An experienced researcher with 30+ years of laboratory experience (including working with air-sensitive compounds) was disposing of a small vial of catalyst and hydride powder left in the laboratory by a post-doc. The researcher emptied the vial into a container of mineral oil inside a glove box, but a small amount of the hydride powder adhered to the wall of the vial. The vial was then removed from the glove box and brought over to a tall waste jar in the laboratory that contained isopropanol. (Isopropanol is the first (slowest-acting) pacifier used when deactivating pyrophoric hydrides.) The vial was opened and inverted over the isopropanol jar and the residue powder was tapped into the jar. There was a "small flash of flame" that quickly extinguished itself.
A guest student was weighing out less than 200 mg of sodium hydride. The material reacted with moisture in the air, producing hydrogen. The heat of the reaction ignited the hydrogen on the end of the spatula being used to transfer the material and at the mouth of the bag holding the stock material (approximately 48 to 50 g). The student attempted to smother the flames with a cotton lab coat hanging nearby. He quickly determined that the lab coat was insufficient to smother the flames and entered the adjoining lab to get a fire extinguisher and warn other lab workers in the area. The other lab workers exited the lab, warned others in the area, pulled the fire alarm and called the laboratory shift supervisor. The student extinguished the fire with the fire extinguisher, then left the view more
During preparation of a new hydrogen storage material, ammonia borane (AB) loaded onto mesoporous carbon, an unexpected incident was observed. As with all procedures with new materials the work is conducted on a small scale and in a laboratory fume hood. They followed the procedures that they had used for absorption of ammonia borane onto mesoporous silica without incident.
To absorb the solid AB into a scaffold material they dissolve AB in a dry aprotic polar solvent, THF. The saturated solution of AB in THF is added to the mesoporous carbon material in a round bottom flask, stirred for 10 minutes to saturate the mesoporous scaffold with AB and then the solvent is slowly removed under vacuum. At this point the sample is assumed to be prepared and ready for transfer to a sample view more