InterfacialWaterandMechanism
Frost Formation/ŶƚĞƌĨĂ Đ ŝĂ ůtĂƚĞƌĂ ŶĚD ĞĐŚĂ ŶŝƐ ŵŽĨof& ƌŽƐƚ&ŽƌŵĂƚŝŽŶAn506
ŶϱϬϲtWILDE/ >    LAB.
>͘Dynamics of Water and Ice on Cold SurfacesǇŶĂŵŝĐƐŽĨtĂƚĞƌĂŶĚ/ĐĞŽŶŽůĚ^ƵƌĨĂĐĞƐ
ĞƉĂƌƚŵĞŶƚŽĨ&ƵŶĚĂŵĞŶƚĂůŶŐŝŶĞĞƌŝŶŐ

Department of Fundamental Engineering^ŽĐŝĂůŽŽƉĞƌĂƚŝŽŶWƌŽŐƌĂŵ͗&ƌŽƐƚWƌŽƚĞĐƚŝŽŶ^ĐŝĞŶĐĞSocial Collaboration Program: Frost Protection Science^SurfaceƵƌĨĂ ĐĞWŚǇƐŝĐĂůŚĞŵŝƐƚƌ
Ǉ
Physical ChemistryŚ ƚ ƚ Ɖ Ɛ ͗ ͬ ͬ https://www.iis.u-tokyo.ac.jp/en/research/department_center/frost-protection-science/ǁ ǁ ǁ͘ ŝ ŝ Ɛ ͘ Ƶ Ͳ ƚ Ž Ŭ Ǉ Ž ͘ Ă Đ ͘ ũ Ɖ ͬ Ğ Ŷ ͬ ƌ Ğ Ɛ Ğ Ă ƌ Đ Ś ͬ Ě Ğ Ɖ Ă ƌ ƚ ŵ Ğ Ŷ ƚ ͺ Đ Ğ Ŷ ƚ Ğ ƌ ͬ Ĩ ƌ Ž Ɛ ƚ Ͳ Ɖ ƌ Ž ƚ Ğ Đ ƚ ŝ Ž Ŷ Ͳ Ɛ Đ ŝ Ğ Ŷ Đ Ğ ͬDŽůĞĐƵůĂƌWĞƌƐƉĞĐƚŝǀĞŽŶ&ƌŽƐƚ&ŽƌŵĂƚŝŽŶŽŶŽůĚ^ƵƌĨĂĐĞƐ&ƌŽƐƚ ĨŽƌŵĂƚŝŽŶ – ƚŚĞ ŐƌŽǁƚŚ ŽĨ ŝĐĞ ĨŝůŵƐ ĨƌŽŵ ǁĂƚĞƌ ǀĂƉŽƌ ŽŶ ĐŽůĚ ƐƵƌĨĂĐĞƐ – Ă ĚĂŝůǇ ůŝĨĞ ƉŚĞŶŽŵĞŶŽŶ
ƚŚĂƚ ƐĞƌŝŽƵƐůǇ ŽďƐƚƌƵĐƚƐ ŚĞĂƚ ƚƌĂŶƐĨĞƌ Ăƚ ƌĞĨƌŝŐĞƌĂƚĞĚ ƐƵƌĨĂĐĞƐ͕ ŝƐ Ɛƚŝůů ŶŽƚ ǁĞůů ƵŶĚĞƌƐƚŽŽĚ Ăƚ ƚŚĞŵŽůĞĐƵůĂƌ ůĞǀĞů͘ dŚŝƐ ůĂďŽƌĂƚŽƌǇ ĞŵƉůŽǇƐ ;ƵůƚƌĂͿͲŚŝŐŚ ǀĂĐƵƵŵ ĞǆƉĞƌŝŵĞŶƚĂů ƚĞĐŚŶŝƋƵĞƐ ƚŽ ƌĞǀĞĂů
