摘要
为制备一种新型的木质纤维素气凝胶,采用化学预处理、溶解再生与冷冻干燥相结合的方法,对废弃的麦秸杆进行提纯、溶解、置换和干燥,并采用绿色、无毒、低廉的氢氧化钠/聚乙二醇溶液作为纤维素溶剂。采用扫描电镜(SEM)、BET比表面积分析、X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FTIR)和热重分析仪(TGA),对制备的新型木质纤维素气凝胶的微观形貌、比表面积与孔径分布、晶型结构、化学结构及热稳定性进行表征。结果表明,制备的新型木质纤维素气凝胶具有连续、层叠的三维网状结构,比表面积为99.17 m2/g,总孔容为0.45 cm3/g;纤维素气凝胶的晶型由纤维素I型转变为纤维素II型,结晶度为72.3%,相对于原料提高了23.4%,热稳定性也略微升高;并利用三甲基氯硅烷(TMCS)进行疏水改性,制备出了具有疏水性能的纤维素气凝胶。提供了一种新的制备木质纤维素气凝胶的有效溶剂,且具有高吸附性能、高承重能力、高结晶度的纤维素气凝胶是一种具有较大应用潜力的新型功能材料。
To obtain novel lignocellulose aerogels, the raw material, namely waste wheat straw, was purified, dissolved, replaced and dried in sequence via corresponding chemical pretreatment, dissolution and regeneration as well as freeze drying. Furthermore, a green, non-toxic and inexpensive NaOH/PEG aqueous solution was chosen to dissolve cellulose. The morphological feature, pore size distribution, crystal form, chemical construction and thermostability of the novel lignocellulose aerogel were analyzed using scanning electron microscopy （SEM）, BET measurement, X-ray diffraction （XRD）, fourier transform infrared spectroscopy （FTIR） and thermogravimetric analysis （TGA）. The results show that the obtained novel lignocellulose aerogel has a continuous and tiered three- dimensional network structure. Moreover, its specific surface area reaches 99.17 m2/g, and total pore volume reaches 0.45 cm2/g. The crystal form of the novel lignocellulose aerogel is transformed from the cellulose I crystalline structure to cellulose II crystalline structure, and the crystallinity reaches 72.3%, increasing by 23.4% as compared with that of the raw material straw. Meanwhile, the thermostability is slightly improved. Moreover, trimethylchlorosilane （TMCS） was used to hydrophobically modify the lignocellulose aerogel. In this article, a new and effective solvent for preparing lignocellulose aerogels is offered, and the novel lignocellulose aerogelhaving superior adsorptive properties, excellent weight capacity and high crystallinity has great application potentials as a new-style functional material.
出处
《科技导报》
CAS
CSCD
北大核心
2014年第4期79-85,共7页
Science & Technology Review
基金
国家自然科学基金面上项目(31270590)
中国博士后科学基金(2013M540263)
<科技导报>"博士生创新研究资助计划"项目(kjdb2012006)
关键词
木质纤维素气凝胶
疏水
吸油
纤维素溶剂
溶解再生
lignocellulose aerogel： hydrophobicity
oil absorption property
cellulose solvent
dissolution and regeneration
