创新背景

材料的变迁发展与建筑物的变革发展息息相关，可持续目标的达成需要建筑更加节能，很大程度上建筑物使用的材料节能与否决定了建筑的可持续性。

创新过程

瑞典皇家理工学院（KTH）瓦伦堡木材科学中心的研究人员用木材开发出一种绝缘材料，新材料具有与普通塑料基绝缘材料一样甚至更好的热性能。新型绝缘材料是在不添加额外物质的情况下制成的气凝胶一体化木材。

研究人员在此前的研究中已经开发出不少先进类型的气凝胶和其他复合材料，木纤维素气凝胶是其中一个研究方向。新方法突破了在木材孔隙中受控创建绝缘纳米结构的限制。生物基强气凝胶可用于取代目前的化石基气凝胶，实现超级隔热，有助于能源效率、生物经济和可持续的社会发展。

气凝胶一体化木材的制造过程从使木材脱脂开始。研究人员先去除木质素，使木材具有颜色和强度，留下空的孔隙或腔。然后通过进入大的空孔并在其内部产生更多的纳米孔进行下一步工作，降低材料的导热性。

这些纳米多孔结构是由细胞壁的部分溶解，然后受控的沉淀产生的。在加入水之前，研究人员先加入离子液体（IL）混合物以部分溶解细胞壁，从而产生纳米纤维网络，使腔内微多孔。

研究人员高度控制沉淀过程，创造精确水平的纳米孔隙率，以实现理想的导热性。研究人员表示，建筑隔热并不是气凝胶的唯一潜在用途。独特的结构使先进的材料能够用于能量储存和转换，甚至组织工程。例如，在包装中，聚苯乙烯等塑料泡沫有助于防止物体与周围环境之间的热传递，因此可以在运输过程中保持货物凉爽。木材的空隙中原位形成纳米纤维网络会导致木材具有高度隔热性。

创新关键点

创新制造纳米多孔结构，通过控制沉淀过程创造高精准的纳米孔隙率，从而产生纳米嫌我网络，开发新型木材绝缘材料。

Creating nanoporous structures to develop highly heat-resistant wood insulation materials

Researchers at the Wallenberg Wood Science Center at Sweden's Royal Institute of Technology (KTH) have developed an insulating material from wood that has the same or better thermal properties than ordinary plastic-based insulation. The new insulation material is an aerogel integrated wood made without adding additional materials.

Wood-cellulose aerogel is one of several advanced types of aerogels and other composites that have been developed by researchers in previous studies. The new method breaks through the limitation of controlled creation of insulating nanostructures in wood pores. Bio-based strong aerogels can be used to replace current fossil-based aerogels to achieve super insulation, contributing to energy efficiency, bioeconomy and sustainable social development.

The process of making aerogel integrated wood starts with degreasing the wood. The researchers first remove lignin, which gives the wood its color and strength, leaving empty pores or cavities. The next step is to reduce the thermal conductivity of the material by entering the large empty hole and creating more nanoparticles inside it.

These nanoporous structures are created by partial dissolution of the cell wall followed by controlled precipitation. Before adding water, the researchers added an ionic liquid (IL) mixture to partially dissolve the cell walls, creating a network of nanofibers that make the cavities microporous.

The researchers highly controlled the precipitation process to create precise levels of nanoporosity to achieve desirable thermal conductivity.Building insulation is not the only potential use of aerogel, according to the researchers. The unique structure enables advanced materials to be used for energy storage and conversion, and even tissue engineering. In packaging, for example, plastic foams such as polystyrene help prevent heat transfer between objects and their surroundings, thus keeping goods cool during transport. The nanofiber network formed in situ in the void of the wood results in a high degree of heat insulation.