particles of diameter ~5 nm. These results showed that NDs could act as a good nanofiller for PVA in terms of improving its stability and mechanical properties.

Download Full-text

Synthesis and Photonics Applications of Afzelechin Conjugated Silver Nanoparticles

Coatings ◽

10.3390/coatings11111295 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1295

Author(s):

Shahid Ali ◽

Muhammad Rahim ◽

Perveen Fazil ◽

Malik Shoaib Ahmad ◽

Azeem Ullah ◽

...

Keyword(s):

Silver Nanoparticles ◽

Band Gap ◽

Band Gap Energy ◽

Visible Absorption ◽

Force Microscopy ◽

Atomic Force ◽

Uv Visible ◽

Size And Morphology ◽

Average Size ◽

20 Nm

The silver nanoparticles were synthesized, functionalized with afzelechin and characterized using UV-Visible spectroscopy. A difference of 20 nm was observed in surface plasmon resonance of bare and functionalized silver nanoparticles which indicates afzelechin conjugation with silver nanoparticles. The atomic force microscopy (AFM) technique was used for the determination of the size and morphology of synthesized silver nanoparticles. The afzelechin conjugated silver nanoparticles were spherical and their sizes ranged from 3 to 10 nm with an average size of 8 nm while the bare silver nanoparticles were also spherical and their sizes ranged from 3 to 10 nm with an average size of 6 nm. The average sizes were also calculated by fitting their UV-Visible absorption spectra. Fitting is based on the Mie and Mie Gans models, which deduced that afzelechin conjugated silver nanoparticles were 96.5% spherical and 3.5% spheroidal with an average size of 5 nm while bare silver nanoparticles were 100% spherical with an average size of 4 nm. Both the fitting model as well as the AFM results showed a difference of 3 nm between the sizes of afzelechin conjugated silver nanoparticles while 2 nm differences was observed for bare silver nanoparticles. The band gap energy of afzelechin conjugated silver nanoparticles and bare silver nanoparticles were calculated via Tauc’s equation and were found to be 5.1 eV and 5.4 eV, respectively. A difference of 0.3 eV was observed in band gap energies of afzelechin conjugated silver nanoparticles and bare silver nanoparticles.

Download Full-text

Synthesis and optical properties of composites based on ZnS nanoparticles embedded in layered magadiite

Clay Minerals ◽

10.1180/claymin.2013.048.5.06 ◽

2013 ◽

Vol 48 (5) ◽

pp. 739-748 ◽

Cited By ~ 9

Author(s):

Yufeng Chen ◽

Gensheng Yu

Keyword(s):

Electron Microscopy ◽

Optical Properties ◽

Interlayer Space ◽

Transmission Spectra ◽

Zns Nanoparticles ◽

X Ray ◽

Transmission Electron ◽

Uv Visible ◽

Photoluminescence Enhancement ◽

Properties Of Composites

AbstractComposites based on ZnS nanparticles embedded in layered magadiite were synthesized via a three step process : protonation of Na-magadiite, ion exchange in order to introduce Zn(NH3)42+ in the interlayer space, and addition of Na2S to form ZnS particles in the interlayer space of magadiite. The composites obtained were characterized by X-ray power diffraction (XRD), Scanning Electron Microscopy coupled with Energy Dispersive Spectroscopy (SEM-EDS), Transmission Electron Microscopy (TEM), Raman spectroscopy, Photoluminscence spectra (PL), and UV-visible transmission spectra (UV-vis). Results indicated that ZnS nanoparticles embedded in magadiite presented different optical properties and photoluminescence enhancement properties compared with those of uncovered ZnS particles (without host magadiite).

Download Full-text

Active Polymer Nanoparticles: Delivery of Antibiotics

MRS Proceedings ◽

10.1557/proc-1019-ff05-06 ◽

2007 ◽

Vol 1019 ◽

Cited By ~ 2

Author(s):

Monica Rabinovich ◽

Shankari N. Somayaji ◽

Rajeev Raghavan Pillai ◽

Michael C. Hudson ◽

J. Kent Ellington ◽

...

