Simultaneous phase change energy storage and thermoresponsive shape memory properties of porous poly(vinyl alcohol)/phase change microcapsule composites

Abstract

Porous poly(vinyl alcohol) (PVA)/phase change microcapsule composites with shape memory properties were prepared by physical foaming, cycles of freezing-thawing and freeze drying. The effects of phase change microcapsules on pore structure, phase change energy storage capacity, thermal stability, crystallinity, mechanical properties, shape memory properties and water absorption and retention of the porous composites were investigated. With an increase of the proportion of phase change microcapsules, the pore density, pore size and water absorption and retention of the porous composite materials were decreased, while the phase change energy storage performance was improved and ΔH m was up to 31.22 J g −1 . The phase change energy storage of the porous composites was stable even after 50 phase transition cycles. Meanwhile, the thermal stability of the porous composites was also not affected by the addition of phase change microcapsules. The entanglement of PVA molecular chains in the porous composites was affected by the microcapsules embedded in the matrix of PVA during freezingthawing cycles, resulting in a change of crystallinity and mechanical properties of the porous composites. The porous composites with phase change energy storage capacity also showed good shape memory performance with shape recovery rate of 100% even after multiple deformation, which was expected to expand the multi-field application of dual-functional materials.

High thermal storage polyurethane composite embedded with microencapsulated phase change materials and analysis of its unsteady heat transfer

“…where ω is the percentage of MPCM added. PU foams containing MPCM (ntetradecane) 13.5 24.86 [42] MicroPCMs/epoxy composites 20 33.24 [43] Porous poly (vinyl alcohol)/phase change microcapsule composites 60 31.22 [44] PU-MPCM24 24 35.95 In this work data, but there were also some differences. Table 4 presents the errors between the simulated and experimental results.…”

Preparation of high‐hydrophobic polyvinyl alcohol‐based composite aerogel fibers containing organosilicon for effective thermal insulation

“…[1][2][3][4][5] Biodegradable and nontoxic polyvinyl alcohol (PVA) aerogels are believed to be very promising candidates for thermal insulation applications due to their high porosity and low thermal conductivity, nontoxicity, low cost, and good environmental acceptance. [6][7][8][9][10] However, the hydrophilicity of PVA makes the pore structure of aerogels vulnerable to destruction in humid environments, which is found during our previous work. 11 The deformation or contraction of aerogels caused by water also occurs in other aerogel systems.…”

“…Aerogel fibers, a class of highly porous materials with low density and large specific surface area, have attracted increasing attention and are considered the next generation of thermal insulation fibers 1–5 . Biodegradable and nontoxic polyvinyl alcohol (PVA) aerogels are believed to be very promising candidates for thermal insulation applications due to their high porosity and low thermal conductivity, nontoxicity, low cost, and good environmental acceptance 6–10 . However, the hydrophilicity of PVA makes the pore structure of aerogels vulnerable to destruction in humid environments, which is found during our previous work 11 .…”

Paraffin@Silica Microencapsulated Phase Change Materials with Improved Anti‐Leakage Properties

“…But there is still a problem for paraffin, that is, the liquid leakage may occur during the solid‐liquid phase transition, which limits the scope of its application [10,11] . The encapsulation method that forms a core‐shell structure has been reported to solve the liquid leakage of solid‐liquid PCMs, it used suitable support materials to cover the phase change material by emulsion polymerization, sol‐gel technology, suspension polymerization, interfacial polymerization, spray drying, and many more [12–21] . The shell material is essential for the morphology, mechanical properties, and thermal properties of the preparation MEPCM [22] .…”

“…[10,11] The encapsulation method that forms a core-shell structure has been reported to solve the liquid leakage of solid-liquid PCMs, it used suitable support materials to cover the phase change material by emulsion polymerization, sol-gel technology, suspension polymerization, interfacial polymerization, spray drying, and many more. [12][13][14][15][16][17][18][19][20][21] The shell material is essential for the morphology, mechanical properties, and thermal properties of the preparation MEPCM. [22] Shell materials are roughly divided into organic and inorganic shells according to their chemical properties.…”