Self-assembly Synthesis and Properties of Microencapsulated n-Tetradecane Phase Change Materials with a Calcium Carbonate Shell for Cold Energy Storage

Abstract

Sodium dodecyl sulfate (SDS) and alkylphenol polyoxyethylene ether (OP-10) mixed templates, microencapsulated phase change materials (MEPCMs) with an n-tetradecane core, and calcium carbonate (CaCO3) shell were prepared by a self-assembly method. The effects of the core/shell mass ratio and the SDS/OP-10 mass ratio on the morphology and the phase change enthalpy of the synthesized MEPCMs were investigated by polarized optical microscope (POM) and differential scanning calorimetry (DSC), respectively. The structure and the thermal performance of the MEPCMs were systematically characterized by the method of Fourier transform infrared spectroscopy (FT-IR), an X-ray diffractometer (XRD), a scanning electron microscope and energy dispersive spectrometer (SEM-EDS), thermogravimetric analysis (TG), and a thermal constants analyzer. The results demonstrated that the self-assembly technique with SDS/OP-10 mixed templates could be successfully applied for the synthesis of n-tetradecane@CaCO3 MEPCMs with an encapsulation efficiency of 25.86%, and the calcium carbonate shell was the mixture of vaterite and calcite. The synthesized MEPCMs possessed nearly spherical morphology with a mean diameter of 5.0 μm, a latent heat capacity of 58.54 kJ/kg, and excellent thermal conductivity (0.61 W/(m·K)) as well as good thermal stability, indicating that it has good application prospects in cold energy storage.

Phase change microcapsules with lead tungstate shell for gamma radiation shielding and thermal energy storage

“…43 The leakage of microcapsules versus times at 60°C is shown in Figure 8. 44 And it is difficult to form a thick PbWO 4 shell on the surface of paraffin. It is can also be found that the leakage rate decreases with the increasing core/shell mass ratios.…”

“…Since the insufficient lead ions on the paraffin micelle surface, the core material could not be compactly encapsulated by PbWO 4 shell. 44 And it is difficult to form a thick PbWO 4 shell on the surface of paraffin. Therefore, the leakage rate of microcapsules with thick shells is significantly less than that of thin shells, indicating a thick PbWO 4 shell is enough to prevent the paraffin from leaking.…”

A Novel Encapsulation Method for Phase Change Materials with a AgBr Shell as a Thermal Energy Storage Material

“…The latent heats of the micro/nanocapsules during the melting and solidifying process changes with the concentrations of silver nitrate and potassium bromide in solutions. Encapsulation ratio (R) and encapsulation efficiency (E) were calculated according to the following Equations [12]:…”

“…To date, numerous PCMs have been developed [11], and the most commonly used are some organic solid-liquid PCMs, like fatty acids and paraffin, which have superior properties such as a high thermal storage capacity, good chemical stability, little or no super-cooling, well-defined phase-change temperatures, and so on [12]. However, the direct utilization of these organic PCMs for thermal storage is limited due to the leakage problem during their solid−liquid phase transition [13].…”

Temperature–humidity dual regulation of a single-core–double-shell microcapsule fabricated by electrostatic-assembly and chemical precipitation

“…This is because the physicochemical and mechanical properties of shell determines the heat transportation efficiency and durability of phase change microcapsules. 8,9 The conventional shell materials contain organic, 10,11 inorganic [12][13][14][15] and organic-inorganic composite. 16,17 For example, a paraffin-based phase change microcapsule with SiO 2 shell achieved high encapsulation efficiency, good latent heat storage and thermal stability.…”