Preparation of Mesocarbon Microbeads and Subsequent Heating Treatment

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Youliang Cheng ◽  
Tiehu Li ◽  
Fengjuan Li ◽  
Qiang Zhuang ◽  
Deqi Jing
Keyword(s):  
Oil Content ◽  
Silicone Oil ◽  
Coal Tar ◽  
Small Diameter ◽  
Coal Pitch ◽  
Microcrystalline Structure ◽  
Small Particles ◽  
Mesocarbon Microbeads ◽  
Heating Treatment ◽  
Graphite Structure

The preparation of mesocarbon microbeads (MCMB) has been studied by heating coal tar pitch with different phenyl silicone oil content at 350°C for 2h.The spheres with diameters ranging from 0.54 to 11.4?m were obtained. The as-extracted MCMB when the silicone oil/coal pitch value was 3 had a very homogeneous size, a small diameter and also an excellent sphericity. The yield of MCMB was 8.3%, and microcrystalline structure was better. After stabilization, the spheres carbonized at 900°C still kept spherical, but broken into small particles during the graphitization. The stabilization destroyed the microcrystalline structure of as-extracted MCMB, but the microcrystalline structure became better after carbonization. The structure of graphitized MCMB at 2300°C was close to the graphite structure, and clear graphitization fringes were observable.

Effects of AlCl3-NaCl Content on the Formation of Mesocarbon Microbeads

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Youliang Cheng ◽  
Tiehu Li ◽  
Xianliang Hou ◽  
Deqi Jing ◽  
Qiang Zhuang ◽  
...  
Keyword(s):  
Molten Salt ◽  
Coal Tar ◽  
Salt Content ◽  
Weight Ratio ◽  
Small Dimension ◽  
Coal Tar Pitch ◽  
Microcrystalline Structure ◽  
Salt Mixture ◽  
Mesocarbon Microbeads ◽  
Molecular Layers

Mesocarbon microbeads (MCMB) have been synthesized from coal tar pitch with the molten salt mixture composed of AlCl3 and NaCl at 300°C for 1h. The effects of the molten salt on the synthesis of MCMB have been studied. The results indicate that the content of molten salt has an important effect on the formation of mesophase, and the polymerization basically reaches the equilibrium when the weight ratio of molten salt mixture to coal tar pitch is 1. The molten salt can promote the formation of mesophase at low temperature, and the pyrolytic products show the optical anisotropy. Microcrystalline structure of extracted product gets more regular and the yield increases with the molten salt content increasing, but microcrystalline structure at the ratio of 1 gets disordered. When the ratio is over 2, the yield is high, and the obtained MCMB show a smooth surface, small dimension and lamellar structures whose building units are molecular layers.

Characteristics of mesocarbon microbeads generated from a coal tar pitch with addition of micro-alumina powder

2005 ◽  
Vol 87 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Tong-Qi Li ◽  
Cheng-Yang Wang ◽  
Xiu-Jun Liu ◽  
Jia-Ming Zheng ◽  
Hui Wang
Keyword(s):  
Coal Tar ◽  
Coal Tar Pitch ◽  
Alumina Powder ◽  
Mesocarbon Microbeads

scholarly journals Mechanical properties of bulk Sylgard 184 and its extension with silicone oil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Moučka ◽  
M. Sedlačík ◽  
J. Osička ◽  
V. Pata
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Ambient Temperature ◽  
Oil Content ◽  
Silicone Oil ◽  
Polymer System ◽  
Industrial Applications ◽  
Curing Temperature ◽  
Rotational Rheometer ◽  
Oil Concentration

AbstractDue to its simple curing and very good mechanical properties, Sylgard 184 belongs to the most widely and frequently used silicones in many industrial applications such as microfluidics and microengineering. On top of that its mechanical properties are further controllable through the curing temperature, which may vary from ambient temperature up to 200 °C; the lower the curing temperature the lower the mechanical properties (Johnston et al. in J Micromech Microeng 24:7, 2014. 10.1088/0960-1317/24/3/035017). However, certain specialised application may require even a softer binder than the low curing temperature allows for. In this study we show that this softening can be achieved with the addition of silicone oil into the Sylgard 184 system. To this end a series of Sylgard 184 samples with varying silicone oil concentrations were prepared and tested (tensile test, rotational rheometer) in order to determine how curing temperature and silicone oil content affect mechanical properties. Curing reaction of the polymer system was found to observe 2nd order kinetics in all cases, regardless the oil concentration used. The results suggest that within the tested concentration range the silicone oil addition can be used to soften commercial silicone Sylgard 184.

