Construction of Carbon Dots Coated Magnetic Hollow Silica Spheres

2019 ◽  
Vol 19 (11) ◽  
pp. 7456-7463 ◽  
Author(s):  
Yue Zhao ◽  
Shizhao Kang ◽  
Pingping Yao ◽  
Yi Zhao ◽  
Xiangnong Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Dots ◽  
Magnetic Particles ◽  
Hydrothermal Reaction ◽  
Carbon Quantum Dots ◽  
Silica Spheres ◽  
Laser Scattering ◽  
Hollow Silica ◽  
X Ray ◽  
Hollow Silica Spheres

Magnetic hollow silica spheres (MHSS) with uniform cavity size and shell thickness were prepared using functionalized SiO2 spheres as templates, on which the magnetic particles were uniformly deposited on their surface. The obtained MHSS exhibited a super-paramagnetic behavior at room temperature. Due to large hollow cavity space and super-paramagnetic characteristics, the MHSS were coated with carbon dots with assistance of (3-Aminopropyl) trimethoxysilane (APS). Thus, the preparedMHSS were mixed with citric acid and APS, followed by hydrothermal reaction at 180 °C, to generate carbon quantum dots coated MHSS (MHSS@CDs). Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder scattering (XRD), X-ray energy dispersive spectral analysis (EDS), Raman spectra and laser scattering particle analyzer were applied to characterize the MHSS and MHSS@CDs.

Effect of hollow silica spheres on water vapor permeability of polyacrylate film

RSC Advances ◽  
2015 ◽  
Vol 5 (15) ◽  
pp. 11485-11493 ◽  
Author(s):  
Yan Bao ◽  
Chunhua Shi ◽  
Yongqiang Yang ◽  
Jianzhong Ma ◽  
Risong Sha
Keyword(s):  
Electron Microscopy ◽  
Shell Thickness ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Silica Spheres ◽  
X Ray Diffraction ◽  
Hollow Silica ◽  
X Ray ◽  
Hollow Silica Spheres ◽  
Transmission Electron

Hollow silica spheres with different hollow size and shell thickness were synthesized via a template method using PS spheres as templates and characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction and Brunauer–Emmett–Teller analysis.

Preparation and Characterization of Hollow Silica Nanospheres

2011 ◽  
Vol 393-395 ◽  
pp. 240-243 ◽  
Author(s):  
Li Li Feng ◽  
Wei Zhao ◽  
Jing Jing Tong ◽  
Guan Hua Yue
Keyword(s):  
Electron Microscopy ◽  
Nitrogen Adsorption ◽  
Silica Shell ◽  
Silica Spheres ◽  
Silica Nanospheres ◽  
Hollow Silica ◽  
Hollow Silica Spheres ◽  
Transmission Electron ◽  
Hollow Silica Nanospheres

Monodisperse hollow silica nanospheres were prepared using functionalized polystyrene (PS) as a template and characterized by transmission electron microscopy (TEM), nitrogen adsorption and thermo gravimetry (TG) techniques. The effect of ammonia amount on hollow silica spheres was explored. It is found that the ammonia amount is important to the fabrication of hollow silica nanospheres. The roughness and thickness of the silica shell increased with the increase of ammonia amount. When ammonia amount reached 20 ml, the product hadn’t been hollow structural. The TGA curves and the BET results of the samples supplied a proof for the formation mechanism of the hollow silica spheres.

scholarly journals Thermoelectric Generator Using Polyaniline-Coated Sb2Se3/β-Cu2Se Flexible Thermoelectric Films

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1518
Author(s):  
Minsu Kim ◽  
Dabin Park ◽  
Jooheon Kim
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Field Emission ◽  
Photoelectron Spectroscopy ◽  
Thermoelectric Generator ◽  
Hydrothermal Reaction ◽  
Water Evaporation ◽  
Pani Film ◽  
Portable Devices ◽  
X Ray

