Communication: The impedance effect on the ion transport of lithium chloride through temperature- and pH-sensitive gel membranes was investigated. Both conductance and loss tangent show a relatively high value at temperatures near the lower critical solution temperature (14degreesC), followed by an abrupt drop with a further rise in temperature. The The Figure shows an example of changes in absolute complex conductance (Y), real conductance (G), and imaginary conductance (B) for a poly(acryloyl-L-proline methyl ester) gel membrane.