Study on the Fabrication of Carbon Nanotube - Mesocarbon Microbead Composites

2013 ◽  
Vol 631-632 ◽  
pp. 486-489
Author(s):  
Zhi Wang
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Coal Tar ◽  
Coal Tar Pitch ◽  
Lower Yield ◽  
Uniform Size ◽  
Thermal Condensation ◽  
Mesocarbon Microbeads ◽  
Uniform Size Distribution ◽  
Made In

Carbon nanotube-Mesocarbon microbead composites were synthesized from coal tar pitch with carbon nanotubes (CNTs) as additive. The effect of CNTs addition and process parameters on the growth and morphologies of Mesocarbon microbeads (MCMBs) was investigated. The results show that adding CNTs enhances the nucleation and inhibits the growth and coalescence of MCMBs. Under the same thermal condensation conditions, the MCMBs made in the presence of CNTs tend to have smaller size, lower yield and more uniform size distribution, but more CNTs can lead to poor spherical degrees. Compared with the raw CNTs, the CNTs treated with blended acid can achieve better sphere and more uniform MCMBs with increasing CNTs ratio.

Study on the properties of coal-based high-purity graphite

2019 ◽  
Vol 9 (6) ◽  
pp. 668-674 ◽  
Author(s):  
Qili Wang ◽  
Mingquan Yu ◽  
Jiannan Gong ◽  
Fengtao Zhang
Keyword(s):  
High Purity ◽  
Raw Materials ◽  
Coal Tar ◽  
Value Added ◽  
Coal Industry ◽  
Coal Pitch ◽  
Skeletal Density ◽  
Pitch Coke ◽  
Chinese Coal ◽  
Value Added Products

As one of the major value-added products of coal processing and utilization, coal pitch coke and coal tar pitch are used as raw materials to prepare high-purity graphite. The structure characteristics and properties were measured by experiments. The results show that the high-purity graphite has excellent physical properties: the skeletal density of 1.81–1.91 g/cm3, the Shore hardness of 45.5–66.6 Hs, the flexural strength of 33.0–46.1 MPa, the compressive strength of 65.6–75.8 MPa, the ash content of 67–181 ppm, the thermal expansion coefficient of 3.71–4.11 × 10–6/°C, and the electrical resistivity of 8.72–12.13 μΩ · m. Consequently, coal-based graphite materials have excellent properties and good application prospects in solar energy industry, which is an effective exploration for the transformation and upgrading of Chinese coal industry.

Preparation, Characterization and Microwave Absorption Properties of Nano/Micro Carbon Fiber

2011 ◽  
Vol 306-307 ◽  
pp. 1712-1716 ◽  
Author(s):  
Xiao Ping Duan ◽  
Jun Hong Jin ◽  
Sheng Lin Yang ◽  
Guang Li
Keyword(s):  
Carbon Fiber ◽  
Microwave Absorption ◽  
Reflection Loss ◽  
Complex Permittivity ◽  
Small Diameter ◽  
Technical Condition ◽  
Drawing Ratio ◽  
Blend Fiber ◽  
Graphite Structure ◽  
Experimental Values

Carbon fiber with diameter in the range of nano to micro meter was prepared by carbonization of polyacrylonitrile (PAN) and polymethylmethacrylate (PMMA) blend fiber which was produced via wet spinning of PAN/PMMA blend solution. At the same technical condition, the high molecular of PAN favored the production of thin diameter of carbon fiber, and the high drawing ratio led to small diameter of the obtained nano/micro carbon fiber. The formation of graphite structure during carbonization was characterized by Raman and X-ray diffraction. The results improved that high temperature of carbonization developed high degree of graphitization and high conductivity of the nano/micro carbon fiber. The composites containing 2-8wt% of the obtained nano/micro carbon fiber were fabricated. The complex permittivity ε’ and ε’ for the composites in the frequency range of 8-12 GHz was measured, and the reflection loss for 180×180×3mm3 composites was also investigated. The microwave absorption property of these composites was improved greatly with increasing content of the nano/micro carbon fibers. At the addition of 8 wt% of the nano/micro carbon fiber, the reflection loss of the composite displayed -16dB at 11.3GHz, and the band with smaller than -5dB was 3GHz. Moreover, the calculated results based on the complex permittivity seem identical with the experimental values.

