INFLUENCE OF DISPERSION ON COATING EFFECT OF ZrB2@Al(OH)3–Y(OH)3 CORE-SHELL COMPOSITE PARTICLES

2009 ◽  
Vol 16 (02) ◽  
pp. 231-239
Author(s):  
JIE-GUANG SONG ◽  
YANG-LIANG LI ◽  
GANG-CHANG JI ◽  
DA-MING DU ◽  
MING-HAN XU ◽  
...  
Keyword(s):  
High Temperature ◽  
Composite Shell ◽  
Composite Particles ◽  
Core Shell ◽  
Coating Process ◽  
Ultrasonic Dispersion ◽  
Shell Composite ◽  
Coating Ratio ◽  
Better Than

ZrB 2 are widely applied because of some excellent performances; however, ZrB 2 is easily oxidized in the high-temperature air. To reach better Al ( OH )3– Y ( OH )3 composite shell and higher coating ratio on the ZrB 2 particles surfaces, ZrB 2 particles must be adequately dispersed in the ZrB 2 suspension during the coating process. The dispersion of ZrB 2 particles and the influence of dispersion on coating effect of ZrB 2@ Al ( OH )3– Y ( OH )3 core-shell composite particles were investigated. The dispersion of ZrB 2 suspension adding the polyelectrolyte dispersant is better than that of ZrB 2 suspension adding the nonionic dispersant; the dispersant content is 2 vol% of ZrB 2 suspension to reach the best dispersion. The best dispersion is obtained by the ultrasonic dispersion for 10 min. ZrB 2 particles are coated using the dispersant and the ultrasonic dispersion in the ZrB 2 suspension to obtain the better coating effect. The dispersion of ZrB 2 particles is increased with increasing the coating content.

THERMODYNAMIC AND KINETIC ANALYSES OF SYNTHESIZING ZrB2@Al(OH)3–Y(OH)3 CORE–SHELL COMPOSITE PARTICLES

2007 ◽  
Vol 14 (01) ◽  
pp. 117-122 ◽  
Author(s):  
JIEGUANG SONG ◽  
LIANMENG ZHANG ◽  
JUNGUO LI ◽  
JIANRONG SONG
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Solubility Product ◽  
Ceramic Materials ◽  
Precipitation Method ◽  
Composite Particles ◽  
Core Shell ◽  
High Temperature Strength ◽  
Co Precipitation ◽  
Shell Composite

ZrB 2 has some excellent performances, but it is easily oxidized at high temperatures to impact the high-temperature strength, which restricts its applied range. To protect from the oxidization and improve the strength of ZrB 2 at high temperature, the surface of ZrB 2 particles is coated with the Al ( OH )3– Y ( OH )3 shell to synthesize ZrB 2@ Al ( OH )3– Y ( OH )3 core–shell composite particles. Through the thermodynamic and kinetic analyses of the heterogeneous nucleation and homogeneous nucleation, the concentration product of precursor ion ( Y 3+ or Al 3+) and OH - (Qi) must be greater than the solubility product (K sp ), respectively; the conditions of Y 3+ and Al 3+ are reached to produce Al ( OH )3– Y ( OH )3 shell on the ZrB 2 surface between the Y 3+ line and the AlO 2- line. Through TEM and XRD analyses, ZrB 2@ Al ( OH )3– Y ( OH )3 core–shell composite particles are successfully synthesized by the co-precipitation method, the shell layer quality is better at pH = 9, which established the foundation for preparing high-performance YAG / ZrB 2 and Al 2 O 3– YAG / ZrB 2 multiphase ceramic materials.

SYNTHESIS AND CHARACTERIZATION OF Si3N4@Al(OH)3–Y(OH)3 CORE-SHELL COMPOSITE PARTIC3LES

2008 ◽  
Vol 15 (05) ◽  
pp. 581-585 ◽  
Author(s):  
JIE-GUANG SONG ◽  
GANG-CHANG JI ◽  
SHI-BIN LI ◽  
LIAN-MENG ZHANG
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Ceramic Materials ◽  
Composite Particles ◽  
Core Shell ◽  
High Temperature Strength ◽  
Bet Analysis ◽  
Co Precipitation ◽  
Shell Composite

Silicon nitride ( Si 3 N 4) has attracted substantial interest because of its extreme chemical and physical properties, but the sintering densification of Si 3 N 4 is difficult, and it is easily oxidized in the high-temperature air to impact high-temperature strength, which restricts its applied range. In order to decrease the oxidization and improve the strength of Si 3 N 4 at high temperature, the surface of Si 3 N 4 is coated with Al ( OH )3 and Y ( OH )3 to synthesis Si 3 N 4@ Al ( OH )3– Y ( OH )3 core-shell composite particles. Through TEM, XRD, and BET analysis, when pH is about 9, Si 3 N 4@ Al ( OH )3– Y ( OH )3 core-shell composite particles are successfully synthesized by co-precipitation methods. Coating layer is about 200 nm, which is compaction and conformability. Dispersion of coated Si 3 N 4 with Al ( OH )3 and Y ( OH )3 particles are very good. Synthesis of Si 3 N 4@ Al ( OH )3– Y ( OH )3 core-shell composite powder will lay the foundation for preparing high-performance YAG/Si 3 N 4 multiphase ceramic materials.

