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Zhao Y, Goodwin DG, Sung L, Ramakrishnan G, Wu Q, Cen J, Petersen EJ, Orlov A. Quantitative evaluation of released nanomaterials from carbon nanotube epoxy nanocomposites during environmental exposure and mechanical treatment. NanoImpact 2023; 32:100486. [PMID: 37777181 DOI: 10.1016/j.impact.2023.100486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 08/17/2023] [Accepted: 09/27/2023] [Indexed: 10/02/2023]
Abstract
Carbon nanotubes (CNTs) are promising nanomaterials exhibiting high thermal and electrical conductivities, significant stiffness, and high tensile strength. As a result, CNTs have been utilized as additives to enhance properties of various polymeric materials in a broad range of fields. In this study, we investigated the release of CNTs from CNT epoxy nanocomposites exposed to environmental weathering and mechanical stresses. The presence and amount of CNTs released from degraded polymer nanocomposites is important because CNTs can impact physiological systems in humans and environmental organisms. The weathering experiments in this study included nanocomposite exposure to both UV and a water spray, to simulate sunlight and rain exposure, whereas mechanical stresses were induced by shaking and ultrasonication. CNT release from epoxy nanocomposites was quantified by a 14C-labeling method that enabled measurement of the CNT release rates after different weathering and mechanical treatments. In this study, a sample oxidizer was used prior to liquid scintillation counting, because it was shown to reduce interferences from the presence of polymeric materials and achieve a high recovery (95%). Polymer nanocomposite degradation was confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and light microscopy. A continuous release of 14C-labeled nanomaterials was observed after each UV and simulated rain exposure period, with 0.23% (mass/mass) of the total embedded mass of CNTs being released from the CNT nanocomposite during the full weathering process, suggesting that the water spray induced sufficient mechanical stress to eliminate the protective effect of the surface agglomerated CNT network. Importantly, additional mechanical stresses imposed on the weathered nanocomposites by shaking and ultrasonication resulted in further release of approximately 0.27% (mass /mass).
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Affiliation(s)
- Yue Zhao
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, USA
| | - David G Goodwin
- Engineering Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Lipiin Sung
- Engineering Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Girish Ramakrishnan
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Qiyuan Wu
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Jiajie Cen
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Elijah J Petersen
- Material Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA.
| | - Alexander Orlov
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NY 11794, USA.
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Cai M, Qi Z, Guy C, An C, Chen X, Wang Z, Feng Q. Insights into the abiotic fragmentation of biodegradable mulches under accelerated weathering conditions. J Hazard Mater 2023; 454:131477. [PMID: 37104954 DOI: 10.1016/j.jhazmat.2023.131477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/17/2023] [Accepted: 04/21/2023] [Indexed: 05/19/2023]
Abstract
Biodegradable mulches (BMs) can be tilled into soils to mitigate disposal and environmental problems. However, the content of biodegradable microplastics (BMPs) would increase with the addition of biodegradable macroplastics (BMaPs). The fragmented particles have a strong affinity to soil pollutants, having the potential to transfer via the terrestrial food web in an agroecosystem. Based on the spectral analysis and particle size analysis, this study explored the physicochemical characteristics of weathered BMaPs and BMP-derived dissolved organic matter (DOMBMP). Ultraviolet (UV) irradiation reduced the mechanical strength of BMaPs and induced oxygenated functional groups, thus increasing surface roughness and hydrophilicity. This promoted the adsorption of aromatic compounds and heavy metals from soils to BMPs. After entering the water environment, the pH of the solution with DOMBMP decreased, whereas the concentration of dissolved organic carbon (DOC) increased. Compared with paper mulch, bioplastic mulch contributed a higher amount of DOMBMP, such as aromatic structure-containing chemicals and carboxylic acids, to the water environment but released fewer and smaller plastic particles. The findings from this study can help manage environmental risks and determine disposal strategies after the use of mulching.
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Affiliation(s)
- Mengfan Cai
- Department of Building, Civil and Environmental Engineering, Faculty of Engineering and Computer Science, Concordia University, Montreal H3G 1M8, Canada
| | - Zhiming Qi
- Department of Bioresource Engineering, McGill University, Sainte-Anne-de-Bellevue H9X 3V9, Canada
| | - Christophe Guy
- University of Technology of Compiègne, Compiègne 60200, France
| | - Chunjiang An
- Department of Building, Civil and Environmental Engineering, Faculty of Engineering and Computer Science, Concordia University, Montreal H3G 1M8, Canada.
