Native and carbonized freeze-cast bacterial cellulose-alginate (BC-ALG) foams possess an ice-templated honeycomb-like architecture with remarkable properties. Their unique pore morphology consists of two levels of porosity: 20–50 µm diameter pores between, and 0.01–10 µm diameter pores within the cell-walls. The mechanical properties of the BC-ALG foams, a Young's modulus of up to 646.2 ± 90.4 kPa and a compressive yield strength of up to 37.1 ± 7.9 kPa, are high for their density and scale as predicted by the Gibson–Ashby model for cellular materials. Carbonizing the BC-ALG foams in an inert atmosphere at 1000–1200 °C in a second processing step, both pore morphology and mechanical properties of the BC-ALG remain well preserved with specific mechanical properties that are higher than those reported in the literature for similar foams. Also the electrical conductivity of the BC-ALG foams is high at 1.68 ± 0.04 S cm⁻¹ at a density of only 0.055 g cm⁻³, and is found to increase with density as predicted, and as a function of the degree of carbonization determined by both carbonization temperature and atmosphere. The property profile makes freeze-cast BC-ALG foams and their carbonized foams attractive for energy applications and as a sorbent.

中文翻译：

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各向异性冷冻铸造天然和碳化细菌纤维素-海藻酸盐泡沫具有优异的机械和电气性能

天然和碳化冷冻铸造细菌纤维素-海藻酸盐 (BC-ALG) 泡沫具有冰模板蜂窝状结构，具有卓越的性能。它们独特的孔隙形态由两个孔隙率组成：细胞壁之间直径为 20-50 µm 的孔隙，细胞壁内直径为 0.01-10 µm 的孔隙。BC-ALG 泡沫的机械性能，杨氏模量高达 646.2 ± 90.4 kPa，压缩屈服强度高达 37.1 ± 7.9 kPa，其密度和规模很高，正如吉布森-阿什比多孔泡沫模型所预测的那样。材料。在第二步处理中，在 1000-1200 °C 的惰性气氛中对 BC-ALG 泡沫进行碳化，BC-ALG 的孔形态和机械性能均保持良好状态，其特定机械性能高于文献报道的机械性能。类似的泡沫。此外，BC-ALG 泡沫的电导率在密度仅为 0.055 g cm ^-3时高达 1.68 ± 0.04 S cm ^-1，并且发现如预测的那样随着密度的增加而增加，并且作为碳化程度的函数由炭化温度和气氛共同决定。这种特性使得冷冻铸造 BC-ALG 泡沫及其碳化泡沫对于能源应用和作为吸附剂具有吸引力。