Thermally Triggered Nanocapillary Encapsulation of Lauric Acid in Polystyrene Hollow Fibers for Efficient Thermal Energy Storage

Abstract

This article describes a green approach to the transportation and encapsulation of lauric acid (LA), a natural food-grade phase change material (PCM), in polystyrene (PS) hollow fibers. By simply tuning the temperature, the obtained LAPS composite fibers achieved an unprecedented thermal energy storage capacity up to 81.6% of pristine LA. This capacity was higher than the reported values in the literature which were generally less than 50%. The thermally triggered nanocapillary transportation and encapsulation of LA did not alter the size and morphology of PS hollow fibers. Furthermore, the LA was contained inside PS hollow fibers, leaving the interfiber space and surface free of LA. Direct SEM observation, IR spectra, Raman spectra, XRD diffractograms, and simultaneous TGA–DSC thermograms of LAPS composite fibers proved that the amount of encapsulated LA declined with the elevation of temperature. The distribution of LA in PS hollow fibers was found to be homogeneous across the membrane by TGA and SEM. Further, the LAPS composite fibers demonstrated a robust cycling stability and reusability without notable deterioration of thermal storage capacity during 100 continuous heating–cooling cycles. Also, the composite fibers showed excellent structural stability without any fiber rupture or LA leakage during prolonged and repeated heating–cooling cycles.

Cellulose Nanofibrils Endow Phase-Change Polyethylene Glycol with Form Control and Solid-to-gel Transition for Thermal Energy Storage

“…For instance, the T m values for PCN prepared with PEG4000 (C-compositions) are reduced from 62.4 to 57.4 °C. The enthalpy of fusion of the PCN compositions (e.g., 146 J/g) competes with those of existing PCMs, such as paraffins (100–200 J/g) 8 and recently reported PCM composites, including encapsulated fatty acids in polystyrene hollow fibers (147 J/g), 12 encapsulated paraffin in nanocellulose (139 J/g), 25 electrospun fiber-supported PCMs (∼166 J/g), 52 electrospun fibers of PEG-cellulose acetate (120 J/g), 18 and PEG incorporated in isocyanate-terminated prepolymer and tetrahydroxy prepolymer (98 J/g). 53 Note that most existing PCMs suffer from drawbacks such as volume change, leakage, fossil fuel-based origin, and instability.…”

“…Various other segments of industry, such as active-packaging, refrigeration, electronics, sensors, and those associated with waste heat recovery can benefit from these versatile materials. 11 , 12 For example, PCM-activated fabrics are used as a thermal buffer in response to drastic environmental temperature changes, for example, to maintain the body comfort, which is attractive for industrial, medical, and aerospace purposes. 13 Lithium-ion batteries protected with PCMs have been shown to be more resistant against breakdown in cold temperatures.…”

Ionic cross-linked polyvinyl alcohol tunes vitrification and cold-crystallization of sugar alcohol for long-term thermal energy storage

“…The increase in the latent heat after storage and cycling originates from the increase in homogeneity and consolidation of the PCM over time and cycling. 30 The material showed excellent structural and mechanical stability without any rupture or leakage of the PCM during prolonged and repeated heating-cooling cycles. The improving effect of cycling has been previously reported for hydrated PVA gels.…”

“…solar energy. 28 Existing PCMs for TES include paraffins, 1,3,17,19 fatty acids 1,3,29,30 and salt hydrates. 1,3,8,10,15,16 However, these PCMs suffer from several drawbacks including flammability, fossilfuel based origin, large volume change, instability and phase segregation issues, 1,3 while, the CC-PCM developed herein is based on green sugar alcohol PCM with the advantages of biobased origin, non-flammability, nontoxicity, non-corrosiveness, and affordable market price, making them suitable for sustainable applications.…”

Silica-Based Core-Shell Nanocapsules: A Facile Route to Functional Textile

“…They have been widely employed in solar energy storage [8], building applications [9], the food industry [10] and pharmaceutical applications [11]. PCM has also been incorporated into wearables such as gloves, shoes, coats, and sleep bags as a smart textile [12]. Paraffin was found to be one of the most promising PCMs for textiles.…”