Table 1.
Material properties of poly(urethane acrylate) aerogels aL-PUAc and aR-PUAc.
| Sample | Linear Shrinkage 1 (%) | Bulk Density ρb (g cm−3) | Skeletal Density ρs (g cm−3) | Porosity 2 Π (% v/v) | BET Surf. Area σ (m2 g−1) [Micropore Surf. Area] 3 | VTotal4 (V1.7–300 nm) 5 (cm3 g−1) | Av. Pore Diameter 6 (nm) | Particle Size 7 (nm) | Fractal Dimension 8 Ds |
|---|---|---|---|---|---|---|---|---|---|
| aL-PUAc-1.5 | 27 ± 1 | 0.081 ± 0.001 | 1.29 ± 0.01 | 94 | 203 | 11.6 (0.5) | 10.2 (228) | 11.4 | 2.59 |
| aL- PUAc-3 | 20 ± 2 | 0.074 ± 0.001 | 1.29 ± 0.02 | 94 | 185 | 12.7 (0.4) | 10.2 (276) | 12.6 | 2.58 |
| aL-PUAc-6 | 20 ± 2 | 0.260 ± 0.006 | 1.275 ± 0.005 | 80 | 225 | 3.1 (0.7) | 12.9 (55) | 10.4 | 2.55 |
| aL-PUAc-12 | 16 ± 2 | 0.31 ± 0.03 | 1.288 ± 0.001 | 76 | 260 | 2.4 (0.8) | 13.4 (38) | 9.0 | 2.54 |
| aR-PUAc-1.5 | 20 ± 2 | 0.041 ± 0.003 | 1.40 ± 0.01 | 97 | 488 [38] | 23.7 (0.8) | 8.2 (193) | 4.5 | 2.65 |
| aR-PUAc-3 | 20 ± 1 | 0.219 ± 0.008 | 1.43 ± 0.02 | 85 | 356 [13] | 3.9 (1.1) | 13.4 (42) | 5.9 | 2.60 |
| aR-PUAc-6 | 19 ± 2 | 0.15 ± 0.02 | 1.454 ± 0.004 | 90 | 374 [18] | 6.0 (0.8) | 9.8 (64) | 5.5 | 2.61 |
| aR-PUAc-12 | 17.5 ± 0.3 | 0.203 ± 0.004 | 1.414 ± 0.006 | 86 | 311 [2] | 4.2 (0.9) | 12.2 (54) | 6.8 | 2.58 |
1 Linear shrinkage calculated according to the following formula: (y1 + y2)/2, where y1 = 100 − [(hfin/hst) × 100] and y2 = 100 − [(dfin/dst) × 100; h: height, d: diameter. 2 Porosity calculated according to the following formula: (ρs − ρb)/ρs, where ρs: skeletal density and ρb: bulk density. 3 Micropore surface area via t-plot analysis, according to the Harkins and Jura model. 4 Total pore volume calculated according to the following formula: VTotal = 1/ρb − 1/ρs. 5 Cumulative volume of pores between 1.7 and 300 nm from N2-sorption data and the BJH desorption method. 6 Calculated by the 4 V/σ method; V was set equal to the maximum volume of N2 adsorbed along the isotherm as P/Po → 1.0. For the number in parentheses, V was set equal to VTotal from the previous column. 7 Particle radii calculated according to formula: r = 3/(ρs × σ). 8 Surface fractal dimension derived from N2-sorption data, calculated from the slope of the following plot: ln(V/Vm) = (Ds − 3) ln(ln(Po/P)) + C, where V is the volume of N2 adsorbed at each equilibrium pressure P, Vm is the volume of N2 adsorbed in a monolayer, and Po is the saturation pressure.