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Synthesis optimization of organic xerogels produced from convective air-drying of resorcinol–formaldehyde gels
| Content Provider | Semantic Scholar |
|---|---|
| Author | Job, Nathalie Panariello, Fabian Marien, J. N. Crine, Michel Pirard, Jean-Paul Léonard, Angélique |
| Copyright Year | 2006 |
| Abstract | Abstract Resorcinol–formaldehyde gels were produced at 50, 70 and 90 °C and with three different R / C ratios (500, 1000 and 2000). The effect of these variables combined with that of aging time was studied in order to optimize the synthesis conditions. The convective air-drying process was used, and the drying duration was studied with regard to the synthesis conditions. The aging time has no effect on the pore texture after 24 h at 90 °C or 48 h at 70 °C, whatever the R / C value. The synthesis-aging step can be shortened by increasing the temperature. Nevertheless, the pore size tends then to decrease, especially when R / C is high, but this can be counterbalanced by increasing R / C . Moreover, bubbles often appear in the gel at high synthesis temperature, which limits the temperature to about 70 °C in the case of monolithic parts. At 70 °C and with an air velocity of 2 m/s, the elimination of 90% of the solvent requires 1 h drying when the pore size reaches 400–600 nm, 2.5 h for 50 nm wide pores and 3 h when the pore size decreases to 15–20 nm. The drying duration does not exceed 8 h in all cases and could be shortened by increasing the temperature at the end of the process. |
| Starting Page | 24 |
| Ending Page | 34 |
| Page Count | 11 |
| File Format | PDF HTM / HTML |
| DOI | 10.1016/j.jnoncrysol.2005.11.024 |
| Alternate Webpage(s) | https://orbi.uliege.be/bitstream/2268/7955/2/JOB_JNonCrystSolids_2006_Orbi.pdf |
| Alternate Webpage(s) | https://doi.org/10.1016/j.jnoncrysol.2005.11.024 |
| Volume Number | 352 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
