Correction- At 8:50 min. in case γsv < γls, then cos θ will be negative, and θ will be greater than 90 degrees (poor wetting) and if γsv > γls, cos θ is positive, and θ will be less than 90 degrees (wetting).
Thanks for the video, can we say higher molecular weight will have higher surface energy/tension? In a sense that if I paint HMW non-newtonian liquid on a wall it will NOT drip as much/easy as pure water?
@@yhs10 The surface energy/tension will depend on chemical nature of the chain than its molecular weight. The reason of using HMW polymers for paint application is mainly because of its shear thickening behavior. Mostly polymers with high molecular weight show shear thickening behavior than polymers with lower molecular weight. Therefore when paint is applied, its viscosity increases and flow/dripping reduces .
I guess if the surface energy of solid-vapor is more than solid-liquid, then theta will be less than 90 and thus the droplet wets the surface and vice versa for other equation you mentioned at 8:48
This is very helpful! The inner molecules pull the outer molecules inward. The outer ones would LIKE to make their own bubbles so they can be surrounded, but the inner molecules prevent that. So I guess that higher surface tension = higher surface energy = the inner molecules are pulling harder inward than the outer molecules can resist = higher contact angle.
I wonder whether it has ever occurred to this girl that Young's force diagram she so carefully reproduces leaves the vertical component of the force acting on the contact line uncompensated.
Surface tension is defined as the force parallel to the surface perpendicular to a unit length line drawn on the surface. The units of surface tension are Nm-1. On the other hand surface energy can be defined as the energy difference between the bulk of the material and the surface of the material. Surface energy is defined as the surface energy per unit surface area. The surface energy per unit area is identical to the surface tension measured. The units of surface energy are Jm-2
How does air solid contact have an effect on liquid drop shape? Shouldn’t we only consider forces of surface tension due to liquid-solid and air-liquid interface only?
Correction- At 8:50 min. in case γsv < γls, then cos θ will be negative, and θ will be greater than 90 degrees (poor wetting)
and if γsv > γls, cos θ is positive, and θ will be less than 90 degrees (wetting).
Thanks for the video, can we say higher molecular weight will have higher surface energy/tension? In a sense that if I paint HMW non-newtonian liquid on a wall it will NOT drip as much/easy as pure water?
@@yhs10 The surface energy/tension will depend on chemical nature of the chain than its molecular weight. The reason of using HMW polymers for paint application is mainly because of its shear thickening behavior. Mostly polymers with high molecular weight show shear thickening behavior than polymers with lower molecular weight. Therefore when paint is applied, its viscosity increases and flow/dripping reduces .
Iwas searching for this correction, Thanks
isn't it surface tension 'surface energy per unit area'. 9:05,kindly check here units are wrong
Wow you explain this in a 10 min video while my professor took the whole class explaining this... very helpful:)
Glad it was helpful!
Thanks for your video, the pictures are very nice and easy to learn
Glad you like them!
I guess if the surface energy of solid-vapor is more than solid-liquid, then theta will be less than 90 and thus the droplet wets the surface and vice versa for other equation you mentioned at 8:48
8:30 WHAT DOES THOSE FORCES PHYSICALLY INDICATE, like which is the cause of them and on which they are acting?
Thank you i understood the concept very clearly
Thanks for the feedback.
I really appreciate you making this lecture. Well done.
Thank you for the feedback!
This is very helpful!
The inner molecules pull the outer molecules inward. The outer ones would LIKE to make their own bubbles so they can be surrounded, but the inner molecules prevent that. So I guess that higher surface tension = higher surface energy = the inner molecules are pulling harder inward than the outer molecules can resist = higher contact angle.
high surface energy and high interfacial tension = low contact angle (more wetting)
Wht is the example of contact angle for 180°
It was much better than I expected , 😃 thankyou mam ❤️❤️
Can we get a link to the follow up video?
I wonder whether it has ever occurred to this girl that Young's force diagram she so carefully reproduces leaves the vertical component of the force acting on the contact line uncompensated.
Why we use ethyl cellosolve and formamide to make dyne solution??
Very intuitive
Thank you for the feedback.
This was really helpful. thank you so much ❤
thankyou dr. helps me alot
Reference book??..
thank you ma'am very helpful
Thank you for watching! Glad it was helpful.
Great explanation,thnk you so much!
Glad it was helpful!
how unit of surace energy is J/m2? Surface energy is Surface tension * area so unit will be J??
Surface tension is defined as the force parallel to the surface perpendicular to a unit length line drawn on the surface. The units of surface tension are Nm-1. On the other hand surface energy can be defined as the energy difference between the bulk of the material and the surface of the material. Surface energy is defined as the surface energy per unit surface area. The surface energy per unit area is identical to the surface tension measured. The units of surface energy are Jm-2
How to measure wettability
Contact angle is a good indicator of the wettability of the surface/material.
How does air solid contact have an effect on liquid drop shape? Shouldn’t we only consider forces of surface tension due to liquid-solid and air-liquid interface only?
thank u very much
Thank you for watching our videos.
very good thanks!
Sound quality poor should be louder
Thank you!
thank you :)
Thanks for watching!
Thanks👌😊
Thank you
Thanks for watching!
🌹🌹
Thank you.
I really need a sub on this :( can somebody add a sub please? the accent is really hard to understand everything
We will try to incorporate sub as soon as possible.
Sub added....
Yes me too. The explanation is good enough and will be better with subs.
@@yusufwaliyuddinazka8949 subtitle is added
Thank you!!
Thank you!!
Welcome!