排序方式: 共有58条查询结果,搜索用时 93 毫秒
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纳米纤维素作为一种性能优越的可再生纳米材料,应用前景极为广阔。然而,由于纳米纤维素结构上富含羟基,使其具有极强的亲水性,严重影响了纳米纤维素的疏水性能,并且在一定程度上限制了其在复合材料领域的应用。综述了纳米纤维素疏水改性的研究进展,从物理吸附、表面化学修饰(甲硅烷化、烷酰化、酯化等)、聚合物接枝共聚3个方面简述了目前应用较为广泛的疏水化改性方法,并对疏水纳米纤维素在包装材料、造纸、水净化等方面的应用现状进行了总结。最后对疏水改性纳米纤维素的未来发展进行了展望,旨在为疏水纳米纤维素的研究和应用提供参考。 相似文献
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A test method to measure cellulose fibril elastic modulus using atomic force microscopy was used to investigate the effects of process and source on the moduli of single cellulose fibrils. The cellulose fibrils were generated from cellulose by mechanical treatments. Individual fibrils were suspended over a micro scale groove etched on a silicon wafer. A nano-scale three-point bending test was performed to obtain the elastic moduli. The results indicated that the elastic moduli of cellulose fibrils were not significantly different between 30 min and 60 min of high intensity ultrasonic treatment for Lyocell fiber, between isolation methods of ultrasonic and homogenizer treatment for pure cellulose fiber, and between different cellulose sources of pulp fibers treated by homogenizer regardless the effects of sample size coupled with inherent variation in the raw material. The elastic modulus of Lyocell fibrils with diameters from 150 to 180 nm was evaluated to be 98 ± 6 GPa. Modulus values decreased dramatically when the diameter was more than 180 nm. 相似文献
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纤维孔隙率的测量及密度法测量的纤维素含量 总被引:2,自引:0,他引:2
利用纤维体积密度和氦比重方法测量纤维素密度、绝对密度、体积密度和孔隙率,进而准确地计算出纤维素的含量。 相似文献
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阳离子淀粉固载β-环糊精用于废水处理 总被引:1,自引:0,他引:1
研究了阳离子淀粉(CS)固载β-环糊精(β-CD)及产物在含微量芳香小分子废水处理中的初步应用。结果表明,提高β-CD与CS的质量比,产物中β-CD固载量逐渐增加,而阳离子取代度和产率均显著下降;当β-CD与CS质量比达到2:1时,β-CD固载量趋于平稳。阳离子取代度越低,对废水中细小粒子的絮凝效果越差;β-CD的固载量越高,对水中微量的芳香类有机小分子的去除效果越好。对于β-CD固载量大于70%的CS-βCD,当添加的质量浓度为120mg/L时,芳香类有机小分子的去除率均在80%以上。 相似文献
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研究了白腐菌Trametes sp. Lg-9粗酶液预处理对磺化化学机械浆(SCMP)性能的影响。结果表明:Lg-9粗酶液预处理可改善SCMP的打浆性能,降低打浆能量消耗,预处理后打浆的纤维平均长度增大,细小组分含量降低,宽度稍有增大。Trametes sp. Lg-9粗酶液预处理可提高SCMP白度,改善强度。Trametes sp. Lg-9粗酶液预处理的漂后浆纤维平均长度较长,细小组分含量较少,粗酶液用量大于8IU/g浆时,随着粗酶液用量的增大,纤维平均长度有所降低,细小组分含量有所提高。 相似文献
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《Journal of power sources》2001,94(2):163-168
The plasticized polymer electrolytes composed of poly(methyl methacrylate-co-Li maleate), lithium perchlorate, and ethylene carbonate as a plasticizer, were newly prepared. The ion conductivities of the plasticized polymer electrolytes based on the poly(methyl methacrylate-co-Li maleate) were found to be dependent on the ion content of the ionomer, poly(methyl methacrylate-co-Li maleate), in the polymer electrolyte, and the polymer electrolyte based on the ionomer with 8.5 mol% ion content showed the maximum ion conductivity.The interfacial resistance at the polymer electrolyte/lithium interface and the cationic transference number were also investigated as a function of the ion content of the ionomer in the polymer electrolyte. The interfacial resistances as well as the cationic transference numbers of the polymer electrolytes were found to be also dependent on the ion content of the ionomer in the polymer electrolyte. Ion aggregations in the ionomer seemed to significantly influence the electrochemical behavior of the polymer electrolytes based on the ionomer. 相似文献
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纤维素酶酶解苇浆纤维微观结构和结晶结构的变化 总被引:16,自引:0,他引:16
采用红外光谱(IR)、X射线衍射分析和扫描电镜对在纤维素酶解进程中苇浆纤维素大分子的结构及纤维形态的变化进行了研究.研究结果表明,纤维素酶酶解进程中,纤维素大分子的晶型没有改变,但结晶度呈现周期性变化,微晶尺寸略有降低.在酶解初期,纤维素酶不仅作用于纤维素无定形区,也开始作用在纤维素结晶区表面;在酶解中、后期,纤维素酶对纤维素结晶区和无定形区的作用呈现周期性变化.纤维素酶解过程中纤维表面呈现周期性"剥皮"现象,并且在纤维表面出现孔洞和沟槽,在孔洞处纤维易断裂,导致纤维长度和粗度的降低. 相似文献