Study on Structure and Properties of Konjac Glucomannan-Gelatin-Starch Aerogels as Filtration Materials

In order to replace the synthetic organic filtration materials which are difficult to degrade and cause environmental pollution and limited resources, the konjac glucomannan-gelatin-starch aerogels filter materials were prepared via sol-gel and lyophilization methods by using food derived ingredients such as konjac glucomannan and potato starch as raw materials. The micromorphology, density and porosity, mechanical properties and filtration properties of the aerogels were characterized, and the optimized formula was KGM, gelatin and starch with the mass ratio of 1:2:2. The KGS2 aerogels prepared by the best formula had uniform pore size, density of 0.0589 g/cm³, porosity of 84.9%, compressive strength of 848.34 kPa, resistance of 116 Pa, and the filtration efficiency of particles with particle size range was 1~10 μm more than 95%. The weight loss rate of the KGS2 aerogels measured by indoor soil burying method showed that KGS2 aerogels had the highest weightlessness rate in the environment with temperature of 40 ℃, relative humidity of 60%, soil pH value of 8, and reached 100% after 28 days. According to the method in standard ISO 14855-1-2012, the biodegradation rate of the KGS2 aerogels was 78.1% on the 62^th day. The acute oral toxicity test showed that the LD₅₀ of KGS2 aerogels was more than 2.4 g/kg BW. The above experimental results show that KGS2 aerogel has good mechanical properties, low filtration resistance and high filtration efficiency. It is a biodegradable material with high biosafety. It has great potential as a new type of filtering material for environmental protection.