1. Real-Time Monitoring on the Adsorption Process ofSalicylic Acid onto Chitosan Membrane Using Dielectric Spectroscopy:Macroscale Concentration Polarization and Dynamics.
- Author
-
Li, Yuhong, Gao, Weidong, Zhao, Kongshuang, Yang, Gang, Zhu, Zhonghe, and Cui, Rongjing
- Subjects
- *
ADSORPTION (Chemistry) , *SALICYLIC acid , *CHITOSAN , *ARTIFICIAL membranes , *POLARIZATION (Electricity) , *DIELECTRIC relaxation , *SPECTRUM analysis , *DYNAMICS - Abstract
Theadsorption process of salicylic acid (SA) onto chitosan membraneis monitored in real time by the dielectric relaxation spectroscopy(DRS) method. A unique dielectric relaxation, which is related tothe macroscale concentration polarization layers (CPLs) in the SAsolution caused by the adsorption, is observed. By modeling the measuredsystems composed of the membrane, the CPLs, and the SA solution, thedielectric spectra are analyzed systematically on the basis of theinterfacial polarization theory. The parameters about the constituentphases, i.e., the dielectric constant εmand theconductivity κmof the chitosan membrane, the conductivitydistribution (κ1to κ2), and thethickness dCPLof the CPL, are obtained.The time-dependent εmand κmgiveinsight into the microstate of the chitosan membrane during the adsorption.Furthermore, the time evolution of the conductivity gradient of theCPL, Δκ/dCPL, is combinedto interpret the adsorption mechanism. It is suggested that the noninvasivedielectric monitoring may be applied to many adsorption and releaseprocesses. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF