scholarly journals Mesoporous Silica CoatedCeF3:Tb3+Particles for Drug Release

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Deyan Kong ◽  
Piaoping Yang ◽  
Zhenling Wang ◽  
Ping Chai ◽  
Shanshan Huang ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Fluorescence Spectra ◽  
Nitrogen Absorption ◽  
X Ray Diffraction ◽  
Green Fluorescence ◽  
Structure Directing Agent ◽  
X Ray ◽  
Transmission Electron ◽  
Large Pore Volume ◽  
Desorption Isotherms

CeF3:Tb3+nanoparticles were successfully prepared by a polyol process using diethylene glycol (DEG) as solvent. After being coated with dense silica, theseCeF3:Tb3+nanoparticles can be coated with mesoporous silica using nonionic triblock copolymerEO20PO70EO20(P 123) as structure-directing agent. The composite can load ibuprofen and release the drug in the PBS. The composite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen absorption/desorption isotherms, fluorescence spectra, and UV/Vis absorption spectra, respectively. The composite particles have considerable large pore volume and large surface area. In addition, the composite still emits strong green fluorescence(Tb3+)and can be used as fluorescent probes in drug delivery system.

Luminescent Properties of Gd2MoO6:Eu3+ Nanophosphor for WLEDs

2021 ◽  
Author(s):  
Yan Chen ◽  
Yuemei Lan ◽  
Dong Wang ◽  
Guoxing Zhang ◽  
Wenlong Peng ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Fluorescence Spectra ◽  
Solvothermal Method ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

A series of Gd2-xMoO6:xEu3+(x=0.18-0.38) nanophosphors were synthesized by the solvothermal method. The properties of this nanophosphor were characterized by x-ray diffraction (XRD), transmission electron microscope (TEM), fluorescence spectra and diffuse...

Preparation, Characterization and Spectroscopy of Eu3+ in Gd2O3 Nanorods

2008 ◽  
Vol 8 (3) ◽  
pp. 1398-1403 ◽  
Author(s):  
Liqin Liu ◽  
En Ma ◽  
Renfu Li ◽  
Xueyuan Chen
Keyword(s):  
Electron Microscopy ◽  
Fluorescence Spectra ◽  
Filling Factor ◽  
Energy Levels ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Eu3+:Gd2O3 nanorods were prepared by a hydrothermal method. X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and Fourier transform-infrared spectroscopy were used to characterize the resulting samples. Emission and excitation spectra were studied using xenon excited spectroscopic experiments at 10 K. Energy transfer from Gd3+ to Eu3+, from the band gap of the host to Eu3+, and from Eu3+ (S6) to Eu3+ (C2) was observed. The energy levels of Eu3+ at the C2 site of cubic Gd2O3 were experimentally determined according to the fluorescence spectra at 10 K, and fit well with the theoretical values. The standard deviation for the optimal fit was 12.9 cm−1. The fluorescent lifetime of 5D0 (2.3 ms at 295 K) was unusually longer than that of the bulk counterparts (0.94 ms), indicating a small filling factor (0.55) for the nanorod volume. However the lifetime of 5D1 was much shorter than that of the bulk counterparts, 65 μs at 10 K, 37 μs at 295 K.

scholarly journals Control the Morphologies and the Pore Architectures of Mesoporous Silicas through a Dual-Templating Approach

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Hairui Wang ◽  
Hao Chen ◽  
Zhen Xu ◽  
Sibing Wang ◽  
Baozong Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mesoporous Silica ◽  
Volume Ratio ◽  
Mesoporous Silicas ◽  
Low Molecular Weight ◽  
Silica Nanospheres ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Microscopy Techniques

Mesoporous silica nanospheres were prepared using a chiral cationic low-molecular-weight amphiphile and organic solvents such as toluene, cyclohexane, and tetrachlorocarbon through a dual-templating approach. X-ray diffraction, nitrogen sorption, field emission scanning electron microscopy, and transmission electron microscopy techniques have been used to characterize the mesoporous silicas. The volume ratio of toluene to water plays an important role in controlling the morphologies and the pore architectures of the mesoporous silicas. It was also found that mesoporous silica nanoflakes can be prepared by adding tetrahydrofuran to the reaction mixtures.

scholarly journals Preparation of Mesoporous Silica-Supported Palladium Catalysts for Biofuel Upgrade

