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- Di-Alkyl adipates as new phase change material for low temperature energy storagePublication . Sequeira, Maria Carolina; Nogueira, Bernardo A.; Caetano, Fernando J. P.; Diogo, Herminio; Fareleira, João M. N. A.; Fausto, RuiThis work is a contribution to the thermal characterization of a selected binary system of two di-n-alkyl adipates that can be used as phase change material for thermal energy storage at low temperatures. The construction of the solid–liquid phase diagram using differential scanning calorimetry (DSC), complemented with Raman Spectroscopy studies for the system composed by diethyl and dibutyl adipates is presented. The solidus and liquidus equilibrium temperatures were determined by DSC for the pure components and 30 binary mixtures at selected molar compositions were used to construct the corresponding solid–liquid phase diagram. The binary system of diethyl and dibutyl adipates presents eutectic behaviour at low temperatures. The eutectic temperature was found at 240.46 K, and the eutectic composition was determined to occur at the molar fraction xdibutyl = 0.46. Additionally, the system shows a polymorphic transition, characteristic of dibutyl adipate, occurring at ca. 238 K, confirmed by optical microscopy. To the best of our knowledge, no reference to the phase diagram of the present system could be found in the literature. Raman spectroscopy was essential to complement the construction of the phase equilibrium diagram, enabling the identification of the solid and liquid phases of the system. Finally, the liquidus curve of the phase diagram was also successfully predicted using a suitable fitting equation, being the root mean square deviation of the data from the correlation equal to 0.54 K. In addition, this fitting operation enabled a correct prediction of the eutectic composition of the system.
- Correction: Di-Alkyl Adipates as new phase change material for low temperature energy storagePublication . Nogueira, Bernardo A.; Diogo, Hermínio P.; Fausto, Rui; Caetano, Fernando J. P.; Fareleira, João; Sequeira, Maria CarolinaThe following is a correction to the supplementary information of the paper titled “Di-Alkyl Adipates as new phase change material for low temperature energy storage” by Maria C.M. Sequeira, Bernardo A. Nogueira, Fernando J.P. Caetano, Hermínio P. Diogo, João M.N.A. Fareleira, Rui Fausto that appeared in International Journal of Thermophysics 44:165 (2023). https://doi.org/10.1007/s10765-023-03274-3
- Thermophysical properties of n-alkane system for low temperature thermal energy storagePublication . Nogueira, Bernardo A.; Nikitin, Timur; Diogo, Hermínio P.; Fausto, Rui; Fareleira, João; Caetano, Fernando J. P.; Sequeira, Maria CarolinaOver the past few decades, the escalating need for energy has posed a significant and pressing challenge. For centuries, fossil fuels stood as the dominant energy source; however, due to their dwindling availability and environmental complications, renewable energies have emerged as the promising solution for the future [1]. The intermittent nature of renewable energy sources often results in a disconnect between energy production and consumption, underscoring the vital role of energy storage technologies in enhancing clean energy utilization [2]. Among various energy storage solutions, thermal energy storage (TES) shines as one of the most promising options, offering substantial energy storage capacity at a relatively low cost [3]. In this context, phase change materials (PCMs) are particularly crucial, namelyfor active cooling systems. N-alkanes have been widely investigated for TES applications due to their singular characteristics including their phase transition performance, among others [4]. The objective of this work is to characterize selected n-alkane systems, involving the construction of the solid-liquid binary phase diagrams, using differential scanning calorimetry (DSC) and Raman Spectroscopy. Additionally, the present research efforts seek to obtain the thermal conductivity of these systems. The ongoing investigations play a critical role towards understanding the properties of these systems, enabling to predict their thermal characteristics and performance as PCMs for TES applications. Particularly, for new PCMs phase equilibrium studies are essential to select the appropriate systems with the desired properties for each application. This work is focused on binary systems composed by odd and even alkanes, in particular the binary mixtures C8–C10, C9–C10, C9–C11 and C10–C12. These systems revealed different solid-liquid phase equilibrium behaviour at low temperatures, although three of these four systems exhibited promising capabilities to be used for TES applications at low temperatures. Detailed results on these binary systems will be presented and discussed.