Certainly! There are several methods for determining the specific surface area of materials, including:

1- Immersion method: This method involves measuring the volume of the material by immersing it in a liquid of known density. The total surface area of the material is then calculated and divided by the measured volume.

2- Absorption method: This method is used for dry materials that have the ability to absorb liquids. A known quantity of the material is placed on a flat surface and sprayed with the liquid, and the specific surface area of the material is then calculated based on the amount of liquid that is absorbed.

3- Reflection method: This method involves measuring the amount of light reflected from the surface of the material, and the specific surface area is calculated based on the amount of light that is reflected.

4- Adsorption method: This method is used for materials that can react with other materials. The quantity of the adsorbed material is measured and used to calculate the specific surface area.

5- BET method: This is a common method for calculating the specific surface area of solid materials with fine surface properties, and it is based on the physical adsorption of gas on the surface of the material. The sample is exposed to a known thermal stability gas such as nitrogen, and the amount of gas adsorbed is measured according to the specified pressure and temperature. These data are then used to calculate the specific surface area based on a mathematical model known as the BET model.

The appropriate method for measuring specific surface area is chosen based on the properties of the material and the desired level of precision in the measurement.

Thank

Dear Dr Alhamad, thank you for the response. I have been using the BET method: carbon protocol, but I am failing to get a decent isotherm. I dried my samples in vacuum for two weeks. Degassed the sample for 72hrs. But the isotherm still looks horrible. Any advise on what I can do to improve the quality of the isotherm for banana peel sample?