81–90 of 397 posts
Will the replacement for PFC be something very similar that is equally dangerous?
perfluorocarbons themselves are among the least dangerous materials in the world, but the materials used to make them are very nasty indeed
Given that many cyclists also have deep climate anxieties and conservative (with a small'c') attitudes it sounds as though 1970's era pvc coated nylon and cotton will make a resurgence
Whilst PVC is most frequently made from salt and oil, in some regions of the world PVC is made without using oil feedstock at all (substituting oil-derived hydrocarbon with bio-derived hydrocarbon feedstock). PVC is therefore far less oil-dependent than other thermoplastics.
Wow there's definitely a money making opportunity to hang on to and resell any goretex shakedry (single layer goretex, Columbia had a similar thing called out-dri). There's really nothing else like it that's as light weight and water proof yet breathable as it was. People paid a premium for it when it was in production. The value is going to skyrocket if it's not available new anymore.
If they didn’t degrade quickly, they wouldn’t be such a threat to the environment.
Edit: Sorry, I didn’t mean PTFE above but PFC.
Wow there's definitely a money making opportunity to hang on to and resell any goretex shakedry (single layer goretex, Columbia had a similar thing called out-dri). There's really nothing else like it that's as light weight and water proof yet breathable as it was. People paid a premium for it when it was in production. The value is going to skyrocket if it's not available new anymore.
PDMS rubber, polypropylene, polyethylene, and PTFE all have very high water contact angles (a measure of the strength of interaction of water and the surface) and low water uptake [1]. I work with a stretched polypropylene film (Celgard — a material that is often used as a support/spacer material in Li-ion batteries) and it’s extremely hydrophobic. I used a piece of this film to build a bubble trap ([2]), for example (bubble traps typically use PTFE membranes…). It is not optimized for water resistance, so it does wet eventually, but it’s pretty good for “not trying”. Surfaces coated with PDMS (or glass coated with short PDMS chains — i.e., silanized glass [3]) are extremely hydrophobic.
The only time I personally use PTFE (or PFA, MFA, FEP, or ETFE) is when I need materials to be resistant (including both resistance to chemical degradation as well as swelling) to strong organic solvents (like NMP, THF, etc.) or strong acids and bases (like piranha, aqua regia, or a nitrating solution). These conditions are unlikely to be encountered while cycling.
This all said, I’m not an expert on the design of Gor-Tex type materials. However, I assume it is highly related to the pore structure of the materials to prevent liquid water intrusion (the same as for membranes designed for membrane distillation). Given the similar hydrophobicity of these materials, it seems like it should be possible to produce similar results with PP, PE, etc. And this is all before introducing the ability of nanomaterials and nanopatterning (perhaps transferred with imprint lithography [4]) to produce metastable ultrahydrophobicity [5] on the surface of materials.
[0] https://www.sungodtech.com/how-much-do-you-know-about-ptfe-w..., https://outdoorguru.com/how-to-en/how-does-waterproof-and-br... [1] https://www.accudynetest.com/polytable_03.html, https://omnexus.specialchem.com/polymer-properties/propertie... [2] https://static.wixstatic.com/media/ec0ae9_aacc723ea77d46619d... [3] https://en.wikipedia.org/wiki/Silanization [4] https://pubs.acs.org/doi/10.1021/acsomega.8b03138 [5] https://en.wikipedia.org/wiki/Wetting#Cassie–Baxter_model
Since I watched the movie “Dark Waters”, I’m trying to avoid those PFO(A|E) as much as I can. Threw all non-stick pans away and learnt how to cook with just cast iron or inox pans. https://en.m.wikipedia.org/wiki/Dark_Waters_(2019_film)
I ditched them a while ago as well. I only use cast iron or stainless steel and it makes me wonder why I ever bothered with non-stick before.
Your stainless steel, high carbon steel, and cast iron pans require using a small amount of oil/butter to have nonstick cooking properties.
Earlier quoted context omitted.
It is, and you’re totally correct to point that out. Also “you know what he meant” is not a good reason to downvote you, because no, nobody knows what is meant by “chemical” if it isn’t literally “chemical”. One could guess that they meant “synthetic chemical”, as if that was somehow meaningfully different than a “natural chemical”, but it’s not and it’s just as wrong.
In most casual English conversation, “chemical” is implied as “[man made] chemical”, though I will admit that may not be obvious to people for whom English is not a first language. It’s obvious to (almost) any native speaker what is being said, and to willfully ignore that is to be pedantic for the sake of arguing.
I am not optimistic about the future of sustainable specialized materials. It seems very likely that the same structures that give modern high tech materials their unique abilities are the same ones that make them so environmentally unfriendly.
Given our ever-expanding definition of "environmentally unfriendly" and our ever-contracting definition of "sustainable", I'm actually not sure that anything actually makes the cut in the long run. Everything "effects the environment" in some way, after all.
If we want there to be humans in the far, far future, more of us need to start going childfree NOW, and encouraging others to do so, AND working on sustainable ways to have a decent standard of living without eviscerating the Earth.
Since I watched the movie “Dark Waters”, I’m trying to avoid those PFO(A|E) as much as I can. Threw all non-stick pans away and learnt how to cook with just cast iron or inox pans. https://en.m.wikipedia.org/wiki/Dark_Waters_(2019_film)
Side note: I wish HN would change Wikipedia links to desktop by default. It seems most people post the mobile version. It is a bit annoying, because when you are on mobile, a desktop version gets switched to mobile by wikipedia; but if you are on desktop, you end up with a mobile version which is not optimized for desktop reading.
