by fuzzfactor | 2025-10-16 23:15:33+00:00
In separation science a partitioning coefficient can be described for an undesirable contaminant, inbetween a solid adsorbent having a certain degree of retention, versus a solvent where it is soluble to its own certain degree, under static equilibrium conditions.

IOW the smoke will have different affinity for different types of furniture, carpets, and window coverings, and when it comes in contact with these they soak it up like a sponge. Because the adsorbent materials are physically like a sponge more often than not, whether on a macro, micro, or molecular level.

The solvent is plain air, but the "solubility" of the raw smoke in air is not a factor because the smoke is not actually dissolved in the solvent (air) at this point, or ever really. The smoke consists of a lot of solid particles that have been forcefully dispersed into the air at uneven concentrations. The smoke itself is not a chemical contaminant that dissolves in the air, it's just dispersed in the air not much differently than an unwanted chemical, for a least a good period of time.

But the solids will eventually settle if they are not purged beforehand. What you're left with after that is then chemical equilibrium.

In a confined enclosure, static equilibrium will eventually be reached between the amount of chemical contaminants dissolved in the air at that temperature, versus the amount adsorbed onto available surfaces. After which no more odor can be released from the furniture once the air is saturated. To really get rid of the smell you're going to have to replace the saturated air with fresh air and one compete air exchange is not usually enough. Also the more efficient air exchange the better, and the fresher the better. If one person smoked one time, or you burned some popcorn and did not let out the smoke right away, that's not much contamination and it's not constant, but it's also not unusual to still smell it a week later when you first walk in from a fresh outdoor air environment. But just don't open the windows when something like a diesel truck is idling outside, new odor could then be coming in in greater quantities than the old odor can escape, one roomful at a time.

You may have grams of "odor" soaked into the carpet along with 100 grams of dirt & dust. But what if the chemical causing the odor only "evaporates" into the air a few milligrams at a time? Because the heavier the liquid, the slower the evaporation and the resulting partitioning coefficient using air as a solvent is such a low number. And it's not too unintuitive to figure that things which are semi-solid like tars or true solids like some pesticides hardly evaporate at all, but can really stink when there's only a few milligrams in the air.

Stuff like that is not going away without a solvent much stronger than air, and also a more concentrated solvent than a gaseous fluid can make contact by the gram much faster than a gram of fresh air can eventually flow by the unwanted material to be removed.

Plain water may not be any better as a solvent at dissolving cooking oils and tars than air is a solvent, but you sure can get a lot more grams into contact with a surface or macro adsorbent quicker compared to air as a gas.

Plain steam dissolves things so much better just from the added heat of the liquid turning it into a stronger solvent, plus so much of the water evaporates so fast at that temperature there is also a purging effect.

Then there's the carpet-cleaning liquids that can improve the partitioning coefficient of water so it will dissolve otherwise insoluble materials without nearly as much heat as steam. Like grams of detergent added to volumes of water to clean a certain area of carpet, or hundreds of grams of water-soluble organic solvent over the same area instead. Or both, simultaneously, or sequentially. Then when you do the math you see how much more effective sequentially is.

Now without doing any carpet cleaning, when you enhance the air exchange rate to do as good a job removing odors as that can accomplish, you are then trying to establish a dynamic equilibrium so odors are being purged outward at an enhanced rate due to increased fresh solvent (air) flow. Kind of like sequential carpet cleaning. One window fan blowing in and one blowing out at opposite ends of the structure can sometimes be more effective than all windows open whether or not using the same fans.

>I wonder what a chemist would have to say about it.

I wouldn't be surprised if people are still wondering :)

Edit: Hopefully they're wondering even more about a lot of things where they didn't know there were equations, actually ;)