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http://dx.doi.org/10.4191/kcers.2017.54.3.12

Flexible and Transparent Silica Aerogels: An Overview  

Parale, Vinayak G. (Department of Materials Science and Engineering, Yonsei University)
Lee, Kyu-Yeon (Department of Materials Science and Engineering, Yonsei University)
Park, Hyung-Ho (Department of Materials Science and Engineering, Yonsei University)
Publication Information
Journal of the Korean Ceramic Society / v.54, no.3, 2017 , pp. 184-199 More about this Journal
Abstract
Silica aerogels are attracting attention due to certain outstanding properties such as low bulk density, low thermal conductivity, high surface area, high porosity, high transparency and flexibility. Due to these extraordinary properties of aerogels, they have become a promising candidate in thermal superinsulation. The silica-based aerogels are brittle in nature, which constrains their large scale-application. It is necessary to achieve transparency and flexibility of silica-based aerogels at the same time and with the same porous structure for optical field applications. Therefore, the present review focuses on the different sol-gel synthesis parameters and precursors in the synthesis of flexible as well as transparent silica aerogels. Also, a brief overview of reported flexible and transparent aerogels with some important properties and applications is provided.
Keywords
Porous ceramics; Thermal conductivity; Flexible aerogels; Transparency; Sol-gel process;
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1 S. B. Jung, S. W. Park, J. K. Yang, H. H. Park, and H. Kim, "Application of $SiO_2$ Aerogel Film for Interlayer Dielectric on GaAs with a Barrier of $Si_3N_4$," Thin Solid Films, 447 580-85 (2004).
2 U. Guenther, I. Smirnova, and R. H. H. Neubert, "Hydrophobic Silica Aerogels as Dermal Drug Delivery Systems-Dithranol as a Model Drug," Eur. J. Pharm. Biopharm., 69 [3] 935-42 (2008).   DOI
3 T. Gao and B. P. Jelle, "Silica Aerogels: A Multifunctional Building Material," pp. 35-41 in Nanotechnology in Construction, Springer International Publishing, Switzerland, 2015.
4 X. Wang and S. C. Jana, "Synergistic Hybrid Organic-Inorganic Aerogels," ACS Appl. Mater. Interfaces, 5 [13] 6423-29 (2013).   DOI
5 L. A. Capadona, M. A. B. Meador, A. Alunni, E. F. Fabrizio, P. Vasilaras, and N. Leventis, "Flexible, Low-Density Polymer Crosslinked Silica Aerogels," Polymer, 47 [16] 5754-61 (2006).   DOI
6 Y. Duan, S .C. Jana, A. M. Reinsel, B. Lama, and M. P. Espe, "Surface Modification and Reinforcement of Silica Aerogels Using Polyhedral Oligomeric Silsesquioxanes," Langmuir, 28 [43] 15362-71 (2012).   DOI
7 T. Asefa, M. J. MacLahlan, N. Coombs, and G. A. Ozin, "Periodic Mesoporous Organosilicas with Organic Groups inside the Channel Walls," Nature, 402 [6764] 867-71 (1999).   DOI
8 P. Van Der Voort, D. Esquivel, E. De Canck, F. Goethals, I. Van Driessche, and F. J. Romero-Salguero, "Periodic Mesoporous Organosilicas: from Simple to Complex Bridges; A Comprehensive Overview of Functions, Morphologies and Applications," Chem. Soc. Rev., 42 [9] 3913-55 (2013).   DOI
9 T. J. Ha, H. G. Im, S. J. Yoon, H. W. Jang, and H. H. Park, "Pore Structure Control of Ordered Mesoporous Silica Film Using Mixed Surfactants," J. Nanomater., 2011 [3] 326472 (2011).
10 K. Kanamori, Y. Kodera, G. Hayase, K. Nakanishi, and T. Halanda, "Transition from Transparent Aerogels to Hierarchically Porous Monoliths in Polymethylsilsesquioxane So-Gel System," J. Colloid Interface Sci., 357 [2] 336-44 (2011).   DOI
11 K. Kanamori, M. Aizawa, K. Nakanishi, and T. Hanada, "New Transparent Methylsilsesquioxane Aerogels and Xerogels with Improved Properties," Adv. Mater., 19 [12] 1589-93 (2007).   DOI
12 M. Kurahashi, K. Kanamori, K. Takeda, H. Kaji, and K. Nakanishi, "Role of Block Copolymer Surfactant on the Pore Formation in Methylsilsesquioxane Aerogel Systems," RSC Adv., 2 [18] 7166-73 (2012).   DOI
13 K. Kanamori, G. Hayase, K. Nakanishi, and T. Hanada, "Pore Structure and Mechanical Properties of Poly(Methylsilsesquioxane) Aerogels," IOP Conf. Ser.: Mater. Sci. Eng., 18 [3] 032001 (2011).
