Hydrogen particles and supersaturation in alkaline water from an Alkali-Ion-Water electrolyzer

The hydrogen content in alkaline water obtained from an electrolytic flow c ell was examined by measuring the diameter distribution of hydrogen microbu bbles (hydrogen particles) in electrolyzed alkaline water using the dynamic light scattering (DLS) method. The influence of electrolysis conditions on the hydrogen content and the diameter distribution of hydrogen particles w ere also examined. The diameter of hydrogen particles changes rapidly with elapsed time after electrolysis, indicating that hydrogen particles grow to form large particles. The distribution of the particle diameter shows two peaks. The mean diameter of hydrogen particles is distributed mainly betwee n 20 and 300 nm, The mean diameter decreases with an increasing current den sity up to 0.03 A dm(-2). The diameter of hydrogen particles is smaller tha n the equilibrium diameter obtained by the concentration of dissolved hydro gen, suggesting that the electrolyzed water is a transition state from supe rsaturated to saturated solutions. Hydrogen exists in particles as a colloi dal solution in a region of hydrogen content in electrolyzed water above 0. 75 mM, which represents the saturation concentration of the dissolved hydro gen. (C) 2001 Elsevier Science B.V. All rights reserved.