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亚甲蓝双分子聚集体的解离平衡 总被引:4,自引:1,他引:4
本通过光主地研究了作为新的光敏剂-亚甲蓝(Methylne Blue,MB)在水溶液中的溶液状态,以及其在不同温度时双分子聚集体的解离平衡,通过差示光谱监测了亚甲蓝在水溶液中,其双分子二聚体在温度30-60℃范围内的构成方式的变化:其单分子倾角9α)为48.3-46.1°,双分子面间距离(r)为0.576-0.580nm,监测了亚甲蓝在水溶液中其单最大吸收波长吸收值随温度的变化,算得其二聚体的解 相似文献
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本文研究了在聚甲叉显色团N-位上,含有不同链长烷基的5,5′,6,6′-四氯咪碳菁碘化物的四个衍生物,在形成分子有序组合体上的差异。研究发现,上述四个染料在甲醇溶剂中都形成单分子溶液。当改变溶剂的极性,如向甲醇中加入水后,染料间的差异表现出来。添加无机盐,有利于易溶解染料的J-聚集态形成,但对微溶性的染料无效。利用AgBr多晶切片或紧压AgBr粉末制得的平片,以研究染料在AgBr上的吸附。实验表明,吸附剂正己酸的加入可导致AgBr表面上已形成的J-聚集态解体。利用循环伏安法研究染料和AgBr间的相互作用。实验结果表明,取代基的碳链越长,AgBr和染料间的相互作用越强。 相似文献
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用吸收光谱法研究亚甲蓝在表面活性剂存在时的聚合状态 总被引:5,自引:0,他引:5
应用紫外-可见吸收光谱研究了光敏试剂亚甲蓝在溶液中的聚合状态及其与表面活性剂之间的关系。当添加阴离子表面活性剂的浓度于其临界胶束浓度时,亚甲蓝二聚体的比例将出现一极大值;用环己烷剂萃取后,测得亚甲蓝二聚体的吸收光谱,其最大吸收波长位于604nm。 相似文献
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槟榔碱主要存在于棕榈科植物槟榔的种子内。槟榔是我国目前亟待开发的天然植物资源,广泛分布于海南、广西、云南、福建及台湾等地。槟榔碱味辛、温,具有杀虫、破积、下气、行水的功能。由于槟榔碱对M—胆碱受体的作用,平时嚼食槟榔,可促使唾液分泌增加、增进 相似文献
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在0.050 mol·L-1磷酸盐缓冲溶液(PBS)中(pH=6.4), 亚甲蓝(MB)在铂电极上于-0.2 V产生一对不明显的伏安峰. 当向溶液中加入阳离子型Gemini表面活性剂Br-C16H33N+(CH3)2-C4H8-N+(CH3)2C16H33Br-, Br-C12H25N+(CH3)2-C4H8-N+(CH3)2C12H25Br-或Br-C8H17N+(CH3)2-C4H8-N+(CH3)2C8H17Br-后, 亚甲蓝的氧化峰显著增高, 还原峰降低, 氧化还原峰峰电位均正移, 这和表面活性剂与MB在电极表面的协同吸附有关. 联接基团相同的Gemini表面活性剂, 其影响程度随烷基链的增长而逐渐增强. 增大表面活性剂的浓度, MB的氧化峰先升高后缓慢降低. 如当Br-C16H33N+(CH3)2-C4H8-N+(CH3)2C16H33Br-的浓度为15 μmol·L-1 时, 5 μmol·L-1 MB的氧化峰峰电流达到最大值. 此外,溶液pH值和富集电位等对MB及表面活性剂的吸附亦有影响. 相似文献
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A slab optical waveguide (SOWG) has been used for study of adsorption of both methylene blue (MB) and new methylene blue (NMB) in liquid–solid interface. Adsorption characteristics of MB and NMB on both bare SOWG and silanized SOWG by octadecyltrichlorosilane (ODS) were compared. Effect of pH on adsorption on MB and NMB was investigated. Binding rate constant analysis showed that both MB and NMB on bare SOWG demonstrates larger association constants than those on ODS-SOWG. Interactions of MB and NMB on bare SOWG and ODS-SOWG were analyzed by molecular mechanics calculation method. The binding energy change was in the following order: ENMB–bare > EMB–bare > ENMB–ODS > EMB–ODS. 相似文献
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A new method for detecting protein by synchronous fluorescence enhancement was developed, based on the combination of near infrared (NIR) fluorescence and the dedimerization phenomenon of methylene blue (MB). Under analytical conditions, there are linear relationships between the enhancing extent of synchronous fluorescence of MB-sodium dodecyl benzene sulfonate (SDBS)-protein at 667 nm and the concentration of protein in the range of 8.0 × 10−8-4.0 × 10−5 g mL−1 for bovine serum albumin (BSA), 1.0 × 10−7-3.5 × 10−5 g mL−1 for egg albumin (EA). The detection limits (S/N = 3) of BSA and EA are 8.9 ng mL−1 and 10.0 ng mL−1, respectively. The fluorescence enhancement mechanism is discussed in detail. Results from multiple techniques indicate that the fluorescence enhancement of the system originates from the hydrophobic microenvironment provided by BSA and SDBS, and the formation of an MB-SDBS-BSA complex, as well as the deaggregation of some MB dimer. 相似文献
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Chubei Wang Guoyang Ma Jianwei Zhou Mingliang Zhang Xinfeng Ma Fangfang Duo Liangliang Chu Jianxin Huang Xinmei Su 《应用有机金属化学》2019,33(9)
Glycine‐functionalized reduced graphene oxide (GRGO) was prepared through the reaction of glycine and chlorine‐functionalized reduced graphene oxide. The product was characterized by SEM, HRTEM, IR, Raman, and XPS. The nitrogen content (8.28%) was high in product, peak at 285.8 eV was assigned to the C–N bond, which implied that the chlorine residues in raw material were substituted by amine group of glycine. The intensity ratio of D and G peak was about 1.5, which also implied that more saturated carbon atoms were present in the product. Results of SEM, IR, and XPS confirmed that glycine molecules were attached to graphene sheets. Compared with reduced graphene oxide (61.5 mg/g) and active carbon (45.2 mg/g), GRGO had a good adsorption capacity (98.9 mg/g) for methylene blue. The adsorption process was fitted to three kinetic models and three adsorption isotherm models. The adsorption process complied with pseudo‐second order kinetic model and Langmuir model. 相似文献
