Abstract
In this study, tailored heat treatment was employed to lower the flammability of hydrophobic silica aerogels (HSA). The effects of heat treatment temperature, time, and heating rate on the pore structure and flammability of the treated SA were investigated in detail. It was revealed that the heat-treated HSA still maintained a mesoporous structure with a lower tap density and a higher specific surface area. The chemical groups of the treated HSA were influenced significantly by the heat treatment temperature but were independent of the heat treatment time and heating rate. Due to the removal of organic groups, the flammability of the heat-treated SA was reduced significantly. Hence, it was demonstrated that reducing the flammability of HSA by tailored heat treatment was feasible, which can provide a simple approach to reduce the flammability of SA and benefited their expansion in thermal insulation field.
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References
Baetens R, Jelle BP, Gustavsen A (2011) Aerogel insulation for building applications: a state-of-the-art review. Energy Build 43:761–769. https://doi.org/10.1016/j.enbuild.2010.12.012
Balzer C, Morak R, Erko M et al (2015) Relationship between pore structure and sorption-induced deformation in hierarchical silica-based monoliths. Z Für Phys Chem 229:1189–1209. https://doi.org/10.1515/zpch-2014-0542
Barrett EP, Joyner LG, Halenda PP (1951) The determination of pore volume and area distributions in porous substances. I Computations from Nitrogen Isotherms J Am Chem Soc 73:373–380. https://doi.org/10.1021/ja01145a126
Brunauer S, Emmett PH, Teller E (1938) Adsorption of gases in multimolecular layers. J Am Chem Soc 60:309–319. https://doi.org/10.1021/ja01269a023
Chen H-B, Wang Y-Z, Schiraldi DA (2014) Preparation and flammability of poly(vinyl alcohol) composite aerogels. ACS Appl Mater Interfaces 6:6790–6796. https://doi.org/10.1021/am500583x
Cuce E, Cuce PM, Wood CJ, Riffat SB (2014) Toward aerogel based thermal superinsulation in buildings: a comprehensive review. Renew Sust Energ Rev 34:273–299. https://doi.org/10.1016/j.rser.2014.03.017
Ghazi Wakili K, Remhof A (2017) Reaction of aerogel containing ceramic fibre insulation to fire exposure. Fire Mater 41:29–39. https://doi.org/10.1002/fam.2367
He S, Huang D, Bi H et al (2015) Synthesis and characterization of silica aerogels dried under ambient pressure bed on water glass. J Non-Cryst Solids 410:58–64. https://doi.org/10.1016/j.jnoncrysol.2014.12.011
He S, Huang Y, Chen G, Feng M, Dai H, Yuan B, Chen X (2019) Effect of heat treatment on hydrophobic silica aerogel. J Hazard Mater 362:294–302. https://doi.org/10.1016/j.jhazmat.2018.08.087
Huang D, Guo C, Zhang M, Shi L (2017) Characteristics of nanoporous silica aerogel under high temperature from 950°C to 1200°C. Mater Des 129:82–90. https://doi.org/10.1016/j.matdes.2017.05.024
Hüsing N, Schubert U (1998) Aerogels—airy materials: chemistry, structure, and properties. Angew Chem Int Ed 37:22–45. https://doi.org/10.1002/(SICI)1521-3773(19980202)37:1/2<22::AID-ANIE22>3.0.CO;2-I
Khedkar MV, Somvanshi SB, Humbe AV, Jadhav KM (2019) Surface modified sodium silicate based superhydrophobic silica aerogels prepared via ambient pressure drying process. J Non-Cryst Solids 511:140–146. https://doi.org/10.1016/j.jnoncrysol.2019.02.004
Koebel M, Rigacci A, Achard P (2012) Aerogel-based thermal superinsulation: an overview. J Sol-Gel Sci Technol 63:315–339. https://doi.org/10.1007/s10971-012-2792-9
Lei Y, Chen X, Song H et al (2017) The influence of thermal treatment on the microstructure and thermal insulation performance of silica aerogels. J Non-Cryst Solids 470:178–183. https://doi.org/10.1016/j.jnoncrysol.2017.05.020
Li LF, Tong P, Zou YM et al (2018a) Good comprehensive performance of Laves phase Hf1-xTaxFe2 as negative thermal expansion materials. Acta Mater 161:258–265. https://doi.org/10.1016/j.actamat.2018.09.029
Li Z, Cheng X, Gong L et al (2018b) Enhanced flame retardancy of hydrophobic silica aerogels by using sodium silicate as precursor and phosphoric acid as catalyst. J Non-Cryst Solids 481:267–275. https://doi.org/10.1016/j.jnoncrysol.2017.10.053
