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Abrishamkar S, Mohammadi A, De La Vega J, Wang DY, Kalali EN. Layer-by-layer assembly of calixarene modified GO and LDH nanostructures on flame retardancy, smoke suppression, and dye adsorption behavior of flexible polyurethane foams. Polym Degrad Stab 2022. [DOI: 10.1016/j.polymdegradstab.2022.110242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Gao Y, Wang Y, Chen C, Zhou J, Cheng Y, Shi L. Preparation of Montmorillonite Nanosheets with a High Aspect Ratio through Heating/Rehydrating and Gas-Pushing Exfoliation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:10520-10529. [PMID: 35981283 DOI: 10.1021/acs.langmuir.2c01320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Montmorillonite (MMT) is an abundant silicate mineral with ultrahigh stability. The exfoliation of stacked MMT into high-aspect-ratio nanosheets is of crucial importance for various applications such as toxic gas suppression, barrier property enhancement, flame retardancy, and ion conduction. In this work, we develop a new heating/rehydrating and gas-pushing method that can successfully exfoliate MMT into nanosheets with aspect ratios (600-5000) far higher than the currently reported values (1-120). The MMT first goes through a "starvation pretreatment" under different heating temperatures to improve its hydrophilicity and is then rehydrated in a hydrogen peroxide solution. The hydrogen peroxide in the MMT interlayer space can decompose into water and oxygen bubbles, thus finally leading to the exfoliation via gas-pushing while preserving the large lateral size (mainly in the range of 1-6 μm) of the nanosheets. By changing the pretreatment temperature and pH value of the hydrogen peroxide solution, the exfoliation performance can be tuned. This simple and low-cost exfoliation method is promising to achieve the mass production of MMT nanosheets with a high aspect ratio and may promote its application in various fields such as energy conversion, drug delivery, and photocatalysis.
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Affiliation(s)
- Yushuan Gao
- Center of Nanomaterials for Renewable Energy (CNRE), State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, P. R. China
| | - Yindong Wang
- Center of Nanomaterials for Renewable Energy (CNRE), State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, P. R. China
| | - Chengxiang Chen
- Center of Nanomaterials for Renewable Energy (CNRE), State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, P. R. China
| | - Jun Zhou
- Center of Nanomaterials for Renewable Energy (CNRE), State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, P. R. China
| | - Yonghong Cheng
- Center of Nanomaterials for Renewable Energy (CNRE), State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, P. R. China
| | - Le Shi
- Center of Nanomaterials for Renewable Energy (CNRE), State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, P. R. China
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Zhang T, Bai H, Zhao Y, Ren B, Wen T, Chen L, Song S, Komarneni S. Precise Cation Recognition in Two-Dimensional Nanofluidic Channels of Clay Membranes Imparted from Intrinsic Selectivity of Clays. ACS NANO 2022; 16:4930-4939. [PMID: 35171573 DOI: 10.1021/acsnano.2c00866] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Various kinds of clays occur naturally and are accompanied by particular cations in their interlayer domains. Here we report the reassembled membranes with nanofluidic channel arrays by using the natural clays montmorillonite, mica, and vermiculite, which were imparted with the natural selectivity for realizing precise recognition and directional regulation of the naturally occurring interlayer cations. A typical surface-governed ionic transport behavior was observed in the clay nanofluidic channels. Through asymmetric structural modification, cationic current rectification was realized in montmorillonite channels that performed as a nanofluidic diode. Interestingly, in the mica nanofluidic channel, the K+ that was naturally occurring in the interlayer domain of mica showed a reciprocating motion and resulted in a periodically fluctuating current. Electrodialysis demonstrated that such a fluctuating current reflects a directional selectivity for K+, achieving at least a 6000 times permeation rate difference with Li+ ions. The specific selectivity for Li+/Mg2+ on vermiculite reached up to 856 times with similar cations by the current technique. As-obtained clay membranes possess application prospects in energy conversion, brine resource development, etc. Such a strategy can achieve the designed selectivity through systematic screening of the building blocks, thus imparting them with the inherent characteristics of natural clays, which provides an alternative solution to the present manufacture of selective membranes.
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Affiliation(s)
- Tingting Zhang
- School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan, Hubei 430023, China
| | - Haoyu Bai
- School of Resources and Environmental Engineering and Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, 122 Luoshi Road, Wuhan, Hubei 430070, China
- Department of Materials, Imperial College London, London, SW7 2AZ, U.K
| | - Yunliang Zhao
- School of Resources and Environmental Engineering and Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, 122 Luoshi Road, Wuhan, Hubei 430070, China
| | - Bo Ren
- School of Resources and Environmental Engineering and Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, 122 Luoshi Road, Wuhan, Hubei 430070, China
| | - Tong Wen
- School of Resources and Environmental Engineering and Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, 122 Luoshi Road, Wuhan, Hubei 430070, China
| | - Licai Chen
- School of Resources and Environmental Engineering and Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, 122 Luoshi Road, Wuhan, Hubei 430070, China
| | - Shaoxian Song
- School of Resources and Environmental Engineering and Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, 122 Luoshi Road, Wuhan, Hubei 430070, China
| | - Sridhar Komarneni
- Department of Ecosystem Science and Management and Materials Research Institute, 204 Energy and the Environment Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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Hejna A. Clays as Inhibitors of Polyurethane Foams' Flammability. MATERIALS (BASEL, SWITZERLAND) 2021; 14:4826. [PMID: 34500914 PMCID: PMC8432671 DOI: 10.3390/ma14174826] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/20/2021] [Accepted: 08/24/2021] [Indexed: 11/22/2022]
Abstract
Polyurethanes are a very important group of polymers with an extensive range of applications in different branches of industry. In the form of foams, they are mainly used in bedding, furniture, building, construction, and automotive sectors. Due to human safety reasons, these applications require an appropriate level of flame retardance, often required by various law regulations. Nevertheless, without the proper modifications, polyurethane foams are easily ignitable, highly flammable, and generate an enormous amount of smoke during combustion. Therefore, proper modifications or additives should be introduced to reduce their flammability. Except for the most popular phosphorus-, halogen-, or nitrogen-containing flame retardants, promising results were noted for the application of clays. Due to their small particle size and flake-like shape, they induce a "labyrinth effect" inside the foam, resulting in the delay of decomposition onset, reduction of smoke generation, and inhibition of heat, gas, and mass transfer. Moreover, clays can be easily modified with different organic compounds or used along with conventional flame retardants. Such an approach may often result in the synergy effect, which provides the exceptional reduction of foams' flammability. This paper summarizes the literature reports related to the applications of clays in the reduction of polyurethane foams' flammability, either by their incorporation as a nanofiller or by preparation of coatings.
