茶梅花色素的提取及其稳定性研究

研究茶梅花红色素的提取方法及稳定性,为开发利用天然色素提供实验依据.在常温下用65%酸性乙醇溶液浸提新鲜茶梅花,过滤得色素原液,然后对该色素的耐酸碱性、耐热性、耐光性及耐氧化还原性等理化性质进行测定和分析.结果显示茶梅花红色素能在酸性乙醇溶液中稳定存在,不耐高温.日光直射、碱性环境、氧化还原剂以及高价金属离子(Fe3 和Al3 )对茶梅花色素稳定性影响较大.但食品添加剂、低价金属离子对色素色泽无不良影响.该天然色素在食品、化妆品等行业具有应用前景.     

碳包覆NbSn_2贮锂材料的制备和性能

用机械球磨-热解法制备了碳包覆NbSn2贮锂材料。通过X射线衍射光谱法(XRD)、透射电子显微镜法(TEM)和电化学测试对材料进行了表征,用非原位XRD测试研究了材料的反应机理。所制备的材料粒径大小分布在0.5~1.5μm,材料表面碳的包覆较均匀,包覆厚度为30~60 nm。在充放电电压1.5~0 V内,初始可逆充电比容量为701 mAh/g,经过20周的循环后,充电比容量仍然保持为524 mAh/g。与没有碳包覆的铌锡负极材料相比,其贮锂容量和循环性能都大大提高。     

预聚体法合成聚氨酯弹性体常见问题分析

对预聚体法合成浇注型聚氨酯弹性体中所出现的气泡多、粘度大、物料变黄等不良现象进行了详细的分析,从它的合成和固化成型过程中查找原因,从而提出解决方法。     

碳包覆锑锌合金贮锂材料的制备及性能

用化学还原-热解法合成了锂离子电池碳包覆锑锌合金负极材料Sb3Zn4/C.通过X射线衍射(XRD)、透射电子显微镜法( TEM)和电化学测试对材料进行了表征.所制备的材料粒径大小分布在0.5～ 1.0 μm,材料表面碳的包覆较均匀,包覆厚度为80～ 100 nm.在充放电电压为0～1.5V范围内,初始可逆充电比容量为5...     

3种食品天然植物包材的抗氧化活性成分对比研究

The antioxidant components and antioxidant functions of three commonly used natural food packaging materials, including Indocalamus leaves, reed leaves and lotus leaves were investigated. The active components were extracted by ultrasonic extraction. The contents of total phenols and total flavonoids, the hydroxyl radical scavenging activity, superoxide radicals scavenging activity, DPPH free radical scavenging activity, ABTS+ free radical scavenging activity, total antioxidant activity and reducing power of plant extracts were determined. The relation between antioxidant functions and antioxidant active ingredients was tested. The results indicated that the contents of total phenols and total flavonoids in lotus leave were higher than these of Indocalamus leaves and reed leaves, and the difference was significant (P<0.05). The total phenol content of three plants was extremely significantly correlated with the hydroxyl radical scavenging activity, superoxide radicals scavenging activity, DPPH radical scavenging activity, ABTS+ scavenging activity, total antioxidant and reducing power (P<0.01). The total flavonoid content was extremely significantly correlated with the total antioxidant and reducing power (P<0.01), and significantly correlated with the ABTS+ free radical scavenging ability (P<0.05). The content of isoquercitrin was high in Indocalamus leaves, and reed leaves and the content of luteolin-6-c-glucoside was high in reed leaves and lotus leaves. These ingredients contained the 4-carbonyl group, 2, 3-double bond and o-dihydroxy group of B ring. In summary, Indocalamus leaf, reed leaf and lotus leaf contained many kinds of polyphenols, which have strong free radicals scavenging activity and other antioxidant function.     

黄麻纤维增强不饱和聚酯树脂初步研究

以油酸为偶联剂,将氢氧化钠-油酸处理后的黄麻纤维布作为填充材料制备了不饱和聚酯复合材料,并对氢氧化钠处理黄麻纤维的适宜浓度、复合材料的拉伸强度、冲击强度、吸水率进行了研究测试。结果表明:氢氧化钠的适宜浓度为20%,黄麻纤维增强不饱和聚酯树脂的冲击强度及拉伸强度最大值分别为12.75 kJ/m2和33.05 MPa,复合材料的最大吸水率为4.07%。经油酸处理的黄麻纤维可有效提高不饱和聚酯复合材料的性能。     

碳包覆MnSn2锂离子电池负极材料合成及性能

用球磨-热解法合成了碳包覆锂离子电池锰锡合金负极材料MnSn2/C.通过XRD、TEM和电化学测试对材料进行了表征.制备的材料粒径大小分布在1～2μm之间,合金材料表面完全被碳包覆,碳层厚度约为60～ 120 nm.在充放电电压为1.5 V到0V范围内,初始可逆充电比容量为675 mAh/g,经过20周的循环后,充电比容量仍然保持为440mAh/g.与没有碳包覆的MnSn2贸极材料相比,其循环性能有较大提高.     

锂离子电池NbSnSb负极材料的制备和性能

通过球磨的方法制备了锂离子电池铌锡锑三元合金负极材料。用XRD、TEM和电化学测试对材料进行了表征,用非原位XRD测试研究了材料的反应机理。所制备的铌锡锑三元合金材料颗粒粒径大小分布在2～5μm之间。在充放电电压为1.5V到0V范围内,初始可逆充电容量为568mAh/g,经过20周的循环后,充电容量保持为初始容量的59.2%。由于铌锡锑材料中非活性物质Nb的作用,在相同条件下,与锡锑二元合金负极材料相比,其贮锂容量和循环性能都有明显的提高。