ĨƵŶĚĂŵĞŶƚĂů ŵŽůĞĐƵůĂƌ ŝŶƚĞƌĂĐƚŝŽŶƐ ĂŶĚ ;ĚĞͲͿƐƵďůŝŵĂƚŝŽŶ ĚǇŶĂŵŝĐƐ ŝŶ ŝŶƚĞƌĨĂĐŝĂů ǁĂƚĞƌ ĂŶĚ ŝĐĞ ĨŝůŵƐ ŽŶƐŽůŝĚ ƐƵƌĨĂĐĞƐ͕ ĞƐƉĞĐŝĂůůǇ ŽĨ ǁĞůůͲĚĞĨŝŶĞĚ ŽǆŝĚĞƐ ĂƐ ŵŽĚĞů ƐǇƐƚĞŵƐ ĨŽƌ ŶĂƚƵƌĂůůǇ ŽǆŝĚŝǌĞĚ ŵĞƚĂůƐ͘ tĞĐůĂƌŝĨǇ ŚŽǁ ƚŚĞ ĐŚĞŵŝĐĂů ĐŽŶƐƚŝƚƵƚŝŽŶ͕ ĂƚŽŵŝĐ ƐƚƌƵĐƚƵƌĞ͕ ĂŶĚ ŵĂĐƌŽƐĐŽƉŝĐ ǁĞƚƚŝŶŐ ƉƌŽƉĞƌƚŝĞƐ ŽĨ ƚŚĞƐƵƌĨĂĐĞ ŝŶĨůƵĞŶĐĞ ŝŶƚĞƌĨĂĐŝĂů ǁĂƚĞƌͲŝĐĞ ƉŚĂƐĞ ƚƌĂŶƐŝƚŝŽŶƐ ĂŶĚ ƚŚĞ ĐƌǇƐƚĂůůŝǌĂƚŝŽŶ ŬŝŶĞƚŝĐƐ ŽĨ ĂŵŽƌƉŚŽƵƐ
ƐŽůŝĚ ǁĂƚĞƌ ĨŝůŵƐ ƉƌĞƉĂƌĞĚ Ăƚ ĐƌǇŽŐĞŶŝĐ ƚĞŵƉĞƌĂƚƵƌĞƐ͘◆ <ĞǇǆƉĞƌŝŵĞŶƚĂůdĞĐŚŶŝƋƵĞƐΘ/ŶĨŽƌŵĂƚŝŽŶ'ĂŝŶ✓ >ŽǁŶĞƌŐǇůĞĐƚƌŽŶŝĨĨƌĂĐƚŝŽŶ;>Ϳ͗→ ƚŽŵŝĐ^ƵƌĨĂĐĞ^ƚƌƵĐƚƵƌĞ;WĞƌŝŽĚŝĐŝƚǇͿŽĨ^ƵďƐƚƌĂƚĞĂŶĚdŚŝŶ/ĐĞ&ŝůŵƐ✓ dŚĞƌŵĂůĞƐŽƌƉƚŝŽŶ^ƉĞĐƚƌŽƐĐŽƉǇ;d^Ϳ͗ → ,ϮK^ƵďůŝŵĂƚŝŽŶͬĞͲƐƵďůŝŵĂƚŝŽŶ<ŝŶĞƚŝĐƐ・ŶĞƌŐŝĞƐŽĨĞƐŽƌƉƚŝŽŶĂŶĚ/ŶƚĞƌŵŽůĞĐƵůĂƌ/ŶƚĞƌĂĐƚŝŽŶƐďĞƚǁĞĞŶ,ϮKŵŽůĞĐƵůĞƐŝŶ/ŶƚĞƌĨĂĐŝĂůtĂƚĞƌͬ/ĐĞ>ĂǇĞƌƐ
✓ /ƐŽdŚĞƌŵĂů ĞƐŽƌƉƚŝŽŶŶĂůǇƐŝƐ;/dͿ͗→ ƌǇƐƚĂůůŝǌĂƚŝŽŶ<ŝŶĞƚŝĐƐŽĨŵŽƌƉŚŽƵƐ^ŽůŝĚtĂƚĞƌ&ŝůŵƐ✓ EƵĐůĞĂƌZĞĂĐƚŝŽŶŶĂůǇƐŝƐ;EZͿ͗ → ,ǇĚƌŽŐĞŶĞƉƚŚWƌŽĨŝůŝŶŐǁŝƚŚEĂŶŽŵĞƚĞƌZĞƐŽůƵƚŝŽŶ・ YƵĂŶƚŝĨŝĐĂƚŝŽŶŽĨ^ƵƌĨĂĐĞ,ǇĚƌŽǆǇů;K,ͿŽǀĞƌĂŐĞƐ・dŚĞƌŵĂů^ƚĂďŝůŝƚǇ͕ĞƉƚŚŝƐƚƌŝďƵƚŝŽŶĂŶĚŝĨĨƵƐŝŽŶŽĨ;KͿ,ŝŶ^ƵƌĨĂĐĞKǆŝĚĞ>ĂǇĞƌƐ
,ϮKĚƐŽƌƉƚŝŽŶ͕,ǇĚƌŽǆǇůĂƚŝŽŶ͕ŽŶĚĞŶƐĂƚŝŽŶ&ƌĞĞǌŝŶŐĂŶĚ&ƌŽƐƚŝŶŐŽŶŽůĚ^ƵƌĨĂĐĞƐdŚĞƌŵĂůĞƐŽƌƉƚŝŽŶ^ƉĞĐƚƌŽƐĐŽƉǇ;d^Ϳ

