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不同表面活性剂反胶束对纳米AgCl性能的影响 总被引:8,自引:1,他引:7
在反胶束中研究了直径10~14nm的AgCl微粒子与曙红间的作用,比较了阴离子型和非离子型表面活性剂组成的反胶束微环境效应.考察了AgCl粒子对曙红吸收光谱、荧光光谱及荧光寿命的影响.讨论了AgCl粒子对曙红荧光猝灭的机制,初步研究了稳定剂苯基巯基四氮唑及四氮茚对曙红-AgCl粒子反胶束体系的影响. 相似文献
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在阴离子型和非离子型表面活性剂组成的反胶束体系中研究了直径为11~14nm的AgCl微粒子与菁染料之间的作用,讨论了AgCl纳米粒子对菁染料的吸附及荧光猝灭现象. 相似文献
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在反胶束体系中研究了菁染料的吸收光谱以及ω值对菁染料荧光光谱的影响.讨论了不同粒径的AgCl纳米粒子对反胶束体系中菁染料的吸附状态及J-聚集体形成的影响.特别研究了反胶束水团空间限定效应对菁染料荧光量子产率及J-聚集体的影响. 相似文献
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F127反相微乳液的组成对AgCl纳米粒子形成及AgCl/F127-PMMA杂化膜结构和性能的影响 总被引:2,自引:2,他引:0
以F127为表面活性剂构成的反相微乳液制备AgCl纳米粒子和AgCl/F127-PMMA杂化膜,通过紫外可见光谱(UV-visible)、透射电镜(TEM)研究了微乳液的增容水量(ω)和盐浓度(Csalt)对AgCl粒子形成与形貌的影响;结合表面ζ电位测定、扫描电镜(SEM)分析和溶胀实验等考察了AgCl/F127-PMMA杂化膜的结构和性能。研究结果表明,低ω下盐浓度增加,胶束中AgCl反应速率增大,导致大量小粒径AgCl粒子的形成;高ω下盐浓度增加,将加快AgCl粒子的生长,从而导致胶束中的AgCl粒子粒径增大;各种ω下盐浓度的增加,都会引起胶束中单质Ag的形成。杂化膜的SEM分析显示,AgCl粒子粒径越小,在杂化膜中的分散性越好,膜表面的ζ电位也越高,膜在苯中的溶胀性能也越高;单质Ag的出现和AgCl粒子数目的增多,杂化膜中将显现明显的粒子团聚现象,这极大地影响了杂化膜在苯中的溶胀性能;而杂化膜在环己烷中的溶胀性能较低,且随ω和盐浓度的变化极小。 相似文献
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用甲基丙烯酸甲酯(MMA)作油相,反相胶束微乳液作为模板,制备了纳米氯化银(AgCl)粒子,再进行原位聚合制备了纳米氯化银/聚甲基丙烯酸甲酯(AgCl/PMMA)复合材料.透射电镜(TEM)分析表明,纳米AgCl的尺寸为20~80 nm.扫描电镜(SEM)测试表明纳米AgCl粒子均匀地存在于PMMA基材中.红外分析证明,胶束中水和表面活性剂AOT的羰基在MMA聚合后微观环境发生变化,纳米粒子同聚合物之间有吸附行为.动态力学(DMTA)分析复合材料,发现纳米AgCl粒子与聚合物之间存在强烈相互作用,形成了中间相层(interphase layer),改变了聚合物的动态力学性能. 相似文献
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F127反相微乳液中纳米AgCl粒子的可控合成和AgCl/F127-PMMA有机/无机杂化膜的研究 总被引:3,自引:2,他引:1
在大分子F127为表面活性剂的反相微乳液体系中,合成AgCl纳米粒子。然后通过聚合制备AgCl/F127-PMMA有机/无机杂化膜,用于苯/环己烷混合物的渗透汽化分离。利用电导率仪、紫外可见光谱及透射电镜研究微乳液的增溶水量(ω)对微乳液结构、胶束中AgCl粒子的生成和形貌的影响。结果表明:合成的AgCl粒子粒径小于10 nm;增加微乳液的ω,生成的AgCl粒子变大。聚合后制备的AgCl/F127-PMMA有机/无机杂化膜中,AgCl粒子能保持较好的分散性。50wt%苯/环己烷混合物的渗透汽化结果表明,在合适的ω下,所制备的AgCl/F127-PMMA有机/无机杂化膜能克服常规高分子膜的trade-off现象,表现出较好的分离性能。 相似文献
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《Electroanalysis》2017,29(5):1310-1315
A novel photo‐induced electrochemical biosensing method has been developed based on fluorescence quenching effect and electrochemical method. In this sensing strategy, the molecular beacon probes labeled with methylene blue were immobilized on the gold nanoparticles modified gold electrode surface firstly; then dopamine was assembled on the electrode surface through electrostatic interaction with gold nanoparticles. Under the continuous illumination, the fluorescence of the methylene blue was quenched by the gold nanoparticles before hybridization; after hybridization with the complementary DNA, methylene blue was far away from the gold nanoparticles and the fluorescence recovered, and then singlet oxygen was generated in the photosensitive reaction of methylene blue in the presence of dissolved oxygen. Singlet oxygen reacted with dopamine, which resulted in the reduction of concentration of the dopamine on the electrode surface. The current of the dopamine on the electrode was used for the sensing of the conformational change of molecular beacon and hence for the detection of target DNA. 相似文献
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Pande S Ghosh SK Nath S Praharaj S Jana S Panigrahi S Basu S Pal T 《Journal of colloid and interface science》2006,299(1):421-427
This article reports the reduction of methylene blue (MB) by thiocyanate ions (SCN(-)) in aqueous and micellar solutions. Thiocyanate ions are found to be an effective reducing agent for the decolorization of methylene blue under ambient condition. Effects of salting-in and salting-out agents have been investigated for real-time application in the reduction process. The salting-in agent urea has been found to uniquely enhance the rate of the reduction of MB by thiocyanate ion in the presence of micelles. Again, the catalytic activity of nanoparticles in the reduction of MB has also been studied. Detailed kinetic and thermodynamic aspects have been considered to realize the interaction between methylene blue and thiocyanate. Kinetic studies revealed that the reaction is reversible and follows first-order reaction kinetics. 相似文献
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Xie Linbei Li Ao Zhou Sijie Zhang Min Ding Yi Wang Ping 《Research on Chemical Intermediates》2021,47(6):2373-2391
Research on Chemical Intermediates - Ag/AgCl/ZnTiO3 nanohybrids were assembled by the photoreduction–precipitation assisted with ultrasonic method. Rhodamine B (RhB), methylene blue (MB) and... 相似文献
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Fales AM Yuan H Vo-Dinh T 《Langmuir : the ACS journal of surfaces and colloids》2011,27(19):12186-12190
