Engineering mesoporous silica for superior optical and thermal properties
Tóm tắt
We report a significant advance in thermally insulating transparent materials: silica-based monoliths with controlled porosity which exhibit the transparency of windows in combination with a thermal conductivity comparable to aerogels. The lack of transparent, thermally insulating windows leads to substantial heat loss in commercial and residential buildings, which accounts for ~4.2% of primary US energy consumption annually. The present study provides a potential solution to this problem by demonstrating that ambiently dried silica aerogel monoliths, i.e., ambigels, can simultaneously achieve high optical transparency and low thermal conductivity without supercritical drying. A combination of tetraethoxysilane, methyltriethoxysilane, and post-gelation surface modification precursors were used to synthesize ambiently dried materials with varying pore fractions and pore sizes. By controlling the synthesis and processing conditions, 0.5–3 mm thick mesoporous monoliths with transmittance >95% and a thermal conductivity of 0.04 W/(m K) were produced. A narrow pore size distribution, <15 nm, led to the excellent transparency and low haze, while porosity in excess of 80% resulted in low thermal conductivity. A thermal transport model considering fractal dimension and phonon-boundary scattering is proposed to explain the low effective thermal conductivity measured. This work offers new insights into the design of transparent, energy saving windows.
Tài liệu tham khảo
Apte J. and Arasteh D.: Window-related energy consumption in the US residential and commercial building stock. LBNL-60146, pp. 1–38 (2008).
Arasteh D., Selkowitz S., Apte J., and LaFrance M.: Zero energy windows. In 2006 ACEEE Summer Study on Energy Efficiency in Buildings, pp. 1–14 (2006).
U.S. Energy Information Administration, Office of Energy Consumption and Efficiency Statistics. 2015 Residential Energy Consumption Survey (2015).
Kamiuto K., Miyamoto T., and Saitoh S.: Thermal characteristics of a solar tank with aerogel surface insulation. Appl. Energy 62, 113–123 (1999).
Buratti C., Moretti E., and Zinzi M.: High energy-efficient windows with silica aerogel for building refurbishment: Experimental characterization and preliminary simulations in different climate conditions. Buildings 7, 1–12 (2017).
Weinstein L.A., McEnaney K., Strobach E., Yang S., Bhatia B., Zhao L., Huang Y., Loomis J., Cao F., Boriskina S.V., Ren Z., Wang E.N., and Chen G.: A hybrid electric and thermal solar receiver. Joule 2, 962–975 (2018).
Strobach E., Bhatia B., Yang S., Zhao L., and Wang E.N.: High temperature annealing for structural optimization of silica aerogels in solar thermal applications. J. Non-Cryst. Solids 462, 72–77 (2017).
Zhao L., Bhatia B., Yang S., Strobach E., Weinstein L.A., Cooper T.A., Chen G., and Wang E.N.: Harnessing heat beyond 200°C from unconcentrated sunlight with nonevacuated transparent aerogels. ACS Nano 13, 7508–7516 (2019).
Baetens R., Jelle B.P., and Gustavsen A.: Aerogel insulation for building applications: A state-of-the-art review. Energy Build. 43, 761–769 (2011).
Jelle B.P.: Traditional, state-of-the-art and future thermal building insulation materials and solutions–properties, requirements and possibilities. Energy Build. 43, 2549–2563 (2011).
Aditya L., Mahlia T.M.I., Rismanchi B., Ng H.M., Hasan M.H., Metselaar H.S.C., Muraza O., and Aditiya H.B.: A review on insulation materials for energy conservation in buildings. Renew. Sustain. Energy Rev. 73, 1352–1365 (2017).
Lemmon E.W. and Jacobsen R.T.: Viscosity and thermal conductivity equations for nitrogen, oxygen, argon, and air. Int. J. Thermophys. 25, 21–69 (2004).
Fricke J. and Emmerling A.: Scaling properties and structure of aerogels. J. Sol.-Gel. Sci. Technol. 8, 781–788 (1997).
Courtens E. and Vacher R.: Experiments on the structure and vibrations of fractal solids. Proc. R. Soc. Math. Phys. Eng. Sci. 423, 55–69 (1989).
Schaefer D.W.: Fractal models and the structure of materials. MRS Bull. 13, 22–27 (1988).