14 A. V. Rao, S. D. Bhagat, H. Hirashima, and G. M. Pajonk, "Synthesis of Flexible Silica Aerogels Using Methyltrimethoxysilane (MTMS) Precursor," J. Colloid Interface Sci., 300 [1] 179-285 (2006).
15 M. K. Carroll and A. M. Anderson, "Aerogels as Platforms for Chemical Sensors," pp. 637-50 in Aerogels Handbook, Springer, New York, 2011.
16 Z. Wang, Z. Dai, J. Wu, N. Zhao, and J. Xu, "Vacuum Dried Robust Bridged Silsesquioxane Aerogels," Adv. Mater., 25 [32] 4494-97 (2013).   DOI
17 Q. Gao, J. feng, C. Zhang, J. Feng, W. Wu, and Y. Jiang, "Mechanical Properties of Aerogel-Ceramic Fiber Composites," Adv. Mater. Res., 105 94-9 (2010).
18 B. Yuan, S. ding, D. Wang, G. Wang, and H. Li, "Heat Insulation Properties of Silica Aerogel/Glass Fiber Composites Fabricated by Press Forming," Mater. Lett., 75 204-6 (2012).   DOI
19 W. J. Malfait, S. Zhao, R. Verel, S. Iswar, D. Rentsch, R. Fener, Y. Zhang, B. Milow, and M. M. Koebel, "Surface Chemistry of Hydrophobic Silica Aerogels," Chem. Mater., 27 [19] 6737-45 (2015).
20 N. D. Hegde and A. V. Rao, "Physical Properties of Methyltrimethoxysilane Based Elastic Silica Aerogels Prepared by the Two-Stage Sol-Gel Process," J. Mater. Sci., 42 [16] 6965-71 (2007).   DOI
21 A. V. Rao and R. R. Kalesh, "Comparative Studies of the Physical and Hydrophobic Properties of TEOS Based Silica Aerogels Using Different Co-Precursors," Sci. Technol. Adv. Mater., 4 [6] 509-15 (2003).   DOI
22 A. V. Rao, R. R. Kalesh, and G. M. Pajonk, "Hydrophobicity and Physical Properties of TEOS Based Silica Aerogels Using Phenyltriethoxysilane as a Synthesis Component," J. Mater. Sci., 38 [21] 4407-13 (2003).   DOI
23 K. Kanamori, "Organic-Inorganic Hybrid Aerogels with High Mechanical Properties via Organotrialkoxysilane-Derived Sol-Gel Process," J. Ceram. Soc. Jpn, 119 [1385] 16-22 (2011).   DOI
24 V. G. Parale, D. B. Mahadik, S. A. Mahadik, M. S. Kavale, P. B. Wagh, S. C. Gupta, and A. V. Rao, "OTES Modified Transparent Dip Coated Silica Coatings," Ceram. Int., 39 [1] 835-40 (2013).   DOI
25 M. A. B. Meador, E. J. Malow, R. Silva, S. Wright, D. Quade, S. L. Vivod, H. Guo, J. Guo, and M. Cakmak, "Mechanically Strong, Flexible Polyimide Aerogels Cross-Linked with Aromatic Triamine," ACS Appl. Mater. Interfaces, 4 [2] 536-44 (2012).   DOI
26 M. Reim, W. Korner, J. Manara, S. Korder, M. Arduini-Schuster, H. P. Ebert, and J. Fricke, "Silica Aerogel Granulate Material for Thermal Insulation and Daylighting," Sol. Energy, 79 [2] 131-39 (2005).   DOI
27 K. I. Jensen, J. M. Schultz, and F. H. Kristiansen, "Development of Windows Based on Highly Insulating Aerogel Glazings," J. Non-Cryst. Solids, 350 351-57 (2004).   DOI
28 T. Stegmaier, M. Linke, and H. Planck, "Bionics in Textiles: Flexible and Translucent Thermal Insulations for Solar Thermal Applications," Philos. Trans. R. Soc., A, 367 [1894] 1749-58 (2009).   DOI
29 N. Bheekhun, A. R. A. Talib, and M. R. Hassan, "Aerogels in Aerospace: An Overview," Adv. Mater. Sci. Eng., 2013 406065 (2013).
