Low-pressure adsorption isotherms of CO2 on low-temperature surface measured on a quartz crystal microbalance

Adsorption Isotherms of Low-Pressure H2O on a Low-Temperature Surface Measured by a Quartz Crystal Microbalance

“…By comparing the isothermals of H 2 O measured in this work with those of CO 2 measured in the previously published work, 50 it shows that the overall trend of each isothermal looks analogous. The CO 2 isotherms are typical type-I isotherms, while the H 2 O isotherms have the characteristics of type-I and type-II isotherms.…”

“…The accuracy of the QCM system has been justified in our previous work by (i) comparing the isotherms measured upon the single point measurement method and the continuous measurement method at six temperatures and (ii) comparing the adsorption and desorption isotherm measured by the continuous measurement method. The maximal error of the continuous measurement method based on the QCM system has been determined within ±(5–20)%, and a detailed analysis can be seen in ref ( 50 ). In this research, a repeated measurement has been carried out and the error of the obtained results is verified in this range.…”

“…In our previous work, a new multilayer adsorption model named the multi-Langmuir model has been developed to describe the adsorption process of CO 2 for the plume contamination effects. The equation is given as 50 where a M is the multi-Langmuir adsorption capacity in ng·cm –2 and b M is the multi-Langmuir affinity parameter in Pa –1 .…”

“…E M is the energy parameter calculated by the empirical expression of b M in the multi-Langmuir model as eq 7 . The corresponding curves of CO 2 50 have also been plotted for comparison.…”

“…The low-pressure CO 2 adsorption isotherms under nine different temperatures have been measured by QCM, and a multi-Langmuir isotherm model based on the data to describe the isotherms has been proposed, which is beneficial to analyze the adsorption process of CO 2 in the plume. 50 For the purpose of providing support for the general adsorption theory, a more in-depth analysis of other gas-phase components of the plume should be carried out. In this study, the low-pressure adsorption isotherms of H 2 O on gold-plated QCM have been experimentally measured at seven temperatures between 233 and 273 K. By means of the fitting, the key parameters of the classical models, including the Langmuir model, the Dubinin–Radushkevich model, the BET model, and the universal model, were determined, and the adsorption capacities indicated the occurrence of multilayer adsorption under the experimental condition.…”