Breaking Bad : Season 1 : Episode 4 : “Cancer Man”
A few weeks in, and it’s exposition time. This episode is quite science-light, and in this post I’ll be talking about using superglue to suture wounds and how Walt blew that car battery up.
If Walt were to go to a hospital with his leg wounds, records would be made and awkward questions would be asked, so he just has to tough it out until he’s healed. We see him applying iodine solution as a disinfectant, and then suturing a wound with acrylate superglue – a method used by the military.
“Super”glues contain a cyanoacrylate (-OC(O)C(CN)=CH2) group, which provides the glueing effects, and another group designed to tweak the glue’s properties to its intended use – the most common household superglues contain ethyl cyanoacrylate, which has an extra ethyl (-CH2CH3) group. In the presence of water (the moisture in air is more than enough), the glue rapidly polymerises (forms large molecules from repeating units of smaller molecules) and forms an extremely strong resin.
Walt is using general-purpose superglue, which is usually a bad idea – suture glues designed for medial use contain longer groups such as octyl, -(CH2)7CH3, as the “tweak” group, which make the resin more flexible. Household glue may also irritate the skin, contain other chemicals and cause local burns due to the heat released in the polymerisation process.
Car battery explosion
While films often show unrealistic detonate-on-impact cars, the battery explosion in this episode can actually happen. As Walt clearly knows, most cars use simple rechargeable lead-acid batteries – overcharging or short-circuiting will cause hydrogen and oxygen to be vented due to the electrolysis (using electrical current to drive a chemical reaction) of water in the electrolyte (liquid that conducts electricity). Although hydrogen is highly explosive in air (and the sparks coming from the squeegee/battery connection would guarantee ignition), it would probably burn off quickly and not cause the extensive fire we see – the (liquid) battery contents are not flammable, so we can assume that the explosion damaged a fuel line.
Elements in the credits
|STeven Michael Quezada||Tellurium|
|Robb Wilson King||Tungsten|