The Story of Aerogels: The Power of Porosity

I apologize for the narration of The Mat Sci Guy. His voice certainly lacks those nice, pear-shaped tones that are so valuable on the radio - or maybe he just needs a better microphone or a decongestant or processing software.

But...his content is interesting and educational, well laid out and thoroughly researched, so I recommend watching the video but maybe not showing it in class.

Today's video sees him exploring the formation, properties, and applications of aerogels in their various forms. 

I'm thrilled that I know something about sol-gel chemistry from a summer of research I did at Miami University some twenty five years ago. I wasn't making aerogels, but I did spend the summer making sol-gels and exploring their applications in chromatography columns. 

I also have a little experience with aerogels...or at least I did until my favorite coworker shattered my large sample. Now I have multiple, smaller samples.

The Material Science of Metal 3D Printing

<cough>Additive manufacturing?</cough>

The first four minutes or so of this video are about the economics of 3d printing with metal and why it is - for now, anyway - restricted mostly to just prototyping rather than mass production.

Then there's a bit of coverage about testing 3d printed parts - particularly in fatigue strength - as compared to traditional machined parts and a bit of explanation as to why their fatigue strengths tend to be significantly lower - including a micrograph exploration of metals while they are sintered . It's surprising to me that there isn't - at least shown - an example of a sintered piece of metal being tested.

Overall, the video is a nice exploration of why mass produced engines will likely not be made by 3d printing experts in the immediate future.

How These Handmade Tiles Lock Up Air Pollution | World Wide Waste

A slacker...I'm entirely a slacker.

That's my first takeaway from watching these videos of young people doing amazing things to better their world and decrease the pollution and waste around them.

At 3:05, the creator states that, "this is the lowest carbon footprint way of making a tile," but I'm curious about that. I've come to understand that cement is a very carbon-intensive material, requiring large amounts of carbon dioxide to be released as the calcium carbonate raw material is heated to produce the calcium oxide for the cement. 

I love the grey/black/white color scheme of the tiles. I'd happily buy those tiles.

Briquettes Made From Coconut Waste Could Reduce Deforestation | World Wide Waste

The squishy black mess looks really gross, but I'm impressed at the ingenuity of turning the coconut husk waste into a usable fuel that can replace wood.

Anything that can be done to get rid of waste in landfills is a good thing.