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Gorgolis G, Kotsidi M, Paterakis G, Koutroumanis N, Tsakonas C, Galiotis C. Graphene aerogels as efficient adsorbers of water pollutants and their effect of drying methods. Sci Rep 2024; 14:8029. [PMID: 38580774 PMCID: PMC10997784 DOI: 10.1038/s41598-024-58651-1] [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: 01/08/2024] [Accepted: 04/02/2024] [Indexed: 04/07/2024] Open
Abstract
Environmental accidents highlight the need for the development of efficient materials that can be employed to eliminate pollutants including crude oil and its derivatives, as well as toxic organic solvents. In recent years, a wide variety of advanced materials has been investigated to assist in the purification process of environmentally compromised regions, with the principal contestants being graphene-based structures. This study describes the synthesis of graphene aerogels with two methods and determines their efficiency as adsorbents of several water pollutants. The main difference between the two synthesis routes is the use of freeze-drying in the first case, and ambient pressure drying in the latter. Raman spectroscopy, Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and contact angle measurements are employed here for the characterisation of the samples. The as-prepared aerogels have been found to act as photocatalysts of aqueous dye solutions like methylene blue and Orange G, while they were also evaluated as adsorbents of organic solvents (acetone, ethanol and methanol), and, oils like pump oil, castor oil, silicone oil, as well. The results presented here show that the freeze-drying approach provides materials with better adsorption efficiency for the most of the examined pollutants, however, the energy and cost-saving advantages of ambient-pressure-drying could offset the adsorption advantages of the former case.
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Affiliation(s)
- G Gorgolis
- Department of Chemical Engineering, University of Patras, 26504, Patras, Greece.
- Foundation for Research and Technology - Hellas (FORTH/ ICE-HT), Institute of Chemical Engineering Sciences, 26504, Patras, Greece.
| | - M Kotsidi
- Department of Chemical Engineering, University of Patras, 26504, Patras, Greece
| | - G Paterakis
- Department of Chemical Engineering, University of Patras, 26504, Patras, Greece
- Foundation for Research and Technology - Hellas (FORTH/ ICE-HT), Institute of Chemical Engineering Sciences, 26504, Patras, Greece
| | - N Koutroumanis
- Foundation for Research and Technology - Hellas (FORTH/ ICE-HT), Institute of Chemical Engineering Sciences, 26504, Patras, Greece
| | - C Tsakonas
- Foundation for Research and Technology - Hellas (FORTH/ ICE-HT), Institute of Chemical Engineering Sciences, 26504, Patras, Greece
| | - C Galiotis
- Department of Chemical Engineering, University of Patras, 26504, Patras, Greece.
- Foundation for Research and Technology - Hellas (FORTH/ ICE-HT), Institute of Chemical Engineering Sciences, 26504, Patras, Greece.
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2
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Wu Y, An C, Guo Y, Zong Y, Jiang N, Zheng Q, Yu ZZ. Highly Aligned Graphene Aerogels for Multifunctional Composites. NANO-MICRO LETTERS 2024; 16:118. [PMID: 38361077 PMCID: PMC10869679 DOI: 10.1007/s40820-024-01357-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/03/2024] [Indexed: 02/17/2024]
Abstract
Stemming from the unique in-plane honeycomb lattice structure and the sp2 hybridized carbon atoms bonded by exceptionally strong carbon-carbon bonds, graphene exhibits remarkable anisotropic electrical, mechanical, and thermal properties. To maximize the utilization of graphene's in-plane properties, pre-constructed and aligned structures, such as oriented aerogels, films, and fibers, have been designed. The unique combination of aligned structure, high surface area, excellent electrical conductivity, mechanical stability, thermal conductivity, and porous nature of highly aligned graphene aerogels allows for tailored and enhanced performance in specific directions, enabling advancements in diverse fields. This review provides a comprehensive overview of recent advances in highly aligned graphene aerogels and their composites. It highlights the fabrication methods of aligned graphene aerogels and the optimization of alignment which can be estimated both qualitatively and quantitatively. The oriented scaffolds endow graphene aerogels and their composites with anisotropic properties, showing enhanced electrical, mechanical, and thermal properties along the alignment at the sacrifice of the perpendicular direction. This review showcases remarkable properties and applications of aligned graphene aerogels and their composites, such as their suitability for electronics, environmental applications, thermal management, and energy storage. Challenges and potential opportunities are proposed to offer new insights into prospects of this material.
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Affiliation(s)
- Ying Wu
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China.
- Institute of Materials Intelligent Technology, Liaoning Academy of Materials, Shenyang, 110004, People's Republic of China.
| | - Chao An
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China
- Institute of Materials Intelligent Technology, Liaoning Academy of Materials, Shenyang, 110004, People's Republic of China
| | - Yaru Guo
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China
- Institute of Materials Intelligent Technology, Liaoning Academy of Materials, Shenyang, 110004, People's Republic of China
| | - Yangyang Zong
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China
- Institute of Materials Intelligent Technology, Liaoning Academy of Materials, Shenyang, 110004, People's Republic of China
| | - Naisheng Jiang
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China
- Institute of Materials Intelligent Technology, Liaoning Academy of Materials, Shenyang, 110004, People's Republic of China
| | - Qingbin Zheng
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Shenzhen, Guangdong, 518172, People's Republic of China.
| | - Zhong-Zhen Yu
- State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China.
