We are working on ultrafiltration membranes and want to know how can we decrease pore size and at the same time increase the amount of pores in the membrane?
Pore size and distribution are controlled by composition of polymer and phase inversion kinetics. Delayed demixing will produce sponge like structure with nearly uniform pore distribution while instantaneous demixing will produce finger like structure. You can study the behaviour of its phase diagram to optimize pore size and distribution. Recently, we have published our report, you may find usefull information.
P.T.P. Aryanti, S. Subagjo, D. Ariono, I.G. Wenten. (2015). Fouling and Rejection Characteristic of Humic Substances in Polysulfone Ultrafiltration Membrane. Journal of Membrane Science and Research (1) 41-45
Well, this depends on how your membranes are prepared. In general, it is difficult to get simultaneously more and smaller pores in porous materials. The same applies to thermally insulating materials (e.g. aerogels), in which the highest number of the smallest pores is required. But most of times, higher porosity just means bigger pores, and separating pore size and porosity is difficult. The way of controlling them both depends on the preparation method.
Alain
Hi Alian,
my membrane is based on PVB and I prepared it with reverse phase method.
anyway thank you so much for answer.
So if the preparation method is well identified, and can't be changed, you should play with the parameters of the process. If you can measure quantitatively the result of each trial, you can even do an experimental design and the corresponding statistical analysis (ANOVA-type) to find the optimum parameters. For that purpose, the software Design-Expert 8.0.7.1 would help much in estimating the kind and the number of experiments.
Alain
Which factors can affect pore size and its distribution in an ultrafiltration membrane?
It is depends on the additives concentration which is mixed with polymer solution before casting. The pore size or increase the number of pores depends on ultrafiltration membranes can be controlled by variation of composition of membrane casting solution, types of the additives(either polymeric or non-polymeric) and molecular weight of additives, evaporation time after casting and etc.
Pore size and distribution are controlled by composition of polymer and phase inversion kinetics. Delayed demixing will produce sponge like structure with nearly uniform pore distribution while instantaneous demixing will produce finger like structure. You can study the behaviour of its phase diagram to optimize pore size and distribution. Recently, we have published our report, you may find usefull information.
P.T.P. Aryanti, S. Subagjo, D. Ariono, I.G. Wenten. (2015). Fouling and Rejection Characteristic of Humic Substances in Polysulfone Ultrafiltration Membrane. Journal of Membrane Science and Research (1) 41-45
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