Abstract
Here, we overview the developments in the past decade made on organic–inorganic hybrid aerogels and xerogels based on silicone (polyorganosiloxanes) through persistent works by the authors to increase the mechanical strength and flexibility and add functionality. Polymethylsilsesquioxane (PMSQ, CH3SiO3/2) has been found to show unusual strength and flexibility against compression, and their bending properties can also be improved by several strategies. Silicone-based networks with organic bridges between inorganic moieties are also beneficial for these improvements. In particular, organic bridges with a higher fraction and more extended length have been found to allow higher durability against large deformations. In addition, functional groups such as vinyl, chloromethyl, and amino can readily be introduced by starting from organoalkoxysilanes with these functional substituents (e.g., FG−Si(OR)3 or (RO)3Si−FG−Si(OR)3, where FG shows an organic substituent containing functional groups and R is typically methyl or ethyl), and other functional groups such as carboxyl can be introduced by post-gelation modifications on the pre-installed FG in the network. Possibilities in applications such as thermal insulators, photoluminescent media, and photocatalysts are also discussed.
Highlights
-
Silicone-based organic–inorganic hybrid aerogels developed by the authors are overviewed.
-
Improved mechanical flexibility allows ambient pressure drying to yield aerogel-like xerogels.
-
Reactive organic functional groups can be introduced in the hybrid networks.
Similar content being viewed by others
References
Brinker CJ, Scherer GW (1990) Sol-gel science: the physics and chemistry of sol-gel processing. Academic Press, San Diego
Aegerter MA, Leventis N, Koebel MM (eds) (2011) Aerogels handbook. Springer, New York
Soleimani Dorcheh A, Abbasi MH (2008) Silica aerogel; synthesis, properties and characterization. J Mater Process Technol 199:10–26
Novak BM, Auerbach D, Verrier C (1994) Low-density, mutually interpenetrating organic-inorganic composite materials via supercritical drying techniques. Chem Mater 6:282–286
Ayers MR, Hunt AJ (2001) Synthesis and properties of chitosan-silica hybrid aerogels. J Non-Cryst Solids 285:123–127
Leventis N, Sotiriou-Leventis C, Zhang G, Rawashdeh A-MM (2002) Nanoengineering strong silica aerogels. Nano Lett 2:957–960
Venkateswara Rao A, Bhagat SD, Hirashima H, Pajonk GM (2006) Synthesis of flexible silica aerogels using methyltrimethoxysilane (MTMS) precursor. J Colloid Interface Sci 300:279–285
Boday DJ, Stover RJ, Muriithi B, Loy DA (2012) Mechanical properties of hexylene- and phenylene-bridged polysilsesquioxane aerogels and xerogels. J Sol-Gel Sci Technol 61:144–150
Kanamori K, Nakanishi K (2011) Controlled pore formation in organotrialkoxysilane-derived hybrids: from aerogels to hierarchically porous monoliths. Chem Soc Rev 40:754–770
Shimizu T, Kanamori K, Nakanishi K (2017) Silicone-based organic–inorganic hybrid aerogels and xerogels. Chem Eur J 23:5176–5187
Kanamori K, Aizawa M, Nakanishi K, Hanada T (2007) New transparent methylsilsesquioxane aerogels and xerogels with improved mechanical properties. Adv Mater 19:1589–1593
Venkateswara Rao A, Pajonk GM (2001) Effect of methyltrimethoxysilane as a co-precursor on the optical properties of silica aerogels. J Non Cryst Solids 285:202–209
Hayase G, Kanamori K, Nakanishi K (2012) Structure and properties of polymethylsilsesquioxane aerogels synthesized with surfactant n-hexadecyltrimethylammonium chloride. Microporous Mesoporous Mater 158:247–252
Kurahashi M, Kanamori K, Takeda K, Kaji H, Nakanishi K (2012) Role of block copolymer surfactant on the pore formation in methylsilsesquioxane aerogel systems. RSC Adv 2:7166–7173
Hayase G, Kanamori K, Maeno A, Kaji H, Nakanishi K (2016) Dynamic spring-back behavior in evaporative drying of polymethylsilsesquioxane monolithic gels for low-density transparent thermal superinsulators. J Non Cryst Solids 434:115–119
Smith DM, Stein D, Anderson JM, Ackerman W (1995) Preparation of low-density xerogels at ambient pressure. J Non Cryst Solids 186:104–112
Liu C (2007) Recent developments in polymer MEMS. Adv Mater 19:3783–3790
Duan G, Jiang S, Moss T, Agarwal S, Greiner A (2016) Ultralight open cell polymer sponges with advanced properties by PPX CVD coating. Polym Chem 7:2759–2764
Hayase G, Kanamori K, Nakanishi K (2011) New flexible aerogels and xerogels derived from methyltrimethoxysilane/dimethyldimethoxysilane co-precursors. J Mater Chem 21:17077–17079
Hayase G, Kanamori K, Fukuchi M, Kaji H, Nakanishi K (2013) Facile synthesis of marshmallow-like macroporous gels usable under harsh conditions for the separation of oil and water. Angew Chem Int Ed 52:1986–1989
Hayase G, Kanamori K, Hasegawa G, Maeno A, Kaji H, Nakanishi K (2013) A superamphiphobic macroporous silicone monolith with marshmallow-like flexibility. Angew Chem Int Ed 52:10788–10791
