At 6:15, the cosine of a greater angle if they're both less than 180 degrees will always be less. Shouldn't you then compare the absolute values of the cosines?
I did an experiment on ABS plastic, the contact angle of smooth ABS plastic is around 70° which means hydrophilic surface, but when I treated the surface of this plastic by grinding using sandpaper 240um and 400um, the contact angle of the ABS plastic grounded is more than 90° ''around 100°", which mean the surface become hydrophobic. So, how can you explain these results ?!! and thank you so much
How can I make a surface Cassie-Baxter rough? (With regular tools and materials) or do I need a really expensive laser etching machine, an electron microscope to verify the surface, etc?
It depends on how you define hydrophobicity, Conditions to be super-hydrophobic are;- 1. WCA>150 deg., 2. low CA hysteresis 150 deg with Wenzel state for moderately rough surface with introducing hydrophillic nano-spikes or by other means. The conclusion is, yes, hydrophobic coating can be in Wenzel state but will definitely show highly adhesive superhydrophobicity.
Excellent! And what you told about the desert beetle left me wondering how evolutionists can fool themselves to think that this highly engineered surface can happen by random chances.
this is literally the best video about the topic
This is what I have been doing in these 2 months!
Studying the water droplet behaviours on surfaces.
Amazing video. This would have saved me an hour of reading wikipedia.
One of the best videos I have ever seen.
That was incredibly helpful and well done.
I know this was 11 years ago but it was still very clear and easy to understand! :)
Thanks a lot. Great job. Superbly Explained. I am exactly looking for this video!
well summarize and easy to understand
Great Explanation ! - More please !
Very well explained, and equally appreciated.
Cool , highly appreciated!
Superb explanation
Thank you! u're a life saviour!
Amazing video. Nice explained
Great job!
superb video... precise and concise
Great explanation. Thank you!
That was an amazing video which helped me a lot. Thank you!!
wow, im not even 14 yet, and i found this fascinating!
Since you're 18 now, how do you feel about it after so many years?
@@Kcd1306 lol true
At 6:15, the cosine of a greater angle if they're both less than 180 degrees will always be less. Shouldn't you then compare the absolute values of the cosines?
Thank you for this video ! it helped me a lot :)
The best one ever.....
Amazing
Thanks a Lot. Can you also provide some link or anything on the derivation of the cassie baxter and wenzal equation
Mind=Blown
Also, at 7:06, is it supposed to be the decimal of the solid?
is this the same lady who made the videos about leaves using phi to grow efficiently?
I did an experiment on ABS plastic, the contact angle of smooth ABS plastic is around 70° which means hydrophilic surface, but when I treated the surface of this plastic by grinding using sandpaper 240um and 400um, the contact angle of the ABS plastic grounded is more than 90° ''around 100°", which mean the surface become hydrophobic. So, how can you explain these results ?!! and thank you so much
6:09 is wrong i think. When Cos(theta*)>Cos(thetaE)，we get theta*
All these people saying thanks for the simplification.
Here I am thinking, "she's going too fast!" lol
what is the disadvantage/side-effect of superhydrophobe ?
are there any textbooks out there that addresses this topic?
How can I make a surface Cassie-Baxter rough? (With regular tools and materials) or do I need a really expensive laser etching machine, an electron microscope to verify the surface, etc?
Hi, just coating your surface with superdrophbic coating
is it possible for a superhydrophobic coating to be in wenzel state?
It depends on how you define hydrophobicity, Conditions to be super-hydrophobic are;- 1. WCA>150 deg., 2. low CA hysteresis 150 deg with Wenzel state for moderately rough surface with introducing hydrophillic nano-spikes or by other means. The conclusion is, yes, hydrophobic coating can be in Wenzel state but will definitely show highly adhesive superhydrophobicity.
Wow so smart
No, that was Vihart.
I want to model in comsol can anyone help?
Excellent! And what you told about the desert beetle left me wondering how evolutionists can fool themselves to think that this highly engineered surface can happen by random chances.
Wait, what?
That is what I thought. Um...
Don't call them unhappy molecule..... Just no.
amazing writing horrible sqaure lol, i mean its square paper how cna you miss it