Keyword(s):

Electron Microscopy ◽

Drug Loading ◽

Plga Nanoparticles ◽

Polymer Nanoparticles ◽

Copolymer Composition ◽

Zns Nanoparticles ◽

Primary Mouse ◽

Evaporation Technique ◽

Uv Visible ◽

Scanning Electron

AbstractAntibiotic-encapsulated PLA and PLGA nanoparticles were prepared by the single emulsion-solvent evaporation technique. Different PLA and PLGA systems were prepared, varying the copolymer composition and the amount of the surfactant polyvinyl alcohol. Characterization and drug loading studies were performed by UV-Visible spectrophotometry, dynamic light scattering, and scanning electron microscopy (SEM).Simultaneously, in order to model the diffusion of the nanoparticles within the osteoblast, QDs such as functionalized InGaP/ZnS and polymer encapsulated InGaP/ZnS nanoparticles were added to confluent cultures of primary mouse osteoblasts. Following PreFer fixation, cultures were examined via confocal microscopy. QDs were clearly visible within osteoblasts.

Download Full-text

Crystalline Quality, Composition Homogeneity, Tellurium Precipitates/Inclusions Concentration, Optical Transmission, and Energy Band Gap of Bridgman Grown Single-Crystalline Cd1−xZnxTe (0 ≤ x ≤ 0.1)

Materials ◽

10.3390/ma14154207 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4207

Author(s):

Ana María Martínez ◽

Paula Giudici ◽

Alicia Beatriz Trigubó ◽

Raúl D’Elía ◽

Eduardo Heredia ◽

...

Keyword(s):

Band Gap ◽

Optical Transmission ◽

Band Gap Energy ◽

Crystalline Quality ◽

Infrared Spectrometry ◽

Scanning Calorimetry ◽

Wavelength Dispersive Spectroscopy ◽

Single Crystalline ◽

Gap Energy ◽

Te Precipitates

Cd1−xZnxTe (0 ≤ x ≤ 0.1) ingots were obtained by Bridgman’s method using two different speeds in order to find the optimal conditions for single-crystalline growth. Crystalline quality was studied by chemical etching, the elemental composition by wavelength dispersive spectroscopy (WDS), tellurium (Te) precipitates/inclusions concentration by differential scanning calorimetry (DSC), optical transmission by Fourier transformed infrared spectrometry (FTIR), and band gap energy (Egap) by photoluminescence (PL). It was observed that the ingots grown at a lower speed were those of the best crystalline quality, having at most three grains of different crystallographic orientation. The average dislocations density in all of them were similar and correspond to materials of good quality. EPMA results indicated that the homogeneity in the composition was excellent in the ingots central part. The concentration of Te precipitates/inclusions in all ingots was below the instrument (DSC) detection limit, 0.25% wt/wt. In the case of wafers from Cd0.96Zn0.04Te and Cd0.90Zn0.10Te ingots, the optical transmission was better than that of commercial materials and varied between 60% and 70%, while for pure CdTe, the transmission range was between 50% and 55%, the latter being decreased by the presence of Te precipitates/inclusions. The band gap energy Eg of different wafers was experimentally obtained by PL measurements at 76 K. We observed that Eg increased with the Zn concentration of the wafers, following a linear regression comparable to those proposed in the literature, and consistent with the results obtained with other techniques.

Download Full-text

Green Synthesis and Antibacterial Activity of Cobalt Nanoparticle from Calotropis gigantae

Journal of the Mexican Chemical Society ◽

10.29356/jmcs.v64i2.1118 ◽

2020 ◽

Vol 64 (2) ◽

Author(s):

