Thermal and capillary behavior of water at interfaces under excitation

Abstract

Previous publications have demonstrated changes of electrochemical reactivity, proton density and evaporation rate of water excited by hydrodynamic cavitation and weak magnetic fields. Proposed explanation of these effects concerns spin-based mechanisms at water–air interfaces, which are of significant technological interest. Following these ideas, we also expect changes in heat capacity and surface tension of excited water. This work provides experimental evidences for these assumptions and describes experiments on capillary effects and thermal dynamics of pure H₂O with focus on hydrodynamic cavitation. Experiments use two calorimetric systems for diathermic measurements and 0.3 mm/0.5 mm capillary tubes. Samples after excitation are degassed at -0.09MPa and thermally equalized in a water bath. Given the critical role of water–air interfaces in these phenomena, a micromanipulation tool was used to sample from the 0.1 mm subsurface layer, with comparisons made to immersion depths of 2 mm and 10 mm. Conducted attempts demonstrated changes in heat capacity of 4.17%–5.72% within 60 min after excitation, decreasing to 2.08% in steady-state dynamics. The surface tension varied between control and experimental samples by 6.7%–11.3% with a maximum of 15.7%. Effects in near-surface layers last for 30-60 min after the excitation. These outcomes are consistent with the results of NMR and four-photon spectroscopy conducted earlier. The described approach can be used for the rapid detection of spin-based phenomena. Given the importance of capillary and electrochemical processes in aquaporin channels and plant fluid transport systems, these techniques hold promise for applications in phytosensing and agricultural production.