Using the large seeds as the bottom layer |
Prevents the infiltration of
seeds into the support pores |
Reduces the effective membrane thickness |
Higher permeance |
|
Forms more inter-crystalline gaps in the bottom layer |
Decreases the
density of the zeolite layer close to the support |
Higher
permeance |
Seed size change at the bottom layer mostly influences the membrane
permeance |
Seed size change at the bottom layer mostly influences the
membrane permeance |
Seed size change at the bottom layer mostly
influences the membrane permeance |
Seed size change at the bottom layer
mostly influences the membrane permeance |
Using the small seeds as the top layer |
Small seeds from top layer
penetrate into the pores of bottom layer |
Eliminates the defects and
non-zeolitic pores |
Higher selectivity |
|
Forms a uniform thin seed layer at the top |
Creates a continuous thin
zeolite layer with smooth surface |
Higher selectivity |
|
Increases the grow rate of small seeds on top which are in contact
with the synthesis solution |
Forms a denser zeolite layer on top |
Higher selectivity |
Seed size change at the top layer mostly influences the membrane
selectivity |
Seed size change at the top layer mostly influences the
membrane selectivity |
Seed size change at the top layer mostly
influences the membrane selectivity |
Seed size change at the top layer
mostly influences the membrane selectivity |