Table 5. Summary of Nanoindentation Measurements (Hardness and Modulus) on Heat-Treated Aerogels, Xerogels, and Heat-Treated Xerogels^a.

sample	hardness (GPa)	modulus (GPa)
Na-HTA	0.0004	0.014
Na-X	0.0277	0.476
	(0.0107)	(0.115)
Na-HTX	0.0651	0.634
	(0.0070)	(0.158)

^aSince replicates were run on the Na-X and Na-HTX, standard deviations (±1σ) are provided in parentheses below each data point.