1. Acidified Water + Surfactant
Synthesis and Diffusion Properties of Ordered Nanoporous Silica Membranes with Controlled Macroscopic Morphology Jerry Y.S. Lin, Dept of Chemical Engineering, Arizona State University, Tempe, AZ 85260
Oxygen permeance of CDSA silica membranes (at 298 K) and porosimetry results
Membrane
Support Permeance
(10-6 mol/m2.Pa.s)*
O2 Permeance
(10-6 mol/m2.Pa.s)
d100
spacing
Wall thickness
(nm)
Pore Volume
(cm3/g)
BET Surface
Area (m2/g)
BJH
Pore Size (nm)
Method A (H>>>h)
120
1.4 -
0.20
312
3.1
Method B
(H>h) **
5.3
4.2
2.1
0.26
379
2.7
Method C
(H=h)
3.7
4.25
0.60
990
Silicon source
Support
Acidified Water + Surfactant
* Theoretical permeance,** Sample mass too low to get an accurate estimate for Surface area and Pore volume
Silica grown inside the support pores in Methods A,
B and C
Permeance decreases by about 100 times after growth
of silica with surfactant
SEM shows plug morphology is typical of MCM-41
fibers
XRD shows ordered pattern for Method B and
Method C
Nitrogen sorption studies shows ordered mesoporous
nature of plugs with high surface area and pore
volume
Typical Nitrogen Adsorption Desorption isotherm for the silica plugs Inset-BJH pore size