30 G. Hayase, K. Kugimiya, M. Ogawa, Y. Kodera, K. Kanamori, and K. Kakanishi, "The Thermal Conductivity of Polymethylsilsesquioxane Aerogels and Xerogels with Varied Pore Sizes for Practical Application as Thermal Superinsulators," J. Mater. Chem. A, 2 [18] 6525 (2014).   DOI
31 F. Rechberger and M. Niederberger, "Synthesis of Aerogels: from Molecular Routes to 3-Dimensional Nanoparticle Assembly," Nanoscale Horiz., 2 [1] 6-30 (2017).   DOI
32 S. Takeshita and S. Yoda, "Chitosan Aerogels: Transparent, Flexible Thermal Insulators," Chem. Mater., 27 [22] 7569-72 (2015).   DOI
33 A. Slosarczyk, "Recent Advances in Research on the Synthetic Fiber Based Silica Aerogel Nanocomposites," Nanomaterials, 7 [2] 44 (2017).   DOI
34 Q. Mi, S. Ma, J. Yu, J. He, and J. Zhang, "Flexible and Transparent Cellulose Aerogels with Uniform Nanoporous Structure by a Controlled Regeneration Process," ACS Sustainable Chem. Eng., 4 656-60 (2016).   DOI
35 F. Fischer, A. Rigacci, R. Pirard, S. Berthon-Fabry, and P. Achard, "Cellulose Based Aerogels," Polymer, 47 7636-45 (2006).   DOI
36 K. Kanamori, M. Aizawa, K. Nakanishi, and T. Hanada, "Elastic Organic-Inorganic Hybrid Aerogels and Xerogels," J. Sol-Gel Sci. Technol., 48 [1-2] 172-81 (2008).   DOI
37 P. B. Wagh, R. Begag, G. M. Pajonk, A. V. Rao, and D. Haranath, "Comparison of Some Physical Properties of Silica Aerogel Monoliths Synthesized by Different Precursors," Mater. Chem. Phys., 57 [3] 214-18 (1999).   DOI
38 C. A. Garcia-Gonzalez, M. C. Camino-Rey, M. Alnaief, C. Zetzl, and I. Smirnova, "Supercritical Drying of Aerogels Using $CO_2$: Effect of Extraction Time on the End Material Textural Properties," J. Supercit. Fluids, 66 297-306 (2012).   DOI
39 M. S. Kavale, D. B. Mahadik, V. G. Parale, A. V. Rao, P. B. Wagh, and S. C. Gupta, "Methyltrimethoxysilane Based Flexible Silica Aerogels for Oil Absorption Applications," AIP Conf. Proceedings, 1447 [1] 1283 (2012).
40 D. Y. Nadargi and A. V. Rao, "Methyltriethoxysilane: New Precursor for Synthesizing Silica Aerogels," J. Alloys Compd., 467 [1] 397-404 (2009).   DOI
41 P. B. Wagh, A. V. Rao, and D. Haranath, "Influence of Catalyst (Citric Acid) Concentration on the Physical Properties of Teos Silica Aerogels," J. Porous Mater., 4 [4] 295-301 (1997).   DOI
42 L. Kocon, F. Despetis, and J. Phalippou, "Ultralow Density Silica Aerogels by Alcohol Supercritical Drying," J. Non-Cryst. Solids, 22 596-100 (1998).
43 D. A. Loy, E. M. Russick, S. A. Yamanaka, and B. M. Baugher, "Direct Formation of Aerogels by Sol-Gel Polymerizations of Alkoxysilanes in Supercritical Carbon Dioxide", Chem. Mater., 9 [11] 2264-68 (1997).   DOI
44 O. Karatum, S. A. Steiner, J. S. Griffin, W. Shi, and D. L. Plata, "Flexible, Mechanically Durable Aerogel Composites for Oil Capture and Recovery," ACS Appl. Mater. Interfaces, 8 [1] 215-24 (2016).   DOI
45 C. R. Ehgartner, S. Grandl, A. Feinle, and N. Husing, "Fexible Organofunctional Aerogels," Dalton Trans., DOI: 10.1039/c7dt00558j (2017).   DOI
46 L. Jiang, K. Kato, K. Mayumi, H. Yokoyama, and K. Ito, "One-Pot Synthesis and Characterization of Polyrotaxane-Silica Hybrid Aerogel," ACS Macro Lett., 6 [3] 281-86 (2017).   DOI
47 D. B. Mahadik, H. N. R. Jung, W. Han, H. H. Cho, and H. H. Park, "Flexible, Elastic, and Superhydrophobic Silica-Polymer Composite Aerogels by High Internal Phase Emulsion Process," Compos. Sci. Technol., 147 45-51 (2017).   DOI
48 K. Y. Lee, H. N. R. Jung, D. B. Mahadik, and H. H. Park, "Characterization of Mechanical Property Change in Polymer Aerogels Depending on the Ligand Structure of Acrylate Monomer," J. Microelectron. Packag. Soc., 23 [3] 15-20 (2016).   DOI
49 D. B. Mahadik, A. V. Rao, V. G. Parale, M. S. Kavale, P. B. Wagh, S. V. Ingle, and S. C. Gupta, "Effect of Surface Composition and Roughness on the Apparent Surface Free Energy of Silica Aerogel Materials," Appl. Phys. Lett., 99 [10] 104104 (2011).   DOI
50 M. Schwan and L. Ratke, "Flexibilisation of Resorcinol-Formaldehyde Aerogels," J. Mater. Chem. A, 1 [43] 13462-68 (2013).   DOI
51 C. J. Brinker and G. W. Scherer, "Particulate Sols and Gels," pp. 235-97 in Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing, Academic Press, San Diego, 1990.