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ling Fei ◽  
Harvind Kumar Reddy ◽  
Joshua Hill ◽  
Qianglu Lin ◽  
Bin Yuan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mesoporous Silica ◽  
Palladium Catalysts ◽  
Methyl Esters ◽  
Catalyst Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Cnts Surface ◽  
Supported Palladium

We report the preparation of two hydrocracking catalysts Pd/CoMoO4/silica and Pd/CNTs/CoMoO4/silica (CNTs, carbon nanotubes). The structure, morphologies, composition, and thermal stability of catalysts were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), and thermogravimetric analysis (TGA). The catalyst activity was measured in a Parr reactor with camelina fatty acid methyl esters (FAMEs) as the feed. The analysis shows that the palladium nanoparticles have been incorporated onto mesoporous silica in Pd/CoMoO4/silica or on the CNTs surface in Pd/CNTs/CoMoO4/silica catalysts. The different combinations of metals and supports have selective control cracking on heavy hydrocarbons.

Synthesis of SBA-15/MCM-41 bimodal mesoporous silica

2016 ◽  
Vol 1817 ◽  
Author(s):  
Leyla Y. Jaramillo ◽  
Wilson A. Henao ◽  
Elizabeth Pabón-Gelves
Keyword(s):  
Mesoporous Silica ◽  
Textural Properties ◽  
New Materials ◽  
X Ray Diffraction ◽  
Main Interest ◽  
Structure Directing Agent ◽  
X Ray ◽  
Synthesis Parameters ◽  
Nanostructured Silica ◽  
Mcm 41

ABSTRACTNanostructured silica materials with different morphologies and adjustable pore size have been studied by researches worldwide for several applications such as catalysis, separation, adsorption, and templates for new materials. The main interest in the development of these materials is to obtain a structure with a specific combination of pore sizes for a particular application. The morphology and textural properties of pores can be easily changed with the modification of the synthesis parameters, among these, the choice of surfactant or structure directing agent (SDA).Accordingly, in this work, three types of nanostructured silica with different mesoporosity were synthesized by using of CTAB and Pluronic 123 as structure directing agents: SBA-15 and MCM-41 unimodal mesoporous silica and SBA-15/MCM-41 bimodal mesoporous silica.To evaluate the effect of surfactant on the morphology and textural properties of pores, the materials were characterized by scanning electron microscopy (SEM), X-ray Diffraction (XRD) and nitrogen sorption (BET).

Preparation and Optical Properties of CuS Nanochains by a Solvothermal Method

2013 ◽  
Vol 634-638 ◽  
pp. 2218-2221
Author(s):  
Xiu Hui Zhu ◽  
Jian Zhen Liu ◽  
Tian Ai ◽  
Hong Mei Yu
Keyword(s):  
Optical Properties ◽  
Solvothermal Method ◽  
Hydrothermal Reaction ◽  
Hexagonal Phase ◽  
X Ray Diffraction ◽  
Structure Directing Agent ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Size And Morphology

CuS nanochains were prepared via a simple hydrothermal reaction at 140 °C for 12 h, employing Cu(Ac)2•H2O and Thiourea as reactants in the absence of any structure-directing agent. The size and morphology of CuS nanochains were characterized by means of X-ray diffraction (XRD) and Transmission electron microscope (TEM); the optical properties of CuS nanochains were investigated by UV–vis absorption spectrum and Fourier transform infrared (FT-IR) measurements. CuS nanochains were found to be constructed by covellite CuS with a hexagonal phase and composed of nanorods with 40-100 nm length and 25 nm Width. The UV–vis absorption of CuS was observed an increased absorption from 300nm to 650 nm and the band gap of CuS nanochains was 1.91 eV.

Biotemplate Synthesis of Porous Ceria Fiber and Study on its Catalytic Performance

2013 ◽  
Vol 745-746 ◽  
pp. 491-498 ◽  
Author(s):  
Feng Chen ◽  
Cheng Bao Liu ◽  
Zhi Gang Chen
Keyword(s):  
Catalytic Performance ◽  
High Specific Surface Area ◽  
Nitrogen Absorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Hierarchical Porous ◽  
Bet Method ◽  
High Resolution Tem ◽  
Crystallite Diameter

Hierarchical porous ceria with nanocrystalline was successfully synthesized using filter paper as biotemplate. Unique biomorphic microstructures were characterized by Field Emission Scanning Electron Microscope (FESEM), transmission electron microscopy (TEM) and nitrogen absorption-desorption technique. The obtained ceria material showed the repetitious biomimetic structure consisting of fibre with diameter of ca. 1-3 μm and nanopores which had 2-4 nm apertures. The small crystallite diameter (6-8 nm) and the high specific surface area (71.3 m2·g-1) of porous CeO2 were measured by wide-angle X-ray Diffraction (XRD), high resolution TEM (HRTEM) and the BET method. While the concentration of acid fuchsine was 20 mg/L, the porous sample had a higher decoloring rate in a shorter time than others. The decoloring rate can reach 100% after 200 min.