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Xu BT, Jin DZ, Yu Y, Zhang Q, Weng WJ, Ren KX, Tai YL. Nanoclay-reinforced alginate aerogels: preparation and properties. RSC Adv 2024; 14:954-962. [PMID: 38174253 PMCID: PMC10759182 DOI: 10.1039/d3ra07132d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 12/11/2023] [Indexed: 01/05/2024] Open
Abstract
Flame-retardant materials that are mechanically robust, low cost and non-toxic from green and renewable resources are highly demanded in many fields. In this work, aerogels of alginate extracted from seaweeds were fabricated and reinforced with nanoclay. The nanoclay particles increase the molecular ordering (crystallinity) of the aerogels through physical interactions with alginate molecules. They also served as cross-linkers and flame-retardant additives to improve the mechanical strength, elasticity, thermal stability and flame-retarding properties of the aerogels. Under exposure to a butane flame (750 °C), the aerogels maintained their structural integrity and did not produce drips. An optimal loading of nanoclay which led to the best flame retardancy (non-flammable) of the aerogel was determined. The results of this work demonstrate that alginate-nanoclay composite aerogels can be promisingly used as flame-retardant thermal insulation materials.
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Affiliation(s)
- Bang-Ting Xu
- School Laboratory of Medicine, Hangzhou Medical College Hangzhou Zhejiang 310053 P. R. China
| | - Da-Zhi Jin
- School Laboratory of Medicine, Hangzhou Medical College Hangzhou Zhejiang 310053 P. R. China
- Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou Medical College Hangzhou Zhejiang 310053 P. R. China
| | - Yi Yu
- School Laboratory of Medicine, Hangzhou Medical College Hangzhou Zhejiang 310053 P. R. China
| | - Qi Zhang
- School Laboratory of Medicine, Hangzhou Medical College Hangzhou Zhejiang 310053 P. R. China
| | - Weng-Jie Weng
- School Laboratory of Medicine, Hangzhou Medical College Hangzhou Zhejiang 310053 P. R. China
| | - Kai-Xiang Ren
- School Laboratory of Medicine, Hangzhou Medical College Hangzhou Zhejiang 310053 P. R. China
| | - Yu-Lei Tai
- School Laboratory of Medicine, Hangzhou Medical College Hangzhou Zhejiang 310053 P. R. China
- Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou Medical College Hangzhou Zhejiang 310053 P. R. China
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4
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Kim Y, Patel R, Kulkarni CV, Patel M. Graphene-Based Aerogels for Biomedical Application. Gels 2023; 9:967. [PMID: 38131953 PMCID: PMC10743039 DOI: 10.3390/gels9120967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023] Open
Abstract
Aerogels are three-dimensional solid networks with incredibly low densities, high porosity, and large specific surface areas. These aerogels have both nanoscale and macroscopic interior structures. Combined with graphene, the aerogels show improved mechanical strength, electrical conductivity, surface area, and adsorption capacity, making them ideal for various biomedical applications. The graphene aerogel has a high drug-loading capacity due to its large surface area, and the porous structure enables controlled drug release over time. The presence of graphene makes it a suitable material for wound dressings, blood coagulation, and bilirubin adsorption. Additionally, graphene's conductivity can help in the electrical stimulation of cells for improved tissue regeneration, and it is also appropriate for biosensors. In this review, we discuss the preparation and advantages of graphene-based aerogels in wound dressings, drug delivery systems, bone regeneration, and biosensors.
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Affiliation(s)
- Yeongsang Kim
- Bio-Convergence, Integrated Science and Engineering Division (ISED), Underwood International College, Yonsei University, 85 Songdogwahak-ro, Yeonsugu, Incheon 21938, Republic of Korea
| | - Rajkumar Patel
- Energy & Environmental Science and Engineering (EESE), Integrated Science and Engineering Division (ISED), Underwood International College, Yonsei University, 85 Songdogwahak-ro, Yeonsugu, Incheon 21938, Republic of Korea;
| | - Chandrashekhar V. Kulkarni
- Centre for Smart Materials, School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, UK;
| | - Madhumita Patel
- Department of Chemistry and Nanoscience, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Republic of Korea
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Machnicki CE, DuBois EM, Fay M, Shrestha S, Saleeba ZSSL, Hruska AM, Ahmed Z, Srivastava V, Chen PY, Wong IY. Graphene oxide nanosheets augment silk fibroin aerogels for enhanced water stability and oil adsorption. NANOSCALE ADVANCES 2023; 5:6078-6092. [PMID: 37941955 PMCID: PMC10628998 DOI: 10.1039/d3na00350g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 10/05/2023] [Indexed: 11/10/2023]
Abstract
Nanocomposite aerogels exhibit high porosity and large interfacial surface areas, enabling enhanced chemical transport and reactivity. Such mesoporous architectures can be prepared by freeze-casting naturally-derived biopolymers such as silk fibroin, but often form mechanically weak structures that degrade in water, which limits their performance under ambient conditions. Adding 2D material fillers such as graphene oxide (GO) or transition metal carbides (e.g. MXene) could potentially reinforce these aerogels via stronger intermolecular interactions with the polymeric binder. Here, we show that freeze-casting of GO nanosheets with silk fibroin results in a highly water-stable, mechanically robust aerogel, with considerably enhanced properties relative to silk-only or silk-MXene aerogels. These silk-GO aerogels exhibit high contact angles with water and are highly water stable. Moreover, aerogels can adsorb up 25-35 times their mass in oil, and can be used robustly for selective oil separation from water. This increased stability may occur due to strengthened intermolecular interactions such as hydrogen bonding, despite the random coil and α-helix conformation of silk fibroin, which is typically more soluble in water. Finally, we show these aerogels can be prepared at scale by freeze-casting on a copper mesh. Ultimately, we envision that these multicomponent aerogels could be widely utilized for molecular separations and environmental sensing, as well as for thermal insulation and electrical conductivity.