52 T. Shimizu, K. Kanamori, and K. Nakanishi, "Siliconebased Organic-Inorganic Hybrid Aerogels and Xerogels," Chem. Eur. J., 23 [22] 5176-87 (2017).   DOI
53 A. S. Dorcheh and M. H. Abbasi, "Silica Aerogels: Synthesis, Properties and Characterization," J. Mater. Process. Technol., 199 [1] 10-26 (2008).   DOI
54 J. L. Gurav, I. K. Jung, H. H. Park, E. S. Kang, and D. Y. Nadargi, "Silica Aerogel: Synthesis and Applications," J. Nanomater., 2010 23 (2010).
55 A. C. Pierre and G. M. Pajonk, "Chemistry of Aerogels and their Applications," Chem. Rev., 102 [11] 4243-66 (2002).   DOI
56 H. Schmidt, "Chemistry of Material Preparation by Sol-Gel Process," J. Non-Cryst. Solids, 100 51-64 (1988).   DOI
57 R. Baetens, B. P. Jelle, and A. Gustavsen, "Aerogel Insulation for Building Applications: A State-of-the-Art Review," Energy Build., 43 [4] 761-69 (2011).   DOI
58 I. Lazar and I. Fabian, "A Continuous Extraction and Pumpless Supercritical $CO_2$ Drying System for Laboratory-Scale Aerogel Production," Gels, 2 [4] 26 (2016).   DOI
59 D. B. Mahadik, Y. K. Lee, N. K. Chavan, S. A. Mahadik, and H. H. Park, "Monolithic and Shrinkage-free Hydrophobic Silica Aerogels via New rapid Supercritical Extraction Process," J. Supercrit. Fluids, 107 84-91 (2016).   DOI
60 G. Hayase, K. Kanamori, K. Abe, H. Yano, A. Maeno, H. Kaji, and K. Nakanishi, "Polymethylsilsesquioxane-Cellulose Nanofiber Biocomposite Aerogels with High Thermal Insulation, Bendability, and Superhydrophobicity," ACS Appl. Mater. Interfaces, 6 [12] 9466-71 (2014).   DOI
61 B. E. Coffman, J. E. Fesmire, S. White, G. Gould, and S. Augustynowicz, "Aerogel Blanket Insulation Materials for Cryogenic Applications," AIP Conf. Proceeding, 1218 [1] 913-20 (2010).
62 S. B. Riffat and G. Qiu, "A Review of State-of-the-Art Aerogel Applications in Buildings," Int. J. Low-Carbon Technol., 8 [1] 1-6 (2013).   DOI
63 http://www.aerogel.com/_resources/common/userfiles/file/SDS-AIS/Spaceloft_SDS.pdf Accessed on 18/03/2017.
64 Q. Zhou, Y. Shen, S. Ai, B. Liu, and Y. Zhao, "Transparent Aerogels with High Mechanical Strength Composed of Cellulose-Silica Cross-Linked Networks," MATEC Web Conf., 64 050001 (2016).
65 D. B. Mahadik, H. N. R. Jung, Y. K. Lee, K. Y. Lee, and H. H. Park, "Elastic and Superhydrophobic Monolithic Methyltrimethoxysilane-based Silica Aerogels by Two-Step Sol-Gel Process," J. Microelectron. Packeg. Soc., 23 [1] 35-9 (2016).
66 K. Sinko, "Influence of Chemical Conditions on the Nanoporous Structure of Silicate Aerogels," Materials, 3 [1] 704-40 (2010).   DOI
67 C. J. Brinker, "Hydrolysis and Condensation of Silicates: Effects on Structure," J. Non-Cryst. Solids, 100 31-50 (1988).   DOI
68 T. Shimizu, K. Kanamori, A. Maeno, H. Kaji, C. M. Doherty, P. Falcaro, and K. Nakanishi, "Transparent, Highly Insulating Polyethyl- and Polyvinylsilsesquioxane Aerogels: Mechanical Improvements by Vulcanization for Ambient Pressure Drying," Chem. Mater., 28 [19] 6860-68(2016).   DOI
69 N. D. Hegde and A. V. Rao, "Organic Modification of TEOS Based Silica Aerogels Using Hexadecyltrimethoxysilane as a Hydrophobic Reagent," Appl. Surf. Sci., 253 [3] 1566-72 (2006).   DOI
70 D. B. Mahadik, A. V. Rao, P. B. Wagh, and S. C. Gupta, "Synthesis of Transparent and Hydrophobic TMOS Based Silica Aerogels," AIP Conf. Proceedings, 1536 [1] 553 (2013).
