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Parale VG, Kim T, Choi H, Phadtare VD, Dhavale RP, Kanamori K, Park HH. Mechanically Strengthened Aerogels through Multiscale, Multicompositional, and Multidimensional Approaches: A Review. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2307772. [PMID: 37916304 DOI: 10.1002/adma.202307772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 10/29/2023] [Indexed: 11/03/2023]
Abstract
In recent decades, aerogels have attracted tremendous attention in academia and industry as a class of lightweight and porous multifunctional nanomaterial. Despite their wide application range, the low mechanical durability hinders their processing and handling, particularly in applications requiring complex physical structures. "Mechanically strengthened aerogels" have emerged as a potential solution to address this drawback. Since the first report on aerogels in 1931, various modified synthesis processes have been introduced in the last few decades to enhance the aerogel mechanical strength, further advancing their multifunctional scope. This review summarizes the state-of-the-art developments of mechanically strengthened aerogels through multicompositional and multidimensional approaches. Furthermore, new trends and future directions for as prevailed commercialization of aerogels as plastic materials are discussed.
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Affiliation(s)
- Vinayak G Parale
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, South Korea
| | - Taehee Kim
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, South Korea
| | - Haryeong Choi
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, South Korea
| | - Varsha D Phadtare
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, South Korea
| | - Rushikesh P Dhavale
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, South Korea
| | - Kazuyoshi Kanamori
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan
| | - Hyung-Ho Park
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, South Korea
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Nagendra B, Cozzolino A, Acocella MR, Daniel C, Rizzo P, Guerra G. Hydrogen Bonded Dimer of an Alcohol with the Derived Carboxylic Acid Triggering their Sorption by Nanoporous-crystalline PPO Films. Chemistry 2023; 29:e202301441. [PMID: 37401565 DOI: 10.1002/chem.202301441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 06/29/2023] [Indexed: 07/05/2023]
Abstract
Films exhibiting nanoporous-crystalline (NC) phases of poly(2,6-dimethyl-1,4-phenylene) oxide (PPO), which are highly effective to absorb apolar organic guest molecules, are also able to absorb polar molecules (like alcohols and carboxylic acids) but only from concentrated organic solutions. NC PPO films, which do not absorb alcohols and carboxylic acids from diluted aqueous solutions, exhibits a huge uptake (even above 30 wt %) of benzyl alcohol (BAL) and benzoic acid (BA), if BA is obtained by spontaneous room temperature oxidation of BAL in aqueous solution. This phenomenon is rationalized by an easy uptake, mainly by the PPO intrahelical crystalline empty channels, of a BAL/BA 1/1 hydrogen-bonded dimer. This huge uptake of BAL/BA dimer by NC PPO films, which is also fast for films exhibiting the orientation of the crystalline helices perpendicular to the film plane (c⊥ orientation), can be exploited for purification of water from BAL, when present in traces. High and fast sorption of a hydrogen bonded dimer and negligible sorption of the two separate compounds is possibly unprecedented for absorbent materials.
