Experimental data showing the influence of different boron nitride particles on the silica network, the butyl stearate and the porogens in shape-stabilized phase change materials.

Shape-stabilized phase change materials (ss-PCMs) based on silica and butyl stearate were thermally enhanced via the addition of different hexagonal boron nitride particles (BN) to the in situ sol-gel synthesis. The dataset is used in conjunction with the experimental data of the influence of the particle size and surface area of BN on the thermal and mechanical properties of ss-PCMs discussed in Marske et al. (2021). To study the effect of the different BN particles on the hydrolysis degree of the silica network and on the chemical nature of the porogens sodium dodecyl sulfate and poly(vinyl alcohol) used for the ss-PCM synthesis, the ss-PCM samples are measured via High Power Decoupling (HPDEC) Magic Angle Spinning (MAS) 29Si NMR and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, respectively. Additionally, data of the influence of BN on the thermal properties is presented as thermogravimetric analysis (TG). The 29Si MAS NMR spectra are referenced to tetramethylsilane and show the different silica species in ppm. The different value of wavenumber and intensity of each reference and ss-PCM sample is listed in the IR spectra. The decomposition points of the ss-PCMs are calculated from the TG data via OriginLab. The spectra and data can be used as a reference for other researchers and engineers to use in synthesizing ss-PCMs based on silica and other polymeric materials or as reference for pure BN, SDS, stabilized silica sol and PVA.

Synthesis of monolithic shape-stabilized phase change materials with high mechanical stability via a porogen-assisted in situ sol-gel process.

The confinement of phase change materials (PCMs) in construction materials has recently solved leakage, supercooling and low thermal conductivity problems in the industrial use of PCMs as monolithic thermal energy storage materials. To produce shape-stabilized PCMs (ss-PCMs) as crack-free monoliths, less than 15-30% v/v pure or encapsulated PCMs can be used in construction materials. Therefore, the heat storage capacity of these monolithic ss-PCM boards is comparatively low. In this study, we synthesized a novel class of monolithic ss-PCM boards with high compressive strength of 0.7 MPa at 30 °C (1.2 MPa at 10 °C), high PCM loadings of 86 wt%, and latent heats in the range of 100 J g-1 via a porogen-assisted in situ sol-gel process. We confined butyl stearate (BS) as PCM in a core-shell-like silica matrix via stabilized silica sol as silica source, sodium dodecyl sulfate as surfactant and poly(vinyl alcohol) as co-polymer. The ss-PCMs obtained are hydrophobic, thermally stable up to 320 °C and perform 6000 state transitions from solid to liquid and vice versa, without losing melting or freezing enthalpies. We analyzed the silica structure in the ss-PCMs to understand in detail the reasons for the high mechanical stability. The silica structure in ss-PCMs consists of spherical meso- and macropores up to 10 000 nm filled with PCM, formed mostly by BS droplets in water as templates during gelation. With an increasing BS amount in the synthesis of ss-PCMs, the total nanopore volume filled with PCM in ss-PCMs increases, resulting in higher compressive strengths up to 500% and thermal conductivities up to 60%.