Wang J H, Copeland E
Proc Natl Acad Sci U S A. 1973 Jul;70(7):1909-11. doi: 10.1073/pnas.70.7.1909.
A simple thermodynamic theory of the equilibrium potentials of membrane electrodes is formulated and applied to the glass electrode for measurement of pH. The new formulation assumes the selective adsorption or binding of specific ions on the surface of the membrane which may or may not be permeable to the ion, and includes the conventional derivation based on reversible ion transport across membranes as a special case. To test the theory, a platinum wire was coated with a mixture of stearic acid and methyl-tri-n-octyl-ammonium stearate. When this coated electrode was immersed in aqueous phosphate solution, its potential was found to be a linear function of pH from pH 2 to 12 with a slope equal to the theoretical value of 59.0 mV per pH unit at 24 degrees .
提出了一种关于膜电极平衡电位的简单热力学理论，并将其应用于测量pH值的玻璃电极。新的公式假设特定离子在膜表面有选择性吸附或结合，膜对该离子可能是可渗透的，也可能是不可渗透的，并且将基于离子跨膜可逆传输的传统推导作为一种特殊情况包含在内。为了验证该理论，用硬脂酸和甲基三正辛基铵硬脂酸盐的混合物涂覆铂丝。当将该涂覆电极浸入磷酸盐水溶液中时，发现其电位在pH值为2至12的范围内是pH的线性函数，斜率等于24摄氏度时每pH单位59.0 mV的理论值。
