Ionic conductivities of hydrated zeolite Li-, Na- and K-A were measured at room temperature and at pressures of up to 4.8GPa. Anomalous increases in conductivity with pressure, from 1.7 to 1.9GPa were observed for all of the zeolites. In this pressure range, the activation volumes for conduction were −1.4, −3.9 and −6.8cm3/mol for Li-, Na- and K-A zeolites, respectively. The conductivity went through a maximum, where pressure-induced amorphization occurred. Beyond the maximum, there was a rapid decrease in conductivity due to the collapse of long-range ordering. Upon decompression, the conductivity increased to values that were higher than the conductivity values at the equivalent pressures during compression.

Ionic Conduction in Hydrated Zeolite Li-, Na- and K-A at High Pressures. M.D.Rutter, R.A.Secco, Y.Huang: Chemical Physics Letters, 2000, 331[2–4], 189–95

Figure 3

Conductivity of Na-X

(a: 100kHz, b: 10kHz, c: 1kHz, d: 100Hz)