Solvent-Assisted Nanochannel Encapsulation of a Natural Phase Change Material in Polystyrene Hollow Fibers for High-Performance Thermal Energy Storage

Abstract

This work demonstrates a green method for the encapsulation of a natural phase change material (PCM), lauric acid (LA), in polystyrene (PS) hollow fibers through a solvent-assisted diffusion process inside fiber nanochannels. The obtained LAPS composite fibers had a melting enthalpy of up to 147.8 J/g, which was 82.0% the heat storage capacity of pristine LA (180.2 J/g). This capacity was higher than the values (generally less than 60%) reported in the literature. The LA content in the composite fibers could be controlled by the solution concentration and the solvent. On the contrary, encapsulation time had little effect on the final LA loading beyond 1 h due to the rapid diffusion of the LA solution. The optimal LA loading (82.2%) was achieved in 0.4 g/mL LA ethanol solution for 1 h, which was more than 4 times the weight of PS fibers. Simultaneous TGA−DSC, ATR, Raman, and SEM measurements confirmed the homogeneous distribution of LA inside the fibers across the whole membranes. Further, the LAPS composite fibers showed a long-lasting stability during cycling without storage capacity deterioration, as well as an exceptional structural stability without LA leaking and fiber rupture during 100 heating−cooling cycles. The energy-dense and form-stable LAPS composite fibers have a great potential for various thermal energy storage applications like "temperature-smart" buildings and textiles.

Nanofibers for Renewable Energy

“…The average enthalpy of melting was found to be 147.8 J/g, corresponding to 82.0% storage capacity with respect to pure LA [30].…”

“…PEGs [23][24][25][26][27], fatty acids and eutectics [28][29][30][31][32][33] as well as others [18].…”

“…DMF was used as the solvent in the fabrication of PS nanofibers [28][29][30]. Since DMF has a lower vapor pressure than water, it was assumed that water saturated the air jet interface and penetrated the jet to act as a nonsolvent at the relative humidity of 42% and 62%, and cause some of the PS to precipitate to the surface of the fibers, forming a sheath layer.…”

Ultrareliable Composite Phase Change Material for Battery Thermal Management Derived from a Rationally Designed Phase Changeable and Hydrophobic Polymer Skeleton

“…During the fast and/or repeated charge–discharge process, lithium-ion batteries (LIBs) generate a considerable amount of heat, leading to a significant temperature rise as well as an ever-increasing temperature gradient in the entire LIB module. In this context, capacity fading, lifespan degradation, or even fire and explosion in some critical cases occur inevitably. − Therefore, it is of great significance to introduce an effective battery thermal management (BTM) system for the LIB modules in large devices represented by electric vehicles (EVs), with the aim of reducing the temperature rise and homogenizing the temperature distribution of the entire module. − Approaches widely devoted to traditional BTM technologies like forced air cooling (FAC) and liquid cooling (LC) have encountered bottlenecks, for example, low heat dissipation efficiency of FAC and tedious pipeline layout accompanying with leakage risk of LC. − Currently, phase change material (PCM) cooling has been considered competitive as a kind of next-generation BTM technology by virtue of its simple/compact structure yet excellent cooling and temperature-homogenizing capabilities. − …”

Fabrication and Characterization of Electrospun Poly(acrylonitrile-co-vinylidene Chloride) Copolymer/Poly(n-tetradecyl acrylate-co-n-hexadecyl Acrylate) Sheath/Core Nanofiber-wrapped Thermo-regulated Filaments

“…When the thermal resistance of clothes is insufficient or too high, human bodies feel uncomfortable. Thermo-regulated fibers (TRFs), , which contains phase change materials (PCMs) with textiles, can decrease the heat fluctuation intensity to a certain degree because PCMs can absorb and release latent heat during melting and crystallization; thus, the temperature difference between human bodies and the environment is eliminated. − In the field of smart fibers for clothing, investigators have been trying to fabricate TRFs with high latent heat and suitable working temperatures. − With the continuous advancement of textile technology, fibers are becoming more functional and intelligent. Fibers are not only traditional materials used in daily necessities, such as clothing and packaging, but they also play a vital role in cutting-edge technologies.…”