Underwater ignition of hexachlorodisilane hydrolyzed deposit

This paper reports an underwater ignition of HCDS hydrolyzed deposit in a reaction calorimeter reactor. The mixture was agitated by using a mechanical stirrer with a speed of 190 revolutions per minute. Prior to the ignition, 33.5 g of HCDS liquid was fed into 550 g of an aqueous solution of potassium hydroxide (5% by weight). The resulting acidic solution contained mainly water, potassium chloride, hydrogen chloride, and HCDS hydrolyzed deposit, which was confirmed by the infrared spectrometer. The ignition took place at 10 cm below liquid level and lasted for less than 0.1 seconds with a concurrent gas release. Fall hammer tests were performed and confirmed that the potassium ions in the solution are the key factor that weakened the Si-Si bonds on the surface of the HCDS hydrolyzed deposit and thereby made the deposit very sensitive towards mechanical impact. The results highlight again the risk associated with the handling and disposal of HCDS hydrolyzed deposit.