基于仿生物矿化的木材细胞壁二氧化硅有机-无机杂化结构形成及调控机制研究

It is the key-point that SiO2’s in-situ generation and ordered-deposition and then forming organic-inorganic hybrid structure on the cell-wall to the gain the biomimetic mineralized wood with excellent performances. Basing on the essential difference that there’s no stumpage’s genetic control function and cell membrane activity inside wood anymore, the research in this proposal will centre on the scientific topic that polyamine inducer and polyethylene catalyst will be artificially and controllable released when SiO2 biomimetic mineralization occurred on wood cell-wall , and will learn from the natural mineralization mechanism that teak can absorb directly silicate from soil, extract and convey the soluble ions to the tissue organs in its trunk then SiO2 deposited in the cortex and cell wall to form highly ordered hybrid structure with excellent performances; and the template theory combined with sedimentary dynamics, and take wood cell-wall as the biomimetic mineralization compartment basement template and by introducing synergists, such as dextran, chitosan and poly amino peptide ,then referring to enzymatic reactions, optimizing the construction of the mineralization micro-environment, the nano-SiO2 replicate in the cell-wall in situ and physically deposited, complex with cellulose, as the result that high strength organic-inorganic hybrid formed and will be characterized. Clarify the structure and the nucleation process of SiO2 and the deposition control factor during biomimetic mineralization, by controlling the nucleation location and growth rate, the controllable biomimetic mineralization made inside the wood, and the formation mechanism of controllable hybrid structure on the wood cell-wall revealed; the theory system and technical method of nano-SiO2 biomimetic mineralization on wood are innovated, and the scientific basis for wood’s inorganic biomimetic functional modifying is established.

纳米SiO2在木材细胞壁上原位生成、有序沉积为有机-无机杂化结构是获性能优异的仿生矿化木材的关键。本项目针对木材相对活树其基因遗传控制及细胞活性缺失等本质差异，围绕聚胺诱导剂、聚乙烯亚胺催化剂等经可控释放，SiO2在木材细胞壁上仿生矿化形成精细杂化结构这一科学问题，借鉴柚木从土壤中吸收硅酸盐后，SiO2沉积在其皮层及胞壁形成高度有序、性能优异杂化结构的自然矿化机制，结合模板理论及沉积动力学原理，以木材细胞壁为仿生矿化隔室模板，引入葡聚糖基底及壳多糖、聚氨基多肽等协效剂，参照酶促反应，优化构建矿化微环境，使纳米SiO2在细胞壁上原位复制、物理沉积、并与纤维素等有机络合，形成高强度杂化结构并表征之，明晰SiO2仿生矿化成核作用及沉积控制因子，通过调控其成核位置和生长速度，实现木材仿生矿化，揭示细胞壁上杂化结构可控形成机理；创新木材纳米SiO2仿生矿化理论和技术方法，为木材仿生改良提供科学依据。

以杉木、杨木、桉树、马尾松等为代表人工林木材，密度、力学强度低；亟需对人工林为主的木材进行功能性改良，实现其高值化利用。自然界中的柚木、龙竹、珊瑚、珍珠等生物自然矿化结构独特、材性优异，为强度极高、软硬适中又不失韧性的天然复合材料。.若能师法自然，通过人工构建与调控不同类型、浓度离子络合等仿生环境条件，模拟柚木等优质木材的天然生物矿化过程，借鉴阴沉木与硅化木中硅质层形成机制，使SiO2等无机物成核、定向及生长，可实现木材细胞壁仿生矿化；解决其仿生矿化过程中，长链聚胺等有机诱导剂、聚乙烯亚胺等矿人工定向可控释放这一关键科学问题。.项目组严格按本项目（31770606）《资助项目计划书》的要求，开展并完成相关研究，全面完成或超额完成各项目标任务；并严格按照《国家自然科学基金条例》和《资助项目计划书》预算专款专用。具体是：通过解明SiO2仿生矿化过程关键影响因子、构建木材仿生矿化微环境，模拟非活立木木材的自然生物矿化过程，调控木材细胞壁仿生矿化形成过程中有机-无机杂化结构，揭示了其矿化机理与调控机制，并构建了木材可控仿生矿化理论技术体系，创新无机物功能化仿生增强人工林木材技术方法。.项目成果：（1）人工构建与优化了木材仿生矿化微环境；（2）获仿生矿化木材细胞壁-纳米SiO2之有机-无机杂化沉积结构；（3）创新纳米SiO2在木材细胞壁上可控仿生矿化理论；（4）发表第一标注期刊论文10篇；获授权国家发明专利2件、申请发明专利3件；共培养硕士4名、博士1名；（5）基于项目相关研究成果，与国内外同行广泛交流并进行合作研究；（6） 项目负责人获湖南省农林生物质复合材料创新团队成员并获湖南省科技创新团队奖， 项目组苌姗姗晋升为教授、梁林富晋升为副教授并访学德国柏林大学两年。.项目研究成果为其木材功能性改良向与物理、生物和化学技术相结合方向发展提供科学依据。