Binary mixtures of fatty alcohols and fatty acid esters as novel solid‐liquid phase change materials

Abstract

Summary The discovery of new eutectic phase change materials (PCMs) will overcome the current PCM challenges such as nonbiodegradability, super‐cooling, and limited thermal stability. This paper reports on the development of new bio‐based PCMs composed of binary mixtures of fatty acid esters and fatty alcohols at their eutectic compositions, which provide potential solid‐liquid PCMs for building applications. Six binary systems, namely 1‐dodecanol (DD) + methyl stearate (MES), DD + methyl palmitate (MEP), DD + methyl laurate (MEL), 1‐tetradecanol (TD) + MES, TD + MEP, and TD + MEL were prepared and their thermal behaviours were deliberated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), long‐term thermal stability test, and mass loss analysis. Amongst the studied systems, phase change transition temperature and latent heat of fusion of the eutectic mixtures of DD‐MES, DD‐MEP, TD‐MES, and TD‐MEP were found to be suitable for the building application with values of 22.46°C/201.91 J/g, 20.34°C/224.45 J/g, 32.05°C/209.38 J/g, and 26.72°C/210.15 J/g, respectively. The average degree of super‐cooling for all PCMs was below 2°C, and no significant changes in thermophysical properties of the developed PCMs were observed after 1000 thermal cycles.

A cycling study for reliability, chemical stability and thermal durability of polyethylene glycols of molecular weight 2000 and 10000 as organic latent heat thermal energy storage materials

“…These materials are categorized as inorganic, organic and eutectic (mixture) PCMs. In comparison to inorganic PCMs, organic PCMs (O‐PCMs) possess more desirable properties, such as high LHTES capacity, non‐toxicity, uniform melting, chemically stable, thermally durable, and relatively low volume change during phase change . The O‐PCMs are further classified as fatty acids, parafin, and alcohol in general and inorganic materials are generally salt hydrates .…”

“…In comparison to inorganic PCMs, organic PCMs (O-PCMs) possess more desirable properties, such as high LHTES capacity, nontoxicity, uniform melting, chemically stable, thermally durable, and relatively low volume change during phase change. 2,3 The O-PCMs are further classified as fatty acids, parafin, and alcohol in general and inorganic materials are generally salt hydrates. 4 Cunha and Eames 5 presented a comprehensive review of PCMs between 0 C and 250 C and concluded that the sutable PCMs below 100 C melting temperature are generally organic PCMs.…”

Towards Phase Change Materials for Thermal Energy Storage: Classification, Improvements and Applications in the Building Sector

“…These are the long-term stability, high phase change enthalpy, and facility of impregnating into porous support material due to their high chemical compatibility and surface tension. The main disadvantage is their high cost [14,18]. Thermal properties of some hydrated salts and eutectic mixtures are presented in Table 4.…”

Thermal properties of 3‐hydroxy fatty acids and their binary mixtures as phase change energy storage materials

“…Following this, an experimental validation of the predicted values for eutectic mixtures was carried out (Table 3). 34 Phase change properties of the sample derived from biopolymeric material, PHOD, containing preset amounts of 3-HFAs (C8 and C10) has been assessed by DSC showing no clear transition peaks (data not shown). In this case, it can be proposed that the peritectic mixture was formed as in case of certain FAs.…”

“…16,33 Recently, binary mixtures of fatty alcohols and FA esters with chain length ≥ C12 were derived and suggested to be suitable as PCMs for building application. 34 Phase change properties of the sample derived from biopolymeric material, PHOD, containing preset amounts of 3-HFAs (C8 and C10) has been assessed by DSC showing no clear transition peaks (data not shown). This could be due to the fact that 3-HFAs mixture obtained from this biopolymer was not simple binary mixture but contained at least two other major components, namely unsaturated and saturated C8 and C10 acids in 16% to 25% (w/w) and 4% to 6% (w/w), respectively.…”