Frosting(De-sublimation)

Condensation
H2O(g)
Ice‘Sub-zero’ T-DT

Cold substrate

Hydroxylation

ASW (LD)+DTFreezing‘Very low’ TCrystallization^ƚƌƵĐƚƵƌĞĂŶĚǇŶĂŵŝĐƐŽĨŝŶƚĞƌĨĂĐŝĂů,ϮKͬŝĐĞĨŝůŵƐŽŶǁĞůůͲĚĞĨŝŶĞĚůϮKϯ ƐƵƌĨĂĐĞƐLEEDH

O2-electron
beam

In-Surface OHion

Hbeam

10NRA

8642

H2O desorption signal

6.370

15N ion energy (MeV)

6.380
6.390
6.400
15
N ion energy [MeV]

I: Crystallization
H2O(g)

ĞƉŽƐŝƚŝŽŶ
ASW (LD)(very)
coldsubstrate

85 K

Ice

II: Plateau: closed filmt

Ice

Ice//////III: Island (droplet) regime• /dƵƌǀĞ/ŶƚĞŐƌĂů͗→ dŽƚĂůĂŵŽƵŶƚŽĨĚĞƉŽƐŝƚĞĚ,ϮKZĞƐŽŶĂŶƚEƵĐůĞĂƌZĞĂĐƚŝŽŶŶĂůǇƐŝƐ;EZͿTDS:͘sŝƐ͘ǆƉƚ͘ϭϬϵ͕ĞϱϯϰϱϮ;ϮϬϭϲͿ

^ƵƌĨ͘^Đŝ͘ZĞƉ͘ϲϵ͕ϭϵϲ;ϮϬϭϰͿ

ŝсƌĞƐϭϱEŝŽŶďĞĂŵŚƚƚƉƐ͗ͬͬĐŽŵŵŽŶƐ͘ǁŝŬŝŵĞĚŝĂ͘ŽƌŐͬǁͬŝŶĚĞǆ͘ƉŚƉ͍ĐƵƌŝĚсϭϵϬϱϱϯϱϯ

:͘ŚĞŵ͘WŚǇƐ͘ϭϲϬ͕ϬϯϰϳϬϯ;ϮϬϮϰͿ

/ƐŽƚŚĞƌŵĂůĞƐŽƌƉƚŝŽŶŶĂůǇƐŝƐ;/dͿ• /ŵĂǆ → ,ϮKͲĐŽǀĞƌĞĚƐƵƌĨĂĐĞĂƌĞĂ

0-2

ad-OH (above surface Al)DT

FWHM = (6.4 ±1.5) keV

In-surface OH
at defects

H density

Surface Al3+Depth(nm)depth [nm]-4-4 -2-2 0 0 2 2 4 4 6 6 8 8g-yield [counts/C]

g-Al2O3/NiAl(110)^͘KŐƵƌĂ͕ŽŵƉĞŶĚŝƵŵŽĨ^ƵƌĨĂĐĞΘ/ŶƚĞƌĨĂĐĞŶĂůǇƐŝƐ͕Ɖ͘ϳϭϵͲϳϮϰ͕^ƉƌŝŶŐĞƌ͕ϮϬϭϴ͘

H2O desorption rate (a.u.)H2O(l)OH OHImaxHOH

Temperature (K),Eg  ΀,ƐƵƌĨĂĐĞ΁g  ΀,ďƵůŬ΁ĞŶĞƌŐǇůŽƐƐŝхƌĞƐ,ϭϱE;ϲ͘ϯϴϱDĞsͿнϭ,→ ϭϮнa нg;ϰ͘ϰϯDĞsͿgͲĚĞƚĞĐƚŽƌ