• Certainly! You can use BET (Brunauer-Emmett-Teller) analysis to determine the surface area of a thin film on a substrate. BET analysis is a commonly used technique for measuring the specific surface area of porous materials, including thin films. To perform BET analysis, you need to measure the adsorption isotherm of a specific gas on the thin film. The isotherm data can then be used to calculate the surface area using the BET equation. However, it's important to note that BET analysis assumes that the thin film is a porous material with a well-defined structure. If your nanotubes thin film has a porous structure, BET analysis can provide an estimation of its surface area. If the film is non-porous or has a complex structure, BET analysis may not be suitable, and alternative techniques may need to be considered. It is recommended to consult with experts in the field or refer to relevant literature to ensure the appropriateness of BET analysis for your specific thin film and substrate.

@Ali Alnazza Alhamad Thanks for your response

Almost welcome