Ultrasonic-hydrothermal Synthesis and Characterization of Mesoporous Anatase TiO2 Microspheres

2011 ◽  
Vol 239-242 ◽  
pp. 2323-2326 ◽  
Author(s):  
Hai Bin Li ◽  
Shu Guang Chen ◽  
Wei Ming Lu ◽  
Qi Cheng Liu
Keyword(s):  
Diffuse Reflectance Spectroscopy ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
Structure Directing Agent ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
Average Size ◽  
Adsorption Desorption

Mesoporous TiO2 microspheres with a combination of large surface and high crystallinity were fabricated by an ultrasonic-hydrothermal method with Octadecylamine as a structure-directing agent and tetrabutyl titanate as a precursor. The mesoporous materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption–desorption measurements, and UV–visible diffuse reflectance spectroscopy (UV-vis). Low-angle XRD and TEM images indicated that the disordered wormhole-like mesoporous architecture of TiO2 microspheres with diameters of about 200-400 nm were actually formed by agglomerization of nanoparticles with an average size of about 10nm. The analysis from N2 adsorption–desorption isotherms showed that the surface area of mesoporous sample was 204.7 m2g-1, with a pore size of 4.3 nm and pore volume of 0.263 cm3g-1 after calcined at 673 K.

Synthesis of Biomorphic Ceria Templated from Crucian Fish Scales

2013 ◽  
Vol 562-565 ◽  
pp. 1353-1357 ◽  
Author(s):  
Feng Chen ◽  
Zhi Gang Chen ◽  
Cheng Bao Liu ◽  
Zheng Ying Wu ◽  
Qiu Yue Lu ◽  
...  
Keyword(s):  
Oxidation Reaction ◽  
Fish Scale ◽  
Fish Scales ◽  
Nitrogen Absorption ◽  
Temperature Programmed Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Oxidation Reaction ◽  
Transmission Electron ◽  
Temperature Programmed

Biomophic ceria with nanocrystalline was successfully synthesized using crucian fish scales as template. Unique biomorphic microstructures were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM) and nitrogen absorption-desorption technique. The obtained ceria material shows the repetitious biomimetic structure consisting of sheet with thickness of ca. 80-100 nm and nanopores which had 2-10 nm apertures. The surface oxygen activity of fish scale-templated CeO2 was enhanced revealed by hydrogen temperature-programmed reduction (H2-TPR) mesurements, because of the higher surface area (113.5 m2/g) and smaller particle size (average of 8.2 nm). Those detailed investigation could infer that the biotemplate product exhibit better catalytic activity in CO oxidation reaction.

scholarly journals Mesoporous Silica SBA-16 Functionalized with Alkoxysilane Groups: Preparation, Characterization, and Release Profile Study

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Gracielle Ferreira Andrade ◽  
Daniel Cristian Ferreira Soares ◽  
Ramon Kenned de Sousa Almeida ◽  
Edésia Martins Barros Sousa
Keyword(s):  
Mesoporous Silica ◽  
Release Rate ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemically Modified ◽  
Transmission Electron ◽  
The Matrix ◽  
Model Drug ◽  
Profile Study

A mesoporous material sphere based on silica, SBA-16, was chemically modified with alkoxysilane using two different solvents: methanol and toluene. The influence of the chemical modification of the matrix on the release rate of a model drug was also studied. The structural characteristics of the materials were evaluated by small-angle X-ray diffraction, N2adsorption, and transmission electron microscopy. The functionalization of the matrix was evaluated using thermal analysis, FTIR spectroscopy,13C and29Si solid-state nuclear magnetic resonance, and elemental analysis, CHN. The results show that alkoxysilane groups have been chemically bonded to silicon atoms on the surface of cubic Im3m mesoporous silica. The influence of the release rate of atenolol molecules from chemically modified mesoporous SBA-16 could be identified, since significant differences could be observed among the release patterns of the different materials.

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