1 research outputs found
Scaling Theory and Numerical Simulations of Aerogel Sintering
A simple scaling theory for the sintering of fractal aerogels is presented.
The densification at small scales is described by an increase of the lower
cut-off length accompanied by a decrease of the upper cut-off length ,
in order to conserve the total mass of the system. Scaling laws are derived
which predict how , and the specific pore surface area should
depend on the density . Following the general ideas of the theory,
numerical simulations of sintering are proposed starting from computer
simulations of aerogel structure based on a diffusion-limited cluster-cluster
aggregation gelling process. The numerical results for , and
as a function of are discussed according to the initial aerogel density.
The scaling theory is only fully recovered in the limit of very low density
where the original values of and are well separated. These numerical
results are compared with experiments on partially densified aerogels.Comment: RevTex, 17 pages + 6 postscript figures appended using "uufiles". To
appear in J. of Non-Cryst. Solid