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Khanyile BS, Numan N, Simo A, Nkosi M, Mtshali CB, Khumalo Z, Madiba IG, Mabakachaba B, Swart H, Coetsee-Hugo E, Duvenhage MM, Lee E, Henini M, Gibaud A, Chaker M, Rezaee P, Lethole N, Akbari M, Morad R, Maaza M. Towards Room Temperature Thermochromic Coatings with controllable NIR-IR modulation for solar heat management & smart windows applications. Sci Rep 2024; 14:2818. [PMID: 38307893 PMCID: PMC10837131 DOI: 10.1038/s41598-024-52021-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 01/12/2024] [Indexed: 02/04/2024] Open
Abstract
Solar heat management & green air-conditioning are among the major technologies that could mitigate heat islands phenomenon while minimizing significantly the CO2 global foot-print within the building & automotive sectors. Chromogenic materials in general, and thermochromic smart coatings especially are promising candidates that consent a noteworthy dynamic solar radiation Infrared (NIR-IR) regulation and hence an efficient solar heat management especially with the expected increase of the global seasonal temperature. Within this contribution, two major challenging bottlenecks in vanadium oxide based smart coatings were addressed. It is validated for the first time that the NIR-IR modulation of the optical transmission (∆TTRANS = T(T〈TMIT) - T(T〉TMIT) of Vanadium oxide based smart coatings can be controlled & tuned. This upmost challenging bottle-neck controllability/tunability is confirmed via a genuine approach alongside to a simultaneous drastic reduction of the phase transition temperature TMIT from 68.8 °C to nearly room temperature. More precisely, a substantial thermochromism in multilayered V2O5/V/V2O5 stacks equivalent to that of standard pure VO2 thin films but with a far lower transition temperature, is reported. Such a multilayered V2O5/V/V2O5 thermochromic system exhibited a net control & tunability of the optical transmission modulation in the NIR-IR (∆TTRANS) via the nano-scaled thickness' control of the intermediate Vanadium layer. In addition, the control of ∆TTRANS is accompanied by a tremendous diminution of the thermochromic transition temperature from the elevated bulk value of 68.8 °C to the range of 27.5-37.5 ºC. The observed remarkable and reversible thermochromism in such multilayered nano-scaled system of V2O5/V/V2O5 is likely to be ascribed to a noteworthy interfacial diffusion, and an indirect doping by alkaline ions diffusing from the borosilicate substrate. It is hoped that the current findings would contribute in advancing thermochromic smart window technology and their applications for solar heat management in glass windows in general, skyscraper especially & in the automotive industry. If so, this would open a path to a sustainable green air-conditioning with zero-energy input.
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Affiliation(s)
- B S Khanyile
- MRD-Tandetron Accelerator & Nanosciences African Network, iThemba LABS-National Research Foundation, P O Box 722, Somerset West, 7129, Western Cape Province, South Africa.
- UNESCO-UNISA Africa Chair in Nanosciences and Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, P.O. Box 392, Pretoria, 003, South Africa.
| | - N Numan
- MRD-Tandetron Accelerator & Nanosciences African Network, iThemba LABS-National Research Foundation, P O Box 722, Somerset West, 7129, Western Cape Province, South Africa
- UNESCO-UNISA Africa Chair in Nanosciences and Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, P.O. Box 392, Pretoria, 003, South Africa
| | - A Simo
- MRD-Tandetron Accelerator & Nanosciences African Network, iThemba LABS-National Research Foundation, P O Box 722, Somerset West, 7129, Western Cape Province, South Africa
- UNESCO-UNISA Africa Chair in Nanosciences and Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, P.O. Box 392, Pretoria, 003, South Africa
| | - M Nkosi
- MRD-Tandetron Accelerator & Nanosciences African Network, iThemba LABS-National Research Foundation, P O Box 722, Somerset West, 7129, Western Cape Province, South Africa
- UNESCO-UNISA Africa Chair in Nanosciences and Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, P.O. Box 392, Pretoria, 003, South Africa
| | - C B Mtshali
- MRD-Tandetron Accelerator & Nanosciences African Network, iThemba LABS-National Research Foundation, P O Box 722, Somerset West, 7129, Western Cape Province, South Africa
| | - Z Khumalo
- MRD-Tandetron Accelerator & Nanosciences African Network, iThemba LABS-National Research Foundation, P O Box 722, Somerset West, 7129, Western Cape Province, South Africa
| | - I G Madiba
- MRD-Tandetron Accelerator & Nanosciences African Network, iThemba LABS-National Research Foundation, P O Box 722, Somerset West, 7129, Western Cape Province, South Africa
- UNESCO-UNISA Africa Chair in Nanosciences and Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, P.O. Box 392, Pretoria, 003, South Africa
| | - B Mabakachaba
- MRD-Tandetron Accelerator & Nanosciences African Network, iThemba LABS-National Research Foundation, P O Box 722, Somerset West, 7129, Western Cape Province, South Africa
