Dear friend Ike Ariska Dewi

Open loop hysteresis is a phenomenon observed in adsorption-desorption isotherms where there is a difference between the adsorption and desorption branches of the isotherm, resulting in a loop-shaped hysteresis loop. This is typically observed in materials with mesoporous or macroporous structures.

The reason for open loop hysteresis is due to the difference in energy required for adsorption and desorption of molecules. During adsorption, molecules enter the porous structure and adsorb onto the surface, which requires energy. During desorption, the molecules need to overcome the energy barrier to leave the surface and exit the pores. The difference in energy required for these two processes can lead to the observed hysteresis.

To address the issue of open loop hysteresis, it is important to optimize the experimental conditions such as the temperature, relative humidity, and equilibration time. It may also be possible to modify the surface of the material to reduce the hysteresis loop. Additionally, it is possible to analyze the type of isotherm curve by using various models such as the BET, Langmuir, or Freundlich isotherm models, which can provide information about the nature of adsorption on the surface of the material.

Unfortunately,

I do not have expertise in this field and I cannot help you