Chemistry Physics

[RTH10260]

Shaking Ordinary Ice (Very Hard) Transformed It Into Something Never Seen Before
The research illustrates how much scientists still have to learn about a molecule as simple as water.

By Kenneth Chang
Feb. 3, 2023 Updated 11:46 a.m. ET

Shaken and chilled — but not stirred — ordinary frozen water turns into something different: a newly discovered form of ice made of a jumble of molecules with unique properties.

“This is completely unexpected and very surprising,” said Christoph Salzmann, a chemistry professor at University College London in England and an author of a paper published on Thursday in the journal Science that described the ice.

Water is a simple molecule that has been intently studied by scientists for centuries: two hydrogen atoms jutting off at a 10.5-degree angle in a V-shape from a central oxygen atom.

The new discovery shows, once again, that water, a molecule without which life is not known to be able to exist, is still hiding scientific surprises yet to be revealed. This experiment employed relatively simple, inexpensive equipment to reveal a form of ice that could exist elsewhere in the solar system and throughout the universe.

In day-to-day life, we encounter three forms of water: a vaporous gas like steam, flowing liquid water and hard, slippery ice. The ice of our everyday lives consists of water molecules lined up in a hexagonal pattern, and those hexagonal lattices neatly stack on top of each other. The hexagonal structure is not tightly packed, which is why ice is less dense than liquid water and floats.

With permutations of temperature and pressure outside what generally occurs on Earth, water molecules can be pushed into other crystal structures. Scientists now know of 20 crystalline forms of water. The 20th form of ice was discovered last year.

In addition, researchers also have documented two types of ice with jumbled molecules, what they call amorphous materials. Because one of the amorphous ices is denser than water, it is known as high-density amorphous ice; the other, with a density less than that of water, is low-density amorphous ice. Amorphous ices are not found on Earth, but they could be prevalent in outer space, in comets, interstellar clouds and icy worlds like Europa, a moon of Jupiter.

There is even a type of water that is both liquid and solid. In 2018, scientists announced the creation of “superionic water,” which was simultaneously solid and liquid.




https://www.nytimes.com/2023/02/03/scie ... glass.html

Gift Link https://www.nytimes.com/2023/02/03/scie ... =share-url

[Flatpoint High]

Not certain this is the proper Physics forum, but here goes:

“How are matter and energy distributed?” asked Peter Schweitzer, a theoretical physicist at the University of Connecticut. “We don’t know.”

Schweitzer has spent most of his career thinking about the gravitational side of the proton. Specifically, he’s interested in a matrix of properties of the proton called the energy-momentum tensor. “The energy-momentum tensor knows everything there is to be known about the particle,” he said.

In Albert Einstein’s theory of general relativity, which casts gravitational attraction as objects following curves in space-time, the energy-momentum tensor tells space-time how to bend. It describes, for instance, the arrangement of energy (or, equivalently, mass) — the source of the lion’s share of space-time twisting. It also tracks information about how momentum is distributed, as well as where there will be compression or expansion, which can also lightly curve space-time.

The rest of the story: https://www.quantamagazine.org/swirling ... -20240314/

[RTH10260]

[keith]

Very nice demo of the speed of electricity.

[media]

[/media]

[tek]

didn't watch the whole thing..
None of the four possible answers was IMHO really a good description of what happens
Then again, I've been dealing with transmission lines for most of my life at this point.. so my perspective is a bit different..
.
also, there is a LOT of technology in, say, that ethernet cable you buy on Amazon for $1.. even though it looks like "just wires"

[RTH10260]

UC Berkeley chemists discover new way to break down common plastics

Lena Howland KGO
Friday, August 30, 2024

BERKELEY, Calif. -- Research published on Thursday out of UC Berkeley explores a newly-discovered chemical process that breaks down the most common plastics in things like water bottles and milk jugs.

"We hope that this method can kind of provide a better alternative to traditional mechanical recycling where instead of a lower value product out of the recycling process, you can get the exact same plastic by just recreating it from scratch," Richard 'RJ' Conk, a UC Berkeley chemistry Ph.D. candidate said.

Conk built off years of prior research by Cal students and found a new way to take apart some of the most difficult plastics to deconstruct.

We're talking about plastic water bottles, soap bottles, shopping bags and more, according to adviser John Hartwig.

"Sandwich bags, but also large objects and construction materials, as well as the milk jug, the yogurt container," John Hartwig, a UC Berkeley professor of chemistry said.

Here's how it works.

Chemists combine waste plastics with two catalysts - sodium and tungsten.

Then seal it inside a high-pressure reactor, add ethylene, heat it and stir for about an hour and a half, open up the reactor and this is the result: no more plastic.

Just raw materials that can now be recycled.



https://abc7chicago.com/post/uc-berkele ... /15244935/

[bill_g]

Very nice demo of the speed of electricity.