Pfeifer P. and Avnir D.: Chemistry in noninteger dimensions between two and three. I. Fractal theory of heterogeneous surfaces. J. Chem. Phys. 79, 3558–3565 (1983).
Jaroniec M.: Evaluation of the fractal dimension from a single adsorption isotherm. Langmuir 11, 2316–2317 (1995).
Vacher R., Courtens E., Coddens G., Pelous J., and Woignier T.: Neutron-spectroscopy measurement of a fracton density of states. Phys. Rev. B 39, 7384–7387 (1989).
Stoll E. and Courtens E.: Connectivity and the fracton dimension of percolation clusters. Z. Für. Phys. B Condens. Matter 81, 1–2 (1990).
Petri A. and Pietronero L.: Multifractal nature of fractons on a percolating cluster. Phys. Rev. B 45, 12864–12872 (1992).
Alexander S. and Orbach R.: Density of states on fractals: “Fractons”. J. Phys. Lett. 43, 625–631 (1982).
Alexander S., Laermans C., Orbach R., and Rosenberg H.M.: Fracton interpretation of vibrational properties of cross-linked polymers, glasses, and irradiated quartz. Phys. Rev. B 28, 4615–4619 (1983).
Kruk M. and Jaroniec M.: Gas adsorption characterization of ordered organic−inorganic nanocomposite materials. Chem. Mater. 13, 3169–3183 (2001).
Scheuerpflug P., Morper H.-J., and Neubert G.: Low-temperature thermal transport in silica aerogels. J. Phys. Appl. Phys. 24, 1395–1403 (1991).
Aegerter M.A., Leventis N., and Koebel M.A.: Aerogels Handbook, Advances in Sol-Gel Derived Materials and Technologies (Springer, 2011), New York.
Zhao L., Strobach E., Bhatia B., Yang S., Leroy A., Zhang L., and Wang E.N.: Theoretical and experimental investigation of haze in transparent aerogels. Opt. Express 27, A39–A50 (2019).
Mandal C., Donthula S., Far H.M., Saeed A.M., Sotiriou-Leventis C., and Leventis N.: Transparent, mechanically strong, thermally insulating cross-linked silica aerogels for energy-efficient windows. J. Sol-Gel Sci. Technol. 92, 84–100 (2019).
Nakanishi Y., Hara Y., Sakuma W., Saito T., Nakanishi K., and Kanamori K.: Colorless transparent melamine–formaldehyde aerogels for thermal insulation. ACS Appl. Nano Mater. 3, 49–54 (2020).
Zu G., Kanamori K., Wang X., Nakanishi K., and Shen J.: Superelastic triple-network polyorganosiloxane-based aerogels as transparent thermal superinsulators and efficient separators. Chem. Mater. 32, 1595–1604 (2020).
Strobach E., Bhatia B., Yang S., Zhao L., and Wang E.N.: High temperature stability of transparent silica aerogels for solar thermal applications. APL Mater. 7, 081104 (2019).
Marszewski M., King S.C., Yan Y., Galy T., Li M., Dashti A., Butts D.M., Kang J.S., McNeil P.E., Lan E., Dunn B., Hu Y., Tolbert S.H., and Pilon L.: Thick transparent nanoparticle-based mesoporous silica monolithic slabs for thermally insulating window materials. ACS Appl. Nano Mater. 2, 4547–4555 (2019).
Schramm R.E., Clark A.F., and Reed R.P.: A Compilation and Evaluation of Mechanical, Thermal, and Electrical Properties of Selected Polymers. (U.S. National Bureau of Standards, 1973), Washington, D.C.
Caps R. and Fricke J.: Aerogels for thermal insulation. In Sol-Gel Technologies for Glass Producers and Users, Aegerter M. A. and Mennig M., eds. (Springer, 2004), Boston, MA; pp. 349–353.
Harreld J.H., Dong W., and Dunn B.: Ambient pressure synthesis of aerogel-like vanadium oxide and molybdenum oxide. Mater. Res. Bull. 33, 561–567 (1998).
Rolison D.R. and Dunn B.: Electrically conductive oxide aerogels: New materials in electrochemistry. J. Mater. Chem. 11, 963–980 (2001).
Dong W.: Electrochemical properties of high surface area vanadium oxide aerogels. Electrochem. Solid-State Lett. 3, 457 (1999).
Orcel G. and Hench L.: Effect of formamide additive on the chemistry of silica sol-gels. J. Non-Cryst. Solids 79, 177–194 (1986).
