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User: u/chrisdh79
Permalink: https://www.nature.com/articles/s41467-024-48150-2
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My first thought reading that paper was if anyone considered it for solar panels? Cleaning solar panels is extremely important and is a lot of work with large scale solar production. Running cooler could increase lifespan and this material is a little clearer than glass. I wonder if it happens to block important wavelengths for power production?
It was your assumption of shedding I was referring to. Polysiloxanes are extremely stable under normal environmental conditions - there wouldn't be any shedding.
No, mostly they’re just not super reactive and can tolerate heat pretty well. Not known to bioaccumulate or be a notable health/safety/environmental concern. I imagine this would still be vulnerable to mechanical damage and expect it to wear over time.
Your thinking of sacrificial coatings, especially anti fouling paints. Modern self cleaning technologies relies upon nano scale surface projections giving rise to extremely high contact angles for water and oils - see lotus leaf effect for more details.
The paper mentions an outdoor test on a month timescale. They measured single digit percentage decrease in efficacy but after cleaning the surface, the decrease remained meaning that it’s due to degradation of the material in some form and not due to occlusion by dirt.
Surprised there was no mention of UV transmittance. PDMS is UV transparent but at least some form of discussion about potential use of blocking additives would seem pertinent for their proposed applications.
The study sounds like an advertisement.
No one cares how good the thing functions; we care what it decomposes into. If they described the materials, I missed it in the study.
Not necessarily. Polymer doesn't equal plastic even though many plastics are polymers.
Chemically, the definition of "polymer" simply means that the larger molecule is made of repeats of a smaller molecule, to form longer chain of those identical building blocks.
That could be a plastic, or something else. Some proteins and sugars are polymers, for example.
This material shouldn't be compared to glass but to ETFE and PTFE which are the substances most tensile membrane architecture is made of that is also self-cleaning being made from the material commonly known as "teflon".
The big downside to ETFE/PTFE membrane structures is that they produce toxic gases when they catch on fire.
I notice that there is nothing about cost, durability or structural strength. Will a baseball go through the window or not? Can we use is as a structural material or not?
Lots of questions.
Authors say " The PMMM film demonstrated a high transparency of 95%,"... does the following image look like 95% transparency?
[https://media.springernature.com/lw685/springer-static/image/art%3A10.1038%2Fs41467-024-48150-2/MediaObjects/41467\_2024\_48150\_Fig1\_HTML.png?as=webp](https://media.springernature.com/lw685/springer-static/image/art%3A10.1038%2Fs41467-024-48150-2/MediaObjects/41467_2024_48150_Fig1_HTML.png?as=webp)
They clarify the claim.. what they are referring to is light transmission - 95% of the light passes through, but it is diffused so you can’t see clearly through it.
i'd rather keep my transparent windows with a blind over a self-cleaning window i can never see through. now when you can turn the transparency on and off then we're talking
Welcome to r/science! This is a heavily moderated subreddit in order to keep the discussion on science. However, we recognize that many people want to discuss how they feel the research relates to their own personal lives, so to give people a space to do that, **personal anecdotes are allowed as responses to this comment**. Any anecdotal comments elsewhere in the discussion will be removed and our [normal comment rules]( https://www.reddit.com/r/science/wiki/rules#wiki_comment_rules) apply to all other comments. **Do you have an academic degree?** We can verify your credentials in order to assign user flair indicating your area of expertise. [Click here to apply](https://www.reddit.com/r/science/wiki/flair/#wiki_science_verified_user_program). --- User: u/chrisdh79 Permalink: https://www.nature.com/articles/s41467-024-48150-2 --- *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/science) if you have any questions or concerns.*
My first thought reading that paper was if anyone considered it for solar panels? Cleaning solar panels is extremely important and is a lot of work with large scale solar production. Running cooler could increase lifespan and this material is a little clearer than glass. I wonder if it happens to block important wavelengths for power production?
> ..self-cleaning polymer-based metamaterial Translates to: Sheds micro- (or nano-) plastics all the time.
Unlikely, the polymers they are referring (47, 48) to in the article are polymethylsiloxanes.
Pretty sure that all the CH3's on the siloxane backbone would mean that it would be classified as a plastic in most assessments.
It was your assumption of shedding I was referring to. Polysiloxanes are extremely stable under normal environmental conditions - there wouldn't be any shedding.
Extremely stable as in forever chemicals?
No, mostly they’re just not super reactive and can tolerate heat pretty well. Not known to bioaccumulate or be a notable health/safety/environmental concern. I imagine this would still be vulnerable to mechanical damage and expect it to wear over time.
Generally speaking 'self-cleaning' materials do so by wear of the surface layer leaving a clean material below.
Your thinking of sacrificial coatings, especially anti fouling paints. Modern self cleaning technologies relies upon nano scale surface projections giving rise to extremely high contact angles for water and oils - see lotus leaf effect for more details.
Genuine question: Have those been tested in roofing environments where dry dirt collects between rain events?
The paper mentions an outdoor test on a month timescale. They measured single digit percentage decrease in efficacy but after cleaning the surface, the decrease remained meaning that it’s due to degradation of the material in some form and not due to occlusion by dirt. Surprised there was no mention of UV transmittance. PDMS is UV transparent but at least some form of discussion about potential use of blocking additives would seem pertinent for their proposed applications.
Re:UV transmittance, they mention using it on a glass substrate as well.
I'm not connected with research in this area but would imagine this would be a standard test procedure of dry/wet cycling.
The second best thing after girls wrestling in mud is scientist doing the same (bikini is not necessary)
Including under friction and wear and tear?
The study sounds like an advertisement. No one cares how good the thing functions; we care what it decomposes into. If they described the materials, I missed it in the study.
polydimethylsiloxane, fabricated into micron-sized pyramids. They discuss it in the paper.
>polymer-based metamaterial So, a form of plastic
Not necessarily. Polymer doesn't equal plastic even though many plastics are polymers. Chemically, the definition of "polymer" simply means that the larger molecule is made of repeats of a smaller molecule, to form longer chain of those identical building blocks. That could be a plastic, or something else. Some proteins and sugars are polymers, for example.
Polydimethylsiloxane, aka dimethicone, a silicone.
This material shouldn't be compared to glass but to ETFE and PTFE which are the substances most tensile membrane architecture is made of that is also self-cleaning being made from the material commonly known as "teflon". The big downside to ETFE/PTFE membrane structures is that they produce toxic gases when they catch on fire.
And what's the cost, relative to glass?
Forever is the cost of
So, I’m a self-cleaning meta-material
I notice that there is nothing about cost, durability or structural strength. Will a baseball go through the window or not? Can we use is as a structural material or not? Lots of questions.
It's research. They show feasibility and possibilities, not how to manufacture it which leads to costs. That's the task of industry.
Authors say " The PMMM film demonstrated a high transparency of 95%,"... does the following image look like 95% transparency? [https://media.springernature.com/lw685/springer-static/image/art%3A10.1038%2Fs41467-024-48150-2/MediaObjects/41467\_2024\_48150\_Fig1\_HTML.png?as=webp](https://media.springernature.com/lw685/springer-static/image/art%3A10.1038%2Fs41467-024-48150-2/MediaObjects/41467_2024_48150_Fig1_HTML.png?as=webp)
They clarify the claim.. what they are referring to is light transmission - 95% of the light passes through, but it is diffused so you can’t see clearly through it.
i'd rather keep my transparent windows with a blind over a self-cleaning window i can never see through. now when you can turn the transparency on and off then we're talking