There are many options.

1. Determine both the porosity and the effective diffusion coefficient. From this you could calculate the tortuosity.

2. Measure with NMR the self-diffusion coefficient of a liquid in the porous layer. Compare with the self-diffusion coefficient in the pure layer and you have the tortuosity.

3. Measure the conductivity.

try fractal dimension. You could measure it by image analysis

By measurements: make a cross section image. With such small dimension I recommend epoxy mount + polishing + SEM imaging. Then from the image measure the tortuosity.

By calculation: it only works if you know the size of the pores, their size distribution and if the pores are homogeneously distributed in the material.

There are many options.

1. Determine both the porosity and the effective diffusion coefficient. From this you could calculate the tortuosity.

2. Measure with NMR the self-diffusion coefficient of a liquid in the porous layer. Compare with the self-diffusion coefficient in the pure layer and you have the tortuosity.

3. Measure the conductivity.

Can you advice some papers on the methods you described, please?

Have a look at this one, it may help.

Alain

Article Porous electrodes-based double-layer supercapacitors: Pore s...

In this paper you can find the constriction factor, f, this is the same than tortuosity

Article Cellular ceramics processed by paraffin emulsified suspensio...

Dear Thierry,

Can you please explain more? Is it possible to use ImageJ for determining the l*?

If

Tortuosity= l*/L

Where l* is determined by ImageJ and L is the membrane thickness.

Gianfranco Giorgianni,

How can I measure the tortuosity using the conductivity test? I attached the SEM cross-section of the membrane. I have to test it in a wet and dried state and compare the results?

Regards

Dear Foroogh Khodadadi,

Tortuosity is the property of curve being tortuous (having many turns). It is commonly used to describe diffusion and fluid flow in porous. It is often used as an adjustable parameter in models of transfer properties through porous media .

Tortuosity is defined as the ratio of the lengths, Lt and L, of the preferential tortuous fluid pathways and the porous media, Tortuocity= Lt/L

For your reference, please look at the article website given below. Article entail the intraparticle tortuosity can be derived from the particle conductivity obtained from the Maxwell equation applied to data at infinite dilution of particles.

https://pubs.acs.org/doi/full/10.1021/ac071377r?src=recsys

Hope article is useful for you.

Ashish