Preparation and characteristics of new type nanocomposite powder

This new type nanocomposite powder was prepared with electroless plating enhanced by ultrasonic wave. High-resolution transmission electron microscopy (HRTEM) showed that As-plated particles have nanometer scale average size. X-ray diffraction (XRD) analysis showed the presence of a noncrystalline structure in the plating layer on the nano-Al₂O₃ matrix. The content of the plating layer was analyzed by energy dispersive X-ray spectroscopy (EDX) technology. The plating layer content was adjustable by changing the solution concentration.     

纳米复合隔热材料高温等效导热系数辨识方法

搭建高温瞬态热特性实验装置,测量获取某纳米复合隔热材料在290~1 090 K温度范围内的高温瞬态热特性数据。基于辐射与导热耦合传热模型和群体智能优化的遗传算法,建立随温度变化等效导热系数的辨识模型。通过数值实验验证了辨识模型的可靠性。结合真实实验测量所得高温瞬态热特性数据,辨识获取材料在290~1 090 K温度范围内的等效导热系数,介于0.027~0.043 W/（m ·K）,随温度升高呈非线性上升趋势。     

Bioinspired hierarchical helical nanocomposite macrofibers based on bacterial cellulose nanofibers

Bio-sourced nanocellulosic materials are promising candidates for spinning high-performance sustainable macrofibers for advanced applications. Various strategies have been pursued to gain nanocellulose-based macrofibers with improved strength. However, nearly all of them have been achieved at the expense of their elongation and toughness. Inspired by the widely existed hierarchical helical and nanocomposite structural features in biosynthesized fibers exhibiting exceptional combinations of strength and toughness, we report a design strategy to make nanocellulose-based macrofibers with similar characteristics. By combining a facile wet-spinning process with a subsequent multiple wet-twisting procedure, we successfully obtain biomimetic hierarchical helical nanocomposite macrofibers based on bacterial cellulose nanofibers, realizing impressive improvement in their tensile strength, elongation and toughness simultaneously. The achievement certifies the validity of the bioinspired hierarchical helical and nanocomposite structural design proposed here. This bioinspired design strategy provides a potential platform for further optimizing or creating many more strong and tough nanocomposite fiber materials for diverse applications.     

Preparation and Photocatalytic Property of CuO/SnO2/TiO2 Nanocomposite

采用溶胶-凝胶法,以硝酸铜、二氯化锡和钛酸四丁酯为原料,加入十六烷基三甲基溴化铵（CTAB）作软模板,制备CuO／Sn02／TiO2纳米复合物。分别用SEM、XRD、IR、UV—vis等对产物进行表征分析,CuO／SnO2／TiO2晶粒由锐钛矿相的TiO2、金红石相的SnO2和单斜晶系的CuO组成。以甲基橙为模拟污染物,研究其催化活性,结果表明CuO／SnO2／TiO2纳米复合物具有较好的光催化活性。     

壳聚糖/SiO_2/CdS纳米复合物作为固相萃取膜测定环境水样中的有机磷农药残留

采用溶胶——凝胶技术制备了壳聚糖/SiO2/CdS纳米复合材料作为固相微萃取膜,用该萃取膜与气相色谱联用测定环境水样中喹硫磷、甲基对硫磷、对硫磷、二嗪磷等有机磷农药残留。对固相微萃取条件,如萃取温度,萃取时间、萃取的pH值以及萃取时溶液中离子强度等因素进行了优化。在优化的实验条件下,各目标农药样品的检测线性范围为2.0~1000 ng/mL,检出限为1.0~1.7 ng/mL。样品加标回收率为81.13%~105.31%,相对标准偏差(RSD)为2.09%~3.71%。方法具有快速、简便、准确、重现性好的特点。     

壳聚糖/SiO2/CdS纳米复合物作为固相萃取膜测定环境水样中的有机磷农药残留

采用溶胶——凝胶技术制备了壳聚糖/SiO2/CdS纳米复合材料作为固相微萃取膜,用该萃取膜与气相色谱联用测定环境水样中喹硫磷、甲基对硫磷、对硫磷、二嗪磷等有机磷农药残留。对固相微萃取条件,如萃取温度,萃取时间、萃取的pH值以及萃取时溶液中离子强度等因素进行了优化。在优化的实验条件下,各目标农药样品的检测线性范围为2.0~1000 ng/mL,检出限为1.0~1.7 ng/mL。样品加标回收率为81.13%~105.31%,相对标准偏差(RSD)为2.09%~3.71%。方法具有快速、简便、准确、重现性好的特点。     

壳聚糖／半导体光催化剂纳米复合材料研究进展

壳聚糖在半导体光催化材料中的应用研究是一个有着广阔前景的新热点,主要介绍了纳米壳聚糖的制备方法及壳聚糖／半导体光催化剂纳米复合材料的研究进展,指出了目前存在的问题和将来的发展方向．     

BaTiO3/聚氨酯纳米复合物弹性体的制备与电致伸缩性能

以聚酯二元醇、甲苯二异氰酸酯、1,4丁二醇、1,1,1三羟甲基丙烷和纳米钛酸钡粉体为原料,采用一步法制备了一系列BaTiO3/聚氨酯复合物弹性体.BaTiO3/聚氨酯复合物弹性体的密度、硬度和介电常数随钛酸钡含量的增加而增加.采用数字散斑相关测量方法研究了复合物弹性体在电场诱导下的应变与复合物中钛酸钡含量的关系.结果表明BaTiO3/聚氨酯复合物弹性体在外加高压电场的作用下,随着高压电源的开合,其应变也随之呈现出相应的收缩与回复.复合物的电致伸缩系数高于相应的聚氨酯弹性体,但复合物的电致伸缩系数随复合物中钛酸钡含量的增加而逐渐减小.     

食品级丁苯橡胶中残留苯乙烯的测定

实验了一种测试食品级丁苯橡胶干胶中残留苯乙烯的新方法,该方法使用二硫化碳作溶剂,将干胶溶解后,用甲醇凝聚溶于二硫化碳中的丁苯橡胶及聚合物,有效地分离苯乙烯单体和丁苯橡胶,以α-甲基苯乙烯做内标物,用FFAP毛细管柱对二硫化碳中的有机单体进行色谱分离,用内标法计算残留苯乙烯的含量.     

尼龙6、尼龙66/粘土纳米复合材料的制备和性能

文章综合近年来国内外关于尼龙/粘土纳米复合材料的文献,详细论述了尼龙/粘土纳米复合材料的制备方法和性能。