OpenAIRE - Collezioni speciali delle ricerche finanziate dalla Commissione Europea per l'Open Access

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In questa comunità si trovano i lavori pubblicati con i finanziamenti relativi al 7 Programma Quadro (clausola 39)

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Author: search.filters.author.Calabrò, VincenzaEnd date: 2017

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    Light scattering methods to test inorganic PCMs for application in buildings
    (IOP, 2017) De Paola, Maria Gabriela; Calabrò, Vincenza; De Simone, Marilena
    Thermal performance and stability over time are key parameters for the characterization and application of PCMs in the building sector. Generally, inorganic PCMs are dispersions of hydrated salts and additives in water that counteract phase segregation phenomena and subcooling. Traditional methods or in “house” methods can be used for evaluating thermal properties, while stability can be estimated over time by using optical techniques. By considering this double approach, in this work thermal and structural analyses of Glauber salt based composite PCMs are conducted by means of non-conventional equipment: T-history method (thermal analysis) and Turbiscan (stability analysis). Three samples with the same composition (Glauber salt with additives) were prepared by using different sonication times and their thermal performances were compared by testing both the thermal cycling and the thermal properties. The stability of the mixtures was verified by the identification of destabilization phenomena, the evaluation of the migration velocities of particles and the estimation of variation of particle size.
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    Thermal and Stability Investigation of Phase Change Material Dispersions for Thermal Energy Storage by T-History and Optical Methods
    (MDPI, 2017-03) De Paola, Maria Gabriela; Arcuri, Natale; Calabrò, Vincenza; De Simone, Marilena De Simone
    Glauber’s salt (sodium sulphate decahydrate) is a promising phase change material (PCM) for use in the building sector, thanks to its high enthalpy of fusion associated with a proper phase transition temperature. It also offers economic and environmental advantages because it can be obtained as a byproduct from the disposal process of lead batteries. However, due to phenomena of phase segregation and supercooling, Glauber’s salt cannot be used in its pure state and requires the addition of rheological modifiers and nucleating agents. In this work, the initial thermal performances of mixtures based on Glauber’s salt with different compositions are compared by using the T-history method and adopting sonication for mixing, and following the same preparation procedure for all the samples. With fixed composition, the effects of the addition sequence of the reagents are also examined. The analysis carried out by optical methods based on light scattering (Turbiscan equipment) allowed us to identify the kinetics of destabilization for each sample and revealed the need to specify in detail the preparation stages of PCMs, in order to make the composition reproducible in the laboratory and on a wider scale
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    Preparation and characterization of PCM from Glauber salt recoverable from the disposal of lead batteries
    (2016-12-20) De Paola, Maria Gabriela; Arcuri, Natale; Calabrò, Vincenza; De Simone, Marilena
    Glauber salt (sodium sulfate decahydrate) is a promising phase change material (PCM) to use in the building sector, thanks to the high enthalpy of fusion associated with a proper phase transition temperature. Also it offers economic and environmental advantages because it can be obtained as by product from the disposal process of lead batteries. However the Glauber salt, due to phenomena of phase segregation and subcooling, cannot be used in the pure state but requires the addition of rheological modifiers and nucleating agents. In this work the thermal performances of mixtures based on Glauber salt with different compositions are compared by using T-history method, by adopting sonication for mixing, and following the same preparation procedure for all the samples. Fixed the composition, also the effects of the sequence of addition of the reagents is examined. The analysis carried out by Turbiscan allowed to identify the kinetic of destabilization of each sample and revealed the need to specify in detail the preparation stages of PCM in order to make the composition reproducible in laboratory and on a wider scale.
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    Crossed analysis by T-history and Turbiscan for the characterization of PCM with Glauber salt
    (2016-12-20) De Paola, Maria Gabriela; De Simone, Marilena; Arcuri, Natale; Calabrò, Vincenza
    The Glauber salt (sodium sulfate decahydrate) is a low-cost Phase Change Material (PCM) with promising characteristics. It offers economic and environmental advantages since it can be recovered as a waste product from the lead battery disposal. However, sub-cooling and phase segregation problems [1] require the addition of appropriate additives capable to reduce the melting temperatures as well as the latent heat [2]. These mixtures are dispersions, heterogeneous systems, for which the T-history method [3] seems to be more suitable respect to the traditional DSC, due to the major and more significant sampling. On the other hand, these systems are not thermodynamically stable and need more detailed information on the kinetics of destabilization. With this aim, the authors propose the analysis by using Turbiscan, an instrument commonly used in the pharmaceutical and cosmetic sector since it allows identification of slow and not visible phenomena that precede the dispersion destabilization [4]. Also the integration of the characterization by this method could provide further information on the effectiveness of the additives addition and on the method of samples preparation.