Hydrothermal synthesis of ZSM-5 membranes. Outline content 1.1. In situ growth 2.2. Secondary growth...
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Hydrothermal synthesis of ZSM-5 membranes
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Transcript of Hydrothermal synthesis of ZSM-5 membranes. Outline content 1.1. In situ growth 2.2. Secondary growth...
Hydrothermal synthesis of ZSM-5 membranes
Outline content
1. In situ growth
2. Secondary growth
3. Work plan
1.
In situ growth
crystallization conditions
Time & Temperature
165℃， 4 h165℃， 4 h
165℃， 12 h165℃， 12 h
165℃， 24 h165℃， 24 h
185℃， 4 h185℃， 4 h
185℃， 24 h185℃， 24 h
165℃， 12 h165℃， 12 h 165℃， 12 h165℃， 12 h
substrate
165℃， 24 h165℃， 24 h 165℃， 24 h165℃， 24 h
Crystallization Time
nucleation
crystal growthC1
t1
t3 24 h
t2
t4
0 10 20 30 40 50 60
inte
nsity
2
substrate 3 sample 3
0 10 20 30 40 50 60
inte
nsity
2
substrate 2 sample 2
020
surface roughness
2.
Secondary growth
Random orientationRandom orientation
Random orientationRandom orientation
Random orientationRandom orientation
0 10 20 30 40 50 60
intensity
2Thickness ~1.8μmThickness ~1.8μm
101
200/020
332/051
151/303
133
Reproducity of secondary growth
Random orientationRandom orientationgood intergrowthgood intergrowth
0.36TPAOH:1TEOS:58H2O:4EtOHaging
Crystallization98℃， 48 h
Centrifugation10000 r/min for 10 min
The amount of seed can be easily controlled.
The obtained seed can be stored in a desiccator for later use.
weighing
Ultrasonication15 min
Preparation of seed
0 1 2 3 4 5
0.1
0.2
0.3
0.4
0.5
Δm
%（
）
concentration(mg/mL)
Impact of seed concentration
Random orientationRandom orientation
seed obtained after centrifugation5 mg/mL in EtOH
25SiO2 ： 9TPAOH ： 1450H2O: 100EtOH
100 ℃ ， 48 h
A gel layer formed Discrete zeolite particles
PH = 12.49 PH = 6.16
Seed coated
Effect of Al
•It facilitate the formation of the gel layer on the support.
•It retard zeolitization in this gel layer.
JH Koegler, H Bekkum, et al., Zeolites,1997,19(4): 262-269.
Re Lai, Yushan Yan, George R. Gavalas, Micropor Mesopor Mater, 2000,37(1-2):9-19
good
stable
unstable
agglomerate
Si/Al
Zet
a p
ote
nti
al(m
v)
Adv. Funct. Mater. 2008, 18, 952–958
Figure1. Zeta potential vs. PH for zeolite silicalite-1 crystals in aqueous suspension.
2 4 6 8 10 12 14-70
-60
-50
-40
-30
-20
-10
0
10
20
zeta
pot
entia
l(mv)
PH
100% （ 101）
100% （ 101）
100% （ 101）
21.9% （ 051）
56.8% （ 051）
59.0% （ 051）
PDF ： #44-0003ZSM-5:Al2O354SiO2
0mg/mL
2mg/mL
5mg/mL
CPO(101)/(051) = ? Concentration（ mg/mL） CPO
I: intensity of （ 101 ） and （ 051）P: PDF#44-0003S: 0mg/mL 、 2mg/mL 、 5mg/mL
0
2 0.0373
5 0.6288
I:intensity of a peak P:powder reference S:film sample
Characteristic planes and growing axis for MFI type zeolite
Plane(Miller index) Growing axis Reference
(501) a-axis [1]
(051) b-axis [2]
[(200)+(020)] [a+b]-axis [1]
(002) c-axis [2,3,4]
(101) Oblique c-axis [3]
(133) Oblique c-axis [1,2,4]
[1] Microporous and Mesoporous Materials, 1999. 28(1): 185-194[2] Journal of Materials Chemistry, 1998, 8(10): 2217-2221.[3]Microporous and Mesoporous Materials, 2009,123(1-3):113-112[4]Microporous and Mesoporous Materials, 2008, 115(1-2): 113-122.
I:intensity of a peak P:powder reference S:film sample
Fig.1. Typical shape of MFI-typ zeolite crystals
CPO definition
100% （ 101）
100% （ 101）
100% （ 101）
21.9% （ 051）
56.8% （ 051）
59.0% （ 051）
PDF ： #44-0003ZSM-5:Al2O354SiO2
0mg/mL
2mg/mL
5mg/mL
CPO(101)/(051) = ? Concentration（ mg/mL） CPO
I: intensity of （ 101 ） and （ 051）P: PDF#44-0003S: 0mg/mL 、 2mg/mL 、 5mg/mL
0
2 0.0373
5 0.6288
3.
Work plan
Work plan
1Sub-layer
SiO2 、 TiO2
ZrO2 、 Al2O3
2Cationic polymer layer
3Characterization
AFMXRD(pole figure 、 GID)
Zeta potential measurement
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Q&AThanks
for your time！
