top-down approach 長庚化材系 郭修伯. grinding l 粗碎： n m 級 to 10 cm 以下 n jaw...

Top-down approach

長庚化材系郭修伯

Grinding

粗碎： m 級 to 10 cm 以下 Jaw crusher Gyratory crusher

Grinding

中碎： 10 cm to 1 cm 以下 ; Crushing roll

Grinding

中碎： 10 cm to 1 cm 以下 ; Hammer mill & Roller mill

Grinding

微粉碎： 1 cm to 10 micron 以下 ; roller mill, jet mill, ball mill,

vibration mill, planetary mill

Low temperature increasing 大小 ball 分佈；最適回轉數 )m(D

32)rpm(N

Grinding

微粉碎： 1 cm to 10 micron 以下 ; roller mill, jet mill, ball mill,

vibration mill, planetary mill

40-50 % fill, several g

Grinding

超微粉碎： 10 micron to 1 micron 以下 ; 介質攪拌型粉碎機 ,

vibration mill, planetary mill

Surface charge distribution

The distributions of ions and counter ions are controlled by Coulomic force or electrostatic force Entropic force or dispersion Brownian motion

Inhomogenous distribution double layer structure separated by the Helmholtz plane

Fig 2.14

Van der Waals attraction potential

The sum of the molecular interaction for all pairs of molecules weak force and becomes significant only at a

very short distance agglomeration of nanoparticles: the

combination of van der Waals force and Brownian motion

Prevent agglomeration: electrostatic repulsion and steric exclusion

Electrostatic repulsion stabilization

Fig 2.18

Steric exclusion stabilization

Also “polymeric stabilization” Widely used in stabilization of colloidal

dispersions thermodynamic stabilization: particles are

always redispersible high concentration can be accommodated not electrolyte sensitive suitable to multiple phase systems

Polymeric stabilization

Fig 2.21

Gas phase particle formation

Gas phase particle formation, CVD

Gas phase particle formation, CVD

Gas phase particle formation, CVD

Formation of particles in solutions

Formation of particles in solutions

Formation of particles in solutions, chemical methods

Formation of particles in solutions, physical methods