Li Z, Cheng X, He S et al (2016a) Aramid fibers reinforced silica aerogel composites with low thermal conductivity and improved mechanical performance. Compos Part Appl Sci Manuf 84:316–325. https://doi.org/10.1016/j.compositesa.2016.02.014
Li Z, Cheng X, He S, Shi X, Yang H (2015) Characteristics of ambient-pressure-dried aerogels synthesized via different surface modification methods. J Sol-Gel Sci Technol 76:138–149. https://doi.org/10.1007/s10971-015-3760-y
Li Z, Cheng X, Shi L, He S, Gong L, Li C, Zhang H (2016b) Flammability and oxidation kinetics of hydrophobic silica aerogels. J Hazard Mater 320:350–358. https://doi.org/10.1016/j.jhazmat.2016.07.054
Li Z, Huang S, Shi L, Li Z, Liu Q, Li M (2019) Reducing the flammability of hydrophobic silica aerogels by doping with hydroxides. J Hazard Mater 373:536–546. https://doi.org/10.1016/j.jhazmat.2019.03.112
Liao J, Gao P, Xu L, Feng J (2018) A study of morphological properties of SiO2 aerogels obtained at different temperatures. J Adv Ceram 7:307–316. https://doi.org/10.1007/s40145-018-0280-6
Mahadik SA, Pedraza F, Parale VG, Park H-H (2016) Organically modified silica aerogel with different functional silylating agents and effect on their physico-chemical properties. J Non-Cryst Solids 453:164–171. https://doi.org/10.1016/j.jnoncrysol.2016.08.035
Malfait WJ, Zhao S, Verel R et al (2015) Surface chemistry of hydrophobic silica aerogels. Chem Mater 27:6737–6745. https://doi.org/10.1021/acs.chemmater.5b02801
Petrella RV (1994) The assessment of full-scale fire hazards from cone calorimeter data. J Fire Sci 12:14–43. https://doi.org/10.1177/073490419401200102
Pierre AC, Pajonk GM (2002) Chemistry of aerogels and their applications. Chem Rev 102:4243–4266. https://doi.org/10.1021/cr0101306
Randall JP, Meador MAB, Jana SC (2011) Tailoring mechanical properties of aerogels for aerospace applications. ACS Appl Mater Interfaces 3:613–626. https://doi.org/10.1021/am200007n
Reichenauer G (2011) Structural characterization of aerogels. In: Aegerter MA, Leventis N, Koebel MM (eds) Aerogels handbook. Springer New York, New York, pp 449–498
Rojas F, Kornhauser I, Felipe C et al (2002) Capillary condensation in heterogeneous mesoporous networks consisting of variable connectivity and pore-size correlation. Phys Chem Phys 4:2346–2355. https://doi.org/10.1039/B108785A
Shi L, Chew MYL (2012) Influence of moisture on autoignition of woods in cone calorimeter. J Fire Sci 30:158–169. https://doi.org/10.1177/0734904111431675
Sundström B (2007) The development of a European fire classification system for building products - test methods and mathematical modelling. Lund University
Tasca AL, Ghajeri F, Fletcher AJ (2018) Novel hydrophilic and hydrophobic amorphous silica: characterization and adsorption of aqueous phase organic compounds. Adsorpt Sci Technol 36:327–342. https://doi.org/10.1177/0263617417692339
Wei W, Hu H, Ji X, Yan Z, Sun W, Xie J (2018) Selective adsorption of organic dyes by porous hydrophilic silica aerogels from aqueous system. Water Sci Technol 78:402–414. https://doi.org/10.2166/wst.2018.313
Zhang W, Li Z, Shi L, Li Z, Luo Y, Liu Q, Huang R (2019) Methyltrichlorosilane modified hydrophobic silica aerogels and their kinetic and thermodynamic behaviors. J Sol-Gel Sci Technol 89:448–457. https://doi.org/10.1007/s10971-018-4882-9
ISO 5660-1:2015 Reaction-to-fire tests—heat release, smoke production and mass loss rate—Part 1: heat release rate (cone calorimeter method) and smoke production rate (dynamic measurement)
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This work was supported by the National Natural Science Foundation of China (No. 51904336), the Fundamental Research Funds for the Central Universities (Nos. 202501003 and 202045001) and the China Scholarship Council (No. 201806375007).
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Wu, X., Li, Z., Joao, G. et al. Reducing the flammability of hydrophobic silica aerogels by tailored heat treatment. J Nanopart Res 22, 83 (2020). https://doi.org/10.1007/s11051-020-04822-w
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DOI: https://doi.org/10.1007/s11051-020-04822-w