From 518ff789cb3023378ad68b49e4fe4e0c25b5500f Mon Sep 17 00:00:00 2001 From: Kenneth Odle Date: Tue, 21 Jan 2025 10:16:40 -0500 Subject: [PATCH] Added information on surfactants --- science-of-cleaning.tex | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/science-of-cleaning.tex b/science-of-cleaning.tex index ce50602..f432487 100644 --- a/science-of-cleaning.tex +++ b/science-of-cleaning.tex @@ -399,12 +399,14 @@ Traditionally, weak lye solutions were obtained by running water through wood as Sodium hydroxide is also used in a lot of drain cleaners and oven cleaners because it excels at getting rid of protein-based dirts, like hair clogs and burnt food. - - \chapter{Surfactants} \paragraph{Soaps and detergents, that is} +A surfactant is a chemical that decreases the surface tension between a liquid and a solid, a gas, or another liquid. Surfactant molecules have a hydrophilic (i.e., attracted to water) ``head'' and one or two hydrophobic (i.e., repelled by water) tails. This means that surfactants can act as emulsifiers, allowing oils and waters to mix. + +Surfactants are one of the most widespread and commercially important chemicals. The most surfactants you'll find at home are soaps and detergents.\footnote{There is a difference between soaps and detergents, but it is beyond the scope of this zine.} They basically work in the same way: the hydrophilic tails are attracted to fats and oils (which are also hydrophobic). If there is enough surfactant, and enough energy (which you can provide in the form of heat or agitation or both) the hydrophilic heads will get pulled away into the water, and the hydrophobic tails will pull some of the oil or fat molecules along for the ride. The entire process is not unlike an electromagnet in a scrap yard picking up iron. + \chapter{Abrasive Cleaners}