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排序方式: 共有673条查询结果,搜索用时 15 毫秒
271.
由端羟基聚丁二烯和甲苯二异氰酸酯合成预聚力,以N,N-双(2-羟丙基)苯胺为扩链剂制备聚氨酯热塑性弹性体,考察了其力学性能随扩链系数的改变而出现的变化。用电子显微镜,红外分光光度计,差示扫描量热仪等分析了热塑性弹性体的微观结构特征。分析结果表明,弹性体内存在相分离,无结晶存在。 相似文献
272.
Degradation of aniline and chloroanilines by sunlight and microbes in estuarine water 总被引:1,自引:0,他引:1
The relative importance in estuarine water of photolysis and microbial degradation on aniline and a series of chloroanilines (p-chloroaniline, 2,4-dichloroaniline, and 2,4,5-trichloroaniline) was determined. Photolysis was important for all compounds with photo-transformation half-lives in surface estuarine water ranging from 2 to 125 h. Photolysis rates were lower in estuarine water relative to distilled water, which we speculate was due to quenching of excited states by humics. There was no microbial degradation of chloroanilines during short-term incubations (up to 3 days). The half-lives of aniline in estuarine water was 27 and 173 h in the light and dark (microbial), respectively. Photolysis and microbial degradation rate constants decreased in winter. The winter decrease in photolysis rates correlated to a decrease in surface irradiance while the microbial degradation decrease correlated to the temperature decrease. There was rapid microbial degradation of the chloroamilines and aniline photoproducts. The mineralization of photoproducts of chloroanilines was carried out by bacteria, while microbes larger than 3 μm, e.g. algae, were responsible for the bioaccumulation of the compounds. 相似文献
273.
纳米Ni/Fe对水中硝基苯的催化还原特性 总被引:1,自引:0,他引:1
采用自制的纳米Ni/Fe对水中硝基苯进行催化还原处理。探讨了硝基苯的还原降解途径,考察了溶液pH、纳米Ni/Fe用量和Ni含量对还原效果的影响。结果表明,纳米Ni/Fe对水中硝基苯的去除是纳米Ni/Fe的吸附作用和还原作用的协同作用的结果,两者对硝基苯去除率的贡献分别为33.7%和66.3%。纳米Ni/Fe可将硝基苯还原为苯胺和中间产物亚硝基苯,亚硝基苯进一步被还原为最终产物苯胺。还原产物苯胺的生成率随溶液pH的升高而降低;随纳米Ni/Fe用量的增加而升高;Ni含量的适当增大有利于硝基苯还原为苯胺,但Ni含量过高时会导致苯胺生成率降低,适宜的Ni含量为1.85%。纳米Ni/Fe对硝基苯的催化还原过程遵循一级反应动力学规律,反应速率常数为0.0226 min-1。 相似文献
274.
纳米二氧化钛薄膜光催化氧化降解苯胺的研究 总被引:11,自引:0,他引:11
以Ti(OC4H9)4为原料,采用溶胶 凝胶法制备了纳米TiO2薄膜光催化剂,利用X射线衍射法对催化剂的物相和粒径进行了表征。通过苯胺光催化降解实验,考察了薄膜厚度等反应条件对纳米TiO2光催化降解效果的影响,并研究了苯胺光催化降解的反应机理。实验结果表明,经500 ℃热处理后的TiO2主要以锐钛矿晶型存在,平均粒径为11.6 nm。纳米TiO2对苯胺具有很好的降解效果,其降解的中间产物主要有硝基苯、偶氮苯和氨基酚等,当初始浓度较低时,降解反应符合L-H方程的一级动力学模型。 相似文献
275.
以一硝基二甲苯为原料,以骨架镍为催化剂,在醇相溶剂中,用液相加氢法替代铁粉还原法,制备二甲基苯胺,成功地完成了多个品种的小试和扩试,积累了重要的工艺参数。其中主要的2,3—二甲基苯胺还进行了批量工业化生产。 相似文献
276.
277.
2-甲基-6-乙基-N-丁氧甲基-N-氯乙酰基苯胺的合成 总被引:2,自引:0,他引:2
以2 甲基 6 乙基苯胺、甲醛、氯乙酰氯和正丁醇等为主要原料,以一种经济环保的工艺路线合成了杀菌剂2 甲基 6 乙基 N 丁氧甲基 N 氯乙酰基苯胺。考察了反应条件对反应结果的影响,获得了较佳的反应条件:烯胺化反应中n(甲醛)/n(2 甲基 6 乙基苯胺)=1 5,反应温度70~75℃,反应时间2h;酰化反应中n(氯乙酰氯)/n(2 甲基 6 乙基苯胺)=1 15,反应温度30~35℃,反应时间1 0h;醚化反应中n(丁醇)/n(2 甲基 6 乙基苯胺)=5 5,反应温度50℃,反应时间5h。在较佳反应条件下,产品质量分数和收率分别达到93%和90%。 相似文献
278.
Yangyang Wang Tianhao Li Zengrong Li Sen Wang Xianyu Deng 《Advanced functional materials》2019,29(45)
Laminated multilayers of perovskite films with different optical and electronic characteristics will easily realize high‐performance optoelectronic devices because it is widely demonstrated that differential distribution of film properties in the vertical direction of devices plays particularly important roles in device performance. However, the existing laminated perovskite films are hardly prepared by a solution process because there is no solvent with sufficient selectivity of solubility for different perovskite materials. Here, it is demonstrated that aniline (AN) has a largely different solubility toward the perovskite MAPbI3 and the MAPbI3 blend with an additive of hydrochloride diethylammonium chloride. By using AN as the solvent in the perovskite precursor solution, two laminated perovskite layers with different crystal size and optical and electrical characteristics are achieved. Inverted perovskite solar cells with the laminated films as active layers achieve an averaged power conversion efficiency of 20.65% originating from the high VOC 1.112 V and fill factor of 80.8%. The devices maintain 98% efficiency after 400 h under 65% RH. This work provides a very simple and feasible method for production of laminated perovskite films to achieve high‐performance perovskite solar cells. 相似文献
279.
Xueying Chang Maher F. El-Kady Ailun Huang Cheng-Wei Lin Stephanie Aguilar Mackenzie Anderson Jason Zi Jie Zhu Richard B. Kaner 《Advanced functional materials》2021,31(32):2102397
The conducting polymer polyaniline (PANI) has been considered to be a promising pseudocapacitive electrode material for supercapacitors due to its high specific capacitance, low cost, and environmental friendliness. However, the poor cycling stability of PANI during the charge–discharge processes limits its widespread practical application. Herein, a facile synthetic method is demonstrated for covalently grafting an aniline tetramer (TANI), the basic building block of PANI, onto 3D graphene networks via perfluorophenylazide coupling chemistry to create a hybrid electrode material for ultralong-life supercapacitors. The design, which substitutes long-chain PANI with short-chain TANI and introduces covalent linkages between TANI and 3D graphene, greatly enhances the charge–discharge cycling stability of PANI-based supercapacitors. The electrode material, as well as the fabricated symmetric all-solid-state supercapacitors, exhibit extraordinary long cycle life (>85% capacitance retention after 30 000 charge–discharge cycles). The capacitance can be further boosted through fast and reversible redox reactions on the electrode surface using a redox-active electrolyte while maintaining outstanding cycling stability (82% capacitance retention after 100 000 cycles for a symmetric all-solid-state device). While conducting polymers are known to be limited by their poor cycling stability, this work provides an effective strategy to achieve enhanced cycle life for conducting polymer-based energy storage devices. 相似文献
280.