Transcript PowerPoint Presentation - BZ and Gels

BZ and Gels
Ye Zhang
Bing Xu’s Group
Videos of Self-oscillating Gels
Self-Walking Gel
Make Gel Oscillate in BZ
BZ components :
H2O
Malonic Acid
(MA)
Oxidant
BrO3-
Catalyst
Ru(bpy)3
Acid
HNO3/H2SO4
Build in
Self-Oscillating Gel
Gel
BZ
oscillation
Gel Types for Self-Oscillating Gel
Crosslinked
Thermo-sensitive
Polymeric
Hydrogel
Uncrosslinked
Nonthermo-sensitive
Gel
Supramolecular
Hydrogel
Crosslinked Thermosensitive Polymeric Self-oscillating Gels
NIPAm-co-Ru(bpy)3
Equilibrium swelling ratio of (NIPAm-co-Ru(bpy)3) gel
under different conditions of reduced Ru(II) state (in
Ce(III) solution) and oxidized Ru(III) state (in Ce(IV)
solution).
Development of Self-oscillating Gels
Uncrosslinked Thermosensitive Polymeric Gels
A
c
i
poly(NIPAm-co-Ru(bpy)y-co-AMPS)
d
F
r
e
e
O
x
poly(NIPAm-co-Ru(bpy)
y-co-MAPTAC)
i
d
a
n
t
F
r
e
e
A
c
poly(NIPAm-co-Ru(bpy)y-co-AMPS-co-MAPTAC)
i
Crosslinked Nonthermosensitive Polymeric Gels
0.5Hz 50 oC
0.03Hz 20 oC
<0.2% volume change
<0.5%volume change
Poly(VP-co-Ru(bpy)3)
poly-vinylpyrrolidone (PVP)
0.003Hz 20 oC
10-20% volume change
NIPAm-co-Ru(bpy)3
Control of Oscillation Behavior
Size-chemical waves Vs. volume change
Concentration of MA-switch on/off oscillation
Temperature-Oscillation frequency
Light illumination-Oscillation frequency
Molecular structure of catalyst
Thermo-Sensitive Polymer Based Self-Oscillatory Materials
Post Self-Assembly Crosslinking
of Supramolecular Nanofbers
1
2
Supramolecular Hydrogel
Condition
Hydrogelator 4 mg
Water
450 μL
pH
7-8
Ru complex 0.5 mg
60X