Effect of surfactant on depressing the hydrolysis process for aluminum nitride powder

The hydrophobic treatment of AlN powders is commonly used for depressing their hydrolysis process. A commercially claimed water-resistant AlN powder (hydrophobic treated) was investigated through hydrolysis with pH measurements of the suspensions. For comparison, an untreated AlN powder was studied with similar hydrolysis condition. The water-contacted powders were subsequently analyzed with XRD. Both pH measurements and XRD results indicated that the water-resistant AlN powders were not resistant to hydrolysis without surfactant addition. It was also found that the surfactant was effective in depressing hydrolysis of the hydrophobic treated AlN powders, but slowed down slightly the hydrolysis process for untreated AlN powders. A critical surfactant concentration of 0.7 wt.% was required for successfully depressing the hydrolysis process.