| 00:00:00 | Welcome |
| 00:01:59 | Adhesion and cohesion |
| 00:02:34 | Abstract |
| 00:03:28 | O2Q |
| 00:03:53 | Agenda |
| 00:05:02 | Difference between cohesion and adhesion |
| 00:06:27 | Gecko Climb |
| 00:06:27 | Does it involve burdock-like attraction? |
| 00:06:58 | … like the “Hook and loop” or “touch” fastener |
| 00:07:32 | US Patent |
| 00:08:02 | Why and how can a gecko walk on the ceiling? |
| 00:08:47 | Why and how can a gecko walk on the ceiling? |
| 00:09:10 | Why and how can a gecko walk on the ceiling? |
| 00:09:34 | Why and how can a gecko walk on the ceiling? |
| 00:10:23 | Healed by a gecko |
| 00:10:48 | DARPA |
| 00:11:35 | Gecko’s foot – Chapter 4 “Clinging to the ceiling” |
| 00:12:08 | What interests me about the gecko’s foot? |
| 00:13:05 | Rumpf – the classic picture…. |
| 00:14:21 | Attraction also on the macroscopic scale!From my bedroom window in the UK… |
| 00:14:41 | And where did I live? Wilton Place, Dymock |
| 00:15:03 | Strength of adhesion – amended and original |
| 00:16:28 | Dry analysis |
| 00:16:51 | Hans Rumpf |
| 00:17:24 | Hans Rumpf – Karlsruhe/Clausthal |
| 00:17:52 | Rumpf – the classic papers |
| 00:18:35 | Rumpf – 1 - 1962 |
| 00:19:32 | Rumpf – adapted by Clyde Orr in “Particulate Technology” The Macmillan Co., (1966) |
| 00:20:03 | Rumpf – comparison of various adhesion mechanisms |
| 00:20:58 | General considerations |
| 00:22:13 | Key modern day players |
| 00:22:54 | Kelcey L. Eccleston & Kelly T. Miller Department of Metallurgical & Materials Engineering Colorado School of Mines Particle pull technique |
| 00:23:59 | slide34 |
| 00:23:59 | Results Analysis: Force |
| 00:24:53 | Van de Waals forces |
| 00:25:26 | TiO2 |
| 00:26:43 | Adhesion forces |
| 00:28:01 | Some examples of the strength of adhesion |
| 00:29:40 | Early history |
| 00:31:40 | Hamaker’s microscopic theory |
| 00:32:44 | Hamaker-Lifshitz-van der Waals |
| 00:33:10 | Attractive (van der Waals) and inertial forces |
| 00:33:53 | Attractive (van der Waals) and inertial forces |
| 00:34:38 | Attractive (van der Waals) and inertial forces |
| 00:35:18 | Van der Waals – effect of changing contact area |
| 00:36:26 | Van der Waals – effect of changing contact area |
| 00:37:03 | Electrostatic – or tribological effect |
| 00:37:51 | Rumpf – building bridges |
| 00:38:19 | Liquid bridges – capillary attraction – not on the moon |
| 00:39:14 | F M Etzler, M N Uddin “Powder Technology and Pharmaceutical Development: Particle Size and Particle Adhesion” KONA Powder and Particle Journal, 30, 125 – 143, (2013) |
| 00:40:14 | Solid Bridges |
| 00:40:39 | Solid bridges |
| 00:41:09 | Solid bridges |
| 00:42:17 | Solid-solid diffusion |
| 00:43:16 | Fick’s Law of diffusion |
| 00:43:53 | Fick’s Law of diffusion |
| 00:44:45 | Fick’s Law of diffusion |
| 00:45:01 | Fick’s Law of diffusion |
| 00:45:46 | Bulk/Primary: solid bridging; room temperature sintering |
| 00:46:10 | Bulk/Primary: solid bridging; room temperature sintering |
| 00:46:50 | Bridging will always occur - in the dry state! |
| 00:47:12 | Powders are a problem!Kendall |
| 00:48:08 | Inertial and van der Waals forces….. |
| 00:48:40 | Dissolution |
| 00:49:00 | Dissolution |
| 00:49:54 | Adhesion forces - dry millingTheoretical limit of a ball mill |
| 00:51:02 | O2Q |
| 00:51:32 | K. Eric Drexler |
| 00:52:03 | Ladybug - 35 mgElephant – cow – not bull – 3500 kg |
| 00:52:42 | References |
| 00:53:22 | Thank you! |
| 00:53:51 | Thank you for your attentionAny questions?Please type your questions in using the Q&A panel on the right side of your screen |
| 01:05:24 | Contact Information |
The basis of agglomeration and aggregation is the attraction that particles and particle groups have for one another. We'll outline the various forms of atttaction (van de Waals, capillary etc ) and thus show how a gecko can walk on the ceiling.