Nanofibrous Membranes in Multilayer Fabrics to Avoid PCM Leakages

Abstract

Incorporating phase change materials (PCMs) into textiles is one facial method to realize personal thermal management (PTM). Despite the significant progress of PCM‐incorporated textiles, the incorporation of PCMs into textiles remains an outstanding challenge. In this work, we described a sandwich‐like multi‐layer PCM fabric, which consisted of nanofibrous membranes as barrier layers and PCM‐loaded viscose fabric as a PCM‐loaded layer. Three common organic PCMs including polyethylene glycol (PEG), paraffin wax (PW) and myristic acid (MA), and the polyurethane (PU) nanofibrous membranes was used. As a result, we achieved that weak interfacial adhesion between melting PCMs and PU nanofibrous membranes accounted for leakage phenomena. Only the sample (UPWV) with PU nanofibrous membranes as barrier layers and paraffin wax (PW) as PCMs had no leakage. Little confinement of PW crystallization in the UPWV was found. Besides, thermal energy storage, phase transition, and thermal buffering effect of UPWV supported various applications.

Structural Analysis of Phase Change Materials (PCMs)/Expanded Graphite (EG) Composites and Their Thermal Behavior under Hot and Humid Conditions

“…The suppressed phase transition of PCM/EG composites in temperature range was caused by limited macromolecular movement of embedded PCMs in EG. For PW/EG composites, two peaks during heating and cooling process were found. The peak 1 was contributed by solid‐solid ( SS ) phase transition and peak 2 was contributed by SL phase transition [46] . In details, both SS and SL phase transition of PW/EG composites was narrower than neat PW (Table S5 and Table S7 in Supporting Information).…”

“…The peak 1 was contributed by solid-solid (SS) phase transition and peak 2 was contributed by SL phase transition. [46] In details, both SS and SL phase transition of PW/ EG composites was narrower than neat PW (Table S5 and Table S7 in Supporting Information). Similarly, the finer PW crystals in EG structure contributed to narrower phase transition range by referring XRD analysis.…”

Sandwich Fibrous PEG Encapsulations for Thermal Energy Storage

“…The leakage of sandwich fibrous PEG encapsulations was measured by following previous published work. [32] The photos of sample before and after heating under temperature of 80 °C were taken for comparison to reveal leakage phenomena. Besides, water droplet (25 mL) was deposited on selected fibrous materials after heating/ cooling cycles and water contact angles were for validation of leakage phenomena.…”

“…(A)) according to previous published work. [31,32] Stable heating temperature of 80 °C was used and measurement lasted 2.5 min. The CA values higher than 90°supported weak adhesion and CA values smaller than 90°supported good adhesion.…”

“…We assumed that the interfacial adhesion between melting PEG 6000 and used fibrous materials accounted for the leakage results according to conclusion from our previous work. [32] The measured contact angle of melting PEG 6000 droplet on the used fibrous materials was shown in Figure 1 (C). The melting PEG droplets stably existing on the surface of hydrophobic PET fabric had contact angle higher than 130°after 2.5 min while contact angle value of melting PEG 6000 droplets on other fibrous materials (including viscose fabric, commercial PET fabric and PU nanofibrous membranes) tends to decrease with time and were already smaller than 90°after 10 s. However, the mechanism of weak adhesion seemed not valid for leakage phenomena since leakage was found in sample C3 (PEG,6000) .…”