Herein, Sb2Se3 and β-Cu2Se nanowires are synthesized via hydrothermal reaction and water evaporation-induced self-assembly methods, respectively. The successful syntheses and morphologies of the Sb2Se3 and β-Cu2Se nanowires are confirmed via X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), and field emission transmission electron microscopy (FE-TEM). Sb2Se3 materials have low electrical conductivity which limits application to the thermoelectric generator. To improve the electrical conductivity of the Sb2Se3 and β-Cu2Se nanowires, polyaniline (PANI) is coated onto the surface and confirmed via Fourier-transform infrared spectroscopy (FT-IR), FE-TEM, and XPS analysis. After coating PANI, the electrical conductivities of Sb2Se3/β-Cu2Se/PANI composites were increased. The thermoelectric performance of the flexible Sb2Se3/β-Cu2Se/PANI films is then measured, and the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is shown to provide the highest power factor of 181.61 μW/m·K2 at 473 K. In addition, a thermoelectric generator consisting of five legs of the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is constructed and shown to provide an open-circuit voltage of 7.9 mV and an output power of 80.1 nW at ΔT = 30 K. This study demonstrates that the combination of inorganic thermoelectric materials and flexible polymers can generate power in wearable or portable devices.

One-Pot Preparation of Hollow Silica Spheres by Using Thermosensitive Poly(N-isopropylacrylamide) as a Reversible Template

Langmuir ◽  
2009 ◽  
Vol 25 (20) ◽  
pp. 12367-12373 ◽  
Author(s):  
Binyang Du ◽  
Zheng Cao ◽  
Zhenbing Li ◽  
Aixiong Mei ◽  
Xinghong Zhang ◽  
...  
Keyword(s):  
Silica Spheres ◽  
One Pot ◽  
Hollow Silica ◽  
Hollow Silica Spheres

Evolution of Crystalline Phase and Morphology of the Products Formed during the Hydrothermal Synthesis of Y2O3 Powders

2011 ◽  
Vol 189-193 ◽  
pp. 1275-1279
Author(s):  
Ying Wang ◽  
Gao Yang Zhao ◽  
Li Yuan
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Treatment ◽  
Crystalline Phase ◽  
Hydrothermal Reaction ◽  
Yttrium Nitrate ◽  
Temperature Reaction ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Transmission Electron

The crystalline phase and morphology of the products formed during the synthesis of yttrium oxide via the hydrothermal treatment yttrium nitrate were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. Products with high OH/NO3ratios are formed with the increasing of hydrothermal treatment. The crystalline phases are evolved from Y2(OH)5.14(NO3)0.86•H2O toY4O(OH)9(NO3) and finally Y(OH)3. The hydrothermal reaction conditions play an important role in the synthesis of the microstructures. Results show the particle size and final morphology of samples could be controlled by reaction temperature, reaction time, and OH-concentration. Sheets, hexagonal and needle-like Y2O3powders are obtained with the hydrothermal treatment of yittrium nitrate at 180 oC to 200oC for 2-8 hours at pH 9-13.

Ultralow thermal conductivity in graphene–silica porous ceramics with a special saucer structure of graphene aerogels

2019 ◽  
Vol 7 (4) ◽  
pp. 1574-1584 ◽  
Author(s):  
Junmei Fan ◽  
Si Hui ◽  
Trevor P. Bailey ◽  
Alexander Page ◽  
Ctirad Uher ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Spark Plasma Sintering ◽  
Porous Ceramics ◽  
Silica Spheres ◽  
Hollow Silica ◽  
Graphene Aerogels ◽  
Hollow Silica Spheres ◽  
Plasma Sintering ◽  
Spark Plasma

Graphene aerogels grown on hollow silica spheres through spark plasma sintering lead to ultralow thermal conductivity and high compressive strength.

Fabrication of hollow silica spheres using droplet templates derived from a miniemulsion technique

2008 ◽  
Vol 321 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Bo Peng ◽  
Min Chen ◽  
Shuxue Zhou ◽  
Limin Wu ◽  
Xiaohua Ma
Keyword(s):  
Silica Spheres ◽  
Hollow Silica ◽  
Hollow Silica Spheres
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