Development and Performance of Eco-Sustainable Form-Stable Phase Change Materials (PCMs) for Mortars to Be Applied in Buildings Located in Different Climatic Areas

Abstract

The growing concern for the environment and the depletion of raw materials such as fossil fuels is driving research towards the exploitation of new materials and the development of new technologies. Phase-change materials (PCMs) are increasingly used to reduce the energy required for the heating/cooling of buildings. The biggest challenge is to find a PCM with suitable characteristics able to meet the needs of the different climates in which it is placed. The originality of our research, therefore, lies in the possibility of selecting the most appropriate polymer to produce a PCM suitable for different climatic conditions that characterize the area in which a building is located. Furthermore, the proposed form-stable PCMs were obtained by including low-toxic, low-flammability polymers in waste stone fragments, according to the principles of a circular economy. These original sustainable PCMs were then used as aggregates by adding them to mortars (based on air lime, hydraulic lime, cement and gypsum). The mortars containing the PCMs were analyzed in fresh (workability) and hardened (flexural and compressive strengths and thermal characteristics) states. The results obtained showed that although the inclusion of PCM reduced the mechanical properties of the mortars, good mechanical properties can be still achieved by using an adequate binder content. The produced mortars were also analyzed by thermal analysis to assess how the addition of a PEG-based PCM affected their thermal behavior. The original PCMs were proven to be effective in improving the indoor temperature when included in mortars applied as plasters.

Selection of PEG-Matrix Combinations to Achieve High Performance Form-Stable Phase Change Materials for Building Applications

“…In another study [30], the development of a form-stable PCM based on PEG1000 embedded into flakes of waste Lecce stone (LS), byproducts of the processing of this very porous stone, was investigated for possible applications in different mortars. Further investigations, reported in [107][108][109][110], analyzed different compositions of PEG800-based and PEG1000-based PCMs within LS, in order to identify the PCM composition giving rise to the best performance when included in mortars based on different binders (aerial and hydraulic limes, gypsum, and cement). In [111][112][113], the thermal performance of PEG800/LS and PEG1000/LS PCMs was assessed, taking as reference two different climate zones (i.e., Mediterranean and continental Europe); the produced PCMs proved to be particularly effective in reducing temperature fluctuations in hot seasons.…”

Experimental investigation of enhanced form‐stable phase change material based on stearic acid/expanded graphite/SEBS composite

“…21 Frigione worked with stone fragments to make the composite which can be integrated with cementitious materials. 22 Although several studies have explored the various strategies of "form-stabilizing" PCMs, there is a dearth of commercially relevant, economically viable, and technologically versatile FSPCMs that may be integrated into thermal energy storage solutions. Most of the materials are focused on building materials.…”

“…Kumar et al worked on porous materials like expanded glass, silica aerogel granules, and expanded perlite to prepare the composite which can be integrated with the cementitious material 21 . Frigione worked with stone fragments to make the composite which can be integrated with cementitious materials 22 …”

A critical review of polymer support‐based shape‐stabilized phase change materials for thermal energy storage applications

“…25 Therefore, encapsulating PCMs within waste plastics offers a dual benefit of mitigating plastic waste pollution while enhancing the energy storage capabilities of the materials. 34 The environmental impact of producing SSPCMs can be evaluated through life cycle analysis frameworks, which examine the ecological footprint at different stages of the product's life cycle, such as raw material extraction, manufacturing, usage, disposal, and recycling options. Incorporating renewable energy sources and energy-efficient techniques can contribute to minimizing the ecological footprint during manufacturing.…”

“…By incorporating waste stone fragments and employing low‐toxic, low‐flammability polymers in SSPCM production, there is an advancement towards aligning with the principles of a circular economy and diminishing the ecological footprint of manufacturing processes 25 . Therefore, encapsulating PCMs within waste plastics offers a dual benefit of mitigating plastic waste pollution while enhancing the energy storage capabilities of the materials 34 …”