Nanocellulose based shape-stabilized phase change material (PCM) for building construction

近年来，绿色工业的要求是限制石油基化学品的使用，因为石油基化学品日益增长的消费正在带来严重的环境问题，包括快速的气候变化、水污染和有害气体排放，以及由于其高昂的成本而威胁到全球经济。此外，重要的是要认识到，化石原材料和有限的资源将在几代人内耗尽，因此应该避免使用石油基聚合物。在以往的文献中，用于包裹相变材料的石油基聚合物通常是三聚氰胺-甲醛、尿素-甲醛、尿素-三聚氰胺-甲醛、聚苯乙烯、苯乙烯、聚氨酯和聚尿素。纳米纤维素是一种生物聚合物，由于它对环境友好，过去已被证明在研究及其在不同领域的应用方面取得了重大进展，因此可以替代它。尚未开发技术来形成具有纳米纤维素的形状稳定的相变材料，并将其纳入建筑系统。研究目的相变材料中出现的常见问题是相变过程中的泄漏，这往往限制了其在热能储存、太阳能储存、建材和纺织等领域的应用。然而，这一问题可以通过形成形状稳定的相变材料来解决，这包括将相变材料集成到支撑材料中，或者将相变材料微胶囊化为壳体材料，从而形成复合相变材料和微胶囊相变材料。该项目的具体目标可概括如下：在该项目中，将采用一种可行的方法来开发基于纳米纤维素聚合物的形状稳定的相变材料，以生产相变材料复合材料或微胶囊/纳米胶囊。将从以前的文献中选择适合于建筑材料的相变材料类型，即具有高潜热值等所需特性的相变材料，而且应该是环境友好的。功能化生物聚合物的开发：从选定的纤维素材料中提取的纳米纤维素将开发出纳米纤维素聚合物。除了对指定的相变材料进行封装以生产微胶囊或复合材料外，该聚合物还将进一步功能化，以达到建筑材料所需的性能。发展以相变材料为基础的建筑材料。将对各种工艺进行调查，以确保能量储存的有效并入、稳定和效率。

In the recent years, the demand of green industry is to limit the usage of petroleum based chemicals since their increasing consumption is posing critical environmental problems, including rapid climate change, water pollution and harmful gas emissions along with threatening global-economy due to their high costs. Furthermore, it is important to realise that fossil raw materials and finite resources will deplete within a few generations, so using petroleum-based polymers should be avoided. In previous literature, the commonly used petroleum-based polymers to encapsulate phase change materials (PCMs) were melamine-formaldehyde, urea-formaldehyde, urea-melamine-formaldehyde, polystyrene, styrene, polyurethane and polyurea. Nanocellulose which is a biopolymer could be used instead since it is environmentally friendly and in the past it has proven to possess significant advancements in research and their applications in different fields. Technologies are yet to be developed to form shape-stabilized PCMs with nanocellulose and their incorporation in building systems. Objectives of the research Common problems arising in PCMs is leakage during the phase transition process which tends to limit their applications in various fields including thermal energy storage, solar energy storage, building materials and textiles. However, this problem can be solved through the formation of shape-stabilized PCMs, which involves either integration of PCM into a supporting material or microencapsulating PCM into a shell material which results in the formation of namely composite PCMs and microencapsulated PCMs. The specific objectives of the project may be summarised as follows: In this project shape-stabilized PCMs based on nanocellulose polymer will be developed by employing a feasible method to produce either PCM composites or microcapsules/ nanocapsules. Suitable type of PCM for building materials will be selected from previous literature i.e. PCM that exhibits desired characteristics such as high latent heat value and moreover, should be environmentally friendly. Development of functionalised biopolymer: Nanocellulose polymer will be developed from nanocellulose extracted from selected cellulosic material. The polymer will be further functionalised for the required properties for building materials, in addition to the encapsulation of the designated PCM to produce microcapsules or composites. PCM based construction materials will be developed. Various processes will be investigated to ensure the effective incorporation, stabilisation and efficiency of energy storage.