I was performing the synthesis of ZIF-8 in MeOH. Because I want to add another metal ion in to the framework, Base was used to increase the yield and ensure the proportion close to reactants. I have found some interesting results.

For example, the particle size of Zn:Hmim:NaOH=1:4:2 is much smaller than 1:4:1, which was indicated by the width of XRD peaks. This is easy to understand.

But if TEA was used as the base, the Zn:Hmim:TEA=1:4:2 sample seems to be smaller than Zn:Hmim:NaOH=1:4:2, because the former products(with NaOH) can be filtered by 220 nm Microporous membrane while sample with TEA would block the membrane and have to be collected by centrifugation. 

Therefore, I want to know the difference between NaOH and TEA. 

The synthesis was carried out in the same mode. Solution A contains Hmim and Base; solution B contains anhydrous zinc acetate(for me with some other transition metal salts like cobalt acetate). Both solutions were stirred until all reactants dissolved, and then A was poured into B under stirring. The mixed solution was stirred for 24 hrs at room temperature. Products were collected by filtration or centrifugation and washed with ethanol, dried at 80℃ in vacumm.

XRD shows the product is pure ZIF-8 with high yield(65% for Zn:Hmim:NaOH= 1:4:1 and nearly 100% for 1:4:2).

I would be thankful if someone could share your synthesis of ZIF-8 and its features. For example, maybe DMF is a good solvent.