71 S. A. Mahadik, V. G. Parale, R. S. Vhatkar, D. B. Mahdik, M. S. Kavale, P. B. Wagh, S. C. Gupta, and J. L. Gurav, "Superhydrophobic Silica Coating by Dip Coating Method," Appl. Surf. Sci., 277 67-72 (2013).   DOI
72 K. Kanamori and K. Nakanishi, "Controlled Pore Formation in Organotrialkoxysilane-Derived Hybrids: from Aerogels to Hierarchically Porous Monoliths," Chem. Soc. Rev., 40 [2] 754-70 (2011).   DOI
73 H. Wu, Y. Chen, Q. Chen, Y. Ding, X. Zhou, and H. Gao, "Synthesis of Flexible Aerogel Composites Reinforced with Electrospun Nanofibers and Microparticles for Thermal Insulation," J. Nanomater., 2013 10 (2013).
74 M. Paakko, J. Vapaavuori, R. Silvennoinen, H. Kosonen, M. Ankerfors, T. Lindstrom, L. Berglund, and O. Ikkala, "Long and Entangled Native Cellulose Nanofibers Allow Flexible Aerogels and Hierarchically Porous Templates for Functionalities," Soft Matter, 4 [12] 2492-99 (2008).   DOI
75 I. Siro and D. Plackett, "Microfibrillated Cellulose and New Nanocomposite Materials: A Review," Cellulose, 17 [3] 459-94 (2010).   DOI
76 M. Nogi and H. Yano, "Transparent Nanocomposites Based on Cellulose Produced by Bacteria Offer Potential Innovation in the Electronics Device Industry," Adv. Mater., 20 [10] 1849-52 (2008).   DOI
77 K. Kanamori, "Liquid-Phase Synthesis and Application of Monolithic Porous Materials Based on Organic-Inorganic Hybrid Methylsiloxanes, Crosslinked Polymers and Carbons," J. Sol-Gel Sci. Technol., 65 [1] 12-22 (2013).   DOI
78 S. Alexander, "Vibrations of Fractals and Scattering of Light from Aerogels," Phys. Rev. B, 40 [11] 7953-65 (1989).   DOI
79 W. Cao and A. J. Hunt, "Improving the Visible Transparency of Silica Aerogels," J. Non-Cryst. Solids, 176 [1] 18-25 (1994).   DOI
80 S. Yun, H. Luo, and Y. Gao, "Ambient-Pressure Drying Synthesis of Large Resorcinol-Formaldehyde-Reinforced Silica Aerogels with Enhanced Mechanical Strength and Superhydrophobicity," J. Mater. Chem. A, 2 [35] 14542-49 (2014).   DOI
81 D. B. Mahadik, Y. K. Lee, C. S. Park, H. Y. Chung, M. H. Hong, H. N. R. Jung, W. Han, and H. H. Park, "Effect of Water Ethanol Solvents Mixture on Textural and Gas Sensing Properties of Tin Oxide Prepared Using Epoxide-Assisted Sol-Gel Process and Dried at Ambient Pressure," Solid State Sci., 50 1-8 (2015).   DOI
82 M. S. Kavale, S. A. Mahadik, D.B. Mahadik, V. G. Parale, A. V. Rao, R. S. Vhatkar, P. B. Wagh, and S. C. Gupta, "Enrichment in Hydrophobicity and Scratch Resistant Properties of Silica Films on Glass by Grafted Microporosity of the Network," J. Sol-Gel Sci. Technol., 64 [1] 9-16 (2012).   DOI
83 U. K. H. Bangi, I. K. Jung, C. S. Park, S. Baek, and H. H. Park, "Optically Transparent Silica Aerogels Based on Sodium Silicate by a Two-Step Sol-Gel Process and Ambient Pressure Drying," Solid State Sci., 18 50-7 (2013).   DOI
84 G. J. Owens, R. K. Singh, F. Foroutan, M. Alqaysi, C. M. Han, C. Mahaptra, H. W. Kim, and J. C. Knowles, "Sol-Gel Based Materials for Biomedical Applications," Prog. Mater. Sci., 77 1-79 (2016).   DOI
85 V. G. Parale, D. B. Mahadik, M. S. Kavale, A. V. Rao, P. B. Wagh, and S. C. Gupta, "Potential Application of Silica Aerogel Granules for Cleanup of Accidental Spillage of Various Organic Liquids," Soft Nanosci. Lett., 1 [04] 97-104 (2011).   DOI
86 J. L. Gurav, A. V. Rao, D. Y. Nadargi, and H. H. Park, "Ambient Pressure Dried TEOS-based Silica Aerogels: Good Absorbents of Organic Liquids," J. Mater. Sci., 45 [2] 503-10 (2010).   DOI
