Thermal insulation is a basic requirement where heat loss or heat gain is a concern, for example, buildings, solar collectors, refrigerators, etc. To reduce the required thickness of insulation, low thermal conductivity is desired. In the recent years, aerogel has emerged as an attractive solution owing to its very low thermal conductivity of around 0.013W/m·K, which is about one-third of the common insulation materials. Polysaccharide-based aerogels are new, sustainable materials, with the potential to transform various industrial processes from petroleum dependent into bio-economic. We have carried out preliminary investigations on bio-sources aerogels prepared from modified KGM and starch to be hydrophobic for hydrophobic property.
The overall aim of the proposed BioCore VIP project is to develop a vacuum insulation panel with eco-friendly bio-sources aerogel as the support core. This bio-sources aerogel will be prepared from natural polysaccharides including konjac glucanmannan (KGM) and those derived from potato starch, chitosan, farm waste, etc. Due to its biodegradable nature, the bio-sources aerogel is a desirable alternative to the conventional silica aerogel. When encapsulated in a vacuum panel, the thermal conductivity of aerogel can be reduced by about a few times due to eliminating convective heat transfer.
The specific objectives of the project are:
i) To investigate the novel use of konjac glucanmannan (KGM) as a skeleton micro-pore structure, and the use of starch, chitosan or other polysaccharides to enhance the mechanical performance of the aerogel. A starch-enhanced KGM aerogel may also have a very good fire-retardant performance.
ii) To control the hydrophilic characteristics of bio-sources aerogel and its degradation rate by formulation, structure modifications and hydrophilic property balance, depending on the application requirement.
iii) To explore the correlations of bio-sources aerogel performances (i.e. thermal insulation and mechanical performances) and its microstructure (i.e. micro-pore structure, size distribution of micro-pore) by regulating the growth of ice crystal and aerogel process conditions, and further to acquire the bio-sources aerogel with desired thermal insulation and mechanical performance.
iv) To establish a procedure to apply the environmentally friendly freeze-drying technique for aerogel preparation, enabling continuous production suitable for industrial scale.