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Affiliation(s)
- Baku Nagendra
- Dipartimento di Chimica e Biologia "A.Zambelli", INSTM Research Unit, Università di Salerno, Via Giovanni Paolo II 132, 84084, Fisciano, SA, Italy
| | - Antonietta Cozzolino
- Dipartimento di Chimica e Biologia "A.Zambelli", INSTM Research Unit, Università di Salerno, Via Giovanni Paolo II 132, 84084, Fisciano, SA, Italy
| | - Maria Rosaria Acocella
- Dipartimento di Chimica e Biologia "A.Zambelli", INSTM Research Unit, Università di Salerno, Via Giovanni Paolo II 132, 84084, Fisciano, SA, Italy
| | - Christophe Daniel
- Dipartimento di Chimica e Biologia "A.Zambelli", INSTM Research Unit, Università di Salerno, Via Giovanni Paolo II 132, 84084, Fisciano, SA, Italy
| | - Paola Rizzo
- Dipartimento di Chimica e Biologia "A.Zambelli", INSTM Research Unit, Università di Salerno, Via Giovanni Paolo II 132, 84084, Fisciano, SA, Italy
| | - Gaetano Guerra
- Dipartimento di Chimica e Biologia "A.Zambelli", INSTM Research Unit, Università di Salerno, Via Giovanni Paolo II 132, 84084, Fisciano, SA, Italy
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Gotad PS, Kafle N, Miyoshi T, Jana SC. Meso- and Macroporous Polymer Gels for Efficient Adsorption of Block Copolymer Surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:13558-13568. [PMID: 36279503 DOI: 10.1021/acs.langmuir.2c02198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
An understanding of surfactant adsorption at solid-liquid interfaces is important for solving many technological problems. This work evaluates surfactant adsorption abilities of high surface area (200-600 m2/g), high porosity (>90%), hierarchically structured open pore polymer gels. Specifically, the interactions of a nonionic block copolymer surfactant, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO), with three polymer gels, namely, syndiotactic polystyrene (sPS), polyimide (PI), and polyurea (PUA) offering different surface energy values, are evaluated at surfactant concentrations below and well above the critical micelle concentration (CMC). Two distinct surfactant adsorption behaviors are identified from the surface tension and nuclear magnetic resonance data. At concentrations below CMC, the surfactant molecules adsorb as a monolayer on polymer strands, inferred from the Langmuir-type adsorption isotherm, with the adsorbed amount increasing with the specific surface area of the polymer gel. The study reports for the first time that the gels show a strong surfactant adsorption above CMC, with the effective surfactant concentration in the gel reaching several folds of the CMC values. The effective surfactant concentration in the gel is analyzed using surfactant micelle size, polymer surface energy, and pore size of the gel. The findings of this study may have strong implications in liquid-liquid separation problems and in the removal of small dye molecules, heavy metal ions, and living organisms from aqueous streams.
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Affiliation(s)
- Pratik S Gotad
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio44325, United States
| | - Navin Kafle
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio44325, United States
| | - Toshikazu Miyoshi
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio44325, United States
| | - Sadhan C Jana
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio44325, United States
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Membrane synthesis via in-situ pore formation in silica gels through dynamic miscibility with soybean oil. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2021.128183] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Leventis N. Polyurea Aerogels: Synthesis, Material Properties, and Applications. Polymers (Basel) 2022; 14:969. [PMID: 35267798 PMCID: PMC8912528 DOI: 10.3390/polym14050969] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 02/23/2022] [Accepted: 02/24/2022] [Indexed: 12/10/2022] Open
Abstract
Polyurea is an isocyanate derivative, and comprises the basis for a well-established class of polymeric aerogels. Polyurea aerogels are prepared either via reaction of multifunctional isocyanates with multifunctional amines, via reaction of multifunctional isocyanates and water, or via reaction of multifunctional isocyanates and mineral acids. The first method is the established one for the synthesis of polyurea, the third is a relatively new method that yields polyurea doped with metal oxides in one step, while the reaction of isocyanates with water has become the most popular route to polyurea aerogels. The intense interest in polyurea aerogels can be attributed in part to the low cost of the starting materials-especially via the water method-in part to the extremely broad array of nanostructural morphologies that allow study of the nanostructure of gels as a function of synthetic conditions, and in part to the broad array of functional properties that can be achieved even within a single chemical composition by simply adjusting the synthetic parameters. In addition, polyurea aerogels based on aromatic isocyanates are typically carbonizable materials, making them highly competitive alternatives to phenolic aerogels as precursors of carbon aerogels. Several types of polyurea aerogels are already at different stages of commercialization. This article is a comprehensive review of all polyurea-based aerogels, including polyurea-crosslinked oxide and biopolymer aerogels, from a fundamental nanostructure-material properties perspective, as well as from an application perspective in thermal and acoustic insulation, oil adsorption, ballistic protection, and environmental cleanup.
