Tyvek round-up

I've been searching for a video showing the production of Tyvek, and I haven't had any luck. I've found a bunch of videos (not those shown below) that show the manufacturing of products made of Tyvek (disposable hazmat suits, festival bracelets, a whole bunch of wallets and tents and bivies), but I haven't found anything that will show me how the original 'fabric' is made.

Along the way of my searches, though, I came upon a number of interesting Tyvek videos...

From what I can tell, DuPont (Tyvek's manufacturer) seems most concerned about distinguishing their product from SMS (spunbond-meltblown-spunbond) and MPF (microporous film).



The further data on the DuPont website isn't terrifically detailed, admittedly, but I very much like the simple method they set up to test the permeability of the different materials.



The Professor Tytonius (?) video is hoaky, but the tests are the sorts of things my students could probably reproduce in the classroom to gauge the permeability of the various underlayments.



That's just gross. However, if I were doing work like they show at the end, I think a Tyvek suit would be appreciated.



Again, a straightforward test that my students would reproduce...




I appreciate that they do end by saying that Tyvek isn't really meant for paintballing.



Simple test...I like it...



So, Tyvek isn't bulletproof? Good to know...

Piezoelectricity round-up

Clearly piezoelectricity is way more common than I knew.

Sugar crystals? DNA? Bones? All are piezoelectric?

And if piezoelectric crystals lack a center of symmetry (2:20), how the heck is quartz piezoelectric? It looks awfully symmetrical to me.

Apparently, though, the quartz crystal is absolutely piezoelectric, as shown by Bill Hammack, the Engineer Guy...



Theoretically, it's possible to make and test your own piezoelectric crystal at home...(though sadly he uses a commercial piezoelectric crystal to make his guitar pickup)



As to how we can make use to piezoelectrcitiy...

• Top uses of piezoelectricity in everyday applications (inkjet printers, earbuds, tennis racquets, course-changing bullets, humidifiers, sonar, pressure sensors)
• Applications of piezoelectricity (from wikipedia)
• Piezoelectricity and its uses (even explaining how some tennis racquets use piezoelectrcity)

Summer camp map 2018

Have you ever had déjà vu?

Or maybe déjà map?

This year's map of the ASM material science summer camps is now available (just in time for the first camp to start in a week and a few days (not Memorial Day week but the week after that).

We progress, as we have the past few years, from red during the early summer through to purple in mid-August. There is one black pin because the dates of the Knoxville camp hadn't been finalized when the list I was working from was published.

If you have any questions about the camps - and I think the vast majority of folks who frequent this blog do so because they've attended a camp - ask 'em in the comments or to me via email (phschemguy at gmail.com).

If you happen to go through the maps from the past five years (linked above), you can also see how Google maps has changed the appearance of its pins. For a more detailed look at the changes, check out Justin O'Beirne's fascinating series of posts.

Matter, Energy, and the Material Scientist

I'm hopeful that there are more creative uses for the formcards that are demonstrated above than just making toothbrush holders.

I do appreciate the demonstration of the formcards' glass transition from solid to flexible solid. I'm curious to see some data as to at what specific temperature that happens for this specific polymer (check the MSDS, and you still won't know).

How It's Made - 1372 Ultra Thin Glass

Standard materials such as lime, sand, soda, and pot ash...plus "smaller, secret ingredients...[to] enhance optical clarity and electrical conductivity"

There's a lot that's not being said there in those quotes.

The real payoff of this video is - to me, anyway - the thin, sagging ribbon of glass at 2:49 through 2:58 then the rolled-up glass at 3:25.

That's stunning.