| | - Xiujuan Chen
- Department of Civil Engineering, University of Texas at Arlington, Arlington 76019, USA
| | - Zheng Wang
- Department of Building, Civil and Environmental Engineering, Faculty of Engineering and Computer Science, Concordia University, Montreal H3G 1M8, Canada
| | - Qi Feng
- Department of Building, Civil and Environmental Engineering, Faculty of Engineering and Computer Science, Concordia University, Montreal H3G 1M8, Canada
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de Oliveira Maciel A, Christakopoulos P, Rova U, Antonopoulou I. Carbonic anhydrase to boost CO 2 sequestration: Improving carbon capture utilization and storage (CCUS). Chemosphere 2022; 299:134419. [PMID: 35364080 DOI: 10.1016/j.chemosphere.2022.134419] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 03/21/2022] [Accepted: 03/23/2022] [Indexed: 06/14/2023]
Abstract
CO2 Capture Utilization and Storage (CCUS) is a fundamental strategy to mitigate climate change, and carbon sequestration, through absorption, can be one of the solutions to achieving this goal. In nature, carbonic anhydrase (CA) catalyzes the CO2 hydration to bicarbonates. Targeting the development of novel biotechnological routes which can compete with traditional CO2 absorption methods, CA utilization has presented a potential to expand as a promising catalyst for CCUS applications. Driven by this feature, the search for novel CAs as biocatalysts and the utilization of enzyme improvement techniques, such as protein engineering and immobilization methods, has resulted in suitable variants able to catalyze CO2 absorption at relevant industrial conditions. Limitations related to enzyme recovery and recyclability are still a concern in the field, affecting cost efficiency. Under different absorption approaches, CA enhances both kinetics and CO2 absorption yields, besides reduced energy consumption. However, efforts directed to process optimization and demonstrative plants are still limited. A recent topic with great potential for development is the CA utilization in accelerated weathering, where industrial residues could be re-purposed towards becoming carbon sequestrating agents. Furthermore, research of new solvents has identified potential candidates for integration with CA in CO2 capture, and through techno-economic assessments, CA can be a path to increase the competitiveness of alternative CO2 absorption systems, offering lower environmental costs. This review provides a favorable scenario combining the enzyme and CO2 capture, with possibilities in reaching an industrial-like stage in the future.
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Affiliation(s)
- Ayanne de Oliveira Maciel
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-97187 Luleå, Sweden
| | - Paul Christakopoulos
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-97187 Luleå, Sweden
| | - Ulrika Rova
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-97187 Luleå, Sweden
| | - Io Antonopoulou
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-97187 Luleå, Sweden.
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Ferreira A, Aras M, Chitre V, Coutinho I, Rajagopal P. Effect of the simulated Indian and Mediterranean climates on the Shore A hardness of maxillofacial silicone. J Indian Prosthodont Soc 2018; 18:305-313. [PMID: 30449958 PMCID: PMC6180737 DOI: 10.4103/jips.jips_197_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 08/06/2018] [Indexed: 11/05/2022] Open
Abstract
Purpose: The purpose of this study was to assess and compare the effect of the simulated Indian and Mediterranean climates on the Shore A hardness of a commercially available nonpigmented room temperature vulcanizing maxillofacial silicone. Materials and Methods: Sixty specimens were fabricated from A-2000 silicone material (Factor II), using a stainless steel mold of dimension 20 mm × 2 mm. The initial Shore A hardness was noted using a digital durometer. Thirty samples were subjected to the simulated Mediterranean climate (Group I), and the remaining thirty samples were subjected to the Indian tropical climate (Group II) in an accelerated weather chamber to simulate 1 year of clinical use. Final Shore A hardness was noted. A one-way ANOVA and Bonferroni post hoc tests were performed for the Shore A hardness at P < 0.05. Results: The mean initial Shore A hardness for both the groups was 24.9833. After accelerated weathering, Group I showed mean Shore A hardness of 33.0000 whereas Group II showed mean Shore A hardness of 38.0000. Conclusions: The Shore A hardness of Factor II, before and after accelerated artificial weathering, was statistically significant at 0.05 level (P < 0.05). The change in Shore A hardness was greater in the simulated tropical climate group (Group II) as compared to the simulated Mediterranean climate group (Group I) but within clinical limits.
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Affiliation(s)
- Amanda Ferreira
- Department of Prosthodontics and Crown & Bridge, Goa Dental College and Hospital, Bambolim, Goa, India
| | - Meena Aras
- Department of Prosthodontics and Crown & Bridge, Goa Dental College and Hospital, Bambolim, Goa, India
| | - Vidya Chitre
- Department of Prosthodontics and Crown & Bridge, Goa Dental College and Hospital, Bambolim, Goa, India
| | - Ivy Coutinho
- Department of Prosthodontics and Crown & Bridge, Goa Dental College and Hospital, Bambolim, Goa, India
| | - Praveen Rajagopal
- Department of Prosthodontics and Crown & Bridge, Goa Dental College and Hospital, Bambolim, Goa, India
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