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Affiliation(s)
- Nicholas Leventis
- Aspen Aerogels, Inc. 30 Forbes Road, Bldg B, Northborough, MA 01532, USA
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Zhao Z, Cui Y, Kong Y, Ren J, Jiang X, Yan W, Li M, Tang J, Liu X, Shen X. Thermal and Mechanical Performances of the Superflexible, Hydrophobic, Silica-Based Aerogel for Thermal Insulation at Ultralow Temperature. ACS APPLIED MATERIALS & INTERFACES 2021; 13:21286-21298. [PMID: 33904728 DOI: 10.1021/acsami.1c02910] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A superflexible hydrophobic silica-based aerogel (FHSA) was prepared via a facile sol-gel process and ambient pressure drying method. The FHSA was treated at different temperatures varying from -196 to 450 °C to evaluate its thermal and mechanical performances. The evolutions of the physical property, hydrophobicity, microstructure, pore structure, and chemical structure of the FHSA with the various treatment temperatures were investigated comprehensively. The structure of the FHSA did not show an obvious change after treatment in the liquid nitrogen. The bulk density of the FHSA increased from 0.047 to 0.077 g cm-3 when the thermal treatment temperature increased from 25 to 450 °C. The specific surface area and pore volume of the FHSA increased with the treatment temperature owing to the decomposition of the organic moieties. The Fourier transform infrared spectra showed that the methyl groups in the FHSA had excellent thermostability up to 400 °C. The water contact angles of the FHSA after treatment at -196, 25, 200, 300, 350, 400, and 450 °C were 131, 151, 162, 150, 132, 119, and 34°, respectively. The thermal conductivity of the FHSA at a low temperature of -10 °C was 0.022 W m-1 K-1. The reversible deformation rate of the FHSA was more than 80% within 100 compression cycles. After treatment in liquid nitrogen, the reversible deformation rate of the FHSA remained at 50%. The synthesis method of the FHSA is simple, the resulting FHSA showed good performance both in thermostability and flexibility, and it is promisingly applied for thermal insulation and sealing in ultralow-temperature environments.
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Affiliation(s)
- Zhiyang Zhao
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing 210009, PR China
- Suqian Advanced Materials Industry Technology Innovation Center of Nanjing Tech University, Suqian 223800, PR China
| | - Yi Cui
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing 210009, PR China
- Suqian Advanced Materials Industry Technology Innovation Center of Nanjing Tech University, Suqian 223800, PR China
| | - Yong Kong
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing 210009, PR China
- Suqian Advanced Materials Industry Technology Innovation Center of Nanjing Tech University, Suqian 223800, PR China
| | - Jian Ren
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing 210009, PR China
- Suqian Advanced Materials Industry Technology Innovation Center of Nanjing Tech University, Suqian 223800, PR China
| | - Xing Jiang
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing 210009, PR China
- Suqian Advanced Materials Industry Technology Innovation Center of Nanjing Tech University, Suqian 223800, PR China
| | - Wenqian Yan
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing 210009, PR China
- Suqian Advanced Materials Industry Technology Innovation Center of Nanjing Tech University, Suqian 223800, PR China
| | - Mengyuan Li
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing 210009, PR China
- Suqian Advanced Materials Industry Technology Innovation Center of Nanjing Tech University, Suqian 223800, PR China
| | - Jinqiong Tang
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing 210009, PR China
- Suqian Advanced Materials Industry Technology Innovation Center of Nanjing Tech University, Suqian 223800, PR China
| | - Xueqiang Liu
- Institute of System Engineering, Beijing 100010, PR China
| | - Xiaodong Shen
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing 210009, PR China
- Suqian Advanced Materials Industry Technology Innovation Center of Nanjing Tech University, Suqian 223800, PR China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009, PR China
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Jin C, Kulkarni A, Teo N, Jana SC. Fabrication of Pill-Shaped Polyimide Aerogel Particles Using Microfluidic Flows. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.0c05424] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chenxi Jin
- School of Polymer Science and Polymer Engineering, The University of Akron, 250 South Forge Street, Akron, Ohio 44325-0301, United States
| | - Akshata Kulkarni
