以纤维素纳米晶体为模板的手性向列结构材料的制备与性能研究材料科学与工程专业论文.docxVIP

北京化工大学硕士学位论文手性向列介孔结构，氮气吸附脱附分析表明薄膜比表面积约为259 北京化工大学硕士学位论文 手性向列介孔结构，氮气吸附脱附分析表明薄膜比表面积约为259 m2／g，BJH平均孔径9．6nm，POM观察介孔薄膜具有明显的双折射 现象。 3、通过将CNC悬浮液与WPU乳液在接近中性条件下混合后 自然干燥成膜，制备了具有手性向列结构的CNC／WPU复合材料 薄膜，薄膜的颜色可以通过WPU的含量来调节，SEM分析表明， 随着WPU含量的增加，复合材料的螺距有增加的趋势。随着WPU 含量增加，复合薄膜拉伸强度先增加后减小，断裂伸长率不断增 加。另外，复合材料薄膜和涂覆在玻璃上的复合涂层对溶剂极性、 水以及湿度的变化都会发生响应而改变颜色，在传感器及智能涂料 方面有应用前景。 关键词：纤维素纳米晶体，介孔二氧化硅，水性聚氨酯，手性 向列结构，环境响应性 II 万方数据 摘要PREPARATIoN 摘要 PREPARATIoN AND PRoPERTIES oF MATERIALS WITH CHIRAL NEMATIC oRDER TEMPLATED BY CELLULOSE NANoCRYSTALS ABSTRACT Cellulose nanocrystals(CNC)，prepared by the acid hydrolysis of wood，cotton or other cellulose—rich raw materials，have been known for more than 5 0 years since it was first produced．Their fascinating properties such as high specific strength and modulus，high specific surface area，and unique optical properties have attracted significant interest．However，until rencently，their ability in templating was discovered by utilizing their self-assembly behavior in water with suitable precursors，in order to develop new functional materials with chiral nematic order and distinct optical properties．In this paper，on one hand， 。。ra。nematicnematic mesoporous silicasilica filmstllmS was frabicatedaDlCate oy mlxmg suspension with silica precursor and removing the templates next．On the other hand，stimuli responsive CNC／WPU composite films with chiral nematic order was prepared by blending CNC suspension with waterborne polyurethane(WPU)latex．The main contents are as follows： III 万方数据 万方数据 万方数据 北京化工大学硕士学位论文1、CNC 北京化工大学硕士学位论文 1、CNC was prepared by sulphuric acid hydrolysis of microcrystalline cellulose(MCC)．TEM and AFM observation confirmed that CNC were 1 00-300nm in length and ca．1 0 nnl in width．XRD analysis showed that the crystallinity of CNC was increased to 89％after acid hydrolysis．The fingerprint texture representative of the chiral nematic phase was observed by polarizing optical microscopy． 2、Chiral nematic mesoporous silica films was prepared by first mixing CNC