酸性氯离子溶液中硫代硫酸根对800合金腐蚀机理

综合采用动电位极化曲线、电化学噪声(EN)技术和3D显微镜相结合,研究了800合金在酸性模拟缝隙水化学中的腐蚀行为,分析了S_2O_3^(2-)浓度对合金在酸性Cl^-环境下腐蚀过程的影响与机理.实验结果表明:在含有Cl^-和S_2O_3^(2-)的酸性溶液中,800合金表面为活性溶解状态,腐蚀速度较快.酸性环境中,极微量的S_2O_3^(2-)对800合金在Cl^-溶液中的腐蚀没有显著影响;随着S_2O_3^(2-)浓度的增加,极化曲线向电位较负方向偏移,相同电位条件下阳极电流密度显著增加,阴极电流略微增大.EN测试结果表明,酸性Cl^-溶液中加入0.075,mol/L S_2O_3^(2-)后噪声电阻降低了约2个数量级,电流标准偏差增加了约2个数量级,这是由于S_2O_3^(2-)的加入加速了合金的阳极溶解过程.

Synthesis of graphene/tourmaline/TiO_2 composites with enhanced activity for photocatalytic degradation of 2-propanol

We report the construction of a graphene/tourmaline/TiO2(G/T/TiO2)composite system with enhanced charge‐carrier separation,and therefore enhanced photocatalytic properties,based on tailoring the surface‐charged state of graphene and/or by introducing an external electric field arising from tourmaline.A simple two‐step hydrothermal method was used to synthesize G/T/TiO2composites and poly(diallyldimethylammonium chloride)‐G/T/TiO2composites.In the photocatalytic degradation of2‐propanol(IPA),the catalytic activity of the composite containing negatively charged graphene was higher than of the composite containing positively charged graphene.The highest acetone evolution rate(223?mol/h)was achieved using the ternary composite with the optimum composition,i.e.,G0.5/T5/TiO2(0.5wt%graphene and5wt%tourmaline).The involvement of tourmaline and graphene in the composite is believed to facilitate the separation and transportation of electrons and holes photogenerated in TiO2.This synergetic effect could account for the enhanced photocatalytic activity of the G/T/TiO2composite.A mechanistic study indicated that O2??radicals and holes were the main reactive oxygen species in photocatalytic degradation of IPA.

等规聚丙烯离聚体增容聚丙烯/尼龙11共混体系研究

以碘代等规聚丙烯为大分子反应中间体,通过季胺化亲核取代反应和点击化学反应,制备了N-甲基咪唑聚丙烯离聚体(IA)和邻巯基苯胺盐酸盐聚丙烯离聚体(IB),并将其作为等规聚丙烯/生物基尼龙11 (i PP/PA11)共混体系的增容剂.通过动态力学分析(DMA)、扫描电镜(SEM)和力学性能测试,对i PP/PA11/聚丙烯离聚体三元共混体系的相形态与性能进行了系统研究. DMA测试结果显示,2种聚丙烯离聚体使i PP/PA11共混体系的玻璃化转变温度Tg相互靠近;SEM结果显示,离聚体的加入使分散相粒子尺寸显著减小,两相界面作用力增加;力学性能测试表明,iPP/PA11/IA、i PP/PA11/IB三元共混体系的拉伸强度和冲击强度保持较好的水平.以上研究结果表明,IA和IB均可以显著改善i PP/PA11共混体系的相容性.