The adsorption and desorption of isoliquiritigenin and liquiritigenin to different types of carbon nanotubes （CNTs） were comparatively studied in this study. The pore structure, specific surface area, surface morpho...The adsorption and desorption of isoliquiritigenin and liquiritigenin to different types of carbon nanotubes （CNTs） were comparatively studied in this study. The pore structure, specific surface area, surface morphologies and functional groups of the CNTs were tested by N2 adsorption, scanning electron microscope （SEM） and infrared spectra （IR）. The investigation of dynamic adsorption, isothermal equilibrium adsorption and desorption of isoliquiritigenin and liquiritigenin to CNTs demonstrated that the adsorption amount on oxidized multi-walled carbon nanotubes （o-MWCNTs） was greater than that on raw multi-walled carbon nanotubes （r-MWCNTs）, especially the adsorption of isoliquiritigenin to o-MWCNTs. The data of equilibrium adsorption were better represented by the Freundlich isotherm model. In addition, the adsorbed amount per unit CNTs was decreased when the temperature got higher. From the results of isothermal equilibrium adsorption and desorption to CNTs, it could be inferred that o-MWCNTs had higher adsorption to isoliquiritigenin and liquiritigenin than r-MWCNTs. Additionally, o-MWCNTs had a better desorption efficiency to isoliquiritigenin and liquiritigenin （about 48.57% and 32.86%） than r-MWCNTs （about 24.56% and 17.46%）.展开更多
Moisture adsorption-desorption tests (MATs) were conducted on simulated mural plaster specimens under different air temperatures (ATs) and relative humidity (RH) to investigate the possible effect of seasonal alterati...Moisture adsorption-desorption tests (MATs) were conducted on simulated mural plaster specimens under different air temperatures (ATs) and relative humidity (RH) to investigate the possible effect of seasonal alteration and visitors’ breath on the deterioration of Mogao Grottoes, Dunhuang, China. Saturated salt solutions were used to maintain a constant RH, and plant growth cabinets were used to maintain a constant or varying temperature in the simulation test. The weight of specimen was periodically measured to determine the adsorbed or desorbed moisture. Test data illustrate that the desorption process is far quicker than the adsorption one, indicating that it is possible to inhibit the disadvantage effect from visitors, such as shortening the staying time in caves. In case of high humidity, an accumulated moisture adsorption was found to correspond to the varying temperature. On the other hand, in case of low humidity, accumulated moisture desorption corresponded. Test data imply that opening caves more often to visitors in humid seasons should be avoided so as to prevent continuous wetting of wall paintings.展开更多
基金National Natural Science Foundation of China (Grant No.30960515)Technological Innovation of Natural Science Project of Shihezi University(Grant No.ZRKX2008064 and No.ZRKX2008067)
文摘The adsorption and desorption of isoliquiritigenin and liquiritigenin to different types of carbon nanotubes （CNTs） were comparatively studied in this study. The pore structure, specific surface area, surface morphologies and functional groups of the CNTs were tested by N2 adsorption, scanning electron microscope （SEM） and infrared spectra （IR）. The investigation of dynamic adsorption, isothermal equilibrium adsorption and desorption of isoliquiritigenin and liquiritigenin to CNTs demonstrated that the adsorption amount on oxidized multi-walled carbon nanotubes （o-MWCNTs） was greater than that on raw multi-walled carbon nanotubes （r-MWCNTs）, especially the adsorption of isoliquiritigenin to o-MWCNTs. The data of equilibrium adsorption were better represented by the Freundlich isotherm model. In addition, the adsorbed amount per unit CNTs was decreased when the temperature got higher. From the results of isothermal equilibrium adsorption and desorption to CNTs, it could be inferred that o-MWCNTs had higher adsorption to isoliquiritigenin and liquiritigenin than r-MWCNTs. Additionally, o-MWCNTs had a better desorption efficiency to isoliquiritigenin and liquiritigenin （about 48.57% and 32.86%） than r-MWCNTs （about 24.56% and 17.46%）.
基金Project supported by the National Key Technology R&D Program during the 11th Five-Year Plan of China (No. 2006BAK30B02)the China National Engineering Research Center for Conservation of Ancient Wall Paintings Program (No. 200806)
文摘Moisture adsorption-desorption tests (MATs) were conducted on simulated mural plaster specimens under different air temperatures (ATs) and relative humidity (RH) to investigate the possible effect of seasonal alteration and visitors’ breath on the deterioration of Mogao Grottoes, Dunhuang, China. Saturated salt solutions were used to maintain a constant RH, and plant growth cabinets were used to maintain a constant or varying temperature in the simulation test. The weight of specimen was periodically measured to determine the adsorbed or desorbed moisture. Test data illustrate that the desorption process is far quicker than the adsorption one, indicating that it is possible to inhibit the disadvantage effect from visitors, such as shortening the staying time in caves. In case of high humidity, an accumulated moisture adsorption was found to correspond to the varying temperature. On the other hand, in case of low humidity, accumulated moisture desorption corresponded. Test data imply that opening caves more often to visitors in humid seasons should be avoided so as to prevent continuous wetting of wall paintings.