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H. Jia S. Navaratnam W. Chen B. J. Parsons G. O. Phillips 《Radiation Physics and Chemistry》1993,42(4-6):1007-1010
Pulse radiolysis experiments were carried out with aqueous solutions of thionine dye methylene blue (MB) and toluidine blue in the presence of polyvinyl alcohol. The transient spectra obtained show maxima at 400 and 880 nm and are assigned to the respective semiquinone radical anions. The semiquinone radical decayed by a second order process. Furthermore, MB in PVA films were bleached by γ-radiolysis and the change in absorption was found to be linear with the dose. 相似文献
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用简单可行的方法合成了功能化的石墨烯(GNSPF6)和磁铁掺杂的还原氧化石墨烯(RGO-Fe3O4),并进一步研究了pH值、接触的时间和温度对它们吸附亚甲基蓝(MB)的影响.结果表明,随着pH值和温度的增加其吸附量也随之变大,从而说明该吸附过程是自发吸热的.因为GNSPF6的吸附过程只用了不到20min的时间,所以它的吸附是高效的.用经典的准一级反应、准二级反应和粒内扩散模型对其吸附过程进行动态分析,从结果可以发现,准二级动力学模型比准一级动力学模型更适用于描述吸附过程.采用传统的Langmuir,Freundlich和L-F吸附等温线模型来模拟分析数据,在20℃时,由Langmuir吸附等温线模型模拟分析得知GNSPF6和RGO-Fe3O4对MB的最大吸附量分别为374.4和118.4mg/g. 相似文献
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Li-Xian Sun A.Mahipal Reddy Akiko Takatsu Tatsuhiro Okada 《Analytica chimica acta》2003,487(1):109-116
A slab optical waveguide (SOWG) has been used for study of adsorption of both methylene blue (MB) and new methylene blue (NMB) in liquid-solid interface. Adsorption characteristics of MB and NMB on both bare SOWG and silanized SOWG by octadecyltrichlorosilane (ODS) were compared. The simultaneous determinations of both MB and NMB were explored by flow injection SOWG spectrophotometric analysis and artificial neural networks (ANNs) for the first time. Concentrations of MB and NMB were estimated simultaneously with the ANNs. Results obtained with SOWG were compared with those got by conventional UV-visible spectrophotometry. 相似文献
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Asif Nisar Muhammad Saeed Muhammad Usman Majid Muneer Muhammad Adeel Iltaf Khan Javaid Akhtar 《国际化学动力学杂志》2020,52(10):645-654
Photodegradation of organic pollutants strongly depends on design of metal oxide semiconductor photocatalysts. Graphene, if composited with ZnO, can effectively enhance its photocatalytic performance for the eradication of pollutants from aqueous medium. Here in, ZnO-rGO is reported as highly active catalyst for degradation of methylene blue. A 200-mg/L solution of methylene blue dye was completely degraded within 1 h in comparison to 74% and 56% degradation over ZnO and rGO, respectively. The commonly used mechanisms of heterogeneous catalytic reactions, the Langmuir-Hinshelwood mechanism, and the Eley-Rideal mechanisms, were used to describe the reaction kinetics. The Langmuir-Hinshelwood mechanism was found as more favorable in this study. Apparent activation energy, Eap, true activation energy, ET, entropy, ΔS, and enthalpy, ΔH were calculated as 36.2 kJ/mol, 13.1 kJ/mol, 197.5 J/mol, and 23.1 kJ/mol, respectively. 相似文献
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Teruyuki Nakato Yumiko Iwata Kuzuyuki Kuroda Chuzo Kato 《Journal of inclusion phenomena and macrocyclic chemistry》1992,13(3):249-256
Intercalation of methylene blue into layered titanic acid H2Ti4O9 was examined by a guest exchange method using a propylammonium-H
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Ti4O9 intercalation compound as the intermediate. Methylene blue cations were arranged in the interlayer space obliquely to the layer surface. The visible spectrum of the intercalation compound suggested that the methylene blue cations were in an associated state in the interlayer space of H2Ti409. The intercalated methylene blue cations underwent a reversible electrochemical redox reaction in the dark, indicating that intercalation compounds of H2Ti4O9 can be applied to a modified electrode. 相似文献