Thank you for the video! It helped me a lot to understand this process that I am about to do. Could you clarify a question, please? I've been looking for a company to order a borosilicate ampoule tube (I couldn't find one in Chemglass for instance). For my experiment, I need a 5mL ampoule. Which specific kind of ampoule and vendor could you suggest to me, please? Thank you!
Doesn't the flame volatilize the reagents? Does the vacuum continue sucking, and is it sucking reagent? How often do you screw up the divot thing and break the vacuum? How would you go about doing this in a garage lab instead of a fancy lab?
Hey, one of the students (Eric Q) answering here! 1. We use relatively small reactant amounts that can tolerate quite a bit of heat before becoming reactive, so it's usually not a concern. However, the bottom of the tube can warm up quite a bit, even if the flame is only on the top of the tube! In those cases, we may submerge the bottom of the tube in liquid nitrogen while we seal the top. 2. The vacuum is dynamic - it continues pulling vacuum the entire time. There typically isn't an issue with losing reactant; there may be some loss with particularly fine powders or if the reactants volatize a bit, but not on any sort of significant scale. For reactants that become gaseous at room temperature (e.g. organic solvents, iodine), keeping the bottom of the tube in liquid nitrogen prevents reactant loss. 3. Depends on experience of the student and size of the tube. For the 13/11 tubes, our new students typically have a 50-70% success rate in their first quarter; from the 2nd year onwards, pretty much 100%. Most students in our group don't need to seal tubes larger than 13/11, but some projects may require larger tubes or thicker tubes, which make the sealing process more complicated. For samples that aren't air/moisture-sensitive, it's fine to carefully break open the tube, pour the reactants into a new tube, and try again. 4. There are a lot of safety concerns that prevent me from recommending a garage setup. Without proper ventilation, the sealing process can cause fine silica particles to damage and scar lung tissue - silicosis. An improperly built torch setup has extreme and potentially explosive consequences for failure. However, there are definitely low-cost options for labs that are just starting up! In a fume hood or other adequately ventilated space, a vacuum setup could be built with standard PVC/steel vacuum pipe fittings, vacuum-compliant rubber/synthetic tubing, and metal vacuum adapters to connect the tubing to fused silica tubes.
I know I'm a bit late to the party, but what is the name for the contraption you guys have for vacuum sealing those ampules? The large glass tube for holding the vacuum specifically.
I tied that using a halogen bulb and put liquid chlorine in it. Used Oxy/new MAPP gas and it barely melted. Didnt manage to seal it, that stuff is on another level!
Thank you for the video! It helped me a lot to understand this process that I am about to do.
Could you clarify a question, please?
I've been looking for a company to order a borosilicate ampoule tube (I couldn't find one in Chemglass for instance). For my experiment, I need a 5mL ampoule. Which specific kind of ampoule and vendor could you suggest to me, please?
Thank you!
Doesn't the flame volatilize the reagents? Does the vacuum continue sucking, and is it sucking reagent? How often do you screw up the divot thing and break the vacuum? How would you go about doing this in a garage lab instead of a fancy lab?
Hey, one of the students (Eric Q) answering here!
1. We use relatively small reactant amounts that can tolerate quite a bit of heat before becoming reactive, so it's usually not a concern. However, the bottom of the tube can warm up quite a bit, even if the flame is only on the top of the tube! In those cases, we may submerge the bottom of the tube in liquid nitrogen while we seal the top.
2. The vacuum is dynamic - it continues pulling vacuum the entire time. There typically isn't an issue with losing reactant; there may be some loss with particularly fine powders or if the reactants volatize a bit, but not on any sort of significant scale. For reactants that become gaseous at room temperature (e.g. organic solvents, iodine), keeping the bottom of the tube in liquid nitrogen prevents reactant loss.
3. Depends on experience of the student and size of the tube. For the 13/11 tubes, our new students typically have a 50-70% success rate in their first quarter; from the 2nd year onwards, pretty much 100%. Most students in our group don't need to seal tubes larger than 13/11, but some projects may require larger tubes or thicker tubes, which make the sealing process more complicated. For samples that aren't air/moisture-sensitive, it's fine to carefully break open the tube, pour the reactants into a new tube, and try again.
4. There are a lot of safety concerns that prevent me from recommending a garage setup. Without proper ventilation, the sealing process can cause fine silica particles to damage and scar lung tissue - silicosis. An improperly built torch setup has extreme and potentially explosive consequences for failure. However, there are definitely low-cost options for labs that are just starting up! In a fume hood or other adequately ventilated space, a vacuum setup could be built with standard PVC/steel vacuum pipe fittings, vacuum-compliant rubber/synthetic tubing, and metal vacuum adapters to connect the tubing to fused silica tubes.
I know I'm a bit late to the party, but what is the name for the contraption you guys have for vacuum sealing those ampules? The large glass tube for holding the vacuum specifically.
I tied that using a halogen bulb and put liquid chlorine in it.
Used Oxy/new MAPP gas and it barely melted.
Didnt manage to seal it, that stuff is on another level!
You can choose to use oxy-hydrogen gas ( HHO gas), it is suitable for quartz tube sealing and melting.
More videos please!
awesome
totally tubular dudes