caa a22 4500 469122722 CHVBK 20180323133143.0 cr unu---uuuuu 170328e19920501xx s 000 0 eng 10.1007/BF02368537 doi (NATIONALLICENCE)springer-10.1007/BF02368537 Buck Richard Department of Chemistry, University of North Carolina, 27599-3290, Chapel Hill, NC aut Impedances of thin and layered systems: Cells with even or odd numbers of interfaces [Elektronische Daten] [Richard Buck] Impedance data, e.g., system responses, from perturbing small amplitude applied sinusoid signals of near DC to high kilohertz frequencies, give chemical information. Analysis of frequency-dependent imaginary and real impedance proceeds from equivalent analog circuit elements to chemical and physical significance determined from many model systems. Already, it is possible to interpret bulk transport processes, surface kinetic effects, diffusion phenomena, and dependencies on the type of contacts: symmetric ion contact, symmetric metal contact or asymmetric metal-ion interfaces, and cell design; even (battery or sensor) and odd numbered (constrained junction or immiscible liquid) interfaces in a system. These analyses cover the chemical origins, locations and meanings of the lumped resistances, capacitances and transmission lines that are introduced by engineers in their strict analog interpretations of the impedance data. Examples cover simple ohmic, simple diffusive behavior, complex behavior with surface interfacial kinetics or surface resistances, and with finite (nonblocking) or infinite (blocking) DC impedance. High and low frequency responses may show socalled constant phase element character that suggests fractal behavior. Low frequency data occasionally appear in the second quadrant of impedance plane plots. These results are caused by negative capacitances and resistances. In this paper, chemical interpretations of analog circuit elements are mainly based on theory and observations of thin cells of electrolytes and solid and liquid films (membranes) that are ionic or mixed ionic/electronic conductors. The information should carry over into thickened, gelled, and tissue electrolyte phases and serve as a basis for medically-oriented, perhaps diagnostic impedance measurement applications already pioneered by Herman Schwan. Pergamon Press Ltd., 1992 Impedances nationallicence Time constants nationallicence Capacitances nationallicence Resistances nationallicence Donnan failure nationallicence I-V curves nationallicence Fermi levels nationallicence Ion exchange nationallicence A : active area nationallicence a i : ion activity nationallicence a red : reduced species activity nationallicence a ox : oxidized species activity nationallicence C : capacitance or capacitance/unit area nationallicence C i : ion concentration nationallicence C red : reduced species concentration nationallicence C ox : oxidized species concentration nationallicence D : diffusion coefficient nationallicence d : half film (membrane) thickness nationallicence F : Faraday constant nationallicence J e : electron flux nationallicence J i : ion flux nationallicence n : number of electrons in half cell reaction nationallicence R : resistance nationallicence R : gas constant appearing with T nationallicence T : absolute temperature nationallicence u e : electron mobility nationallicence u i : ion mobility nationallicence Z (jω) : impedance nationallicence z i : ion charge nationallicence z red : reduced species charge nationallicence z ox : oxidized species charge nationallicence α : parameter of Cole-Cole plot nationallicence ε : dielectric constant nationallicence Annals of Biomedical Engineering Kluwer Academic Publishers 20/3(1992-05-01), 363-383 0090-6964 20:3<363 1992 20 10439 https://doi.org/10.1007/BF02368537 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02368537 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Buck Richard Department of Chemistry, University of North Carolina, 27599-3290, Chapel Hill, NC aut NATIONALLICENCE 773 0- Annals of Biomedical Engineering Kluwer Academic Publishers 20/3(1992-05-01), 363-383 0090-6964 20:3<363 1992 20 10439 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer