Rahemipoor Sahand, Kuenzel Carsten, Valdemārs Eiduks Toms, Shishkin Andrei, Izadifar Mohammadreza, Ukrainczyk Neven, Koenders Eduardus, Ranjbar Navid
Department of Civil and Mechanical Engineering, Technical University of Denmark, Kgs Lyngby, 2800, Denmark.
Department of Civil and Environmental Engineering, Imperial College London, London, SW72AZUK, UK.
Adv Sci (Weinh). 2025 Jul;12(26):e2417350. doi: 10.1002/advs.202417350. Epub 2025 Apr 11.
The escalating global energy demand underscores the critical need for advanced solutions for energy-efficient buildings. Passive thermal energy storage systems using microencapsulated phase change materials (PCMs) offer promise but face integration challenges in cementitious materials due to weakening mechanical strength, which arises from poor shell strength and weak interfacial bonding with cementitious phases. This study introduces a novel approach for synthesizing functionalized microencapsulated PCMs from fly ash-based cenospheres addressing interfacial compatibility. Cenospheres are perforated for PCM encapsulation and sealed using two different materials: 1) melamine-formaldehyde (MF), a standard polymeric shell; and 2) silica, selected for its chemical compatibility with cementitious phases. Experimental results show that the silica sealing improved mechanical strength by 50% over those of MF, corroborated by molecular dynamic simulations showing silica's binding energy with calcium silicate hydrate exceeded threefold, with more than twice the uniaxial tensile strength. Thermal analyses confirmed the preservation of PCM in both sealing approaches. This work establishes a transformative pathway for advancing PCM-based thermal energy storage in building materials.
全球能源需求不断升级，凸显了对高能效建筑先进解决方案的迫切需求。使用微胶囊相变材料（PCM）的被动式热能存储系统具有潜力，但由于壳强度差和与胶凝相的界面结合薄弱导致机械强度减弱，在胶凝材料中面临集成挑战。本研究引入了一种从基于粉煤灰的空心微珠合成功能化微胶囊PCM的新方法，以解决界面兼容性问题。对空心微珠打孔以封装PCM，并使用两种不同材料进行密封：1）三聚氰胺 - 甲醛（MF），一种标准的聚合物壳；2）二氧化硅，因其与胶凝相的化学兼容性而被选用。实验结果表明，二氧化硅密封使机械强度比MF提高了50%，分子动力学模拟证实二氧化硅与硅酸钙水合物的结合能超过三倍，单轴拉伸强度是MF的两倍多。热分析证实了两种密封方法中PCM均得以保存。这项工作为推进建筑材料中基于PCM的热能存储建立了一条变革性途径。
