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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 crusher n Gyratory crusher.

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Presentation on theme: "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 crusher n Gyratory crusher."— Presentation transcript:

1 Top-down approach 長庚化材系 郭修伯

2 Grinding l 粗碎: n m 級 to 10 cm 以下 n Jaw crusher n Gyratory crusher

3 Grinding l 中碎: n 10 cm to 1 cm 以下 ; Crushing roll

4 Grinding l 中碎: n 10 cm to 1 cm 以下 ; Hammer mill & Roller mill

5 Grinding l 微粉碎: n 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

6 Grinding l 微粉碎: n 1 cm to 10 micron 以下 ; roller mill, jet mill, ball mill, vibration mill, planetary mill 40-50 % fill, several g

7 Grinding l 超微粉碎: n 10 micron to 1 micron 以下 ; 介質攪拌型粉碎機, vibration mill, planetary mill

8 Surface charge distribution l The distributions of ions and counter ions are controlled by n Coulomic force or electrostatic force n Entropic force or dispersion n Brownian motion l Inhomogenous distribution n double layer structure n separated by the Helmholtz plane

9 Fig 2.14

10 Van der Waals attraction potential l The sum of the molecular interaction for all pairs of molecules n weak force and becomes significant only at a very short distance n agglomeration of nanoparticles: the combination of van der Waals force and Brownian motion n Prevent agglomeration: electrostatic repulsion and steric exclusion

11 Electrostatic repulsion stabilization Fig 2.18

12 Steric exclusion stabilization l Also “polymeric stabilization” l Widely used in stabilization of colloidal dispersions n thermodynamic stabilization: particles are always redispersible n high concentration can be accommodated n not electrolyte sensitive n suitable to multiple phase systems

13 Polymeric stabilization Fig 2.21

14 Gas phase particle formation

15 Gas phase particle formation, CVD

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18 Formation of particles in solutions

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20 Formation of particles in solutions, chemical methods

21 Formation of particles in solutions, physical methods


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