3 Cool Videos about Hydrophilic, Hydrophobic, & Hygroscopic Materials

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hygroscopic-material-silica-gel-desiccant

As long as we're exploring the wonderful world of water, we ought to show some of the cool stuff it does. In my article Introduction to the Physics of Water in Porous Materials, I described hydrophilic, hydrophobic, and hygroscopic materials. Turns out they're pretty important to building science. Yesterday I saw a video of hydrophobic sand and that got me looking on Youtube for other good videos of this sort.

Hydrophobic and hydrophilic materials

Hydrophobic (water fearing) materials don't like water and try to keep their distance. Hydrophilic (water loving) materials can't get close enough. The first video dramatically illustrates these properties.

The second video shows that hydrophobic sand I mentioned above. How cool is that!?

 

Hygroscopic materials

And then there's hygroscopic materials. This stuff likes to pull water vapor in. (Yikes! I almost said, "pull water vapor out of the air." That would've killed my chances to get into Don Gatley's Psychrometric Fools Society.) Silica gel, a common desiccant, is hygroscopic.

Some hygroscopic materials not only snag water vapor from the surrounding space, but they also dissolve as they do so. Of course, this property has to have a special name, and that name is deliquescence. Salt (sodium chloride) is one such deliquescent material, as you can see below.

So there's your phun physics lesson of the day!

 

Related Articles

Introduction to the Physics of Water in Porous Materials

Are You Making This Mistake with Humidity?

Moisture and the Quirkiness of OSB

 

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Comments

Don Gatley

Great topic and thanks for the cool videos. That’s the GOOD NEWS.

The BAD NEWS is that the Board of Directors has banned for 60 days any applications for your entry into the SOCIETY OF PSYCHROMETRIC FOOLS for four spelling errors in the quoted paragraph below.

“And then there's hygroscopic materials. This stuff likes to pull water vapor in. (Ykes! I almost said, "pull water vapor out of the air." That would've killed my chances to get into Don Gatley's Pychrometric Fools Society.) Sillica gel, a common dessicant, is hygroscopic.”

Now Alistair Frazier’s BAD PSYCHROMETRICS shuns the phrase that AIR HOLDS WATER VAPOR or that WATER VAPOR HOLDS AIR. But your phrase PULL WATER VAPOR OUT OF THE AIR is still under review.

In lieu of application to the SOCIETY OF PSYCHROMETRIC FOOLS you may wish to apply to the English PSYCHROLOUSIA SOCIETY.

Don Gatley

Great topic and thanks for the cool videos. That’s the GOOD NEWS.

The BAD NEWS is that the Board of Directors has banned for 60 days any applications for your entry into the SOCIETY OF PSYCHROMETRIC FOOLS for four spelling errors in the quoted paragraph below.

“And then there's hygroscopic materials. This stuff likes to pull water vapor in. (Ykes! I almost said, "pull water vapor out of the air." That would've killed my chances to get into Don Gatley's Pychrometric Fools Society.) Sillica gel, a common dessicant, is hygroscopic.”

Now Alistair Frazier’s BAD PSYCHROMETRICS shuns the phrase that AIR HOLDS WATER VAPOR or that WATER VAPOR HOLDS AIR. But your phrase PULL WATER VAPOR OUT OF THE AIR is still under review.

In lieu of application to the SOCIETY OF PSYCHROMETRIC FOOLS you may wish to apply to the English PSYCHROLOUSIA SOCIETY.

Allison A Bailes III

Now that's downright embarrassing, Don. At first I thought maybe you were going to say I'd misspelled vapor incorrectly—four times—but then I looked and found the four you undoubtedly were referring to: Ykes, sillica, dessicant, and pychrometric. You'd never have known that I used to win medals in spelling competitions when I was in high school.

So I guess you're throwing cold water on my chances for selection to the Society of Psychrometric Fools. Is that why you suggest the Psychrolousia Society?

Allison A Bailes III

Now that's downright embarrassing, Don. At first I thought maybe you were going to say I'd misspelled vapor incorrectly—four times—but then I looked and found the four you undoubtedly were referring to: Ykes, sillica, dessicant, and pychrometric. You'd never have known that I used to win medals in spelling competitions when I was in high school.

So I guess you're throwing cold water on my chances for selection to the Society of Psychrometric Fools. Is that why you suggest the Psychrolousia Society?