87 V. G. Parale, D. B. Mahadik, M. S. Kavale, S. A. Mahadik, A. V. Rao, and S. Mullens, "Sol-Gel Preparation of PTMS Modified Hydrophobic and Transparent Silica Coatings," J. Porous Mater., 20 [4] 733-39 (2013).   DOI
88 T. Graham, "On the Molecular Mobility of Gases," J. Chem. Soc., 17 334-62 (1864).   DOI
89 T. Shimizu, K. Kanamori, A. Maeno, H. Kaji, and K. Nakanishi, "Transparent Ethylene-Bridged Polymethylsiloxane Aerogels and Xerogels with Improved Bending Flexibility," Langmuir, 32 [50] 13427-34 (2016).   DOI
90 G. Hayase, K. Kanamori, M. Fukuchi, H. Kaji, and K. Nakanishi, "Facile Synthesis of Marshmallow-like Macroporous Gels Usable under Harsh Conditions for the Separation of Oil and Water," Angew. Chem., Int. Ed., 52 [7] 1986-89 (2013).   DOI
91 Y. Aoki, T. Shimizu, K. Kanamori, A. Maeno, H. Kaji, and K. Nakanishi, "Low-Density, Transparent Aerogels and Xerogels Based on Hexylene-Bridged Polysilsesquioxane with Bendability," J. Sol-Gel Sci. Technol., 81 [1] 42-51 (2017).   DOI
92 S. A. Mahadik, F. Pedraza, V. G. Parale, and H. H. Park, "Organically Modified Silica Aerogel with Different Functional Silylating Agents and Effect on their Physico-Chemical Properties," J. Non-Cryst. Solids, 453 164-71 (2016).   DOI
93 D. Y. Nadargi, S. S. Latthe, and A. V. Rao, "Effect of Post-Treatment (Gel Aging) on the Properties of Methyltrimethoxysilane Based Silica Aerogels Prepared by Two-Step Sol-Gel Process", J. Sol-Gel Sci. Technol., 49 [1] 53-9 (2009).   DOI
94 P. R. Aravind, P. Niemeyer, and L. Ratke, "Novel Flexible Aerogels Derived from Methyltrimethoxysilane/3-(2,3-epoxypropoxy)Propyltrimethoxysilane Co-Precursor," Microporous Mesoporous Mater., 181 111-15 (2013).   DOI
95 G. Hayase, K. Kanamori, K. Kazuki, and T. Hanada, "Synthesis of New Flexible Aerogels from MTMS/DMDMS via Ambient Pressure Drying," IOP Conf. Ser.: Mater. Sci. Eng., 18 [3] 032013 (2011).
96 M. Du, N. Mao, and S. J. Russell, "Control of Porous Structure in Flexible Silicone Aerogels Produced from Methyltrimethoxysilane (MTMS): the Effect of Precursor Concentration in Sol-Gel Solutions," J. Mater. Sci., 51 [2] 719-31 (2016).   DOI
97 T. Matias, C. Varino, H. C. de Sousa, M. E. M. Braga, A. Portugal, J. F. J. Coelho, and L. Duraes, "Novel Flexible, Hybrid Aerogels with Vinyl and Methyltrimethoxysilane in the Underlying Silica Structure," J. Mater. Sci., 51 [14] 6781-92 (2016).   DOI
98 S. S. Kistler, "Coherent Expanded Aerogels and Jellies," Nature, 127 741 (1931).
99 N. D. Kaushika and K. Sumathy, "Solar Transparent Insulation Materials: A Review," Renew. Sustainable Energy Rev., 7 [4] 317-51 (2003).   DOI
100 B. N. Nguyen, M. A. B. Meador, A. Meodoro, V. Arendt, J. Randall, L. McCorkie, and B. Shonwiler, "Elastic Behavior of Methyltrimethoxysilane Based Aerogels Reinforced with Tri-Isocyanate," ACS Appl. Mater. Interfaces, 2 [5] 1450-45 (2010).
101 L. Zhong, X. Chen, H. Song, K. Guo, and Z. Hu, "Highly Flexible Silica Aerogels Derived from Methyltriethoxysilane and Polydimethylsiloxane," New J. Chem., 39 [10] 7832-38 (2015).   DOI
102 S. Iswar, W. J. Malfait, S. Balog, F. Winnefeld, M. Lattuada, and M. M. Koebel, "Effect of Aging on Silica Aerogel Properties," Microporous Mesoporous Mater., 241 293-302 (2017).   DOI
103 H. Omranpur, A. Dourbash, and S. Motahari, "Mechanical Properties Improvement of Silica Aerogel through Aging: Role of Solvent Type, Time and Temperature," AIP Conf. Proc., 1593 [1] 298-302 (2014).
