Structure and Physicochemical Properties of Water Treated Under Methane with Low-Temperature Glow Plasma of Low Frequency

Our former studies delivered a strong evidence that water indirectly treated with low-temperature, low-pressure glow plasma of low frequency (GP) changed its structure depending on the atmosphere in which such treatment was performed (air, ammonia, and nitrogen) and on the time of the treatment (0 to 120 min). In every case, water of different physicochemical characteristics and interesting biological functions was produced. Therefore, the relevant studies were extended to treating deionized water with GP under methane. The resulting samples were characterized by means of ultraviolet/visible (UV/VIS), Fourier transformation infrared—attenuated total reflectance (FTIR-ATR), electron spin resonance (ESR) and Raman spectroscopies, differential scanning calorimetry (DSC), thermogravimetry, pH, conductivity, and refractive index. The generated samples of water had entirely different physicochemical properties from those recorded for water treated with GP in the air and under both ammonia and nitrogen. The treatment of water with GP under methane did not produce clathrates hosting methane molecules. Thermogravimetry delivered an evidence that the treatment with GP increased the aqueous solubility of methane. That solubility non-linearly changed against the treatment time.