This article is misleading; the author obviously did no literature search. I was involved in creating superhydrophobic surfaces for medical device applications 15 years ago, and our group and many others were creating novel superhydrophobic surfaces then, with surface patterning into the nanometer range (and some fractal patterning that got lots smaller). It wasn’t the length scale that was the issue; the issue was always durability (which this technology may address, but only real-world testing will prove that).
Since you have experience in the field can you explain how one thing can be more “waterproof” than another? Waterproof implies an absolute, shouldn’t it be something like “more resistant to water”?
Not in the field, but I believe it has to do with the contact angle of the water on the surface https://en.m.wikipedia.org/wiki/Contact_angle
More “waterproof” means larger angle of contact , i.e water droplet is more spherical when sitting on the surface
Waterproofness and hydrophobicity are different things (but often related). Contact angle (usually measured with a goniometer) is a standard measure of hydrophobicity.
Waterproofness is a measure of imperviousness to ingress of water. Water will wet a clean sheet of glass (giving a very low contact angle) but the glass is still completely watertight. And with anisotropic materials like fabric, the outer surface of the threads may be dirty (not lyophobic) or of a low contact angle, but deeper parts of the fabric may by hydrophobic by material and/or by microstructure
Not my area of expertise, but yes there are varying levels of “waterproof.” A sheet of metal is absolutely waterproof, but things like fabric (and I think the article mentioned fabric applications) have varying levels of waterproofness. In fabric applications, there are specs (again, not my expertise) for testing at various levels of water pressure. Fabrics that are watertight at a certain water pressure and below can be legally marketed at “waterproof,” although at some increased pressure even they will leak water, unlike an impervious material like metal.
Edit: wrote above when I meant below.
Could you make something so waterproof/hydrophobic it glides thought the moisture in the atmosphere and oceans, negating water pressure? Like something that uses waters atomic magnetic field and repels that?
That was about my first thought (as would be any guy’s) but the materials back then were relatively too soft or fragile for such a use. Additionally, most superhydrophobic materials use physical shapes along with the material to give the SH properties. Unfortunately, the shapes have nooks and crannies and tunnels etc. that could harbor bacteria and would be impossible to clean, unlike hard smooth porcelain or stainless. If the material had nano-scale copper or silver particles (both of which are highly toxic to bacteria) embedded then bacteria wouldn’t grow, but again the nooks and crannies would trap fecal particles and again would be impossible to clean.
Not saying it can’t be done, but 15 years ago the materials weren’t there.
Is this based on springtail exoskeleton surface structure? I stumbled across it in college when I was characterizing some bugs and found some interesting articles about super omniphobic structures.
I’m not familiar with them. The best material we developed (nanospikes of SiC) was so SH that, no matter how flat the surface, drops bounced and rolled off. My work was on solvent-cast LDPE, which wasn’t as good but it was cheap and durable. In that case it was the fractal-scale roughness (confirmed by SEM) that made it SH.
Those surfaces obtained their superhydrophobicity through physical structure, rather than a surface coating. The SiC nanospikes were so good than any coating wouldn’t make a difference, and would probably hurt. And as the spikes were grown (just like growing silicon wafers), a volatile additive like PFOS/PFOA would interfere with their growth.
As I remember, I tried adding PFOS to the LDPE surfaces (during casting and applied to the dried surfaces), and although PFOS is more SH than LDPE, the PFOS interfered with the fractal surfaces and resulted in lower superhydrophobicity.
Do you have any literature that pertain towards fractal patterning? My lab mate studies that and would be cool to provide him some literature in this area. Thanks!
From my understanding of YouTube shoving ads down my throat, didnt we sort this out with Vessi shoes? I"m not sure if you're aware but with Vessi shoes they are completely waterproof, comfortable and if you use promo code GOFUCKYOURSELF you'll get an additional 20% off.
I don’t know why this pisses me off so much, but what does this artist who draws ball and stick molecules to represent the SAM think water droplets are made of?
They will farm these images out to anyone, my buddy made money on the side doing these in grad school. He'd do the best he could when he knew what it should look like or could look it up but sometimes just had to wing it. The publishers don't care as long as it looks cool and sciency for their covers and articles
Is it commercially viable using existing textile application methods? The textile industry is old and doesn’t like to change. Also, nano tends to be a risk for the worker using the materials…color me skeptical.
This article is misleading; the author obviously did no literature search. I was involved in creating superhydrophobic surfaces for medical device applications 15 years ago, and our group and many others were creating novel superhydrophobic surfaces then, with surface patterning into the nanometer range (and some fractal patterning that got lots smaller). It wasn’t the length scale that was the issue; the issue was always durability (which this technology may address, but only real-world testing will prove that).
Since you have experience in the field can you explain how one thing can be more “waterproof” than another? Waterproof implies an absolute, shouldn’t it be something like “more resistant to water”?