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Affiliation(s)
- Catherine E Machnicki
- School of Engineering, Brown University 184 Hope St, Box D. Providence RI 02912 USA
- Department of Chemistry, Brown University 324 Brook St, Box H. Providence RI 02912 USA
| | - Eric M DuBois
- School of Engineering, Brown University 184 Hope St, Box D. Providence RI 02912 USA
| | - Meg Fay
- School of Engineering, Brown University 184 Hope St, Box D. Providence RI 02912 USA
- Department of Chemistry, Brown University 324 Brook St, Box H. Providence RI 02912 USA
| | - Snehi Shrestha
- Department of Chemical and Biomolecular Engineering, University of Maryland 4418 Stadium Dr College Park MD 20742 USA
| | | | - Alex M Hruska
- School of Engineering, Brown University 184 Hope St, Box D. Providence RI 02912 USA
| | - Zahra Ahmed
- School of Engineering, Brown University 184 Hope St, Box D. Providence RI 02912 USA
| | - Vikas Srivastava
- School of Engineering, Brown University 184 Hope St, Box D. Providence RI 02912 USA
| | - Po-Yen Chen
- Department of Chemical and Biomolecular Engineering, University of Maryland 4418 Stadium Dr College Park MD 20742 USA
| | - Ian Y Wong
- School of Engineering, Brown University 184 Hope St, Box D. Providence RI 02912 USA
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6
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Qi P, Zhu H, Borodich F, Peng Q. A Review of the Mechanical Properties of Graphene Aerogel Materials: Experimental Measurements and Computer Simulations. MATERIALS (BASEL, SWITZERLAND) 2023; 16:1800. [PMID: 36902915 PMCID: PMC10004370 DOI: 10.3390/ma16051800] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 02/01/2023] [Accepted: 02/20/2023] [Indexed: 06/15/2023]
Abstract
Graphene aerogels (GAs) combine the unique properties of two-dimensional graphene with the structural characteristics of microscale porous materials, exhibiting ultralight, ultra-strength, and ultra-tough properties. GAs are a type of promising carbon-based metamaterials suitable for harsh environments in aerospace, military, and energy-related fields. However, there are still some challenges in the application of graphene aerogel (GA) materials, which requires an in-depth understanding of the mechanical properties of GAs and the associated enhancement mechanisms. This review first presents experimental research works related to the mechanical properties of GAs in recent years and identifies the key parameters that dominate the mechanical properties of GAs in different situations. Then, simulation works on the mechanical properties of GAs are reviewed, the deformation mechanisms are discussed, and the advantages and limitations are summarized. Finally, an outlook on the potential directions and main challenges is provided for future studies in the mechanical properties of GA materials.
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Affiliation(s)
- Penghao Qi
- School of Engineering, Cardiff University, Cardiff CF24 3AA, UK
| | - Hanxing Zhu
- School of Engineering, Cardiff University, Cardiff CF24 3AA, UK
| | - Feodor Borodich
- College of Aerospace Engineering, Chongqing University, Chongqing 400044, China
| | - Qing Peng
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
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7
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Wang D, Wu X, Owens G, Xu H. Porous carbon-based thermally conductive materials: fabrication, functions and applications. CHINESE JOURNAL OF STRUCTURAL CHEMISTRY 2022. [DOI: 10.1016/j.cjsc.2022.100006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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8
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Oh T, Lee S, Kim H, Ko TY, Kim SJ, Koo CM. Fast and High-Yield Anhydrous Synthesis of Ti 3 C 2 T x MXene with High Electrical Conductivity and Exceptional Mechanical Strength. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2203767. [PMID: 36069279 DOI: 10.1002/smll.202203767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/05/2022] [Indexed: 05/04/2023]
Abstract
2D transition metal carbides or nitrides (MXenes) have attracted considerable attention from materials scientists and engineers owing to their physicochemical properties. Currently, MXenes are synthesized from MAX-phase precursors using aqueous HF. Here, in order to enhance the production of MXenes, an anhydrous etching solution is proposed, consisting of dimethylsulfoxide as solvent with its high boiling point, NH4 HF2 as an etchant, CH3 SO3 H as an acid, and NH4 PF6 as an intercalant. The reaction temperature can be increased up to 100 °C to accelerate the etching and delamination of Ti3 AlC2 MAX crystals; in addition, the destructive side reaction of the produced Ti3 C2 Tx MXene is suppressed in the etchant. Consequently, the etching reaction is completed in 4 h at 100 °C and produces high-quality monolayer Ti3 C2 Tx with an electrical conductivity of 8200 S cm-1 and yield of over 70%. The Ti3 C2 Tx MXene fabricated via this modified synthesis exhibits different surface structures and properties arising from more F-terminations than those of Ti3 C2 Tx synthesized in aqueous HF2 T. The atypical surface structure of Ti3 C2 Tx MXene results in an exceptionally high ultimate tensile strength (167 ± 8 MPa), which is five times larger than those of Ti3 C2 Tx MXenes synthesized in aqueous HF solution (31.7 ± 7.8 MPa).
