Superhydrophobic surface of glass powder derived from wet milling with aliphatic chemicals modification

Abstract

Glass frit has emerged recently as a promising material for incorporation in adhesive of electronic components owing to its high sealing density, environmental stability and easy processing. This requires the glass surface to be hydrophobic to ensure high dispersity, grinding uniformity, and high-temperature sintering performance of the glass frit. However, the glass surface is usually hydrophilic. In this work, we developed a wet milling method to effectively produce hydrophobic glass powder by using aliphatic chemicals modification. We employed a series of aliphatic chemicals containing nucleophilic functional groups to prepare ultrafine lead aluminosilicate electronic glass powders. The nucleophilic substitution reaction of amino groups, carboxylic acid groups, hydroxyl groups and phosphoric acid groups reduces the hydroxyl content on the surface of the glass powder to 0.10 mg/m2, and generates steric hindrance and hydrophobicity (contact angle: 153.0°) through the long carbon chain. The obtained powder therefore shows a uniform particle size distribution, anti-agglomerated property, and maximum 25 °C lower hemispheric point temperature compared to powder prepared by conventional hydrophilic milling method. This work provides a versatile method to simultaneously control the structural and surface properties of glass powders at their formation stage.