0.25
0.5
0.75
1.25
1.5
1.75
2
Second critical point in supercooled water: Fact or fiction?
Published on Mar 14, 20164195 Views
The nature of water substance continues to attract a large amount of debate and controversy. High on the list of controversies is the idea that supercooled water has a second critical point, below whi
Related categories
Chapter list
Second critical point in supercooled water: fact or fiction?00:00
Beam layout00:22
ISIS Disordered Materials Group02:07
SANDALS (liquids diffractometer)03:53
ISIS XRD05:07
Out of the instrument comes some data05:13
The liquid structure factor05:50
Introduce Empirical Potential Structure Refinement, EPSR07:34
Water data09:15
Water partial g(r)’s11:05
Beyond g(r): the spatial density function11:12
1%11:42
2%11:43
3%11:44
4%11:45
5%11:46
7%11:55
9%11:55
12%12:12
15%12:12
18%12:13
21%12:14
25%12:32
30%12:33
Water under pressure12:34
Water at 268K, 0.26kbar12:38
Water at 268K, 2.09kbar13:13
Water at 268K, 4.00kbar13:17
Motivation for this talk - 113:45
Motivation for this talk - 214:32
Motivation for this talk - 315:14
Motivation for this talk - 416:09
Motivation for this talk - 517:48
Motivation for this talk - 618:16
So what is all the fuss about? - 118:26
So what is all the fuss about? - 219:19
Second critical point scenario - 119:38
So what is all the fuss about? - 321:02
Second critical point scenario - 225:13
Chen's experiment26:37
Something odd here - 128:09
Something odd here - 228:48
Something odd here - 329:42
Diffraction pattern from dry MCM4131:24
Chen experiment concentrates on (100) peak32:34
From these data, speculate on LL transition33:45
Many problems with existing analysis!34:18
They don't know the pore size34:22
It is claimed MCM41 is not microporous. Not proven35:47
EPSR simulations - MCM41 plus N236:44
It is claimed water cannot freeze in MCM41 pore if small enough37:37
Observing hysteresis does not prove liquid-liquid transition38:15
Most vexing of all: where are the density fluctuations?38:27
Anyone who has ever done a scattering experiment near a critical point knows there will be a large rise in scattering at low Q39:10
My own EPSR simulations of water in MCM41 (Soper, CPL 2013)39:56
Pure water excess pair entropy calculations41:28
Acknowledgements41:36
Try to summarise41:46
What we CAN say...44:48
Thank you for your attention!46:10