This paper reports the synthesis and characterization of surface-enhanced Raman scattering (SERS) label-tagged gold nanostars, coated with a silica shell containing methylene blue photosensitizing drug for singlet-oxygen generation. To our knowledge, this is the first report of nanocomposites possessing a combined capability for SERS detection and singlet-oxygen generation for photodynamic therapy. The gold nanostars were tuned for maximal absorption in the near-infrared (NIR) spectral region and tagged with a NIR dye for surface-enhanced resonance Raman scattering (SERRS). Silica coating was used to encapsulate the photosensitizer methylene blue in a shell around the nanoparticles. Upon 785 nm excitation, SERS from the Raman dye is observed, while excitation at 633 nm shows fluorescence from methylene blue. Methylene-blue-encapsulated nanoparticles show a significant increase in singlet-oxygen generation as compared to nanoparticles synthesized without methylene blue. This increased singlet-oxygen generation shows a cytotoxic effect on BT549 breast cancer cells upon laser irradiation. The combination of SERS detection (diagnostic) and singlet-oxygen generation (therapeutic) into a single platform provides a potential theranostic agent. 相似文献
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Ranjana Sharma Mahender Pal 《Phosphorus, sulfur, and silicon and the related elements》2016,191(1):41-47
Kinetic studies on the Cu(II) catalyzed oxidation of mercaptoacetic acid (thioglycolic acid, TGA) by the model electron receptor methylene blue in acidic medium show that the reaction follows a second order kinetics in TGA. The order in methylene blue is unity but at higher [TGA], the order is 3/4. The rate shows an inverse relationship with [H+] and a second order dependence on [Cu(II)]. The reaction conforms to Arrhenius behavior in aqueous medium but resorts to anti-Arrhenius behavior in aqueous methanol and in aqueous acetone media. The reaction involves the in situ participation of nanoparticles which has been confirmed by SEM, XRD, and FTIR techniques. In aqueous medium, cauliflower shaped nanoparticles (44.21–74.33 nm) are obtained but in the presence of acetone and methanol, nanogranules (38.96–70.73 nm) and nanodisks (47.30–72.16 nm), respectively, are produced at 35°C as revealed by SEM images and XRD data. The reaction is characterized by the participation of two transition states in aqueous acetone medium and the kinetics of the reaction, especially the temperature dependence, is governed by the adsorption of methylene blue on copper nanoparticles as influenced by morphology inter alia dielectric constant of the reaction medium. 相似文献
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We developed a selective solvothermal synthesis of palladium nanoparticles on nanodiamond (ND)–graphene oxide (GO) hybrid material in solution. After the GO and ND materials have been added in PdCl2 solution, the spontaneous redox reaction between the ND–GO and PdCl2 led to the creation of nanohybrid Pd@ND@GO material. The resulting Pd@ND@GO material was characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectrometry, scanning electronic microscopy (SEM), and atomic absorption spectrometry methods. The Pd@ND@GO material has been used for the first time as a catalyst for the reduction for 2-nitrophenol and the degradation of methylene blue in the presence of NaBH4. GO plays the role of 2D support material for Pd nanoparticles, while NDs act as a nanospacer for partly preventing the re-stacking of the GO. The Pd@ND@GO material can lead to high catalytic activity for the reduction reaction of 2-nitrophenol and degradation of methylene blue with 100% conversion within ~15 s for these two reactions even when the content of Pd in it is as low as 4.6 wt%. 相似文献
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Synthesis and characterization of TiO<Subscript>2</Subscript>-montmorillonite nanocomposites and their photocatalytic activity 总被引:1,自引:0,他引:1
Aiqin Zhang Rongbin Zhang Ning Zhang Sanguo Hong Ming Zhang 《Kinetics and Catalysis》2010,51(4):529-533
TiO2 nanoparticles have been synthesized on the surface of exfoliated montmorillonite at a low temperature in benzyl alcohol medium.
According to X-ray diffraction (XRD), N2 adsorption-desorption isotherm and transmisson electron microscopy (TEM), it was found that the intercalation of TiO2 nanoparticles destroyed the ordered structure of montmorillonite to some extent, and the crystallites of the nanocomposites
are assembled to form a house-of-cards structure. The size of the nanoparticles in the interlamellar space is about 4 nm.
The nanocomposites exhibited excellent photocatalytic activity in methylene blue degradation due to the synergetic effect
of the adsorptive ability to organic compound of cetyl trimethylammonium bromide—montmorillonite and the catalytic ability
of TiO2 nanoparticles in it. 相似文献