scholarly journals Growth of β-NaYF4:Eu3+ Crystals by the Solvothermal Method with the Aid of Oleic Acid and Their Photoluminescence Properties

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3711 ◽  
Author(s):  
Jianhua Huang ◽  
Xiaojing Wang ◽  
An Shao ◽  
Guoping Du ◽  
Nan Chen

Lanthanide-doped hexagonal β-NaYF4 crystals have received much attention in recent years due to their excellent photoluminescence properties. However, lanthanide-doped β-NaYF4 crystals with micron and submicron scales as well as uniform morphology have received less attention. In this study, Eu3+-doped β-NaYF4 (β-NaYF4:Eu3+) crystals of micron and submicron size scales were synthesized using the solvothermal method with ethylene glycol as the solvent. The β-NaYF4:Eu3+ crystals were highly crystallized. A comparison of the characteristics of the β-NaYF4:Eu3+ crystals synthesized with and without the use of oleic acid as a surfactant was conducted. It was found that the utilization of oleic acid as a surfactant during their synthesis greatly decreased their particle size from micron to submicron scale, while adding a small amount of ethanol further reduced their particle size. In addition, they exhibited much smoother surfaces and more uniform morphologies, which were hexagonal prism bipyramids. The microstructural characteristics and photoluminescence properties of the β-NaYF4:Eu3+ crystals were studied in detail. Results showed that β-NaYF4:Eu3+ crystals prepared with the aid of oleic acid as a surfactant during their synthesis exhibited stronger photoluminescence.

2013 ◽  
Vol 813 ◽  
pp. 399-402
Author(s):  
Chimsook Thitipha ◽  
Thitiphan Chimsook

The aim of present work was to prepare floating microsphere of ketoprofen using matrix polymer of chitosan and poly (ethylene glycol) by solvent diffusion method. The floating microsphere of ketoprofen was prepared from matrix polymer of chitosan and poly (ethylene glycol) with various composition ratios and evaluated such as particle size, drug compatibility and drug release of microspheres. The scanning electron microscopy of microspheres confirmed their hollow structures with smooth surface. Formulation CPK 4 to CPK 6 exhibited the best controlled release pattern in ketoprofen. The concentration and size of poly (ethylene-glycol) affected the particle size, percentage yield and drug release of microspheres.


2016 ◽  
Vol 5 (6) ◽  
Author(s):  
Trinh Xuan Anh ◽  
Duong Thanh Tung ◽  
Do Quy Nhan ◽  
Tran Vinh Hoang ◽  
Do Quang Trung ◽  
...  

AbstractAntimony-doped tin oxide (ATO) nanoparticles (NPs) (Sb-doped content 3%, 10%, and 15%) were synthesized by the (2 l autoclave, medium-scale) solvothermal method followed by sintering at various temperatures (500°C, 800°C, 900°C and 1000°C) so they would crystallize. The particle size increased from several to tens of nanometers with the increase of sintered temperature from 500°C to 1000°C, sharply from 800°C to 1000 °C; ~30 g of final product was received for each experiment. More interestingly, the crystallinity of the as-synthesized ATO was also increased with the increasing Sb doped content from 3% to 15%. The ATO NPs were coated onto glass substrates and then sintered at 500°C, which effectively prevented transmittance of infrared (IR) wavelengths (>800 nm) with 10% wt Sb-doped content, which is useful for thermal insulated glass coating application.


2013 ◽  
Vol 634-638 ◽  
pp. 2276-2279 ◽  
Author(s):  
Gang Xu ◽  
Min Zhang ◽  
Ping Ou ◽  
Yi Zhang ◽  
Gao Rong Han

Monodispersed Fe3O4 magnetite nanoparticles were successfully synthesized via a simple solvothermal method, in which Fe(NO3)3•9H2O was used as the starting materials, KOH as the mineralizer, and ethylene glycol (en) as the solvent. X-ray diffraction (XRD) and selected area electron diffraction (SAED) were employed to characterize the phase composition, transmission electron microscope (TEM) to observe the morphology and the particle size, and physical property measurement system (PPMS) to investigate the magnetic property of the synthesized powders, respectively. The synthesized Fe3O4 magnetite nanoparticles are of 50-100nm in size, and of notable ferromagnetic property. The saturation magnetization, remanent magnetization, and coercive field are 68.8emu•g-1, 12.9emu•g-1, 138.5Oe, respectively. Based on the experimental resuts, the formation mechanism and the well monodispersed reason of the solvothersized Fe3O4 nanoparticles are discussed.


2008 ◽  
Vol 8 (11) ◽  
pp. 5776-5780 ◽  
Author(s):  
C. Manikyala Rao ◽  
V. Sudarsan ◽  
R. S. Ningthoujam ◽  
U. K. Gautam ◽  
R. K. Vatsa ◽  
...  

ZnGa2O4 nanoparticles doped with lanthanide ions (Tb3+ and Eu3+) were prepared at a low temperature of 120 °C based on urea hydrolysis in ethylene glycol medium. X-ray diffraction studies have confirmed that strain associated with nanoparticles changes as Tb3+ gets incorporated in the ZnGa2O4 lattice. Based on steady state emission and excitation studies of ZnGa2O4:Tb nanoparticles, it has been inferred that ZnGa2O4 host is characterized by a broad emission around 427 nm and there exists energy transfer between the host and Tb3+ ions. Unlike this, for ZnGa2O4:Eu nanoparticles, very poor energy transfer between the host and Eu3+ ions is observed. These nanoparticles when coated with ligands like oleic acid results in their improved dispersion in organic solvents like chloroform and dichloromethane.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Wei Kong ◽  
Bo Liu ◽  
Bo Ye ◽  
Zhongping Yu ◽  
Hua Wang ◽  
...  

