Abstract 3D-structured silica exoskeletons-diatomite was used as reactive inorganic ingredient, with and without metakaolin to produce sustainable multifunctional diatomite-based geopolymeric foams. Suitable amount of Silicon powder and vegetable surfactant were used as foaming agents, while polysilicate solution was used as reactive crosslinker. The resulting porous materials, characterized by hierarchical porosity ranging from macro to nano-scale, were fabricated at 40 °C for 24 h and characterized by means of chemical and morphological investigations, contact angle, thermal and acoustic properties and fire reaction. The presence of diatomite in the produced foams provides an increase of thermal inertia, and the thermal insulation performance firstly due to the intrinsically low thermal conductivity of diatomite and also because silicon and vegetable surfactant are able to promote the formation of a co-continuous mesoporous structure. Furthermore, the created morphological structure provides a good acoustic absorption coefficient in a wide range of frequency. Finally, due to their hydrophilicity/oleophobicity character, diatomite-based geopolymeric foams could, potentially, be proposed as oil/water separation membranes.

中文翻译：

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基于 3D 结构二氧化硅外骨骼、硅藻土的可持续多孔材料的设计：化学物理和功能特性

摘要 以 3D 结构二氧化硅外骨骼-硅藻土为反应性无机成分，添加或不添加偏高岭土，制备可持续的多功能硅藻土基地质聚合物泡沫。适量的硅粉和植物表面活性剂作为发泡剂，聚硅酸盐溶液作为反应交联剂。所得多孔材料具有从宏观到纳米级的分级孔隙率，在 40°C 下制备 24 小时，并通过化学和形态学研究、接触角、热学和声学特性以及火灾反应进行表征。产生的泡沫中硅藻土的存在提供了热惯性的增加，其绝热性能首先是由于硅藻土固有的低导热性，也因为硅和植物表面活性剂能够促进共连续介孔结构的形成。此外，所创建的形态结构在很宽的频率范围内提供了良好的吸声系数。最后，由于其亲水性/疏油性，基于硅藻土的地质聚合物泡沫可能被提议用作油/水分离膜。