Organic Preforms of Biological Origin: Natural Plant Tissues as Templates for Inorganic and Zeolitic Macrostructures
Organic Preforms of Biological Origin: Natural Plant Tissues as Templates for Inorganic and Zeolitic Macrostructures
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生物来源的有机预成型件：天然植物组织作为无机和沸石宏观结构的模板
DOI：
10.1002/9783527619443.ch38
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Peter Greil
中科院分区：
文献类型：
--
作者：
Alessandro Zamperi;Wilhelm Schwieger;Cordt Zollfrank;Peter Greil
作为进化过程的结果，自然界展示了大量具有复杂层次结构的生物材料和各种各样的细胞/多孔结构和功能结构。这些材料中的大多数都表现出微观/宏观结构特征，这些特征很难或不可能通过技术过程来复制。然而，将这种生物结构复制到工程材料中可能是开发具有新结构和性能的无机材料的关键。特别是，从技术角度来看，廉价、丰富和可再生的生物结构（如植物组织）代表了制造生物形态陶瓷基板的有趣的预成型/模板。开放的细胞解剖结构为液体或气体反应物的渗透提供了通道，将生物预成型物或碳模板转化为碳化物或氧化物基陶瓷。这种生物形态细胞陶瓷可以作为沸石层的新型单片支撑，产生具有独特结构和性能的分层多孔复合材料。另一方面，细胞生物预成型可以直接用作牺牲模板，以获得具有复杂形态和开放多孔结构的生物启发自支撑沸石宏观结构。由于其独特的结构和功能，沸石基生物形态材料可能在催化剂、分子筛、吸附剂和具有分层孔隙和组织的膜的发展中开辟新的前景。在本章中，我们提出了两种实现具有分层孔隙度的生物形态细胞无机沸石基材料/复制品的方法。一方面，细胞生物载体受到三步生物模板过程的影响：(i)生物模板的热解；（ii）液态硅渗透（LSI），用于开发生物形态的SiSiC细胞陶瓷支架；（iii）支持沸石晶体在上述多孔基质的内腔中生长的自转化（SST）。另一方面，生物结构如luffasongse和纤维素纤维已被用作合成自支撑沸石复制品的牺牲模板，它们模拟了有机材料的形态和微观结构。
Nature displays a huge number of biological materials with complex hierarchically built anatomies and a large variety of cellular/porous structures and functional architectures, as the result of evolutionary processes. Most of these materials exhibit micro‐/macro‐structural features which are difficult, or impossible, to reproduce via technical processes. Nonetheless, reproducing such biostructures into engineering materials might be the key for the development of inorganic materials with novel structures and properties. In particular, inexpensive, abundant, and renewable biological structures such as plant tissues represent, from the technical point of view, interesting preforms/templates for the manufacturing of biomorphous ceramic substrates. The open cellular anatomy provides access for infiltration with liquid or gaseous reactants to convert the biological preform or the carbon template into carbide‐ or oxide‐based ceramics. Such biomorphous cellular ceramics can be used as novel monolithic supports for zeolite layers, producing hierarchically porous composites with unique structures and properties. On the other hand, cellular biological preforms could be used directly as sacrificial templates, in order to obtain bio‐inspired self‐supporting zeolite macrostructures with complex morphologies and open‐porous architectures. Owing to their unique structures and functionalities, zeolite‐based biomorphous materials might open new scenarios in the development of catalysts, molecular sieves, adsorbents and membranes with hierarchical porosity and organization. In this chapter we present two approaches towards the realization of biomorphous cellular inorganic zeolite‐based materials/replica with hierarchical porosity. On the one hand, cellular biological supports have been subjected to a three‐step biotemplating process: (i) pyrolysis of the biotemplate; (ii) liquid silicon infiltration (LSI) for the development of biomorphous SiSiC cellular ceramic supports; and (iii) support self‐transformation (SST) for the growth of zeolite crystals in the inner cavities of the above‐mentioned porous substrate. On the other hand, biological structures such asLuffasponges and cellulose fibers have been used as sacrificial templates for the synthesis of self‐supporting zeolite replicas, which mimic the morphology and microstructure of the organic materials.