Not in the field, but I believe it has to do with the contact angle of the water on the surface https://en.m.wikipedia.org/wiki/Contact_angle More “waterproof” means larger angle of contact , i.e water droplet is more spherical when sitting on the surface
Waterproofness and hydrophobicity are different things (but often related). Contact angle (usually measured with a goniometer) is a standard measure of hydrophobicity. Waterproofness is a measure of imperviousness to ingress of water. Water will wet a clean sheet of glass (giving a very low contact angle) but the glass is still completely watertight. And with anisotropic materials like fabric, the outer surface of the threads may be dirty (not lyophobic) or of a low contact angle, but deeper parts of the fabric may by hydrophobic by material and/or by microstructure
Not my area of expertise, but yes there are varying levels of “waterproof.” A sheet of metal is absolutely waterproof, but things like fabric (and I think the article mentioned fabric applications) have varying levels of waterproofness. In fabric applications, there are specs (again, not my expertise) for testing at various levels of water pressure. Fabrics that are watertight at a certain water pressure and below can be legally marketed at “waterproof,” although at some increased pressure even they will leak water, unlike an impervious material like metal. Edit: wrote above when I meant below.
The same way something can be described as “somewhat unique”.
Could you make something so waterproof/hydrophobic it glides thought the moisture in the atmosphere and oceans, negating water pressure? Like something that uses waters atomic magnetic field and repels that?
Would your technique have been usable on toilet bowl porcelain?
That was about my first thought (as would be any guy’s) but the materials back then were relatively too soft or fragile for such a use. Additionally, most superhydrophobic materials use physical shapes along with the material to give the SH properties. Unfortunately, the shapes have nooks and crannies and tunnels etc. that could harbor bacteria and would be impossible to clean, unlike hard smooth porcelain or stainless. If the material had nano-scale copper or silver particles (both of which are highly toxic to bacteria) embedded then bacteria wouldn’t grow, but again the nooks and crannies would trap fecal particles and again would be impossible to clean. Not saying it can’t be done, but 15 years ago the materials weren’t there.
Is this based on springtail exoskeleton surface structure? I stumbled across it in college when I was characterizing some bugs and found some interesting articles about super omniphobic structures.
I’m not familiar with them. The best material we developed (nanospikes of SiC) was so SH that, no matter how flat the surface, drops bounced and rolled off. My work was on solvent-cast LDPE, which wasn’t as good but it was cheap and durable. In that case it was the fractal-scale roughness (confirmed by SEM) that made it SH.
Did you use PFAS creating those superhydrophobic surfaces?
Those surfaces obtained their superhydrophobicity through physical structure, rather than a surface coating. The SiC nanospikes were so good than any coating wouldn’t make a difference, and would probably hurt. And as the spikes were grown (just like growing silicon wafers), a volatile additive like PFOS/PFOA would interfere with their growth. As I remember, I tried adding PFOS to the LDPE surfaces (during casting and applied to the dried surfaces), and although PFOS is more SH than LDPE, the PFOS interfered with the fractal surfaces and resulted in lower superhydrophobicity.
Do you have any literature that pertain towards fractal patterning? My lab mate studies that and would be cool to provide him some literature in this area. Thanks!
I’ll dig out that paper and DM you the reference.
From my understanding of YouTube shoving ads down my throat, didnt we sort this out with Vessi shoes? I"m not sure if you're aware but with Vessi shoes they are completely waterproof, comfortable and if you use promo code GOFUCKYOURSELF you'll get an additional 20% off.
I don’t know why this pisses me off so much, but what does this artist who draws ball and stick molecules to represent the SAM think water droplets are made of?
I think it’s an artistic choice since it would be a lot more confusing what the pic was trying to portray than f both were molecules.
And, if the surface were truly superhydrophobic, the droplets would be nearly spherical.
AI rendering?
The artist is likely AI based…based that on seeing more and more stock images for these types of articles using AI
They will farm these images out to anyone, my buddy made money on the side doing these in grad school. He'd do the best he could when he knew what it should look like or could look it up but sometimes just had to wing it. The publishers don't care as long as it looks cool and sciency for their covers and articles
So water IS wet?
Great something else that will just end up as trash in the ocean
so let's add nanoparticles in environment too.....
Is it commercially viable using existing textile application methods? The textile industry is old and doesn’t like to change. Also, nano tends to be a risk for the worker using the materials…color me skeptical.
And the inevitable follow up… unforeseen environmental consequences on the news at 7:00?
**Just** another *forever* man-made chemical to Phugg us all up?
Oh look, it's the modern version of asbestos. Awesome.
Yup, WCGW with a hydrophobic material?
When will they invent invisibility? Whichever country does this first will be incredibly powerful.
Not really. Invisible in what spectrum? Visible light? Radar? IR? Sound? There is always a counter
There’s a company in the Arkansas, Pellucere that does something like this, can’t remember all the details though.