Titanium dioxide (TiO2) nanocrystals of different shape were successfully synthesized in a new microemulsion system through a solvothermal process. The TiO2nanocrystals were prepared from the reaction of tetrabutyl titanate (TBT),H2O, and oleic acid (OA), which were used as solvent and surfactant at 300∘Cand 240∘Cin a stainless steel autoclave. The sphere, polygon, and rhombus-shaped nanocrystals have been prepared at 300∘Cand the dot- and- rod shaped nanocrystals have been synthesized at 240∘C. The effect of the reaction time on the shape and size of TiO2nanocrystals in this method was studied in the present paper. The size distribution of TiO2nanocrystals prepared at 300∘Cfor different hours is also studied. In addition, an attempt to describe the mechanism of shape change of TiO2nanocrystals was presented in this paper.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2181
Author(s):  
Ryan D. Mellor ◽  
Andreas G. Schätzlein ◽  
Ijeoma F. Uchegbu

Gold nanoparticles (AuNPs) are used experimentally for non-invasive in vivo Raman monitoring because they show a strong absorbance in the phototherapeutic window (650–850 nm), a feature that is accompanied by a particle size in excess of 100 nm. However, these AuNPs cannot be used clinically because they are likely to persist in mammalian systems and resist excretion. In this work, clustered ultrasmall (sub-5 nm) AuNP constructs for in vivo Raman diagnostic monitoring, which are also suitable for mammalian excretion, were synthesized and characterized. Sub-5 nm octadecyl amine (ODA)-coated AuNPs were clustered using a labile dithiol linker: ethylene glycol bis-mercaptoacetate (EGBMA). Upon clustering via a controlled reaction and finally coating with a polymeric amphiphile, a strong absorbance in the phototherapeutic window was demonstrated, thus showing the potential suitability of the construct for non-invasive in vivo detection and monitoring. The clusters, when labelled with a biphenyl-4-thiol (BPT) Raman tag, were shown to elicit a specific Raman response in plasma and to disaggregate back to sub-5 nm particles under physiological conditions (37 °C, 0.8 mM glutathione, pH 7.4). These data demonstrate the potential of these new AuNP clusters (Raman NanoTheranostics—RaNT) for in vivo applications while being in the excretable size window.


Author(s):  
В.Я. Рудяк ◽  
А.В. Минаков ◽  
М.И. Пряжников

AbstractThe electric conductivity is experimentally studied in nanofluids based on water and ethylene glycol containing copper and aluminum particles. Other properties, such as heat conductivity and rheological characteristics, were evaluated as well. The electric conductivity of nanofluids is shown to increase almost linearly with a nanoparticle concentration, but, unlike the heat conductivity, a gain in electric conductivity is due to a decrease in particle size. In this respect, the mechanisms of electric conductivity and heat conductivity are assumed to have the fundamentally different nature.


2011 ◽  
Vol 10 (2) ◽  
pp. 25
Author(s):  
Anirut Leksomboon ◽  
Bunjerd Jongsomjit

In this present study, the spherical silica support was synthesized from tetraethyloxysilane (TEOS), water, sodium hydroxide, ethylene glycol and n-dodecyltrimethyl ammonium bromide (C12TMABr). The particle size was controlled by variation of the ethylene glycol co-solvent weight ratio of a sol-gel method preparation in the range of 0.10 to 0.50. In addition, the particle size apparently increases with high weight ratio of co-solvent, but the particle size distribution was broader. The standard deviation of particle diameter is large when the co-solvent weight ratio is more than 0.35 and less than 0.15. However, the specific surface area was similar for all weight ratios ranging from 1000 to 1300 m2/g. The synthesized silica was spherical and has high specific surface area. The cobalt was impregnated onto the obtained silica to produce the cobalt catalyst used for CO2 hydrogenation.</


2018 ◽  
Vol 56 (1) ◽  
pp. 31
Author(s):  
Luong Thi Quynh Anh ◽  
Nguyen Van Dan ◽  
Do Minh Nghiep

The crystalline nanoparticles of Ni0.2Zn0.8Fe2O4 ferrite were synthesized by chemical co-precipitation with precursor concentration of 0.1M, then modified by 0.25M solution of oleic acid in pentanol, finally heated at temperatures 120, 140, 160 and 180oC for 6h in autoclave. The XRD, EDS and TEM confirmed that all of samples are crystalline and their particle size are 6, 6.5, 7 and 8 nm. The magnetic properties showed that the coercive force, the remanence of samples are about zero, the saturation magnetization Ms has values from 14.20 to 27.12 emu/g.


2021 ◽  
Vol 2056 (1) ◽  
pp. 012048
Author(s):  
A M Dorokhina ◽  
V V Bakhmetyev ◽  
H Kominami ◽  
A Toru ◽  
M Hisashi

Abstract To date, nanophosphors have found application in various fields, one of which is medicine. These phosphors were developed with the aim to become one of the components of a drug for photodynamic therapy of oncological diseases. The aim of this work was to study the effect of the duration, environment, and stabilizers of solvothermal synthesis on the microstructure and luminescent properties of the YF3:Ce nanophosphor. The solvothermal synthesis technique was carried out in three different media: water, ethanol, and ethylene glycol. The optimal duration of the synthesis was also determined (the synthesis was carried out at a temperature of 200°C for 4…20 hours). The dependence of the YF3 luminescence on the phase composition and the solvothermal synthesis medium was studied. Using SEM, the morphology and particle size of YF3:Ce phosphors were studied depending on different stabilizers (polyethylene glycol, polyethyleneimine, polyvinylpyrrolidone). The luminescence intensity of YF3:Ce and Na(Y1,5Na0,5)F6:Ce samples was compared.


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