Відео

Scwoll down? And you have the nerve to be a dick about other people's speech? Grow up.

Hello, thank you for your work. What is the best wavelength for doppler electrophoresis?

In your schematic, the Debye length decreases as electrolyte concentration increases, but why does a decreased Debye length lead to decreased Zeta potential. Since the stern layer does not change in position presumably. From the four figures you have, the stern potential seems to be the same value, so I guess that's why I am a bit confused. Thanks, Dr. Miller

I just wanted to express my deepest gratitude for your incredible contributions to the field of electrochemistry. Your work has been enlightening and inspiring, and it has significantly advanced our understanding and application of this important scientific discipline. Thank you for sharing your knowledge with the world.

The video is misleading - it confuses the stern layer with the slipping layer! 1:27

Thank you!👍

I think the slipping plane should be between the diffusion layer and the bulk and not between stern and diffusion.

very good

This is nice explanation. Some may find it easier to understand the potential definitions by turning things around. Rather than starting with the surface potential and then considering how the potential falls off as one moves away from the surface, instead start with the (arbitrary) definition of zero potential at infinity. From there, consider bringing a positive test change towards the surface. Moving through the neutral bulk, we are far from the positively charged surface and do little work. As we approach closer, we do more and more work causing the total work done (q*V) to rise. The value when we reach the surface is the surface potential. The values as we cross various critical points along the way define other values, such as the zeta potential. I came here searching for an understanding of the definition of the slipping plane. I hope sharing my (hopefully correct!) way of thinking about the electrostatics will be helpful to someone else. It is entirely consistent with what was presented, but is just another way to think about it that some may prefer.

Dear John, thank you for this great video. How does instrument know what the charge of the particle is during zeta potential measurements? I cant find any relationship between the sign of the charge on the particle and the sign of the zeta potential that the instrument reports.

Hi John, Could you please clarify the concept of effective potential in the bulk solution? To my understanding, the effective potential decays exponentially to ~0 when moving away from the electrodes (due to the charge screening effect). Wouldn't this cause charged particles in the bulk to experience no net electric field? (Unless the thickness of the bulk is comparable to the double layers of the electrodes, i.e. with a dilute electrolyte or low dielectric constant). Thanks!

Hi John, Thanks for the clear and insightful webinar series! Could you please explain how the optical properties affect attractive forces between particles? I could see how the size/shape affect the relative strength of attractive VDW forces due to differences in contacting surface area between particles, but I'm unsure how optical properties come into play here.

Pak tolong di jawab, benda apa yang ada kandungan zeta.?

Hello sir how does one ascertain the zeta potential of carbonaceous or polymeric composites or solids that are not used in drug delivery since the zeta sizer analysis is not an indication of the surface charge Help your answer will assist in my investigations Kindly show me some good articles to support your directions

Dear Mr Miller, I understand that electrolytes play a role in decreasing the EDL thickness but does this theory also apply to when adding acids or bases? Both acid and base disassociate to positive and negative ions, so theoretically it should perform similarly except one increases H+ or OH- ions. Thanks in advance.

Dear Mr. Miller, I have a curiosity: if generally zeta potential is expressed as the potential difference between the slipping plane and the bulk solution, how this value would compare to the potential difference between the actual particle surface and the slipping plane?

Thanks thanks thanks....this helped a lot

Excelent presentation and explanation of zeta potential (I have seen your video serie) and a very good example to cast light on the pitfalls and challenges when measuring it and utilizing it in real life. Thank you for sharing.

thank you

Dear John, thank you very much for sharing this fantastic presentation. I have read all the comments but I have still two doubts about what you said. 1. The paper you recommended (Delgado et al., 2007) describes that "The potential at the plane where slip with respect to bulk solution is postulated to occur is identified as the electrokinetic or zeta potential,ζ". Instead you locate the zeta potential between the rigid layer associate with the particle and the diffuse layer of ions. There is something I am missing. 2. In the previous video, you define de EDL as the sum of the rigid layer and the diffuse layer of ions. However, in the plots you define the EDL as that represented by the length 1/k which does not take into account the rigid layer. I would really appreciate any help to understand. Thank you very much.

Can you calculate human red blood cell zeta potential? do we need same pH and same electrolytes as in blood? Also there is a significant amount albumin in blood that is also negative charge in blood pH. Do we need to add it to calculation? And also container of the fluid effect the zeta potential? for example glass tube is negative charged but charge. can plastic tube change this?

Dear John, I am so impressed with your explanation. Can I get in touch with You? I am a PhD student from the university of Witwatersrand in South Africa. I am working on project which aims at understanding the relationship between the generation of micro-cavitation on the leaching kinetics (EDL and mostly the thickness of the diffusion layer). My email address is: jeanjacquesmils@gmail.com

Hi sir. Could we use those formulas for stern potential (single layer)?

Why do you abruptly cut your videos? Anyway, they are very helpful. Thank you very much!

Hi, why the potential of the inner slipping plane is defined as the zeta potential, not the outer plane of the slipping plane? If it is the inner plane, then what make it different than the stern potential? I though the zeta potential is the potential at the outer slipping plane. Dr. John Miller please address my confusion, thank you .

thank you Mr.Miller. your videos are really helpful.

Dear John, do you have any videos regarding to contact angle calculation? Thanks a lot

Thank you! Where have you been all these while when i was confused in class?

Hi~ Mr. Miller Your illustration is really helpful! I would like to translate your video to mandarin. Could you please activate the function of the viewer's subtitle submission in all of your videos? Thanks!