Functional aerogels with sound absorption and thermal insulation derived from semi-liquefied waste bamboo and gelatin

Abstract

The conversion of biomass waste resources into value-added products is an interesting subject. In this paper, a functional biobased aerogel derived from waste bamboo fibres and gelatin was successfully developed. Hydrochloric acid, phenol, and leather shavings were used as additives, and under the action of microwaves, the waste bamboo was semi-liquefied. Semi-liquefied bamboo (SLB) was dispersed in gelatin (G) solution, and then the solution was cross-linked and freeze-dried to obtain SLB-G aerogels. The prepared SLB-G aerogels possessed high porosity (93.6–95.7 %), low density (26.7–35.3 mg cm −3 ), low thermal conductivity (0.057–0.098 W m −1 K −1 ) and excellent sound absorption performance. The results show that SLB is a mixture of bamboo fibres as the key component, showing its compatibility with gelatin solution to produce SLB-G aerogels. Compared with gelatin aerogels alone, SLB-G aerogels have higher thermal stability and mechanical strength, which are important indicators of their application value. The successful development of these aerogels provides a new way to effectively treat bamboo and leather wastes. • Leather shavings were applied to the semi-liquefaction process of waste bamboo. • An oversimplified method to convert waste bamboo into aerogel has been developed. • The semi-liquefied waste bamboo has the function of strength support in aerogel. • The semi-liquefied bamboo − gelatin aerogel has potential in terms of thermal and sound insulation.