104 T. L. Metroke, R. L. Parkhil, and E. T. Knobbe, "Passivation of Metal Alloys Using Sol-Gel-Derived Materials − A Review," Prog. Org. Coat., 41 [4] 233-38 (2001).   DOI
105 L. M. Rueda, C. Nieves, C. A. Hernandez Barrios, A. E. Coy, and F. Viejo, "Design of TEOS-GPTMS Sol-Gel Coatings on Rare-Earth Magnesium Alloys Employed in the Manufacture of Orthopaedic Implants," J. Phys.: Conf. Ser., 687 012013 (2016).   DOI
106 S. Kim, A. Cho, S. Kim, W. Cho, M. H. Chung, F. S. Kim, and J. H. Kim, "Multi-Purpose Overcoating Layers Based on PVA/Silane Hybrid Composites for Highly Transparent, Flexible, and Durable AgNW/PEDOT:PSS Films," RSC Adv., 6 [23] 19280-87 (2016).   DOI
107 U. K. H. Bangi, C. S. Park, S. Baek, and H. H. Park, "Improvement in Optical and Physical Properties of TEOS Based Aerogels Using Acetonitrile via Ambient Pressure Drying," Ceram. Int., 38 [8] 6883-88 (2012).   DOI
108 Y. Pan, S. He, L. Gong, X. Cheng, C. Li, Z. Li, Z. Liu, and H. Zhang, "Low Thermal-Conductivity and High Thermal Stable Silica Aerogels Based on MTMS/Water-Glass Co-Precursor Prepared by Freeze Drying," Mater. Des., 113 246-53 (2017).   DOI
109 U. K. H. Bangi, M. S. Kavale, S. Baek, and H. H. Park, "Synthesis of MWCNT's Doped Sodium Silicate Based Aerogels by Ambient Pressure Drying," J. Sol-Gel Sci. Technol., 62 [2] 201-7 (2012).   DOI
110 V. G. Parale, D. B. Mahadik, S. A. Mahadik, M. S. Kavale, A. V. Rao, and P. B. Wagh, "Wettability Study of Surface Modified Silica Aerogels with Different Silylating Agents," J. Sol-Gel Sci. Technol., 63 [3] 573-79 (2012).   DOI
111 P. B. Sarawade, J. K. Kim, H. K. Kim, and H. T. Kim, "High Specific Surface Area TEOS-Based Aerogels with Large Pore Volume Prepared at an Ambient Pressure," Appl. Surf. Sci., 254 [2] 574-79 (2007).   DOI
112 G. S. Kim, S. H. Hyun, and H. H. Park, "Synthesis of Low-Dielectric Silica Aerogel Films by Ambient Drying," J. Am. Ceram. Soc., 84 [2] 453-55 (2001).   DOI
113 S. Haereid, E. Nilsen, V. Ranum, and M. A. Einarsrud, "Thermal and Temporal Aging of Two Step Acid-Base Catalyzed Silica Gels in Water/Ethanol Solutions," J. Sol-Gel Sci. Technol., 8 [1] 153-57 (1997).
114 N. K. On, A. A. Rashid, M. M. M. Nazlan, and H. Hamdan, "Thermal and Mechanical Behavior of Natural Rubber Latex-Silica Aerogel Film," J. Appl. Polym. Sci., 124 [4] 3108-16 (2012).   DOI
115 T. Woignier, J. Phalippou, H. Hdach, and G. W. Scherer, "Mechanical Properties of Silica Alcogels and Aerogels," pp. in 1087-99 in MRS Proceedings, Cambridge University Press, 1990.
116 U. K. H. Bangi, A. V. Rao, and A. P. Rao, "A New Route for Preparation of Sodium-Silicate-Based Hydrophobic Silica Aerogels via Ambient-Pressure Drying," Sci. Technol. Adv. Mater., 9 [3] 035006 (2008).   DOI
117 M. A. Einarsrud and E. Nilsen, "Thermal and Temporal Aging of Silica Gels in Monomer Solutions," J. Sol-Gel Sci. Technol., 13 [1] 317-22 (1998).   DOI
118 M. A. Einarsrud, E. Nilsen, A. Rigacci, G. M. Pajonk, S. Buathier, D. Valette, M. Durant, B. Cevalier, P. Nitz, and F. E. Dolle, "Strengthening of Silica Gels and Aerogels by Washing and Aging Processes," J. Nom-Cryst. Solids., 285 [1] 1-7 (2001).   DOI
119 R. A. Strom, Y. Masmoudi, A. Rigacci, G. Petermann, L. Gulberg, B. Chevalier, and M .A. Einarsrud, "Strengthening and Aging of Wet Silica Gels for Up-Scaling of Aerogel Preparation," J. Sol-Gel Sci. Technol., 41 [3] 291-98 (2007).   DOI
120 Z. Li, L. Gong, X. Cheng, S. He, C. Li, and H. Zhang, "Flexible Silica Aerogel Composites Strengthened with Aramid Fibers and their Thermal Behavior," Mater. Design, 99 349-55 (2016).   DOI
121 M. Shi, C. Tang, X. Yang, J. Zhou, F. Jia, Y. Han, and Z. Li, "Superhydrophobic Silica Aerogels Reinforced with Polyacrylonitrile Fibers for Adsorbing Oil from Water and Oil Mixtures," RSC Adv., 7 [7] 4039-45 (2017).   DOI