- School of Polymer Science and Polymer Engineering, The University of Akron, 250 South Forge Street, Akron, Ohio 44325-0301, United States
| | - Nicholas Teo
- School of Polymer Science and Polymer Engineering, The University of Akron, 250 South Forge Street, Akron, Ohio 44325-0301, United States
| | - Sadhan C. Jana
- School of Polymer Science and Polymer Engineering, The University of Akron, 250 South Forge Street, Akron, Ohio 44325-0301, United States
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Malakooti S, Zhao E, Tsao N, Bian N, Soni RU, Doulah ABMSU, Sotiriou-Leventis C, Leventis N, Lu H. Synthesis of aerogel foams through a pressurized sol-gel method. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.122925] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Chen J, Liu F, Li Y, Dou Y, Liu S, Xiao L. Self-standing zeolite foam monoliths with hierarchical micro-meso-macroporous structures. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200981. [PMID: 32968534 PMCID: PMC7481723 DOI: 10.1098/rsos.200981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
The zeolite monoliths were synthesized by a facile polymer scaffold template assisted hydrothermal method. The selected foam-shaped template of a polyurethane (PU) foam monolith, was used to prepare the self-standing zeolite foam (ZF) monolithic materials. The obtained ZF products can preserve the same size, shape and macroporous network structure of the original PU foam scaffold template, although the zeolite nano-crystallites had been fully substituted for the PU template to form the new skeleton struts and walls. The as-synthesized ZF products demonstrated abundant hierarchical porosity (involving triple micro-, meso- and macropores). Meanwhile, compared with the conventional zeolite powders, the self-standing ZF monolithic materials exhibited greater total pore volume and nearly three times higher mesopore volume, suggesting wider applications as catalysts, catalyst supports and adsorbents in industry.
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Affiliation(s)
- Jiawei Chen
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, People's Republic of China
| | - Fangfang Liu
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, People's Republic of China
| | - Yongfeng Li
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, People's Republic of China
| | - Yongshen Dou
- Foshan Shunde Kinglei Environment and Technology Co. Ltd, Foshan 528308, People's Republic of China
| | - Sanmao Liu
- Foshan Shunde Kinglei Environment and Technology Co. Ltd, Foshan 528308, People's Republic of China
| | - Liangjun Xiao
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, People's Republic of China
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Teo N, Jin C, Kulkarni A, Jana SC. Continuous fabrication of core-shell aerogel microparticles using microfluidic flows. J Colloid Interface Sci 2020; 561:772-781. [DOI: 10.1016/j.jcis.2019.11.053] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/12/2019] [Accepted: 11/14/2019] [Indexed: 11/25/2022]
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Liu J, Yang H, Liu K, Miao R, Fang Y. Gel-Emulsion-Templated Polymeric Aerogels for Water Treatment by Organic Liquid Removal and Solar Vapor Generation. CHEMSUSCHEM 2020; 13:749-755. [PMID: 31863570 DOI: 10.1002/cssc.201902970] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/01/2019] [Indexed: 06/10/2023]
Abstract
The importance of water cannot be overstated. It is the most important natural resource for our survival and development. The development of suitable materials for efficient water purification will provide a critical contribution for sustainable water use. In this context, a gel-emulsion-templated synthesis of a polymeric aerogel has been developed for water treatment. Owing to its hydrophobic nature, the aerogel shows high sorption (nearly 20 times its weight) for organic liquids, such as toluene, phenol, and nitrobenzene, and can be used to remove them from water. The aerogel shows low thermal conductivity (0.032 W m-1 K-1 ) and excellent light absorption efficiency (>92 %) after carbonization, which provides the possibility for the construction of an interfacial solar vapor generation system. The as-prepared materials are used to develop a two-step approach to remove both organic and inorganic contaminants (salts) from water. Importantly, the aerogel shows excellent reusability and high efficiency both for oil sorption and for solar vapor generation. Moreover, the low cost and easy scale-up of the preparation process lay a solid foundation for practical application. It is anticipated that the prepared aerogels would contribute not only to water purification but also to other related areas.
