Look for a mercury porosimeter. A good user will appreciate information regarding matrix, mechanical properties and expected pore sizes/distribution. Then you will realize your material is at good hands.

So thanks. i used it.

If there is no equipment like mercury porosimeter or gas gravimetric sorption, what can i do for characterize the pore size and pore size distribution?

We used of MWCO test, with different PEG molecular weight. By this way you can characterize the pore size of your membrane but it's not possible to discuss about the pore size distribution. For MWCO test with PEG use this reference :

A.D. Sabde, M.K. Trivedi, V. Ramachandhran, M.S. Hanra, B.M. Misra, Casting and characterization of cellulose acetate butyrate based UF membranes, Desalination 114 (1997) 223–232.

Thanks, would you give me the link, because its hard to find the link?

I have attached the article file.

ok thanks a lot, I'll learn it first

To Sheila Rozitawati - There are many methods/techniques available to measure pore size/pore size distribution of a membrane. One of them is based on the rejection rate of a membrane against neutral solutes of different molecular weights.

to Lau W.J. - could you give the reference? i still confuse how it work.

thanks

There are many papers available reporting the use of neutral solutes for pore size determination. Depending on the type of the membranes you studied (MF, UF or NF), you can choose suitable size of neutral solute for the experiments.