Fabrication and characterization of thermally-insulating coconut ash-based geopolymer foam. (October 2018) - Hassan, Hassan Soltan
Highlights: Different alumina slag, and water contents were added to activated-coconut ash. Compressive strength, bulk density, porosity and thermal conductivity were evaluated. Porous CA-based geopolymer foam characterized by high thermal insulation property. Abstract: This study aims at synthesizing porous coconut ash (CA)-based geopolymer foam with high thermal insulation property. Sodium hydroxide (NaOH), alumina slag (AS) and water contents as the main parameters, which affect the performance hardened CA, have been studied. The porosity was developed by hydrogen gas resulted from the interaction of Al metal, in AS, with NaOH. The compressive strength, bulk density, porosity and thermal conductivity were evaluated. The results proved that the AS has a potential impact on the reduction of thermal conductivity of CA-based geopolymer foam by creation of high porous system. Open celled hardened CA-based geopolymer with high porosity (∼87%), low thermal conductivity (∼0.045 W/m·K), compressive strength (1.3 MPa) and bulk density (∼0.60 g/cm 3 ) was obtained when 7% AS (by weight of CA powder) and water to CA powder ratio of 0.4 were used.