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Affiliation(s)
- Taegon Oh
- Materials Architecturing Research Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea
| | - Seungjun Lee
- Materials Architecturing Research Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, Republic of Korea
| | - Hyerim Kim
- Materials Architecturing Research Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea
| | - Tae Yun Ko
- Materials Architecturing Research Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea
| | - Seon Joon Kim
- Materials Architecturing Research Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea
- Division of Nano and Information Technology, KIST School, University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Chong Min Koo
- Materials Architecturing Research Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, Republic of Korea
- Division of Nano and Information Technology, KIST School, University of Science and Technology, Daejeon, 34113, Republic of Korea
- School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- School of Chemical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
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9
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Zhao HY, Yu MY, Liu J, Li X, Min P, Yu ZZ. Efficient Preconstruction of Three-Dimensional Graphene Networks for Thermally Conductive Polymer Composites. NANO-MICRO LETTERS 2022; 14:129. [PMID: 35699797 PMCID: PMC9198159 DOI: 10.1007/s40820-022-00878-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 05/13/2022] [Indexed: 06/02/2023]
Abstract
Electronic devices generate heat during operation and require efficient thermal management to extend the lifetime and prevent performance degradation. Featured by its exceptional thermal conductivity, graphene is an ideal functional filler for fabricating thermally conductive polymer composites to provide efficient thermal management. Extensive studies have been focusing on constructing graphene networks in polymer composites to achieve high thermal conductivities. Compared with conventional composite fabrications by directly mixing graphene with polymers, preconstruction of three-dimensional graphene networks followed by backfilling polymers represents a promising way to produce composites with higher performances, enabling high manufacturing flexibility and controllability. In this review, we first summarize the factors that affect thermal conductivity of graphene composites and strategies for fabricating highly thermally conductive graphene/polymer composites. Subsequently, we give the reasoning behind using preconstructed three-dimensional graphene networks for fabricating thermally conductive polymer composites and highlight their potential applications. Finally, our insight into the existing bottlenecks and opportunities is provided for developing preconstructed porous architectures of graphene and their thermally conductive composites.
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Affiliation(s)
- Hao-Yu Zhao
- Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
- College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Ming-Yuan Yu
- College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Ji Liu
- School of Chemistry, CRANN and AMBER, Trinity College Dublin, Dublin, Ireland.
| | - Xiaofeng Li
- Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China.
| | - Peng Min
- College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Zhong-Zhen Yu
- Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China.
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10
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Xia Y, Gao C, Gao W. A review on elastic graphene aerogels: Design, preparation, and applications. JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1002/pol.20220179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Yuxing Xia
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering Zhejiang University Hangzhou China
| | - Chao Gao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering Zhejiang University Hangzhou China
| | - Weiwei Gao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering Zhejiang University Hangzhou China
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11
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Lan X, Hou Y, Dong X, Yang Z, Thai BQ, Yang Y, Zhai W. All-Ceramic SiC Aerogel for Wide Temperature Range Electromagnetic Wave Attenuation. ACS APPLIED MATERIALS & INTERFACES 2022; 14:15360-15369. [PMID: 35315653 DOI: 10.1021/acsami.1c23087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A novel type of all-ceramic SiC aerogel was fabricated by freeze casting and carbothermal reduction reaction processes using graphene oxide (GO) doped SiC nanowires suspensions as starting materials. The effect of GO addition (0, 1, 2, and 4 mg/mL) on the porous morphologies, chemical composition, and the electromagnetic (EM) performance of the SiC aerogels were investigated. The optimum all-ceramic SiC aerogel exhibits effective whole X-band attenuation (>90%) at a fixed thickness of 3.3 mm from room temperature to 400 °C. It is ultralight with a density of 0.2 g/cm3 and possesses a low thermal conductivity of about 0.05 W/mK. The material composition remains stable at temperatures up to 800 °C. The lightweight, high thermal stability, low thermal conductivity, and excellent X-band attenuation performance at a fixed thin thickness make the all-ceramic SiC aerogels potential EM attenuation materials for many applications in harsh environments.
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Affiliation(s)
- Xiaolin Lan
- National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
| | - Yi Hou
- National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
| | - Xinyu Dong
- National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
| | - Zhihong Yang
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, 138634, Singapore
| | - Ba Quoc Thai
- National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
| | - Yong Yang
- National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
| | - Wei Zhai
- National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
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12
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Yang G, Tetik H, Weker JN, Xiao X, Lei S, Lin D. In situ imaging of three dimensional freeze printing process using rapid x-ray synchrotron radiography. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:013703. [PMID: 35104987 DOI: 10.1063/5.0077141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/28/2021] [Indexed: 06/14/2023]
Abstract
Three dimensional freeze printing (3DFP) combines the advantages of freeze casting and additive manufacturing to fabricate multifunctional aerogels. Freeze casting is a cost-effective, efficient, and versatile method capable of fabricating micro-scale porous structures inside the aerogels for many different applications. The 3DFP provided the capability of fabricating highly customized geometries with controlled microporous structures as well. However, there are still many unexplained phenomena and features because of the complexity of post-processes and indirect observation methods. This study demonstrates the design and construction of the in situ imaging systems, which use the x-ray synchrotron radiography to observe freeze casting and 3DFP processes. With the advantages provided by the in situ x-ray imaging techniques, the ice crystal growth with its unique lamellar structures can be observed during the freeze casting process. The movement of freeze front, material deposition, and growth of ice crystals can also be visualized during the inkjet-based 3DFP process.