- UNESCO-UNISA Africa Chair in Nanosciences and Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, P.O. Box 392, Pretoria, 003, South Africa
- Physics Department, University of the Western Cape, P.O. Box 1906, Bellville, 7535, South Africa
| | - H Swart
- Faculty of Natural and Agricultural Sciences, Physics Department, University of the Free State, P.O. Box 339, Bloemfontein, 9300, Republic of South Africa
| | - E Coetsee-Hugo
- Faculty of Natural and Agricultural Sciences, Physics Department, University of the Free State, P.O. Box 339, Bloemfontein, 9300, Republic of South Africa
| | - Mart-Mari Duvenhage
- Faculty of Natural and Agricultural Sciences, Physics Department, University of the Free State, P.O. Box 339, Bloemfontein, 9300, Republic of South Africa
| | - E Lee
- Faculty of Natural and Agricultural Sciences, Physics Department, University of the Free State, P.O. Box 339, Bloemfontein, 9300, Republic of South Africa
| | - M Henini
- School of Physics & Astronomy, Nottingham University, Nottingham, NG7 2RD7, UK
| | - A Gibaud
- IMMM, UMR 6283 CNRS, Bd O. Messiaen, University of Le Maine, 72085, Le Mans Cedex 09, France
| | - M Chaker
- INRS-Energie et Matériaux, 1650 Lionel-Boulet, Varennes, Québec, J3X 1S2, Canada
| | - P Rezaee
- MRD-Tandetron Accelerator & Nanosciences African Network, iThemba LABS-National Research Foundation, P O Box 722, Somerset West, 7129, Western Cape Province, South Africa
- UNESCO-UNISA Africa Chair in Nanosciences and Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, P.O. Box 392, Pretoria, 003, South Africa
| | - N Lethole
- Department Physics, University of Fort Hare, Alice, Eastern Cape Province, South Africa
| | - M Akbari
- MRD-Tandetron Accelerator & Nanosciences African Network, iThemba LABS-National Research Foundation, P O Box 722, Somerset West, 7129, Western Cape Province, South Africa
- UNESCO-UNISA Africa Chair in Nanosciences and Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, P.O. Box 392, Pretoria, 003, South Africa
| | - R Morad
- MRD-Tandetron Accelerator & Nanosciences African Network, iThemba LABS-National Research Foundation, P O Box 722, Somerset West, 7129, Western Cape Province, South Africa
- UNESCO-UNISA Africa Chair in Nanosciences and Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, P.O. Box 392, Pretoria, 003, South Africa
| | - M Maaza
- MRD-Tandetron Accelerator & Nanosciences African Network, iThemba LABS-National Research Foundation, P O Box 722, Somerset West, 7129, Western Cape Province, South Africa.
- UNESCO-UNISA Africa Chair in Nanosciences and Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, P.O. Box 392, Pretoria, 003, South Africa.
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Hlahla JM, Mafa MS, van der Merwe R, Alexander O, Duvenhage MM, Kemp G, Moloi MJ. The Photosynthetic Efficiency and Carbohydrates Responses of Six Edamame ( Glycine max. L. Merrill) Cultivars under Drought Stress. Plants (Basel) 2022; 11:plants11030394. [PMID: 35161375 PMCID: PMC8840725 DOI: 10.3390/plants11030394] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/13/2022] [Accepted: 01/14/2022] [Indexed: 05/06/2023]
Abstract
Vegetable-type soybean, also known as edamame, was recently introduced to South Africa. However, there is lack of information on its responses to drought. The aim of this study was to investigate the photosynthetic efficiency and carbohydrates responses of six edamame cultivars under drought stress. Photosynthetic efficiency parameters, including chlorophyll fluorescence and stomatal conductance, were determined using non-invasive methods, while pigments were quantified spectrophotometrically. Non-structural carbohydrates were quantified using Megazyme kits. Structural carbohydrates were determined using Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Drought stress significantly increased the Fv/Fm and PIabs of AGS429 and UVE17 at pod filling stage. Chlorophyll-a, which was most sensitive to drought, was significantly reduced in AGS429 and UVE17, but chlorophyll-b was relatively stable in all cultivars, except UVE17, which showed a significant decline at flowering stage. AGS354 and AGS429 also showed reduced chlorophyll-b at pod filling. UVE17 showed a significant reduction in carotenoid content and a substantial reduction in stomatal conductance during pod filling. Drought stress during pod filling resulted in a significant increase in the contents of trehalose, sucrose and starch, but glucose was decreased. Chlorophyll-a positively correlated with starch. The FTIR and XRD results suggest that the cell wall of UVE14, followed by UVE8 and AGS429, was the most intact during drought stress. It was concluded that carotenoids, stomatal conductance, starch and hemicellulose could be used as physiological/biochemical indicators of drought tolerance in edamame. This information expands our knowledge of the drought defense responses in edamame, and it is essential for the physiological and biochemical screening of drought tolerance.
