Fast Synthesis, Formation Mechanism, and Control of Shell Thickness of CuS Hollow Spheres

2009 ◽  
Vol 48 (15) ◽  
pp. 7099-7104 ◽  
Author(s):  
Haitao Zhu ◽  
Jixin Wang ◽  
Daxiong Wu
Keyword(s):  
Formation Mechanism ◽  
Shell Thickness ◽  
Hollow Spheres ◽  
And Control ◽  
Fast Synthesis

scholarly journals Synthesis and Control of the Shell Thickness of Polyaniline and Polypyrrole Half Hollow Spheres Using the Polystyrene Cores

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Su-Ryeon Yun ◽  
Gyeong-Ok Kim ◽  
Chan Woo Lee ◽  
Nam-Ju Jo ◽  
Yongku Kang ◽  
...  
Keyword(s):  
Shell Thickness ◽  
Hollow Spheres ◽  
Core Shell ◽  
Chemical Structures ◽  
The Core ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Core Shell Structure ◽  
And Control ◽  
Ft Ir Spectroscopy

Polyaniline (Pani) and polypyrrole (Ppy) half hollow spheres with different shell thicknesses were successfully synthesized by three steps process using polystyrene (PS) as the core. The PS core was synthesized by emulsion polymerization. Aniline and pyrrole monomers were polymerized on the surface of the PS core. The shells of Pani and Ppy were fabricated by adding different amounts of aniline and pyrrole monomers. PS cores were dissolved and removed from the core shell structure by solvent extraction. The thicknesses of the Pani and Ppy half hollow spheres were observed by FE-SEM and FE-TEM. The chemical structures of the Pani and Ppy half hollow spheres were characterized by FT-IR spectroscopy and UV-Vis spectroscopy. The shell thicknesses of the Pani half hollow spheres were 30.2, 38.0, 42.2, 48.2, and 52.4 nm, while the shell thicknesses of the Ppy half hollow spheres were 16.0, 22.0, 27.0, and 34.0 nm. The shell thicknesses of Pani and Ppy half hollow spheres linearly increased as the amount of the monomer increased. Therefore, the shell thickness of the Pani and Ppy half hollow spheres can be controlled in these ranges.

Synthesis of thermally stable porous SiC hollow spheres and control of the shell thickness

2014 ◽  
Vol 199 ◽  
pp. 11-17 ◽  
Author(s):  
Seong-Cheol Noh ◽  
Seung-Young Lee ◽  
Sungrye Kim ◽  
Sungho Yoon ◽  
Yong Gon Shul ◽  
...  
Keyword(s):  
Shell Thickness ◽  
Hollow Spheres ◽  
Thermally Stable ◽  
And Control ◽  
Porous Sic

Solvothermal Synthesis of Single-Crystal Magnetite Hollow Sub-Microspheres: A Novel Formation Mechanism and Magnetic Properties

2016 ◽  
Vol 69 (7) ◽  
pp. 798
Author(s):  
Gongqin Yan ◽  
Guanlin Zhao ◽  
Fei He
Keyword(s):  
Magnetic Properties ◽  
Single Crystal ◽  
Formation Mechanism ◽  
Solvothermal Synthesis ◽  
Shell Thickness ◽  
Ostwald Ripening ◽  
Hollow Spheres ◽  
Diameter Distribution ◽  
Key Factor ◽  
Different Diameters

In this paper, single-crystal magnetite hollow sub-microspheres with a narrow diameter distribution are synthesized through a simple solvothermal process in ethylene glycol in the presence of urea and a small amount of water. The determining role of water in the solvothermal synthesis is studied. It is found that a small amount of water is crucial for the formation of the magnetite hollow spheres. A novel formation mechanism of the magnetite hollow spheres is proposed based on the bubble-assisted Ostwald ripening. It is believed that the appropriate amount of CO2 gas bubbles produced in situ by urea hydrolysis is crucial for the formation of hollow spheres. Because of the existence of gas microbubbles, magnetite solid spheres with a loose core and compact shell form, which is the key factor for the following inside-out Ostwald ripening and the formation of the hollow spheres. Thus, by simple changing of the water dosage, magnetite hollow spheres with different diameters and shell thicknesses are obtained controllably. The magnetic properties of the obtained magnetite hollow spheres are studied. It is found that the saturation magnetization of the magnetite hollow sub-microspheres decreases with the increasing shell thickness, whereas the coercivity and remanent magnetization increase with increasing shell thickness.

Preparation of Silica Hollow Spheres Used as Filler for Paper

2012 ◽  
Vol 200 ◽  
pp. 339-342 ◽  
Author(s):  
Wen Juan Gu ◽  
Ying Li ◽  
Xiao Hui Zhang
Keyword(s):  
Formation Mechanism ◽  
Shell Thickness ◽  
Sol Gel ◽  
Hollow Spheres ◽  
Hollow Structure ◽  
Silica Spheres ◽  
Hollow Silica ◽  
Calcination Process ◽  
Gel Method ◽  
Hollow Silica Spheres

Silica of hollow structure exhibits a number of special characteristic. In this paper, a new way to prepare hollow silica spheres which can be used as filler for paper was reported. In this approach, when silica shells were coated on polyvinylacetate (PVAc) template particles by the sol-gel method, the PVAc cores would be dissolved synchronously, forming hollow spheres. Neither additional dissolution nor a calcination process was needed to remove the PVAc cores. The morphology of the hollow silica spheres was also characterized by TEM. It was shown that the hollow silica spheres with 130-400nm in diameter and 15-35nm in the shell thickness could be synthesized. The possible formation mechanism was also brought forward. The possibility and potential advantages in usage as filler for paper were analyzed theoretically. We confer that this filler can improve the printability of the paper, and reduce its density compared with traditional fillers.

The formation mechanism and control methods of high temperature infrared radiant coating defects

2013 ◽  
Vol 28 (6) ◽  
pp. 1091-1095
Author(s):  
Jing Ye ◽  
Helong Lan ◽  
Chuanbin Wang ◽  
Guoqiang Luo ◽  
Lianmeng Zhang
Keyword(s):  
High Temperature ◽  
Formation Mechanism ◽  
Control Methods ◽  
And Control

Process Simulation and Formation Mechanism of Shear Band in Soil

2014 ◽  
Vol 580-583 ◽  
pp. 175-179
Author(s):  
Shi Wei Hou ◽  
Jin Hong Qu ◽  
Yi Fang Zhang ◽  
Xiu Li Du
Keyword(s):  
Shear Band ◽  
Formation Mechanism ◽  
Deformation Process ◽  
Strain Energy ◽  
Impact Action ◽  
Initial Defect ◽  
Modified Cam Clay ◽  
End Restraint ◽  
And Control ◽  
Cam Clay

Shape multiformity and formation mechanism of shear band in normal consolidated soil were analyzed based on Modified Cam-Clay model under plane strain condition. The results proved that shear band forms because of impact action caused by strain energy releasing. End restraint and initial defect can induce and control the formation process and shape of shear band. The interaction of different boundary and initial defect settings was analyzed in order to obtain the mechanism and deformation process of shear band.

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