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Affiliation(s)
- Guang Yang
- Industrial and Manufacturing Systems Engineering, Kansas State University, Manhattan, Kansas 66506, USA
| | - Halil Tetik
- Industrial and Manufacturing Systems Engineering, Kansas State University, Manhattan, Kansas 66506, USA
| | - Johanna Nelson Weker
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Xianghui Xiao
- Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Shuting Lei
- Industrial and Manufacturing Systems Engineering, Kansas State University, Manhattan, Kansas 66506, USA
| | - Dong Lin
- Industrial and Manufacturing Systems Engineering, Kansas State University, Manhattan, Kansas 66506, USA
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13
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Liu S, Lyu M, Wang C. Mechanical Properties and Deformation Mechanisms of Graphene Foams with Bi-Modal Sheet Thickness by Coarse-Grained Molecular Dynamics Simulations. MATERIALS (BASEL, SWITZERLAND) 2021; 14:5622. [PMID: 34640013 PMCID: PMC8509715 DOI: 10.3390/ma14195622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 11/17/2022]
Abstract
Graphene foams (GrFs) have been widely used as structural and/or functional materials in many practical applications. They are always assembled by thin and thick graphene sheets with multiple thicknesses; however, the effect of this basic structural feature has been poorly understood by existing theoretical models. Here, we propose a coarse-grained bi-modal GrF model composed of a mixture of 1-layer flexible and 8-layer stiff sheets to study the mechanical properties and deformation mechanisms based on the mesoscopic model of graphene sheets (Model. Simul. Mater. Sci. Eng. 2011, 19, 54003). It is found that the modulus increases almost linearly with an increased proportion of 8-layer sheets, which is well explained by the mixture rule; the strength decreases first and reaches the minimum value at a critical proportion of stiff sheets ~30%, which is well explained by the analysis of structural connectivity and deformation energy of bi-modal GrFs. Furthermore, high-stress regions are mainly dispersed in thick sheets, while large-strain areas mainly locate in thin ones. Both of them have a highly uneven distribution in GrFs due to the intrinsic heterogeneity in both structures and the mechanical properties of sheets. Moreover, the elastic recovery ability of GrFs can be enhanced by adding more thick sheets. These results should be helpful for us to understand and further guide the design of advanced GrF-based materials.
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Affiliation(s)
- Shenggui Liu
- School of Mechanics and Civil Engineering, China University of Mining and Technology, Beijing 100083, China; (S.L.); (M.L.)
| | - Mindong Lyu
- School of Mechanics and Civil Engineering, China University of Mining and Technology, Beijing 100083, China; (S.L.); (M.L.)
| | - Chao Wang
- LNM, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
- School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China
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Yang P, Tontini G, Wang J, Kinloch IA, Barg S. Ice-templated hybrid graphene oxide-graphene nanoplatelet lamellar architectures: tuning mechanical and electrical properties. NANOTECHNOLOGY 2021; 32:205601. [PMID: 33494085 DOI: 10.1088/1361-6528/abdf8f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The traditional freeze-casting route for processing graphene-based aerogels is generally restricted to aqueously dispersed flakes of graphene oxide (GO) and post-processing reduction treatments, which brings restrictions to the aerogels electrical properties. In this work, we report a versatile aqueous processing route that uses the ability of GO todisperse graphene nanoplatelets (GNP) to produce rGO-GNP lamellar aerogels via unidirectional freeze-casting. In order to optimise the properties of the aerogel, GO-GNP dispersions were partially reduced by L-ascorbic acid prior to freeze-casting to tune the carbon and oxygen (C/O) ratio. The aerogels were then heat treated after casting to fully reduce the GO. The chemical reduction time was found to control the microstructure of the resulting aeorgels and thus to tune their electrical and mechanical properties. An rGO-GNP lamellar aerogel with density of 20.8 ± 0.8 mg cm-3 reducing using a reduction of 60 min achieved an electrical conductivity of 42.3 S m-1. On the other hand, an optimal reduction time of 35 min led to an aerogel with compressive modulus of 0.51 ±0.06 MPa at a density of 23.2 ± 0.7 mg cm-3, revealing a compromise between the tuning of electrical and mechanical properties. We show the present processing route can also be easily applied to produce lamellar aerogels on other graphene-based materials such as electrochemically exfoliated graphene.
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Affiliation(s)
- Pei Yang
- Henry Royce Institute and Department of Materials, The University of Manchester, Oxford Rd, Manchester, M13 9PL, United Kingdom
- National Graphene Institute, The University of Manchester, M13 9PL, United Kingdom
| | - Gustavo Tontini
- Henry Royce Institute and Department of Materials, The University of Manchester, Oxford Rd, Manchester, M13 9PL, United Kingdom
| | - Jiacheng Wang
- Henry Royce Institute and Department of Materials, The University of Manchester, Oxford Rd, Manchester, M13 9PL, United Kingdom
- National Graphene Institute, The University of Manchester, M13 9PL, United Kingdom
| | - Ian A Kinloch
- Henry Royce Institute and Department of Materials, The University of Manchester, Oxford Rd, Manchester, M13 9PL, United Kingdom
- National Graphene Institute, The University of Manchester, M13 9PL, United Kingdom
| | - Suelen Barg
- Henry Royce Institute and Department of Materials, The University of Manchester, Oxford Rd, Manchester, M13 9PL, United Kingdom
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15
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Khan MB, Wang C, Wang S, Fang D, Chen S. The mechanical property and microscopic deformation mechanism of nanoparticle-contained graphene foam materials under uniaxial compression. NANOTECHNOLOGY 2021; 32:115701. [PMID: 33361558 DOI: 10.1088/1361-6528/abcfe8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Nanoparticle-contained graphene foams have found more and more practical applications in recent years, which desperately requires a deep understanding on basic mechanics of this hybrid material. In this paper, the microscopic deformation mechanism and mechanical properties of such a hybrid material under uniaxial compression, that are inevitably encountered in applications and further affect its functions, are systematically studied by the coarse-grained molecular dynamics simulation method. Two major factors of the size and volume fraction of nanoparticles are considered. It is found that the constitutive relation of nanoparticle filled graphene foam materials consists of three parts: the elastic deformation stage, deformation with inner re-organization and the final compaction stage, which is much similar to the experimental measurement of pristine graphene foam materials. Interestingly, both the initial and intermediate modulus of such a hybrid material is significantly affected by the size and volume fraction of nanoparticles, due to their influences on the microstructural evolution. The experimentally observed 'spacer effect' of such a hybrid material is well re-produced and further found to be particle-size sensitive. With the increase of nanoparticle size, the micro deformation mechanism will change from nanoparticles trapped in the graphene sheet, slipping on the graphene sheet, to aggregation outside the graphene sheet. Beyond a critical relative particle size 0.26, the graphene-sheet-dominated deformation mode changes to be a nanoparticle-dominated one. The final microstructure after compression of the hybrid system converges to two stable configurations of the 'sandwiched' and 'randomly-stacked' one. The results should be helpful not only to understand the micro mechanism of such a hybrid material in different applications, but also to the design of advanced composites and devices based on porous materials mixed with particles.
