Three series of BaO-CaO-SiO2-Al2O3, SrO-SiO2-Al2O3, and SrO-CaO-SiO2-Al2O3 glasses are prepared. Their basic physical properties are measured using dilatometry and differential scanning calorimetry from room temperature to the softening temperature. Their structures are characterized with infrared spectroscopy. The wetting characteristics of all glasses are examined by monitoring the change in shape of a cube specimen on crofer22 substrates from room temperature to flow temperature with a high temperature shape microscope. Five main absorption bands can be distinguished in the infrared absorption spectra of the three systems. The optimum ranges of sealing temperature of the glasses are determined. The 24SrO-16CaO-25SiO(2)-8Al(2)O(3) glass is found to be the best sealant for the solid oxide electrolyzer/fuel cells under low loading without leakage. SrO improves the wetting ability of the glass by decreasing the contact angle between the glass and crofer22 substrates. The thermal properties of all the glasses fulfill the requirements for sealing solid oxide electrolysis/fuel cells. In terms of air tightness, the SrO-containing glass shows the best wetting ability among other glasses, and is the most suitable sealant for planar solid oxide electrolyzers/fuel cells. (C) 2012 Elsevier B.V. All rights reserved.