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Affiliation(s)
- Jianfei Liu
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, P.R. China
| | - Hui Yang
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, P.R. China
| | - Kaiqiang Liu
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, P.R. China
| | - Rong Miao
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, P.R. China
| | - Yu Fang
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, P.R. China
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13
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Yeo SJ, Oh MJ, Yoo PJ. Structurally Controlled Cellular Architectures for High-Performance Ultra-Lightweight Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1803670. [PMID: 30462862 DOI: 10.1002/adma.201803670] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 08/24/2018] [Indexed: 06/09/2023]
Abstract
The design and synthesis of cellular structured materials are of both scientific and technological importance since they can impart remarkably improved material properties such as low density, high mechanical strength, and adjustable surface functionality compared to their bulk counterparts. Although reducing the density of porous structures would generally result in reductions in mechanical properties, this challenge can be addressed by introducing a structural hierarchy and using mechanically reinforced constituent materials. Thus, precise control over several design factors in structuring, including the type of constituent, symmetry of architectures, and dimension of the unit cells, is extremely important for maximizing the targeted performance. The feasibility of lightweight materials for advanced applications is broadly explored due to recent advances in synthetic approaches for different types of cellular architectures. Here, an overview of the development of lightweight cellular materials according to the structural interconnectivity and randomness of the internal pores is provided. Starting from a fundamental study on how material density is associated with mechanical performance, the resulting structural and mechanical properties of cellular materials are investigated for potential applications such as energy/mass absorption and electrical and thermal management. Finally, current challenges and perspectives on high-performance ultra-lightweight materials potentially implementable by well-controlled cellular architectures are discussed.
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Affiliation(s)
- Seon Ju Yeo
- Nanophotonics Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Min Jun Oh
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Pil J Yoo
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
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Teo N, Jana SC. Surfactant-Free Process for the Fabrication of Polyimide Aerogel Microparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:2303-2312. [PMID: 30650304 DOI: 10.1021/acs.langmuir.8b03841] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This work focuses on the fabrication of polyimide aerogel microparticles of diameter 200-1000 μm from a surfactant-free, two-phase, silicone oil/dimethylformamide (DMF) oil-in-oil (O/O) system using a simple microfluidic device. The polyimide sol prepared in DMF is turned into droplets suspended in silicone oil in the microfluidic device. The droplets are guided to a heated silicone oil bath to accelerate sol-gel transition and imidization reactions, thereby yielding spherical, discrete gel microparticles that do not undergo coalescence. The discrete gel microparticles are isolated and supercritically dried to obtain aerogel microparticles. The microparticle size distribution shows dependence on dispersed and continuous phase flowrates in the microfluidic channels. The microparticle surface morphology shows dependence on the silicone oil bath temperature.
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Affiliation(s)
- Nicholas Teo
- Department of Polymer Engineering , The University of Akron , 250 South Forge Street , Akron , Ohio 44325-0301 , United States
| | - Sadhan C Jana
- Department of Polymer Engineering , The University of Akron , 250 South Forge Street , Akron , Ohio 44325-0301 , United States
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15
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16
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Teo N, Jana SC. Open Cell Aerogel Foams via Emulsion Templating. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:12729-12738. [PMID: 29048907 DOI: 10.1021/acs.langmuir.7b03139] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The water-in-oil emulsion-templating method is used in this work for fabrication of open cell aerogel foams from syndiotactic polystyrene (sPS). A surfactant-stabilized emulsion is prepared at 60-100 °C by dispersing water in a solution of sPS in toluene. sPS gel, formed upon cooling of the emulsion to room temperature, locks the water droplets inside the gel. The gel is solvent exchanged in ethanol and then dried under supercritical condition of carbon dioxide to yield the aerogel foams. The aerogel foams show a significant fraction of macropores with a diameter of a few tens of micrometers, defined as macrovoids that originated from the emulsified water droplets. In conjunction, customary macropores of diameter 50-200 nm are derived from sPS gels. The macrovoids add additional openness to the aerogel structures. This paper evaluates the structural characteristics of the macrovoids, such as diameter distribution, macrovoid interconnect density, and skin layer density, in conjunction with the final aerogel foam properties.
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Affiliation(s)
- Nicholas Teo
- Department of Polymer Engineering The University of Akron , 250 South Forge Street, Akron, Ohio 44325-0301, United States
| | - Sadhan C Jana
- Department of Polymer Engineering The University of Akron , 250 South Forge Street, Akron, Ohio 44325-0301, United States
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