Silicone oil content in ophthalmic viscosurgical devices

2004 ◽  
Vol 30 (6) ◽  
pp. 1278-1280 ◽  
Author(s):  
Arne Ohrstrom ◽  
Bengt Svensson ◽  
Susan Tegenfeldt ◽  
Celadet Celiker ◽  
Borje Lignell
Keyword(s):  
Oil Content ◽  
Silicone Oil

scholarly journals Facile One-Step Method to Fabricate a Slippery Lubricant-Infused Surface (LIS) with Self-Replenishment Properties for Anti-Icing Applications

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 119 ◽  
Author(s):  
Juantao Zhang ◽  
Bei Liu ◽  
Yan Tian ◽  
Fushan Wang ◽  
Qingguo Chen ◽  
...  
Keyword(s):  
Surface Water ◽  
Oil Content ◽  
Silicone Oil ◽  
Sliding Angle ◽  
Step Method ◽  
Oil Film ◽  
One Step ◽  
Dimethyl Silicone ◽  
Short Time ◽  
Surface Observations

In this work, a slippery lubricant-infused surface (LIS) was prepared by simple one-step mixing of polydimethylsiloxane (PDMS) resin and dimethyl silicone oil (PMX-200) directly. Silicone oil showed good compatibility with PDMS resin, and the added amount of silicone oil had no significant effect on the surface morphology of LIS. According to the results of surface observations, once the silicone oil film anchored on the LIS was removed, the silicone oil inside the PDMS polymer automatically diffused to the surface and formed a new silicone oil film again in a short time. Furthermore, with the increase of silicone oil content, the oil self-replenishment speed and amount of the LIS were enhanced, which also promoted a decrease of the surface water sliding angle and the improvement of the lubrication ability of the LIS. In the icing/deicing cycle tests, the slippery LIS still maintained very low ice adhesion strength after 24 cycles, showing excellent anti-icing performance.

scholarly journals Mechanisms and characteristics of mesocarbon microbeads prepared by co-carbonization of coal tar pitch and direct coal liquefaction residue

2019 ◽  
Vol 6 (4) ◽  
pp. 633-642 ◽  
Author(s):  
Bingfeng Yan ◽  
Guangyao Wang
Keyword(s):  
Coal Tar ◽  
Proton Donor ◽  
Coal Liquefaction ◽  
Electrical Performance ◽  
Coal Tar Pitch ◽  
Particle Sizes ◽  
Mesocarbon Microbeads ◽  
Tap Density ◽  
Direct Coal Liquefaction ◽  
Coal Liquefaction Residue

Abstract DCLR-P was prepared by direct coal liquefaction residue (DCLR) with ash removal. In the present experiments, mesocarbon microbeads (MCMBs) were prepared by co-carbonization of coal tar pitch (CTP) and DCLR-P. With the increase of DCLR-P content, the yield of MCMBs increased from 47.8% to 56.8%. At the same time, the particle sizes distribution of MCMBs was narrowed, resulting in the decrease of D90/D10 ratio from 154.88 to 6.53. The results showed that DCLR-P had a positive effect on the preparation of MCMBs. 1H-NMR, FTIR, SEM and XRD were used to analyze the mechanisms and characteristics of MCMBs prepared by co-carbonization of CTP and DCLR-P. The results showed that the Proton Donor Quality Index (PDQI) of DCLR-P was 13.32, significantly higher than that of CTP (0.83). This indicated that DCLR-P had more naphthenic structure than CTP, which leads to hydrogen transferring in polycondensation reaction. The aliphatic structure of DCLR-P can improve the solubility and fusibility of mesophase, thereby making the structure of MCMBs more structured. The microstructure of the graphitized MCMBs had a substantially parallel carbon layer useful for its electrical performance. The performance of graphitized MCMBs as a negative electrode material for Li-ion batteries was tested. The particle sizes, tap density, specific surface area and initial charge–discharge efficiency of graphitized MCMBs met the requirements of CMB-I in GB/T-24533-2009. However, the initial discharge capacity of graphitized MCMB was only 296.3 mA h g−1 due to the low degree of graphitization of MCMBs.

Dependence of the Softening Temperature of Coal Pitch on the Conditions of Coal-Tar Distillation

2021 ◽  
Vol 64 (2) ◽  
pp. 73-79
Author(s):  
A. P. Kozlov ◽  
T. G. Cherkasova ◽  
S. P. Subbotin ◽  
V. S. Solodov ◽  
A. G. Pimonov
Keyword(s):  
Coal Tar ◽  
Softening Temperature ◽  
Coal Pitch
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