122 X. Yang, Y. Sun, D. Shi, and J. Liu, "Experimental Investigation on Mechanical Properties of a Fiber-Reinforced Silica Aerogel Composite," Mater. Sci. Eng., A, 528 [13] 4830-36 (2011).   DOI
123 S. A. Mahadik, D. B. Mahadik, M. S. Kavale, V. G. Parale, P. B. Wagh, H. C. Barshilia, S. C. Gupta, N. D. Hegde, and A. V. Rao, "Thermally Stable and Transparent Superhydrophobic Sol-Gel Coatings by Spray Method," J. Sol-Gel Sci. Technol., 63 [3] 580-86 (2012).   DOI
124 D. J. Boday, R. J. Stover, B. Muriithi, and D. A. Loy, "Mechanical Properties of Hexylene- and Phenylene-Bridged Polysilsesquioxane Aerogels and Xerogels," J. Sol-Gel Sci. Technol., 61 144-50 (2012).   DOI
125 D. A. Loy and K. J. Shea, "Bridged Polysilsesquioxanes. Highly Porous Hybrid Organic-Inorganic Materials," Chem. Rev., 95 [5] 1431-22 (1995).   DOI
126 D. Lin, L. Hu, S. H. Tolbert, Z. Li, and D. A. Loy, "Controlling Nanostructure in Periodic Mesoporous Hexylene-Bridged Polysilsesquioxanes," J. Non-Cryst. Solids, 419 6-11 (2015).   DOI
127 F. Zou, P. Yue, X. Zheng, D. Tang, W. Fu, and Z. Li, "Robust and Superhydrophobic Thiourethane Bridged Polysilsesquioxane Aerogels as Potential Thermal Insulation Materials," J. Mater. Chem. A, 4 [28] 10801-5 (2016).   DOI
128 D. B. Mahadik, A. V. Rao, A. P. Rao, P. B. Wagh, S. V. Ingle, and S. C. Gupta, "Effect of Concentration of Trimethylchlorosilane (TMCS) and Hexamethyldisilazane (HMDZ) Silylating Agents on Surface Free Energy of Silica Aerogels," J. Colloid Interface Sci., 356 [1] 298-302 (2011).   DOI
129 H. Maleki, L. Duraes, and A. Portugal, "Synthesis of Mechanically Reinforced Silica Aerogels via Surface-Initiated Reversible Additionfragmentation Chain Transfer (RAFT) Polymerization," J. Mater. Chem. A, 3 1594-600 (2015).   DOI
130 B. N. Nguyen, M. A. B. Meador, M. E. Tousley, B. Shonkwiler, L. McCorkie, D. A. Scheiman, and A. Palczer, "Tailoring Elastic Properties of Silica Aerogels Cross-Linked with Polystyrene," ACS Appl. Mater. Interfaces, 1 [3] 621-30 (2009).   DOI
131 H. Guo, B. N. Nguyen, L. S. McCorkie, B. Shonwalker, and M. A. B. Meador, "Elastic Low Density Aerogels Derived from Bis[3-(Triethoxysilyl)Propyl]Disulfide, Tetramethylorthosilicate and Vinyltrimethoxysilane via a Two-Step Process," J. Mater. Chem., 19 [47] 9054-62 (2009).   DOI
132 M. Venkataraman, R. Mishra, T. M. Kotresh, J. Militky, and H. Jamshid, "Aerogels for Thermal Insulation in High-Performance Textiles," Text. Prog., 48 [2] 55-118 (2016).   DOI
133 B. C. Dunn, P. Cole, D. Covington, M. C. Webster, R. J. Pugmire, R. C. Ernst, E. M. Eyring, N. Shah, and G. P. Huffman, "Silica Aerogel Supported Catalysts for Fischer-Tropsch Synthesis," Appl. Catal., A, 278 [2] 233-38 (2005).   DOI
134 A. V. Rao, N. D. Hegde, and H. Hirashima, "Absorption and Desorption of Organic Liquids in Elastic Superhydrophobic Silica Aerogels," J. Colloid Interface Sci., 305 [1] 127-32 (2007).
135 D. Y. Nadargi, S. S. Latthe, H. Hirashima, and A. V. Rao, "Studies on Rheological Properties of Methyltriethoxysilane (MTES) Based Flexible Superhydrophobic Silica Aerogels," Microporous Mesoporous Mater., 117 [3] 617-26 (2009).   DOI
136 Y. Yu, X. Wu, D. Guo, and J. Fang, "Preparation of Flexible, Hydrophobic, and Oleophilic Silica Aerogels Based on a Methyltriethoxysilane Precursor," J. Mater. Sci., 49 [22] 7715-22 (2014).   DOI
137 S. A. Mahadik, D. B. Mahadik, V. G. Parale, P. B. Wagh, S. C. Gupta, and A. V. Rao, "Recoverable and Thermally Stable Superhydrophobic Silica Coating," J. Sol-Gel Sci. Technol., 62 [3] 490-94 (2012).   DOI
138 S. A. Mahadik, F. D. Pedraza, B. P. Relekar, V. G. Parale, G. M. Lohar, and S. S. Thorat, "Synthesis and Characterization of Superhydrophobic-Superoleophilic Surface," J. Sol-Gel Sci. Technol., 78 [3] 475-81 (2016).   DOI