| 00:00:00 | Dispersion and nanotechnology |
| 00:01:51 | Can I say anything new? |
| 00:02:06 | But…. |
| 00:03:11 | Dispersion – have we moved forward? |
| 00:03:47 | Abstract |
| 00:04:32 | The Laws of Physics or The Crunch |
| 00:05:40 | The 4 S’s of nanotechnology |
| 00:06:55 | Bulk/Primary |
| 00:07:45 | Solid-solid diffusion |
| 00:09:19 | Important reference paper |
| 00:10:06 | Look how quickly coalescence occurs… |
| 00:10:43 | Inertial and van der Waals forces….. |
| 00:12:14 | Bridging will always occur - in the dry state! |
| 00:12:50 | Strength of adhesion – amended and original |
| 00:13:45 | Surface and size |
| 00:15:13 | Qualitative measure of dispersion efficiency |
| 00:16:04 | Agglomeration Factor, Fag - Agglomeration Number, FN |
| 00:16:52 | Surface – the 3 C’s |
| 00:17:50 | Surface sensitive techniques |
| 00:18:56 | Surface Composition/chemistry |
| 00:20:40 | TiO2 pigment |
| 00:21:54 | Bulk and surface composition |
| 00:23:21 | Surface atoms dominate as the size decreases |
| 00:23:52 | Nanoclusters |
| 00:24:10 | Chemisorption induced segregation |
| 00:24:56 | (Surface) charge |
| 00:25:50 | Producing a stable dispersion |
| 00:29:50 | Producing a stable dispersion |
| 00:31:23 | The beaker or vial test (charge stabilization) |
| 00:32:52 | Vial test with CeO2 polishing agent |
| 00:34:12 | Indications that there is a stability issue |
| 00:35:04 | The scientific (not empirical) route |
| 00:37:00 | Measurement with optimum conditions |
| 00:37:12 | Measurement with optimum conditions |
| 00:37:37 | Comparison between properly dispersed and poorly dispersed material |
| 00:37:57 | A few more words on stabilization |
| 00:38:21 | The +/- 30 mV stuff… |
| 00:39:21 | Stabilization – early literature |
| 00:40:02 | Steric stabilization |
| 00:40:58 | Powders are the problem! |
| 00:41:48 | Powders – after Adair |
| 00:42:46 | Adhesion forces - dry milling |
| 00:43:23 | More information in recent webinars |
| 00:43:38 | Useful paper |
| 00:44:02 | This leads to the comminution limit (CL) |
| 00:44:23 | Bottom up – not bottoms up…. |
| 00:45:34 | Top down or bottom up? |
| 00:46:11 | Time for grinding/rate of grinding |
| 00:46:29 | Ultrafine (”Nano”) grinding |
| 00:46:43 | So we really need to do it in the wet… |
| 00:47:18 | Ball Mill – Fischer: Colloidal Dispersions |
| 00:47:48 | Colloid Mill |
| 00:48:01 | High energy input to break solids |
| 00:48:31 | And a lot of time…. |
| 00:48:50 | Dissolution |
| 00:49:26 | Stress corrosion milling/cracking |
| 00:49:47 | Bottom up |
| 00:50:25 | Tests for ‘nano’ |
| 00:50:42 | Settling rates – taken from ASTM E2490-09 (15) |
| 00:51:09 | Settling rates - comments |
| 00:51:40 | K. Eric Drexler |
| 00:52:14 | Question & Answers |
| 00:55:27 | Thank you for your attentionalan.rawle@malvernpanalytical.com+ 1 508 768 6434 |
'Nano’ is all about small. A dispersed system is smaller than its agglomerated or aggregated precursor. The fundamental physical principles outlining dispersion in small systems will be discussed. This should act as a primer to those interested in making stable systems < 100 nm
Présentateur
- Alan Rawle Ph.D. - Principal Scientist Laser Diffraction
Pour en savoir plus
Who should attend?
Anyone concerned with nanotechnology especially those new to dispersion of larger systems to nominally nanosystems (< 100 nm)
What will you learn?
The difficulties of making small dispersed materials from top-down processes and the general factors in achieving ‘good’ dispersion in systems