[media]
https: //youtu.be/2AXv49dDQJw?si=WDjG94ZHEabr5_1N
[/media]

That was pretty neat. I've never had to trigger a couple dozen channels simultaneously. That was impressive.

I would see reflections like that on transmission systems monitors, and from that you could see distance to fault ... which would be none if we did our job right. But, you could make out the bends in the cable, where the connections were, and if there was a functioning antenna on the end.

[Sam the Centipede]

UC Berkeley chemists discover new way to break down common plastics

My knowledge of chemistry is very limited, but I have been disappointed that there has been relatively little progress on the plastics recycling front in the last decade or two, either by chemical or biochemical means, especially as it could be a big money maker for those who get it right.

As there must be some very intelligent, skilled and knowledgeable people working on it, the problem must be much, more more difficult than I expected, not just breaking a few carbon-carbon bond, job done!

I expected more progress on enzymatic, bioengineered solutions, but, again, it's clearly a difficult problem.

I hope that they and others succeed in producing scaleable processes that can do as they describe and convert scrap plastic into low molecular weight feedstuffs, usable for making more plastics or useful chemicals.

Then, future generations might be able to both close the recycling loop and make a start on cleaning up some of the mountains of waste. Ideally at some point some of those vast mountains of city waste might be dismantled and processed back to metals, organic compounds, feed gas, etc.

[Volkonski]

The most difficult part of recycling is not the chemistry. The logistics is the big challenge.

The process described in that article will only work with polyethylene.

Collecting the used polyethylene (and only the PE) from the general waste stream and then delivering it to processing facilities will be challenging.

PE is quite cheap. About 20 to 50 cents a pound. The costs of collecting, sorting and transporting used PE would be several cents per pound. Adding the cost of the depolymerization process may make recycled PE more expensive than newly made PE.

The process described in that article is a batch process. Batch processes are inherently less efficient than continuous processes. Perhaps that chemistry could be accomplished in a continuous process but they aren't there yet.

PE is a very simple molecule, just carbon and hydrogen. Many common plastics which contain chlorine like polyvinyl chloride will be more challenging.

I do not mean to say that efforts to recycle plastics are futile. But I worked in plastics for many years. I have seen several recycling efforts that looked great at first fail.

[Volkonski]

Just playing with some numbers. A modern PE plant might produce 100,000 pounds per hour of PE on a single production line.

A gallon PE milk jug weighs about 0.13 pounds.

To recycle at the rate of 100,000 pounds per hour you would have to handle about 770,000 milk jugs per hour.

[keith]

My fantasy thoughts have always floated around NOT having to separate soft and hard plastics, but to congeal them somehow into hard lumps that have long, safe, half-lives and turn them into something useful like artificial reefs, piers, fence posts, etc.

I suppose it might be too flamable for housing construction, but its already being done for fence posts and decking.

But the current market and manufacturing scale makes it more expensive than cutting down more trees. And I don't know what the recipe for the stuff is, whether any plastic will do or only certain types, which means expensive separation.

[RTH10260]

But the current market and manufacturing scale makes it more expensive than cutting down more trees. And I don't know what the recipe for the stuff is, whether any plastic will do or only certain types, which means expensive separation.

For the small recycling enthusiast community the solution is to collect plastics and hand separate by imprinted chemical component code, like PE, PET, and others. Then pass the pure material thru one of the hand or electric motor operated small shredding machines. Then melt down in one of s selection of small melting and extrusion machines and press into the form of the desired product.

For the large scale recycling as done in Europe the plastics are run unsorted thru a coarse shredder to produce flakes of approx 1" square size. The flakes are poured onto a flat conveyor belt, spread out and not overlapping. The flakes will pass an optical detection and analysis device programmed for a specific material. Further down the flakes pass thru a selection device that will blow with pressured air either the chosen or the foreign material off of the conveyor belt into container for later procession in a large scale extruder, usually run by a third party.

Youtube is your friend to view above.

[W. Kevin Vicklund]

The most difficult part of recycling is not the chemistry. The logistics is the big challenge.

The process described in that article will only work with polyethylene.

Collecting the used polyethylene (and only the PE) from the general waste stream and then delivering it to processing facilities will be challenging.

PE is quite cheap. About 20 to 50 cents a pound. The costs of collecting, sorting and transporting used PE would be several cents per pound. Adding the cost of the depolymerization process may make recycled PE more expensive than newly made PE.

The process described in that article is a batch process. Batch processes are inherently less efficient than continuous processes. Perhaps that chemistry could be accomplished in a continuous process but they aren't there yet.

PE is a very simple molecule, just carbon and hydrogen. Many common plastics which contain chlorine like polyvinyl chloride will be more challenging.

I do not mean to say that efforts to recycle plastics are futile. But I worked in plastics for many years. I have seen several recycling efforts that looked great at first fail.

Correction: it works with polyethylene, polypropylene, or mixtures of both. Everything else you said is still true (polypropylene just has an extra carbon atom in the monomer)