Figure 10.

(a) Charge (nC) plotted against pressure (kPa) for a polyester sample at temperatures of $T={37}^{\circ }\text{C}$ (red solid circles) and $T={23}^{\circ }\text{C}$ (blue solid squares) establishes the dependence of net charge on the thermodynamic variables.(b) Evolving the system through states A–D completes a closed thermodynamic cycle through adsorption and desorption when either the pressure or temperature is varied while keeping the other fixed. Red ($T={37}^{\circ }\text{C}$) and blue ($T={23}^{\circ }\text{C}$) curves are experimental data plotted in (a). (Online version in colour.)