Sauban Ghani ◽

Farheen Ghani

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Antibacterial Activities ◽

Indirect Measurement ◽

Cobalt Nanoparticles ◽

Wild Plant ◽

Infrared Spectrometry ◽

Calotropis Gigantea ◽

Uv Visible ◽

Average Size

Abstract. Cobalt nanoparticles (CoNPs) were successfully synthesized by taking a simple green synthetic route using metal salts and flower extracts of a wild plant Calotropis gigantea which act as reducing as well as the stabilizing agent. The synthesized Cobalt nanoparticles (CoNPs) were characterized using various techniques such as UV-visible spectrophotometry and Fourier transform infrared spectrometry. Size characterization of the samples was made by Dynamic light-scattering (DLS) and Transmission electron microscope (TEM). The micrographs of the synthesized CoNPs showed the formation of spherical nanoparticles with an average size of 13 ± 5 nm. The CoNPs were stable at room temperature (25 °C) for six months. Zeta potential values provided an indirect measurement of the net charge on the Cobalt nanoparticles (CoNPs) surface. The antibacterial activities of cobalt nanoparticles (CoNPs) were studied under varying concentrations of CoNPs with respect to Staphylococcus aureus and Escherichia coli. Resumen. Las nanopartículas de cobalto (CoNPs) se sintetizaron con éxito al tomar una ruta sintética verde simple usando sales metálicas y extractos de flores de una planta silvestre Calotropis gigantea que actúa como agente reductor y estabilizador. Las nanopartículas de cobalto sintetizadas (CoNPs) se caracterizaron utilizando diversas técnicas, como la espectrofotometría UV-visible y la espectrometría infrarroja por transformada de Fourier. La caracterización del tamaño de las muestras se realizó mediante dispersión dinámica de luz (DLS) y microscopio electrónico de transmisión (TEM). Las micrografías de los CoNPs sintetizados mostraron la formación de nanopartículas esféricas con un tamaño promedio de 13 ± 5 nm. Los CoNPs fueron estables a temperatura ambiente (25 °C) durante seis meses. Los valores potenciales de Zeta proporcionaron una medición indirecta de la carga neta en la superficie de nanopartículas de cobalto (CoNPs). Las actividades antibacterianas de las nanopartículas de cobalto (CoNPs) se estudiaron bajo concentraciones variables de CoNPs con respecto a Staphylococcus aureus y Escherichia coli.

Download Full-text

Preparation and lower critical solution temperature behavior investigation of new thermoresponsive poly(N-isopropylacrylamide-co-phthalocyanine) magnetic nanocomposites containing phthalocyanine-coated Fe3O4 hybrid

Canadian Journal of Chemistry ◽

10.1139/cjc-2016-0109 ◽

2016 ◽

Vol 94 (8) ◽

pp. 723-731

Author(s):

Ali Reza Karimi ◽

Leila Rahimi ◽

Farnaz Azadikhah ◽

Sahar Ghadimi

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Hybrid Nanoparticles ◽

Solution Temperature ◽

Magnetic Nanocomposites ◽

Scanning Calorimetry ◽

Magnetic Hydrogel ◽

Average Size ◽

Scanning Electron ◽

Critical Solution Temperatures

New thermoresponsive poly(N-isopropyl acrylamide-co-phthalocyanine) magnetic nanocomposites were prepared by in situ dispersion polymerization. 4-Nitrophthalic acid and CoCl2 were employed to synthesize tetranitrophthalocyanine and then it was converted to tetraaminophthalocyanine by sodium sulfide. The cobalt tetra(N-carbonylacrylic)aminophthalocyanine monomer was obtained by reaction of tetraaminophthalocyanine with maleic anhydrid. N-isopropylacrylamide as the main monomers, N,N′-methylenebisacrylamide as the cross-linker, poly(N-vinylpyrrolidone) as the steric stabilizer, potassium persulfate as the initiator, and new Fe-phthalocyanine oligomer/Fe3O4 nanohybrid particles (FePc/Fe3O4) as nanoparticles were used. The magnetite nanocomposites were characterized by Fourier-transform infrared spectrum, X-ray diffraction spectroscopy, scanning electron microscopy, thermogravimetric analysis, vibrating sample magnetometer, and differential scanning calorimetry. The results showed that the lower critical solution temperatures of the hydrogel nanocomposits were influenced by the content of FePc/Fe3O4 hybrid nanoparticles. The lower critical solution temperatures of the magnetic hydrogel nanocomposites F3 and F4 were at about 34 and 40 °C. The results show that the increase of FePc/Fe3O4 nanoparticle content caused the LCSTs of the hydrogels to increase. FePc/Fe3O4 nanoparticles were prepared from 4,4′-isopropyliden-bis-dioxydiphthalonitrile and FeCl3·6H2O via the solvothermal route. The sizes of nanoparticles were determined by scanning electron microscopy. They are spherical in shape and the average size of them is between 30 and 70 nm.

