摘要
采用超临界CO2流体对木材-SiO2醇凝胶复合材的干燥工艺进行研究。结果表明:由于受到木材的包围,木材-SiO2醇凝胶复合材的超临界干燥工艺条件最终确定为动态和静态干燥温度为50℃,动态和静态压力为25MPa,动态干燥时间为180min。经扫描电镜观察,木材-SiO2气凝胶在微观上有良好的网络结构,SiO2气凝胶与木材有良好的结合并保持木材的孔隙结构。通过透射电镜观测,所制备的木材-SiO2气凝胶复合材料中的SiO2气凝胶是由直径约13～300nm的SiO2颗粒构成的连续网络结构。超临界CO2流体干燥的木材-SiO2气凝胶复合材表现突出的增容现象,由于紫椴与西南桤木结构不同,两者的增容率有较大的差异,西南桤木的增容率约为紫椴木材的1/2左右。
The supercritical fluid CO2 （SFC） dry process of wood-SiO2 alcogel composites was researched in this paper. The results show that for the wood surround the SiO2 alcogel supercriticul drying process of the dynamic and static press is 25 MPa, the dynamic press time is 180 rain, the dynamic and static dry temperature is 50 ℃ . The SiO2 aerogel of net micro-structure was observed that coalescence with wood and keep the wood porous structure very well. According to transmission electron microscope observing, the silica aerogels were coherent, nanosized porous solids that mean diameter of particles is about 13 - 300 nm. Wood-SiO2 aerogel composites have specially bulking ratio. For different structure of basswood and alder, the bulking ratio have greatly diversity in basswood and alder, alder＇ s bulking ratio is half of basswood.
出处
《林业科学》
CAS
CSCD
北大核心
2008年第7期62-67,共6页
Scientia Silvae Sinicae
基金
国家自然科学基金资助项目(30630052)