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Affiliation(s)
- Aleksander Hejna
- Department of Polymer Technology, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland
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Exceptionally flame-retardant flexible polyurethane foam composites: synergistic effect of the silicone resin/graphene oxide coating. Front Chem Sci Eng 2020. [DOI: 10.1007/s11705-020-1988-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Kundu S, Korin Manor N, Radian A. Iron-Montmorillonite-Cyclodextrin Composites as Recyclable Sorbent Catalysts for the Adsorption and Surface Oxidation of Organic Pollutants. ACS APPLIED MATERIALS & INTERFACES 2020; 12:52873-52887. [PMID: 33169983 DOI: 10.1021/acsami.0c17510] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Iron-clay-cyclodextrin composites were designed as sorbent catalysts to adsorb and oxidize pollutants from water. The clay-iron backbone served as a mechanical support and as a heterogeneous Fenton catalyst, and the cyclodextrin monomers or polymers cross-linked with polyfluorinated aromatic molecules were used to accommodate adsorption of the pollutants. The composite based on iron-clay-cyclodextrin-polymers (Fe-MMT-βCD-DFB) exhibited superior adsorption and degradation of the model pollutants, bisphenol A (BPA), carbamazepine (CBZ), and perfluorooctanoic acid (PFOA), compared to the monomer-based composite and the native iron clay. The variety of adsorption sites, such as the polyfluorinated aromatic cross-linker, cyclodextrin toroid, and iron-clay surface, resulted in high adsorption affinity toward all pollutants; BPA was primarily adsorbed to the cyclodextrin functional groups, CBZ showed high affinity toward the Fe-MMT surface and the Fe-MMT-βCD-DFB composite, whereas PFOA was adsorbed mainly to the βCD-DFB polymer. Degradation, using H2O2, was highly efficient, reaching over 90% degradation in 1 h for BPA and CBZ and ∼80% for PFOA. The composite also showed excellent degradation efficiency in a multicomponent system with all three model pollutants. Furthermore, the composite's activity remained steady for five consecutive cycles of adsorption and degradation. The ability to remediate a broad range of pollutants, and the high overall removal exhibited by this novel material, demonstrates the potential for future application in water remediation technologies.
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Affiliation(s)
- Samapti Kundu
- Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Naama Korin Manor
- Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Adi Radian
- Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
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Hai Y, Wang C, Jiang S, Liu X. Layer-by-Layer Assembly of Aerogel and Alginate toward Self-Extinguishing Flexible Polyurethane Foam. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b05590] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yun Hai
- School of Mechanical and Automotive Engineering, South China University of Technology, Wushan Road 381, Guangzhou 510641, P. R. China
- Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou 510641, P. R. China
| | - Chuhui Wang
- School of Mechanical and Automotive Engineering, South China University of Technology, Wushan Road 381, Guangzhou 510641, P. R. China
- Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou 510641, P. R. China
| | - Saihua Jiang
- School of Mechanical and Automotive Engineering, South China University of Technology, Wushan Road 381, Guangzhou 510641, P. R. China
- Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States
- Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou 510641, P. R. China
| | - Xinyi Liu
- School of Mechanical and Automotive Engineering, South China University of Technology, Wushan Road 381, Guangzhou 510641, P. R. China
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Nanoreinforcements of Two-Dimensional Nanomaterials for Flame Retardant Polymeric Composites: An Overview. ADVANCES IN POLYMER TECHNOLOGY 2019. [DOI: 10.1155/2019/4273253] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Polymer materials are ubiquitous in daily life. While polymers are often convenient and helpful, their properties often obscure the fire hazards they may pose. Therefore, it is of great significance in terms of safety to study the flame retardant properties of polymers while still maintaining their optimal performance. Current literature shows that although traditional flame retardants can satisfy the requirements of polymer flame retardancy, due to increases in product requirements in industry, including requirements for durability, mechanical properties, and environmental friendliness, it is imperative to develop a new generation of flame retardants. In recent years, the preparation of modified two-dimensional nanomaterials as flame retardants has attracted wide attention in the field. Due to their unique layered structures, two-dimensional nanomaterials can generally improve the mechanical properties of polymers via uniform dispersion, and they can form effective physical barriers in a matrix to improve the thermal stability of polymers. For polymer applications in specialized fields, different two-dimensional nanomaterials have potential conductivity, high thermal conductivity, catalytic activity, and antiultraviolet abilities, which can meet the flame retardant requirements of polymers and allow their use in specific applications. In this review, the current research status of two-dimensional nanomaterials as flame retardants is discussed, as well as a mechanism of how they can be applied for reducing the flammability of polymers.
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