Dr. Abraham H. Aaron

Effects of Non-Thermal Plasma on the Transition from Nano-Crystalline to Amorphous Structure in Water and Subsequent Effects on Viscosity

“…Although the transition between the amorphous and structured states involves a change of structure, it does not appear to be a first-order phase transition. A first-order transition would require the first derivative of free energy with respect to temperature to be discontinuous [29]. Entropy is given by s = − δ f δT [29].…”

“…A first-order transition would require the first derivative of free energy with respect to temperature to be discontinuous [29]. Entropy is given by s = − δ f δT [29]. Therefore, a first-order transition must have a discontinuous entropy, or in other words, a latent heat.…”

“…Many continuous transitions show a discontinuous second derivative of free energy with respect to temperature [32]. Isobaric heat capacity is given by C p = T δs δT p [29], so a discontinuous second derivative of free energy with respect to temperature would result in a discontinuous C p . However, while the amorphous to nano-crystalline transition is occurring, isobaric heat capacity remains continuous [30].…”

“…An equation is introduced for the Gibbs free energy of water. Gibbs free energy is typically given by f = u + Pv − Tσ [29], where f is Gibbs free energy, P is pressure, T is temperature, and u, v, and σ are internal energy, volume, and entropy per unit structure, respectively. This equation was expanded by Tanaka et al to account for the two different states of liquid water, which are structured and amorphous [30]:…”

“…For any thermodynamic system, equilibrium occurs when (d f ) T,P = 0 [29]. So, in this case, the equilibrium condition is…”