Thermal performance of nanoencapsulated phase change material in high molecular weight polystyrene

Abstract

A novel nanoencapsulation of n-hexadecane in high molecular weight polystyrene nanoparticles for thermal energy storage was carried out by miniemulsion polymerization using an iron-containing imidazolium-based ionic liquid (IL) as catalyst. The particle size, morphology, molecular weight, and thermal performance of nanoparticles containing the phase change material (PCM) were measured by dynamic light scattering, transmission electron microscopy, gel permeation chromatography, and differential scanning calorimetry, respectively. The nanoparticles were regular spherical, with narrow size distribution and particle size ranged from 138 nm to 158 nm. The enthalpy of melting for the nanoencapsulated PCM increased from 19 J/g to 72 J/g, as the content of n-hexadecane used increased from 20 wt% to 50 wt%. In addition, the nanoparticles showed thermal reversibility after 100 thermal cycles. The high molecular weights of the polymer, up to 1800 kDa, that could be reached with this IL may have contributed positively to this thermal behavior.

Polymerization of N‐Butyl Vinyl Ether Catalyzed by Iron‐Containing Imidazolium‐Based Ionic Liquid

“…The high molecular weights reached may have contributed positively to the thermal behavior of polystyrene nanoparticles containing a phase change material encapsulated by miniemulsion polymerization. [28] Up to now, to the best of our knowledge, only the cationic polymerization of 𝛼-pinene, [16,17] isobutylene, [18][19][20] and styrene [21][22][23] mediated by ILs has been studied in detail, while the catalytic efficiency for other monomer polymerizations is still unknown. N-butyl vinyl ether (n-BVE) is a commercially available vinyl ether monomer that undergoes polymerization via a cationic mechanism.…”

“…The high molecular weights reached may have contributed positively to the thermal behavior of polystyrene nanoparticles containing a phase change material encapsulated by miniemulsion polymerization. [ 28 ]…”

Cationic polymerization of styrene using iron-containing ionic liquid catalysts in an aqueous dispersed medium

“…In this direction, it is worth highlighting the controlled cationic polymerizations of styrene in the presence of water [3,13] and the polymerizations of other cationically polymerized monomers in the presence of ionic liquids, such as p-methyl styrene [14] , vinyl ether and its derivatives [15,16] , and isobutylene [17][18][19] . We recently described the efficient encapsulation of hexadecane in high molar mass polystyrene nanoparticles obtained through cationic miniemulsion polymerization [20] , and the synthesis of several ILs catalysts intended to produce tailored polystyrene through bulk polymerization process [21] .…”