Using plastic waste to help solve sand shortages

Source - bbc article

I've mentioned the possible shortage of sand for use in concrete construction around the world before and - admittedly - haven't heard much of an update on that shortage in the past few years.

Today's article describes an attempt to solve the sand shortage - at least partially - as well as to use some of the seemingly endless supply of plastic trash that we continue to produce in our world by replacing some of that sand with ground up plastic pieces.

There isn't much detail, and I would want to know a few things before considering plastic as a sand alternative...

• Is the plastic post- or pre-consumer plastic?
• What polymers can be used for this?
• Does anything leach from the plastic over the life of the concrete?
• As the concrete structure wears, are microplastics released?
• How does the plastic change the hardness, toughness, strength of the concrete material?

In the long run, this might help extend our construction forward a bit, but I'm coming to realize that maybe we just need to use less stuff.

Heineken WOBO Bottle | Object in Focus | V&A

Reduce, reuse, recycle

Glass is a generally a fairly environmentally-friendly material, being made primarily of sand, so the idea of reusing glass bottles to build homes after they were used for their initial, beer-transporting purpose is brilliant.

I wish it would have worked out...and I also kind of wish I had one of the WOBO bottles, but with only 100,000 of them having been made, I'm guessing the sell for a pretty penny.

Least I Could Do: the Comic

Source: https://leasticoulddo.com/comic/20211003

 Yup...good questions there, young Rayne.

A Brief Scientific History of Glass

 

Source - https://glass.com.ng/glass-fact-history-glass/

Smithsonian magazine has a great article tracing both the history of glass and the modern scientific techniques used to reveal that history - everything from traditional archeology to radioisotope tracers to mass spectrometry.

Could be a really useful crossover between a chemistry and a materials science course, or just an introduction to a glass unit.

Afraid of heights? This is not the job for you | SciTech Now

As opposed to last week's less-then-professional-sounding narrator, this week's video host sounds like he belongs on local television reading the news or interviewing a woman who lost her cat.

He does, however, tell an interesting story of people climbing St Louis's Gateway Arch - one of my favorite places in the world, honestly - to figure out what was causing some staining on the underside of the Arch. One concern was the possibility of damage or corrosion on the surface of the arch.

Luckily, the exploration found that the stains are superficial...and they decided not to clean the Arch - as of the time of this video in 2016.

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.