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Moreno-Velarde F, Martín EI, Hidalgo Toledo J, Sánchez-Coronilla A. DFT Study on the Enhancement of Isobaric Specific Heat of GaN and InN Nanosheets for Use as Nanofluids in Solar Energy Plants. MATERIALS (BASEL, SWITZERLAND) 2023; 16:915. [PMID: 36769922 PMCID: PMC9917575 DOI: 10.3390/ma16030915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/13/2022] [Accepted: 01/16/2023] [Indexed: 06/18/2023]
Abstract
In this work, GaN and InN nanosheets with dodecylamine (DDA) as surfactant have been studied as nanofluids to be used in solar plants. The interactions between the sheets and the surfactants have been performed using density functional theory. The most favorable interaction site on the surface corresponds to the metallic atom of the sheet with the N atom of the surfactant. In this interaction, the pair of electrons of N from the surfactant with the metal atom of the sheet play a stabilizing role, which is corroborated by electron localization function (ELF), quantum theory of atoms in molecules (QTAIM), and density of states (DOS) analysis. The isobaric specific heat values for the most favorable interaction were obtained in the presence of water, ethylene glycol, and diphenyl oxide as solvents for the first time. The highest value corresponds to systems with diphenyl oxide, being the values obtained of 0.644 J/gK and 0.363 J/gK for GaN-DDA and InN-DDA systems, respectively. These results open the possibilities of using GaN-DDA and InN-DDA systems in solar energy applications.
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Affiliation(s)
- Francisco Moreno-Velarde
- Departamento de Química Física, Facultad de Farmacia, Universidad de Sevilla, E-41012 Sevilla, Spain
| | - Elisa I. Martín
- Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, E-41012 Sevilla, Spain
| | - José Hidalgo Toledo
- Departamento de Química Física, Facultad de Farmacia, Universidad de Sevilla, E-41012 Sevilla, Spain
| | - Antonio Sánchez-Coronilla
- Departamento de Química Física, Facultad de Farmacia, Universidad de Sevilla, E-41012 Sevilla, Spain
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Interface-inspired formulation and molecular-level perspectives on heat conduction and energy storage of nanofluids. Sci Rep 2019; 9:7595. [PMID: 31110192 PMCID: PMC6527549 DOI: 10.1038/s41598-019-44054-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 05/08/2019] [Indexed: 11/12/2022] Open
Abstract
Aiming for the introduction of stability requirements in nanofluids processing, an interface-based three-step method is proposed in this work. It is theory-based design framework for nanofluids that aims for a minimum tension at the solid-liquid interface by adjusting the polar and dispersive components of the base fluid to meet those of disperse nanomaterial. The method was successfully tested in the preparation of aqueous nanofluids containing single-walled carbon nanotubes that resulted to be stable and to provide good thermal properties, i.e. thermal conductivity increases by 79.5% and isobaric specific heat by 8.6% for a 0.087 vol.% load of nanotubes at 70 °C. Besides, a system for these nanofluids was modelled. It was found to be thermodynamically consistent and computationally efficient, providing consistent response to changes in the state variable temperature in a classical Molecular Dynamics environment. From an analysis of the spatial components of the heat flux autocorrelation function, using the equilibrium approach, it was possible to elucidate that heat conduction through the host fluid is enhanced by phonon propagation along nanotubes longitudinal axes. From an analysis of the structural features described by radial distribution functions, it was concluded that additional heat storage arises from the hydrophobic effect.
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Aguilar T, Carrillo-Berdugo I, Gómez-Villarejo R, Gallardo JJ, Martínez-Merino P, Piñero JC, Alcántara R, Fernández-Lorenzo C, Navas J. A Solvothermal Synthesis of TiO₂ Nanoparticles in a Non-Polar Medium to Prepare Highly Stable Nanofluids with Improved Thermal Properties. NANOMATERIALS 2018; 8:nano8100816. [PMID: 30309047 PMCID: PMC6215110 DOI: 10.3390/nano8100816] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 10/02/2018] [Accepted: 10/09/2018] [Indexed: 12/05/2022]
Abstract
Nanofluids are systems with several interesting heat transfer applications, but it can be a challenge to obtain highly stable suspensions. One way to overcome this challenge is to create the appropriate conditions to disperse the nanomaterial in the fluid. However, when the heat transfer fluid used is a non-polar organic oil, there are complications due to the low polarity of this solvent. Therefore, this study introduces a method to synthesize TiO2 nanoparticles inside a non-polar fluid typically used in heat transfer applications. Nanoparticles produced were characterized for their structural and chemical properties using techniques such as X-ray Diffraction (XRD), Raman spectroscopy, Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The nanofluid showed a high stability, which was analyzed by means of UV-vis spectroscopy and by measuring its particle size and ζ potential. So, this nanofluid will have many possible applications. In this work, the use as heat transfer fluid was tested. In this sense, nanofluid also presented enhanced isobaric specific heat and thermal conductivity values with regard to the base fluid, which led to the heat transfer coefficient increasing by 14.4%. Thus, the nanofluid prepared could be a promising alternative to typical HTFs thanks to its improved thermal properties and high stability resulting from the synthesis procedure.