Download Full-text

Incorporation of CdFe2O4SiO2 nanoparticles in SbPO4-ZnO-PbO glasses by melting quenching process

Eclética Química Journal ◽

10.26850/1678-4618eqj.v43.2.2018.p32-43 ◽

2018 ◽

Vol 43 (2) ◽

pp. 32 ◽

Cited By ~ 1

Author(s):

Juliane Orives ◽

Wesley R. Viali ◽

Marina Magnani ◽

Marcelo Nalin

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Sio2 Nanoparticles ◽

Silica Layer ◽

Scanning Calorimetry ◽

Optimum Parameters ◽

Transmission Electron ◽

Vis Spectroscopy ◽

Quenching Method ◽

Average Size

The development of glasses containing nanoparticles dispersed homogeneously with controlled size and optimum parameters for functionality is a challenge. Glasses in the ternary system 60SbPO4-30ZnO-10PbO containing CdFe2O4-SiO2 nanoparticles were studied. The CdFe2O4 nanoparticles were synthesized by the coprecipitation method and the average size was 3.9 nm and then, they were protected by a silica layer. The nanoparticles were mixed with the glass precursors and transformed into glasses by melt-quenching method. Thermal and structural properties were evaluated by differential scanning calorimetry, Raman spectroscopy, scanning electronic microscopy and transmission electron microscopy. While the optical properties were studied by M-Lines spectroscopy and UV-VIS spectroscopy. The glass samples obtained were completely transparent, with amber color and showed no sign of crystallization according to the techniques used. Scanning and transmission electron microscopy confirm that the methodology used for the incorporation of nanoparticles was efficient. The nanoparticle protection methodology prior to incorporation into glasses may contribute towards the development of glasses containing nanoparticles useful for magneto-optics devices.

Download Full-text

Synthesis and Applications of a Novel Copolymer of Chitosan as Heavy Metal Removal Agent

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.233-235.741 ◽

2011 ◽

Vol 233-235 ◽

pp. 741-746

Author(s):

Hong Jie Tang ◽

Juan Juan Guo ◽

Bao Tian Shan ◽

Jin Ren Lu

Keyword(s):

Electron Microscopy ◽

Heavy Metal ◽

Heavy Metal Ions ◽

Graft Polymerization ◽

Metal Removal ◽

Heavy Metal Removal ◽

Infrared Spectrometry ◽

Scanning Calorimetry ◽

Adsorption Capacities ◽

Scanning Electron

The graft copolymer, chitosan-g-AM-AA, was prepared through graft polymerization of acryamide and acryl acid onto chitosan by K2S2O8 initiation under homogeneous conditions in 2 wt% acetic acid. The product was characterized by infrared spectrometry (IR), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The adsorption capacities and removal ratioes of the copolymer for heavy metal ions were studied by using medium concentration (about 50mg/L) of Cu2+ ,Zn 2+and Pb2+ at pH 6. The results indicated the copolymer exhibited higher adsorbability than chitosan.

Download Full-text

Biosynthesis and Antimicrobial Activity of Semiconductor Nanoparticles against Oral Pathogens

Bioinorganic Chemistry and Applications ◽

10.1155/2014/347167 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 63

Author(s):

C. Malarkodi ◽

S. Rajeshkumar ◽

K. Paulkumar ◽

M. Vanaja ◽

G. Gnanajobitha ◽

...

Keyword(s):

Antimicrobial Activity ◽

Blood Circulation ◽

Cadmium Sulphide ◽

Zinc Sulphide ◽

X Ray Diffraction ◽

Zns Nanoparticles ◽

Transmission Electron ◽

Oral Pathogens ◽

Amine Groups ◽

Average Size

Dental care is an essential phenomenon in human health. Oral pathogens can cause severe break which may show the way to serious issues in human disease like blood circulation and coronary disease. In the current study, we demonstrated the synthesis and antimicrobial activity of cadmium sulphide and zinc sulphide nanoparticles against oral pathogens. The process for the synthesis of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles is fast, novel, and ecofriendly. Formation of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles was confirmed by surface plasmon spectra using UV-Vis spectrophotometer. The morphology of crystalline phase of nanoparticles was determined from transmission electron microscopy (TEM) and X-ray diffraction (XRD) spectra. The average size of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles was in the range of 10 nm to 25 nm and 65 nm, respectively, and the observed morphology was spherical. The results indicated that the proteins, which contain amine groups, played a reducing and controlling responsibility during the formation of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles in the colloidal solution. The antimicrobial activity was assessed against oral pathogens such asStreptococcussp.Staphylococcussp.Lactobacillussp., andCandida albicansand these results confirmed that the sulphide nanoparticles are exhibiting good bactericidal activity.

Download Full-text