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Affiliation(s)
- Muhammad Bilal Khan
- Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, People's Republic of China
- Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Chao Wang
- LNM, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Engineering Science, University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Shuai Wang
- Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, People's Republic of China
- Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Daining Fang
- Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, People's Republic of China
- Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Shaohua Chen
- Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, People's Republic of China
- Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
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16
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Kumar A, Sengupta N, Dutta S. Simplified Approach for Preparing Graphene Oxide TEM Grids for Stained and Vitrified Biomolecules. NANOMATERIALS 2021; 11:nano11030643. [PMID: 33808009 PMCID: PMC7999706 DOI: 10.3390/nano11030643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/22/2021] [Accepted: 02/24/2021] [Indexed: 11/16/2022]
Abstract
In this manuscript, we report the application of graphene oxide (GO) in the preparation of cryo-electron microscopy (cryo-EM) and transmission electron microscopy (TEM) grids. We treated GO with water and organic solvents, such as, methanol, ethanol and isopropanol separately to isolate significantly large GO monolayer flake to fabricate the grids for cryo-EM and TEM study. We implemented a simplified approach to isolate flakes of GO monolayer for constructing the TEM grids, independent of expensive heavy equipment (Langmuir-Blodgett trough, glow-discharge system, carbon-evaporator or plasma-cleaner or peristaltic pumps). We employed confocal microscopy, SEM and TEM to characterize the flake size, stability and transparency of the GO monolayer and atomic force microscopy (AFM) to probe the depth of GO coated grids. Additionally, GO grids are visualized at cryogenic condition for suitability of GO monolayer for cryo-EM study. In addition, GO-Met-H2O grids reduce the effect of preferred orientation of biological macromolecules within the amorphous ice. The power-spectrum and contrast-transfer-function unequivocally suggest that GO-Met-H2O fabricated holey grids have excellent potential for application in high-resolution structural characterization of biomolecules. Furthermore, only 200 movies and ~8000 70S ribosome particles are selected on GO-coated grids for cryo-EM reconstruction to achieve high-resolution structure.
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Affiliation(s)
| | | | - Somnath Dutta
- Correspondence: ; Tel.: +91-080-2293-3453; Fax: +91-080-2360-0535
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17
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Feng J, Su BL, Xia H, Zhao S, Gao C, Wang L, Ogbeide O, Feng J, Hasan T. Printed aerogels: chemistry, processing, and applications. Chem Soc Rev 2021; 50:3842-3888. [PMID: 33522550 DOI: 10.1039/c9cs00757a] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
As an extraordinarily lightweight and porous functional nanomaterial family, aerogels have attracted considerable interest in academia and industry in recent decades. Despite the application scopes, the modest mechanical durability of aerogels makes their processing and operation challenging, in particular, for situations demanding intricate physical structures. "Bottom-up" additive manufacturing technology has the potential to address this drawback. Indeed, since the first report of 3D printed aerogels in 2015, a new interdisciplinary research area combining aerogel and printing technology has emerged to push the boundaries of structure and performance, further broadening their application scope. This review summarizes the state-of-the-art of printed aerogels and presents a comprehensive view of their developments in the past 5 years, and highlights the key near- and mid-term challenges.
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Affiliation(s)
- Junzong Feng
- Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, UK.
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18
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19
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Sun Z, Fang S, Hu YH. 3D Graphene Materials: From Understanding to Design and Synthesis Control. Chem Rev 2020; 120:10336-10453. [PMID: 32852197 DOI: 10.1021/acs.chemrev.0c00083] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Carbon materials, with their diverse allotropes, have played significant roles in our daily life and the development of material science. Following 0D C60 and 1D carbon nanotube, 2D graphene materials, with their distinctively fascinating properties, have been receiving tremendous attention since 2004. To fulfill the efficient utilization of 2D graphene sheets in applications such as energy storage and conversion, electrochemical catalysis, and environmental remediation, 3D structures constructed by graphene sheets have been attempted over the past decade, giving birth to a new generation of graphene materials called 3D graphene materials. This review starts with the definition, classifications, brief history, and basic synthesis chemistries of 3D graphene materials. Then a critical discussion on the design considerations of 3D graphene materials for diverse applications is provided. Subsequently, after emphasizing the importance of normalized property characterization for the 3D structures, approaches for 3D graphene material synthesis from three major types of carbon sources (GO, hydrocarbons and inorganic carbon compounds) based on GO chemistry, hydrocarbon chemistry, and new alkali-metal chemistry, respectively, are comprehensively reviewed with a focus on their synthesis mechanisms, controllable aspects, and scalability. At last, current challenges and future perspectives for the development of 3D graphene materials are addressed.
