Theory of Nuclear Relaxation in Confining Systems. Application to Non Wetting Liquids in Porous Silica Glasses

1992 ◽  
Vol 290 ◽  
Author(s):  
J.-P. Korb ◽  
A. Delville ◽  
Shu Xu ◽  
J. Jonas
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Sol Gel ◽  
Porous Silica ◽  
Nuclear Relaxation ◽  
Narrow Pore Size Distribution ◽  
Silica Glasses ◽  
Frequency Dependences ◽  
Wetting Liquid

AbstractThis work shows how the geometrical confinements enhances the nuclear relaxation of a non wetting liquid in a model porous systems. Application of the proposed theory is made to interpret the size and frequency dependences of the 1H relaxation of methylcyclohexane liquid in sol-gel porous silica glasses with narrow pore-size distribution.

Sol-Gel Processing of Low Dielectric Constant Nanoporous Silica Thin Films

2001 ◽  
Vol 703 ◽  
Author(s):  
Deok-Yang Kim ◽  
Henry Du ◽  
Suhas Bhandarkar ◽  
David W. Johnson
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Average Pore Size ◽  
Sol Gel ◽  
Porous Silica ◽  
Dielectric Constants ◽  
Gelling Agent ◽  
Porous Films ◽  
Average Pore

ABSTRACTTetramethyl ammonium silicate (TMAS) is known as a structuring agent in zeolite synthesis. We report its first use to prepare porous silica films for low k dielectric applications in microelectronics. A solution of TMAS 18.7 wt. % was spin coated on silicon substrates with a 3000 Å thick thermal oxide. The spin coated films were subsequently heat-treated at 450°C to obtain porous silica. The use of TMAS solution without gelation led to films of only moderate porosity value of 10%. The addition of methyl lactate, a gelling agent, significantly increased film porosity and improved the pore size distribution. For example, 50% porosity and uniform pore size distribution (average pore size ∼ 40 Å) has been achieved. Dielectric constants (k) of our porous films are as low as 2.5.

Sign in / Sign up

Export Citation Format

Share Document