Production of Carbon Foams from Rice Husk

Abstract

The production of a material with rigid, multifunctional three-dimensional porous structure at a low cost is still challenging to date. In this work, a light and rigid carbon foam was prepared using rice husk as the basic element through a simple fermentation process followed by carbonization. For the fermentation process, the amount of biological yeast (7.5 g for the carbon foam CA-1P and 5 g for the carbon foam CA-2P) was used to evaluate its influence on the morphology of the foams. In order to prove that the heat treatment made in the foam alters the hydrophilic character of the rice husk foam, a chemical treatment with steam deposition was carried out. The foams were characterized by the following analyzes: apparent density, micrograph, thermogravimetry, contact angle, water sorption capacity and thermal conductivity. Visually, the CA-1P foams presented a structure with larger pores due to the greater amount of yeast used in its formulation. The heat treatment of rice potato foams proved to be as efficient as the chemical treatment for water contact angle above 90º, proving the ability of the foams to repel water/moisture. The thermal conductivity of the foams (0.029 and 0.026 W m-1 K-1 for CA-1P and CA-2P, respectively) was close to the conductivity of polyurethane foams (0.032 W m-1 K-1). Thus, the method used in the production of the carbon foams produced from the rice husk proved to be effective. In addition, the foams produced have the potential to be used for thermal insulation.

One/Two-Step Contribution to Prepare Hierarchical Porous Carbon Derived from Rice Husk for Supercapacitor Electrode Materials

“…A total mass loss of 78% was observed in the studied temperature range after the above three decomposition stages. The residual mass was approximately 22%, consistent with other recent findings …”

“… 39 , 40 At a lower carbonization temperature, the RH-based carbon material showed an uneven surface morphology owing to the loss of water and incomplete decomposition of biomass in the RH. 32 When the carbonization temperature was above 900 °C, crystallization occurred in the RH, and the structure became clear and orderly arranged. When the carbonization temperature reached 1000 °C, according to the previous thermogravimetric analysis and hydrogen element analysis, the cellulose, hemicellulose, and lignin in the RH were basically decomposed, and thus the obtained RH-based carbon material showed a highly uniform pore size and a relatively high specific surface area and pore volume.…”

“…However, the carbonization temperature had some influence on the micromorphology of the RH-based carbon material. With the temperature increasing, the organic components in the RH were pyrolyzed, and the released low-molecular volatiles facilitated the formation of the pore structure, resulting in a noticeable rough morphology with cracks. , At a lower carbonization temperature, the RH-based carbon material showed an uneven surface morphology owing to the loss of water and incomplete decomposition of biomass in the RH . When the carbonization temperature was above 900 °C, crystallization occurred in the RH, and the structure became clear and orderly arranged.…”

Enhanced biodegradation and processability of biodegradable package from poly(lactic acid)/poly(butylene succinate)/rice‐husk green composites

“…In‐situ crosslinking between RH and PLA with MA coupling agent during the preparation of PLA/PBS/RH green composites via a twin‐screw extruder at high temperatures was investigated by FTIR and the results are shown in Figure 2 (Figure S1, for clarity). RH shows typical absorption bands of cellulose at 3330 cm −1 (OH stretching), 2890 and 2970 cm −1 (CH vibration) and 1047 cm −1 (COH stretching) and the absorption peak of silica at 780 cm −1 (SiOSi stretching) 28 . Typical absorption bands of neat PLA were found at 2999 cm −1 (asymmetric stretching vibration of CH from CH 3 ), 1752 cm −1 (CO stretching of aliphatic ester), 1454 and 1386 cm −1 (asymmetric and symmetric bending vibration of CH from CH 3 ), 1356 cm −1 (bending vibration of CH), 1182 and 1082 cm −1 (asymmetric and symmetric stretching of COC), and 1043 cm −1 (stretching of COH) 29–32 …”

Low-Isocyanate Polyurethane Foams with Improved Stability and Compression Modulus Prepared from Biosourced and Landfill-Diverted Materials

“…35,37 Both have peaks at 1635 cm −1 which indicate alkene groups and possibly −OH bending from adsorbed water molecules. 37,38 The peaks at 1030 cm −1 (CC) and 1049 cm −1 (RH) indicate carbonyl stretching. 35,37,38 Prepolymer samples were analyzed with FT-IR immediately after the 30 min prepolymer reaction was completed, with representative spectra displayed in Figure 2b.…”