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Affiliation(s)
- Zhuxing Sun
- Department of Materials Science and Engineering, Michigan Technological University, Houghton, Michigan 49931-1295, United States
| | - Siyuan Fang
- Department of Materials Science and Engineering, Michigan Technological University, Houghton, Michigan 49931-1295, United States
| | - Yun Hang Hu
- Department of Materials Science and Engineering, Michigan Technological University, Houghton, Michigan 49931-1295, United States.,School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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20
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Gao W, Wang M, Bai H. A review of multifunctional nacre-mimetic materials based on bidirectional freeze casting. J Mech Behav Biomed Mater 2020; 109:103820. [PMID: 32543396 DOI: 10.1016/j.jmbbm.2020.103820] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 03/03/2020] [Accepted: 04/20/2020] [Indexed: 12/13/2022]
Abstract
Nacre has achieved an excellent combination of strength and toughness through its unique brick-and-mortar structure of layered aragonite platelets bonded with biopolymers. Mimicking nacre has been considered as a practical way for the development of high-performance structural composites. Over the past years, many techniques have been developed to fabricate multifunctional nacre-mimetic materials, including freeze casting, layer-by-layer assembly, vacuum filtration, 3D printing and so on. Among them, freeze casting, especially bidirectional freeze casting, as an environmentally friendly and scalable method, has attracted extensive attention recently. In this review, we begin with the introduction and discussion of various fabrication techniques comparing their advantages and disadvantages, focusing on the most recent advances of the bidirectional freeze casting technique. Then, we summarize representative examples of applying the bidirectional freeze casting technique to assemble various building blocks into multifunctional nacre-mimetic materials and their wide applications. At the end, we discuss the future direction of using bidirectional freeze casting to make nacre-mimetic materials.
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Affiliation(s)
- Weiwei Gao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, China
| | - Mengning Wang
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Hao Bai
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
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21
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Shao G, Hanaor DAH, Shen X, Gurlo A. Freeze Casting: From Low-Dimensional Building Blocks to Aligned Porous Structures-A Review of Novel Materials, Methods, and Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1907176. [PMID: 32163660 DOI: 10.1002/adma.201907176] [Citation(s) in RCA: 178] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/30/2019] [Indexed: 05/19/2023]
Abstract
Freeze casting, also known as ice templating, is a particularly versatile technique that has been applied extensively for the fabrication of well-controlled biomimetic porous materials based on ceramics, metals, polymers, biomacromolecules, and carbon nanomaterials, endowing them with novel properties and broadening their applicability. The principles of different directional freeze-casting processes are described and the relationships between processing and structure are examined. Recent progress in freeze-casting assisted assembly of low dimensional building blocks, including graphene and carbon nanotubes, into tailored micro- and macrostructures is then summarized. Emerging trends relating to novel materials as building blocks and novel freeze-cast geometries-beads, fibers, films, complex macrostructures, and nacre-mimetic composites-are presented. Thereafter, the means by which aligned porous structures and nacre mimetic materials obtainable through recently developed freeze-casting techniques and low-dimensional building blocks can facilitate material functionality across multiple fields of application, including energy storage and conversion, environmental remediation, thermal management, and smart materials, are discussed.
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Affiliation(s)
- Gaofeng Shao
- School of Chemistry and Materials Science, Nanjing University of Information Science & Technology, Nanjing, 210044, China
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Technische Universität Berlin, Hardenbergstr. 40, Berlin, 10623, Germany
| | - Dorian A H Hanaor
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Technische Universität Berlin, Hardenbergstr. 40, Berlin, 10623, Germany
| | - Xiaodong Shen
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Aleksander Gurlo
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Technische Universität Berlin, Hardenbergstr. 40, Berlin, 10623, Germany
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22
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Kröner A, Hirsch T. Current Trends in the Optical Characterization of Two-Dimensional Carbon Nanomaterials. Front Chem 2020; 7:927. [PMID: 32047734 PMCID: PMC6997542 DOI: 10.3389/fchem.2019.00927] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 12/18/2019] [Indexed: 11/13/2022] Open
Abstract
Graphene and graphene-related materials have received great attention because of their outstanding properties like Young's modulus, chemical inertness, high electrical and thermal conductivity, or large mobility. To utilize two-dimensional (2D) materials in any practical application, an excellent characterization of the nanomaterials is needed as such dimensions, even small variations in size, or composition, are accompanied by drastic changes in the material properties. Simultaneously, it is sophisticated to perform characterizations at such small dimensions. This review highlights the wide range of different characterization methods for the 2D materials, mainly attributing carbon-based materials as they are by far the ones most often used today. The strengths as well as the limitations of the individual methods, ranging from light microscopy, scanning electron microscopy, transmission electron microscopy, scanning transmission electron microscopy, scanning tunneling microscopy (conductive), atomic force microscopy, scanning electrochemical microscopy, Raman spectroscopy, UV-vis, X-ray photoelectron spectroscopy, X-ray fluorescence spectroscopy, energy-dispersive X-ray spectroscopy, Auger electron spectroscopy, electron energy loss spectroscopy, X-ray diffraction, inductively coupled plasma atomic emission spectroscopy to dynamic light scattering, are discussed. By using these methods, the flake size and shape, the number of layers, the conductivity, the morphology, the number and type of defects, the chemical composition, and the colloidal properties of the 2D materials can be investigated.
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Affiliation(s)
| | - Thomas Hirsch
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, Regensburg, Germany
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23
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Ultralight, hydrophobic, anisotropic bamboo-derived cellulose nanofibrils aerogels with excellent shape recovery via freeze-casting. Carbohydr Polym 2018; 208:232-240. [PMID: 30658796 DOI: 10.1016/j.carbpol.2018.12.073] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 12/18/2018] [Accepted: 12/21/2018] [Indexed: 12/24/2022]
Abstract
Cellulose aerogels have shown outstanding potential as renewable functional materials; however, their practical applications are still limited by inherent hydrophilicity and weak mechanical properties. To overcome hydrophilicity and fragility issues of aerogels, in this study, silylated bamboo-derived cellulose nanofibrils (CNF) aerogels with aligned porous structures were achieved by directionally freeze-casting a mixture of CNF suspension and methyltrimethoxysilane sol. The silylated CNF aerogels exhibited distinct aligned lamellar structures and significantly anisotropic mechanical properties. They had improved strength and stiffness in the axial direction (along the freezing direction) and excellent rapid shape recovery ability in the radial direction (perpendicular to the freezing direction) with a significant high shape recovery ratio of 92% after 100 cycles at 80% compression. Owing to their ultra-low density, hydrophobicity, and high compressive recoverability, the silylated CNF aerogels can be potentially used in a wide range of industrial applications, such as hydrophobic polymer nanocomposites, absorbents, and biomedical scaffolds.
