We have developed a variety of methods for measuring permeability of gels. We have also studied the errors resulting when conventional characterization techniques are applied to gels and aerogels.

Relevant papers:

"Mechanics of Syneresis: I. Theory", G.W. Scherer, J. Non-Cryst. Solids 108 (1989) 18-27

"Mechanics of Syneresis: II. Experimental Study", G.W. Scherer,  J. Non-Cryst. Solids 108 (1989) 28-36

Conventional permeametry:

“Measurement of  Permeability: I. Theory”, G.W. Scherer, J. Non-Cryst. Solids 113 [2-3] (1990) 107-118

“Measurement of  Permeability: II. Silica Gel”, G.W. Scherer and R.M. Swiatek, J. Non-Cryst. Solids 113 [2-3] (1990) 119-129

Beam bending:

Bending of Gel Beams: method of characterizing mechanical properties and permeability”, G.W. Scherer, J. Non-Cryst. Solids, 142 [1-2] (1992) 18-35

“Relaxation of a Viscoelastic Gel Bar:  I. Theory”, G.W. Scherer, J. Sol-Gel Sci. Tech. 1 (1994) 169-175

“Relaxation of a Viscoelastic Gel Bar:  II. Silica Gel”, G.W. Scherer, J. Sol-Gel Sci. Tech. 2 [1/2/3] (1994) 199-204

This paper shows how to correct for indentation of the gel by the pushrod:

“Bending of gel beams: Effect of deflection rate and Hertzian indentation”, G.W. Scherer, J. Non-Cryst. Solids 201 (1996) 1-25

“Bending of a gel rod with an impermeable surface”, G.W. Scherer, J. Non-Cryst. Solids 204 [1] (1996) 73-77

Thermopermeametry:

“Thermal Expansion of Gels: A Novel Method for Measuring Permeability”, G.W. Scherer, H. Hdach, and J. Phalippou, J. Non-Cryst. Solids, 130 (1991) 157-170; errata, J. Non-Cryst. Solids 194 (1996) 326

“Measuring permeability by the thermal expansion method for rigid or highly permeable gels”, G.W. Scherer, J. Sol-Gel Sci. Tech. 3 (1994) 31-40

“Thermal expansion of a viscoelastic gel”, G.W. Scherer, J. Sol-Gel Sci. Tech. 4 [3] (1995) 169-177

“Influence of viscoelasticity and permeability on the stress response of silica gel”, G.W. Scherer, Langmuir 12 [5] (1996) 1109-1116

“Thermal expansion of a gel layer on a rigid substrate”, G.W. Scherer, J. Non-Cryst. Solids 204 [2] (1996) 118-124

Dynamic pressurization:

“Dynamic Pressurization: Novel method for measuring fluid permeability”, J. Gross and G.W. Scherer, J. Non-Cryst. Solids 325 (2003) 34-47

Nitrogen sorption:

“Adsorption in sparse networks: I. Cylinder model”, G.W. Scherer, J. Colloid Interface Sci. 202 (1998) 399-410

We originally thought that this work explained the erroneous results obtained from nitrogen sorption measurements on aerogels, but we later realized that the real problem is the contraction described in the following papers by Reichenauer:

“Adsorption in sparse networks: II. Application to silica aerogels”, G.W. Scherer, S. Calas, and R. Sempéré, J. Colloid Interface Sci. 202 (1998) 411-416

“Adsorption in aerogel networks”, G.W. Scherer, J. Non-Cryst. Solids 225 (1998) 192-199

“Effects upon nitrogen sorption analysis in aerogels”, G. Reichenauer and G.W. Scherer, J. Colloid Interface Sci. 236 (2001) 385-386

“Extracting the pore size distribution of compliant materials from nitrogen adsorption”, G. Reichenauer and G.W. Scherer, Colloids and Surfaces A 187-188 (2001) 41-50

“Nitrogen sorption in aerogels”, G. Reichenauer and G.W. Scherer, J. Non-Cryst. Solids 285 (2001) 167-174

Deformation during Characterization

“Characterization of aerogels”, G.W. Scherer, Advances in Colloid and Interface Science 76-77 (1998) 321-339

“Deformation of aerogels during characterization”, G.W. Scherer, D.M. Smith, and D. Stein, J. Non-Cryst. Solids 186 (1995) 309-315

“Compression of aerogels”, G.W. Scherer, D.M. Smith, X. Qiu, and J.M. Anderson, J. Non-Cryst. Solids 186 (1995) 316-320