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Affiliation(s)
- Teresa Aguilar
- Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
| | - Ivan Carrillo-Berdugo
- Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
| | - Roberto Gómez-Villarejo
- Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
| | - Juan Jesús Gallardo
- Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
| | - Paloma Martínez-Merino
- Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
| | - José Carlos Piñero
- Departamento de Ciencias de los Materiales, Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
| | - Rodrigo Alcántara
- Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
| | - Concha Fernández-Lorenzo
- Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
| | - Javier Navas
- Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
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Mejías FJR, Gutiérrez MT, Durán AG, Molinillo JMG, Valdivia MM, Macías FA. Provitamin supramolecular polymer micelle with pH responsiveness to control release, bioavailability enhancement and potentiation of cytotoxic efficacy. Colloids Surf B Biointerfaces 2018; 173:85-93. [PMID: 30273872 DOI: 10.1016/j.colsurfb.2018.09.057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/21/2018] [Accepted: 09/22/2018] [Indexed: 12/22/2022]
Abstract
Encapsulation techniques to generate core/shell systems provide a method that improves physicochemical properties, which are very important in biological applications. β-carotene is a common carotenoid that has shown preventive effects in skin diseases and vitamin A deficiency but this compound has limited water solubility and bioavailability, which hinder its broad application. The use of polyrotaxane compounds formed from cyclodextrins has allowed supramolecular polymer micelles (SMPMs) to be synthesized to encapsulate β-carotene. The polymeric compound Pluronic F127® was also used to create core/shell nanoparticles (NPs) that contain β-carotene. Bioactive compound encapsulation was fully confirmed by nuclear magnetic resonance spectroscopy and by scanning and transmission electron microscopy. The method based on cyclodextrin and lecithin allow to release slowly when the systems were exposed to an aqueous medium by pH control, with an increase of 16 times of bioavailability comparing with free carotenoid. This allowed to potentiate the cytotoxic activity on a melanoma cell line by enhancing the water solubility to more than 28 mg/L, and present promising applications of SMPMs to provitamins.
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Affiliation(s)
- Francisco J R Mejías
- Allelopathy Group, Department of Organic Chemistry, Institute of Biomolecules (INBIO), Campus de Excelencia Internacional (ceiA3), School of Science, University of Cadiz, C/ República Saharaui, 7, 11510, Puerto Real, Cádiz, Spain
| | - M Teresa Gutiérrez
- Allelopathy Group, Department of Organic Chemistry, Institute of Biomolecules (INBIO), Campus de Excelencia Internacional (ceiA3), School of Science, University of Cadiz, C/ República Saharaui, 7, 11510, Puerto Real, Cádiz, Spain
| | - Alexandra G Durán
- Allelopathy Group, Department of Organic Chemistry, Institute of Biomolecules (INBIO), Campus de Excelencia Internacional (ceiA3), School of Science, University of Cadiz, C/ República Saharaui, 7, 11510, Puerto Real, Cádiz, Spain
| | - José M G Molinillo
- Allelopathy Group, Department of Organic Chemistry, Institute of Biomolecules (INBIO), Campus de Excelencia Internacional (ceiA3), School of Science, University of Cadiz, C/ República Saharaui, 7, 11510, Puerto Real, Cádiz, Spain
| | - Manuel M Valdivia
- Department of Biomedicine, Biotechnology and Public Health, Institute of Biomolecules (INBIO), School of Science, University of Cadiz, C/República Saharaui, 7, 11510 Puerto Real, Cádiz, Spain
| | - Francisco A Macías
- Allelopathy Group, Department of Organic Chemistry, Institute of Biomolecules (INBIO), Campus de Excelencia Internacional (ceiA3), School of Science, University of Cadiz, C/ República Saharaui, 7, 11510, Puerto Real, Cádiz, Spain.
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