Synthesis and characterisation of silica aerogel/fibrous material composites for the purposes of thermal insulation.

全球变暖是人类目前面临的最重大挑战之一，并将在未来几年继续面临。正如IPCC第五次特别报告所指出的，2010年，建筑物占全球能源使用总量的约32%，占全球能源相关温室气体排放总量的约20%[1]。根据IPCC第五次特别报告，到2050年，与建筑物直接相关的能源消耗和相关温室气体可能会增加一倍或两倍[1]。气凝胶被定义为目前存在的最多孔的材料之一。它们的分类是指高度纳米多孔固体的集合，其可以由各种前体产生，使每个气凝胶具有高度可变的特性[2]。因此，气凝胶可以为现有技术提供解决方案并增强现有技术。这些应用包括气凝胶在隔热、药物输送和催化技术中的应用[2]。研究人员的目标是设计并随后合成阻燃气凝胶复合材料，相对于传统的二氧化硅气凝胶，通过在二氧化硅基质中加工纤维材料，具有上级机械性能。预期的应用是作为一种可持续的，轻质的，低成本的替代目前的隔热材料。在进行合成程序之后，还将进行这些复合材料的优化。另一个目的是开发一种大规模的加工方法，其中可以合成相当大的气凝胶。由于溶剂交换老化过程，气凝胶目前在尺寸上受到限制，该过程是扩散限制的，因为如果厚度太大，则溶剂不能充分渗透气凝胶的孔[2]。目的：利用一系列分析技术来确定复合材料的关键参数，以确定材料作为隔热形式的有效性。这些参数包括机械强度（压缩强度，拉伸强度和弯曲强度），导热性和阻燃性。Methodologies：研究人员打算合成单片二氧化硅气凝胶复合材料，通过使用一种新的二氧化硅气凝胶合成技术，涉及某些可持续的，低成本的，无毒的组件，加上一个特定的二氧化硅前体剂。此外，将分析利用上述技术的修改版本的有效性，以确定是否可能使用该方法绕过溶剂交换老化过程，从而合成相当大的气凝胶。这些方法将被用作大规模生产气凝胶的理论加工基础。

Global warming is one of the most significant challenges that humanity is currently facing and will continue to face within the coming years. As noted in the Fifth Special Report by the IPCC, in 2010 buildings were responsible for approximately 32% of the overall global energy usage and approximately 20% of total global energy-associated greenhouse gas emissions [1]. According to the aforementioned IPCC Fifth Special Report, it is believed that the energy consumption and associated greenhouse gases that are directly linked with buildings may double or triple by 2050 [1]. Aerogels are defined as one of the most porous materials currently in existence. Their classification refers to a collection of highly nano-porous solids, which can be produced from a variety of precursors, imbuing each aerogel with highly variable properties [2]. As such, aerogels can provide solutions to, and enhance, current technologies. Such applications include aerogel implementation within heat insulation, drug delivery, and catalysis technologies [2]. The researcher aims to design and subsequently synthesise flame-resistant aerogel composites with superior mechanical properties, relative to that of conventional silica aerogels, through fibrous materials processing within the silica matrix. The intended application is for use as a sustainable, lightweight, and low-cost alternative for current thermal insulation. After the synthesis procedure has been carried out, optimisation of these composites will also be performed. Another aim is to develop a large-scale processing method in which sizable aerogels may be synthesised. Aerogels are currently limited in size due to the solvent-exchange aging process, which is diffusion limited, as the solvents cannot adequately penetrate the pores of the aerogels if the thickness is too significant [2]. Objectives: Utilise an array of analytical techniques in order to determine key parameters of the composites in order to establish the validity of the materials as forms of thermal insulation. Such parameters include the mechanical strength (compressive strength, tensile strength, and flexural strength), thermal conductivity, and flame-resistance.Methodologies: The researcher intends to synthesise monolithic silica aerogel composites, via using a novel silica aerogel synthesis technique involving certain sustainable, low-cost, and non-toxic components, coupled with a specific silica precursor agent. Moreover, the validity of utilising a modified version of the aforementioned technique will be analysed in order to determine if it possible to use this method to bypass the solvent-exchange aging process and therefore synthesise sizeable aerogels. Such methodologies will be utilised as the theoretical processing basis for the large-scale production of aerogels.