Physico‐mechanical properties and flammability of PUR/PIR foams containing expandable graphite core‐shell composite particles

2019 ◽  
Vol 40 (10) ◽  
pp. 3805-3813 ◽  
Author(s):  
Kamila Gosz ◽  
Józef Haponiuk ◽  
Aleksandra Mielewczyk‐Gryń ◽  
Łukasz Piszczyk
Keyword(s):  
Mechanical Properties ◽  
Composite Particles ◽  
Expandable Graphite ◽  
Core Shell ◽  
Shell Composite

Controlled detonation synthesis of nano Fe-based oxides/SiO2 core-shell composite particles

2020 ◽  
Vol 740 ◽  
pp. 137016
Author(s):  
Xiaohong Wang ◽  
Liang Guo ◽  
Xiaojie Li ◽  
Xueqi Li ◽  
Lingjie Kong ◽  
...  
Keyword(s):  
Composite Particles ◽  
Core Shell ◽  
Detonation Synthesis ◽  
Shell Composite

OXIDATION RESISTANCE MECHANISM OF ZrB2–Al2O3–Y2O3 COMPOSITE PARTICLES

2007 ◽  
Vol 14 (05) ◽  
pp. 945-950 ◽  
Author(s):  
J. G. SONG ◽  
J. G. LI ◽  
J. R. SONG ◽  
L. M. ZHANG
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Resistance Mechanism ◽  
Composite Particles ◽  
Good Oxidation Resistance ◽  
High Temperature Materials ◽  
Better Than

Although ZrB 2 has some excellent performances, it is easily oxidized in the high-temperature air, which is deadly shortcoming as high-temperature materials. To increase the high-temperature performances of ZrB 2, Al 2 O 3 and Y 2 O 3 particles are coated on the ZrB 2 surface to prepare ZrB 2– Al 2 O 3– Y 2 O 3 composite particles. The oxidation resistance mechanism of ZrB 2– Al 2 O 3– Y 2 O 3 composite particles is investigated by DTA-TG, TEM, and XRD. The surface of ZrB 2 particle is coated with compact Al 2 O 3 and Y 2 O 3 particles, which establishes the foundation to attain good oxidation resistance. ZrB 2 particle is mainly oxidized to increase the weight, from 600°C to 800°C. B 2 O 3, obtained through the oxidization reaction, might coat on the surface of ZrB 2 particle to retard the oxidization reaction, which further increases the oxidation resistance. The oxidation resistance of coated ZrB 2 particle is far better than that of original ZrB 2 particle.

INFLUENCE OF SYNTHESIS CONDITIONS ON Al(OH)3–Y(OH)3/ZrB2 COMPOSITE PARTICLES

2007 ◽  
Vol 14 (06) ◽  
pp. 1135-1141 ◽  
Author(s):  
JIE-GUANG SONG ◽  
LIAN-MENG ZHANG ◽  
JUN-GUO LI ◽  
JIAN-RONG SONG
Keyword(s):  
High Temperature ◽  
Reaction Time ◽  
Precipitation Method ◽  
Composite Particles ◽  
Coating Quality ◽  
Ultrasonic Dispersion ◽  
High Temperature Properties ◽  
Synthesis Conditions ◽  
Solution Reaction ◽  
Co Precipitation

Although Zirconium diboride ( ZrB 2) is a desirable combination with some good properties, it is easily oxidized in the high-temperature air to impact high-temperature properties, which dwindles the applied range. In order to decrease oxidization and improve the high-temperature properties of ZrB 2, the surface of ZrB 2 is coated with Al ( OH )3– Y ( OH )3 to synthesize Al ( OH )3– Y ( OH )3/ ZrB 2 composite particles. In this paper, the conditions of synthesizing Al ( OH )3– Y ( OH )3/ ZrB 2 composite particles by the co-precipitation method are investigated. Al ( OH )3– Y ( OH )3/ ZrB 2 composite particles are synthesized under different conditions, but the conditions of synthesizing Al ( OH )3– Y ( OH )3/ ZrB 2 composite particles with the better coating quality require pH = 9, the appropriate concentration ( Al 3+ = 0.017 mol/L , Y 3+ = 0.01 mol/L ) of composite solution, reaction time of 60 min, titration speed of 0.05 ml/s, using the dispersant in the ZrB 2 suspension and the ultrasonic dispersion, respectively.

Effect of core–shell composite particles on the sintering behavior and properties of nano-Al2O3/polystyrene composite prepared by SLS

2006 ◽  
Vol 60 (9-10) ◽  
pp. 1219-1223 ◽  
Author(s):  
Haizhong Zheng ◽  
Jian Zhang ◽  
Shiqiang Lu ◽  
Gaochao Wang ◽  
Zhifeng Xu
Keyword(s):  
Composite Particles ◽  
Sintering Behavior ◽  
Core Shell ◽  
Shell Composite
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