Levy D. and Zayat M.: The Sol-Gel Handbook (Wiley-VCH Verlag GmbH & Co. KGaA, 2015), Weinheim, Germany.
Brinker C.J. and Scherer G.W.: Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing (Academic Press, 1990), Boston.
Lenza R.F.S. and Vasconcelos W.L.: Preparation of silica by sol-gel method using formamide. Mater. Res. 4, 189–194 (2001).
Sing K.S.W.: Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity (recommendations 1984). Pure Appl. Chem. 57, 603–619 (1985).
Thommes M., Kaneko K., Neimark A.V., Olivier J.P., Rodriguez-Reinoso F., Rouquerol J., and Sing K.S.W.: Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC technical report). Pure Appl. Chem. 87, 1051–1069 (2015).
Pisal A.A. and Venkateswara Rao A.: Development of hydrophobic and optically transparent monolithic silica aerogels for window panel applications. J. Porous Mater. 24, 685–695 (2017).
Wei T.-Y., Lu S.-Y., and Chang Y.-C.: Transparent, hydrophobic composite aerogels with high mechanical strength and low high-temperature thermal conductivities. J. Phys. Chem. B 112, 11881–11886 (2008).
Wei T.-Y., Chang T.-F., Lu S.-Y., and Chang Y.-C.: Preparation of monolithic silica aerogel of low thermal conductivity by ambient pressure drying. J. Am. Ceram. Soc. 90, 2003–2007 (2007).
Rubio F., Rubio J., and Oteo J.L.: A FT-IR study of the hydrolysis of tetraethylorthosilicate (TEOS). Spectrosc. Lett. 31, 199–219 (1998).
Al-Oweini R., and El-Rassy H.: Synthesis and characterization by FTIR spectroscopy of silica aerogels prepared using several Si(OR)4 and R′′Si(OR′)3 precursors. J. Mol. Struct. 919, 140–145 (2009).
Prakash S.S., Brinker C.J., Hurd A.J., and Rao S.M.: Silica aerogel films prepared at ambient pressure by using surface derivatization to induce reversible drying shrinkage. Nature 374, 439–443 (1995).
Berardi U.: The development of a monolithic aerogel glazed window for an energy retrofitting project. Appl. Energy 154, 603–615 (2015).
Fricke J., Lu X., Wang P., Büttner D., and Heinemann U.: Optimization of monolithic silica aerogel insulants. Int. J. Heat Mass Transfer 35, 2305–2309 (1992).
Jain A., Rogojevic S., Ponoth S., Gill W.N., Plawsky J.L., Simonyi E., Chen S.-T., and Ho P.S.: Processing dependent thermal conductivity of nanoporous silica xerogel films. J. Appl. Phys. 91, 3275–3281 (2002).
Ebert H.-P.: Thermal properties of aerogels. In Aerogels Handbook, Michel A. Aegerter, Nicholas Leventis and Matthias M. Koebel, eds. (Springer, 2011) New York.
Touloukian Y.S.: Thermal Conductivity: Nonmetallic Solids, Thermophysical Properties of Matter, Vol. 2, (IFI/Plenum, 1970), New York.
Ziman J.M.: Electrons and Phonons: The Theory of Transport Phenomena in Solids (Oxford Classic Texts in the Physical Sciences, Clarendon Press, Oxford University Press, 2001), Oxford, New York.
Scheuerpflug P., Hauck M., and Fricke J.: Thermal properties of silica aerogels between 1.4 and 330 K. J. Non-Cryst. Solids 145, 196–201 (1992).
Heinemann U.: Wärmetransport in Semitransparenten Nichtgrauen Medien Am Beispiel von SiO2-Aerogelen (University of Würzburg, 1993), Würzburg, Germany.
Harreld J.H., Ebina T., Tsubo N., and Stucky G.: Manipulation of pore size distributions in silica and ormosil gels dried under ambient pressure conditions. J. Non-Cryst. Solids 298, 241–251 (2002).
Kargar F., Ramirez S., Debnath B., Malekpour H., Lake R.K., and Balandin A.A.: Acoustic phonon spectrum and thermal transport in nanoporous alumina arrays. Appl. Phys. Lett. 107, 171904 (2015).
Romano G., and Grossman J.C.: Phonon bottleneck identification in disordered nanoporous materials. Phys. Rev. B 96 (2017).