Hayase G, Kanamori K, Abe K, Yano H, Maeno A, Kaji H, Nakanishi K (2014) Polymethylsilsesquioxane-cellulose nanofiber biocomposite aerogels with high thermal insulation, bendability, and superhydrophobicity. ACS Appl Mater Interfaces 6:9466–9471
Kobayashi Y, Saito T, Isogai A (2014) Aerogels with 3D ordered nanofiber skeletons of liquid-crystalline nanocellulose derivatives as tough and transparent insulators. Angew Chem Int Ed Engl 53:10394–10397
Takeshita S, Yoda S (2015) Chitosan aerogels: transparent, flexible thermal insulators. Chem Mater 27:7569–7572
Aoki Y, Shimizu T, Kanamori K, Maeno A, Kaji H, Nakanishi K (2017) Low-density, transparent aerogels and xerogels based on hexylene-bridged polysilsesquioxane with bendability. J Sol-Gel Sci Technol 81:42–51
Shimizu T, Kanamori K, Maeno A, Kaji H, Nakanishi K (2016) Transparent ethylene-bridged polymethylsiloxane aerogels and xerogels with improved bending flexibility. Langmuir 32:13427–13434
Shimizu T, Kanamori K, Maeno A, Kaji H, Doherty CM (2017) Transparent ethenylene-bridged polymethylsiloxane aerogels: mechanical flexibility and strength and availability for addition reaction. Langmuir 33:4543–4550
Shimizu T, Kanamori K, Maeno A, Kaji H, Doherty CM, Falcaro P, Nakanishi K (2016) Transparent, highly insulating polyethyl- and polyvinylsilsesquioxane aerogels: mechanical improvements by vulcanization for ambient pressure drying. Chem Mater 28:6860–6868
Zu G, Shimizu T, Kanamori K, Zhu Y, Maeno A, Kaji H, Shen J, Nakanishi K (2018) Transparent, superflexible doubly cross-linked polyvinylpolymethylsiloxane aerogel superinsulators via ambient pressure drying. ACS Nano 12:521–532
Gunji T, Okonogi H, Sakan T, Takamura N, Arimitsu K, Abe Y (2003) Preparation and properties of organic–inorganic hybrid gel films based on polyvinylpolysilsesquioxane synthesized from trimethoxy(vinyl)silane. Appl Organo Chem 17:580–588
Gunji T, Kawaguchi Y, Okonogi H, Sakan T, Arimitsu K, Abe Y (2005) Preparation and properties of organic-inorganic hybrid gel films based on polyvinylpolysilsesquioxane synthesized from trimethoxy(vinyl)silane. J Sol-Gel Sci Technol 33:9–13
Zu G, Kanamori K, Shimizu T, Zhu Y, Maeno A, Kaji H, Nakanishi K, Shen J (2018) A versatile double-crosslinking approach to transparent, machinable, super-compressible, highly bendable aerogel thermal superinsulators Chem Mater 30:2759–2770
Sanda S, Kanamori K, Takei T, Tashiro K (2018) Aerogel photocatalyst composed of transparent mesoporous polymethylsilsesquioxane softly post-modified with a visible-light-absorbing metal complex. ChemNanoMat 4:52–55
Shimizu T, Kanamori K, Nakanishi K (2017) Transparent polyvinylsilsesquioxane aerogels: investigations on synthetic parameters and surface modification. J Sol-Gel Sci Technol 82:2–14
Ketelson HA, Brook MA, Pelton RH (1995) Sterically stabilized silica colloids: radical grafting of poly(methyl methacrylate) and hydrosilylative grafting of silicones to functionalized silica. Polym Adv Technol 6:335–344
Cicero RL, Linford MR, Chidsey CED (2000) Photoreactivity of unsaturated compounds with hydrogen-terminated silicon(111). Langmuir 16:5688–5695
Kimura T, Shimizu T, Kanamori K, Maeno A, Kaji H, Nakanishi K (2017) Aerogels from chloromethyltrimethoxysilane and their functionalizations. Langmuir 33:13841–13848
Dong Y, Wang R, Li H, Shao J, Chi Y, Lin X, Chen G (2012) Polyamine-functionalized carbon quantum dots for chemical sensing. Carbon N Y 50:2810–2815
Keppeler M, Hüsing N (2011) Space-confined click reactions in hierarchically organized silica monoliths. New J Chem 35:681
Meador MAB, Fabrizio EF, Ilhan F, Dass A, Zhang G, Vassilaras P, Johnston JC, Leventis N (2005) Cross-linking amine-modified silica aerogels with epoxies: mechanically strong lightweight porous materials. Chem Mater 17:1085–1098
Cui S, Cheng W, Shen X, Fan M, Russell A, Wu Z, Yi X (2011) Mesoporous amine-modified SiO2 aerogel: a potential CO2 sorbent. Energy Environ Sci 4:2070–2074
Boury B, Corriu JP (2002) Auto-organisation of hybrid organic–inorganic materials prepared by sol–gel process. Chem Commun 8:795–802
Kramer SJ, Rubio-Alonso F, Mackenzie JD (1996) Organically modified silicate aerogels, ‘aeromosils’. Mater Res Soc Symp Proc 435:295–300
Hüsing N, Schubert I (1997) Organofunctional silica aerogels. J Sol-Gel Sci Technol 8:807–812
Acknowledgements
This study has been performed under financial supports from Advanced Low Carbon Technology Research and Development Program (ALCA, Japan Science and Technology Agency) and JSPS KAKENHI Grant Number 17K06015.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Rights and permissions
About this article
Cite this article
Kanamori, K., Ueoka, R., Kakegawa, T. et al. Hybrid silicone aerogels toward unusual flexibility, functionality, and extended applications. J Sol-Gel Sci Technol 89, 166–175 (2019). https://doi.org/10.1007/s10971-018-4804-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10971-018-4804-x