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Affiliation(s)
- Jeremiah M. Hlahla
- Department of Plant Sciences-Botany Division, Faculty of Natural and Agricultural Sciences, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa; (J.M.H.); (R.v.d.M.)
| | - Mpho S. Mafa
- Carbohydrates and Enzymology Laboratory (CHEM-LAB), Department of Plant Sciences-Botany Division, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa;
| | - Rouxléne van der Merwe
- Department of Plant Sciences-Botany Division, Faculty of Natural and Agricultural Sciences, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa; (J.M.H.); (R.v.d.M.)
| | - Orbett Alexander
- Department of Chemistry, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa;
| | - Mart-Mari Duvenhage
- Department of Physics, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa;
| | - Gabre Kemp
- Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa;
| | - Makoena J. Moloi
- Department of Plant Sciences-Botany Division, Faculty of Natural and Agricultural Sciences, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa; (J.M.H.); (R.v.d.M.)
- Correspondence: ; Tel.: +27-51-4019483
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Som S, Kumar V, Kumar V, Gohain M, Pandey A, Duvenhage MM, Terblans JJ, Bezuindenhoud BCB, Swart HC. Dopant distribution and influence of sonication temperature on the pure red light emission of mixed oxide phosphor for solid state lighting. Ultrason Sonochem 2016; 28:79-89. [PMID: 26384886 DOI: 10.1016/j.ultsonch.2015.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 06/08/2015] [Accepted: 07/01/2015] [Indexed: 06/05/2023]
Abstract
In this study, europium doped yttrium gadolinium (Y1.4Gd0.5Eu0.1O3) mixed oxide phosphors were synthesized by a sonochemical method at different growth temperatures (50°C, 100°C, 150°C and 200°C) for pure red light emission applications. The compositional identification, presence of dopants and the distribution of doping materials in the crystal lattice was studied by TOF-SIMS. The formation and growth mechanisms in the sonochemical synthesis of Y1.4Gd0.5Eu0.1O3 nanophosphors are discussed in detail. Different spectral and Judd-Ofelt parameters were estimated from photoluminescence data. Optical gain and efficiency parameters were calculated with the variation of synthesis environment and an efficient synthesis method to make good red emitting phosphors for solid-state lighting and display applications were proposed.
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Affiliation(s)
- S Som
- Department of Physics, University of Free State, P.O. Box 339, Bloemfontein, ZA 9300, South Africa
| | - Vijay Kumar
- Department of Physics, University of Free State, P.O. Box 339, Bloemfontein, ZA 9300, South Africa.
| | - Vinod Kumar
- Department of Physics, University of Free State, P.O. Box 339, Bloemfontein, ZA 9300, South Africa
| | - Mukut Gohain
- Department of Chemistry, University of Free State, P.O. Box 339, Bloemfontein, ZA 9300, South Africa
| | - Anurag Pandey
- Department of Physics, University of Free State, P.O. Box 339, Bloemfontein, ZA 9300, South Africa
| | - M M Duvenhage
- Department of Physics, University of Free State, P.O. Box 339, Bloemfontein, ZA 9300, South Africa
| | - J J Terblans
- Department of Physics, University of Free State, P.O. Box 339, Bloemfontein, ZA 9300, South Africa
| | - B C B Bezuindenhoud
- Department of Chemistry, University of Free State, P.O. Box 339, Bloemfontein, ZA 9300, South Africa
| | - H C Swart
- Department of Physics, University of Free State, P.O. Box 339, Bloemfontein, ZA 9300, South Africa.
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