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24
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Kim J, Han NM, Kim J, Lee J, Kim JK, Jeon S. Highly Conductive and Fracture-Resistant Epoxy Composite Based on Non-oxidized Graphene Flake Aerogel. ACS APPLIED MATERIALS & INTERFACES 2018; 10:37507-37516. [PMID: 30270621 DOI: 10.1021/acsami.8b13415] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Graphene aerogel (GA) has shown great promise as reinforcement of polymeric composites with exceptional electrical and mechanical characteristics. Although there has been significant progress in controlling the structure of GAs, no studies have appeared on the enhanced properties of GAs by employing high-quality precursor graphene flakes (GFs). However, the assembly of high-quality GFs is particularly challenging due to their highly hydrophobic and agglomerative nature in aqueous media, and of the few methods available to synthesize high-quality GFs, most produce flakes with very small lateral sizes. Herein, we report the fabrication of highly crystalline GAs using large nonoxidized graphene flakes (NOGFs) prepared by a novel graphite intercalation compound-based method. Bidirectional freeze casting is utilized for aligning NOGFs in two orthogonal directions, vertically and laterally, where the NOGF walls individually function as effective conductive pathways. The as-prepared nonoxidized graphene aerogel (NOGA) exhibits a defect concentration as low as 1.4% of impurity oxygen with an excellent electrical conductivity of 202.9 S/m at a low density of 5.7 mg/cm3. The corresponding NOGA-epoxy composite shows a remarkable electrical conductivity of 122.6 S/m and a fracture toughness of 1.74 MPa·m1/2 at a low filler content of 0.45 vol %.
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Affiliation(s)
- Jin Kim
- Department of Materials Science and Engineering , Korea Advanced Institute of Science and Technology , Daejeon 305-701 , Republic of Korea
| | - Ne Myo Han
- Department of Mechanical and Aerospace Engineering , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong
| | - Jungmo Kim
- Department of Materials Science and Engineering , Korea Advanced Institute of Science and Technology , Daejeon 305-701 , Republic of Korea
| | - Jinho Lee
- Department of Materials Science and Engineering , Korea Advanced Institute of Science and Technology , Daejeon 305-701 , Republic of Korea
| | - Jang-Kyo Kim
- Department of Mechanical and Aerospace Engineering , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong
| | - Seokwoo Jeon
- Department of Materials Science and Engineering , Korea Advanced Institute of Science and Technology , Daejeon 305-701 , Republic of Korea
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25
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Chen K, Gao H, Wang D, Li X, Wang D, Khan WU. The preparation of a three dimensional terbium doped reduced graphene oxide aerogel with photoluminescence and paramagnetic properties. RSC Adv 2018; 8:9287-9292. [PMID: 35541858 PMCID: PMC9078696 DOI: 10.1039/c7ra12087g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 02/05/2018] [Indexed: 01/24/2023] Open
Abstract
A 3D reduced graphene oxide (rGO) material with good photoluminescence (PL) and magnetism properties was self-assembled using the hydrothermal method. The resultant material possessed a flower-like structure, which leads to a high surface area. To dehydrate the hydrogel for conservation, the sublimation process we use can effectively maintain the porosity as it uses the freeze drying method. Then, rGO was endowed with paramagnetism and green photoluminescence properties via the introduction of Tb ions, which also reinforces the significance of the building block. Finally, the coordination between Tb ions and the carbonyl was proven with photoluminescence excitation (PLE) spectra and the UV-vis absorption spectra, which are likely to offer an effective way to study the carbonyl compound. A detailed mechanism for the ferromagnetism and photoluminescence of a composite, reduced graphene oxide doped with terbium ions (rGO/Tb), is proposed.![]()
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Affiliation(s)
- Keqin Chen
- School of Physical Science and Technology, Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University Lanzhou 730000 P. R. China +86-931-8913554 +86-18993181143.,National & Local Joint Engineering Laboratory for Optical Conversion Materials and Technology, Key Laboratory of Special Function Materials and Structure Design, Ministry of Education P. R. China
| | - Hui Gao
- School of Physical Science and Technology, Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University Lanzhou 730000 P. R. China +86-931-8913554 +86-18993181143.,National & Local Joint Engineering Laboratory for Optical Conversion Materials and Technology, Key Laboratory of Special Function Materials and Structure Design, Ministry of Education P. R. China
| | - Dongdong Wang
- School of Physical Science and Technology, Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University Lanzhou 730000 P. R. China +86-931-8913554 +86-18993181143.,National & Local Joint Engineering Laboratory for Optical Conversion Materials and Technology, Key Laboratory of Special Function Materials and Structure Design, Ministry of Education P. R. China
| | - Xiaolong Li
- Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences Shanghai 201204 P. R. China
| | - Deying Wang
- School of Physical Science and Technology, Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University Lanzhou 730000 P. R. China +86-931-8913554 +86-18993181143.,National & Local Joint Engineering Laboratory for Optical Conversion Materials and Technology, Key Laboratory of Special Function Materials and Structure Design, Ministry of Education P. R. China
| | - Waheed Ullah Khan
- School of Physical Science and Technology, Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University Lanzhou 730000 P. R. China +86-931-8913554 +86-18993181143.,National & Local Joint Engineering Laboratory for Optical Conversion Materials and Technology, Key Laboratory of Special Function Materials and Structure Design, Ministry of Education P. R. China
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