N-乙烯基吡咯烷酮可控合成多形貌金纳米颗粒

为了探究在N-乙烯基吡咯烷酮（NVP）体系下其对金纳米颗粒形貌的影响,分别在不同的操作条件下进行了金纳米颗粒合成实验,并通过TEM、UV-vis、XRD等手段对合成的金纳米颗粒进行了表征分析。随后,以三角片状金纳米颗粒为例对合成机理进行了探讨。结果表明：N-乙烯基吡咯烷酮不仅可以同时作为还原剂和稳定剂制备出能够稳定存在的金纳米颗粒,而且还能够诱导金纳米颗粒发生非均向生长,产生三角形和六边形金纳米片。在此发现的基础上,针对不同反应条件对该体系制备金纳米颗粒的影响进行了全面系统的实验研究,发现该方法还能制备出棒状和带有支脚的金纳米颗粒。     

银纳米粒子的绿色合成及其光谱特性

以糊精为还原剂和稳定剂,采用微波高压液相绿色合成法制备了黄色银纳米粒子。用吸收光谱和共振散射光谱研究银纳米粒子的光谱特性。结果表明,在优化的最佳条件下,用该法制备的纳米银最大吸收峰在418 nm处,最强共振散射峰在486 nm处,银纳米粒子颗粒呈球形,粒度均匀,平均粒径为20 nm,单分散性较好。该法操作简单反应快速。     

低温油相合成金钯纳米粒子及其催化性能研究

采用低温油相法合成了不同金钯量比的双金属纳米催化剂,对其形貌和电催化性能进行了分析。透射电镜表征结果显示,金钯的量比对催化剂的分散性和纳米颗粒的尺寸有一定的影响。当金钯等量比时,分散性最好、纳米颗粒的粒径最小。而电化学测试表明,当金钯等量比时,高分散、小尺寸的金钯纳米催化剂更易于裸露有效活性位点,从而对甲酸和乙醇显示出较高的催化活性和稳定性。     

氧化石墨烯负载金纳米颗粒及其催化活性研究

在不外加任何还原剂的情况下,利用氯金酸和氧化石墨烯之间的氧化还原反应将金纳米颗粒成功负载到氧化石墨烯上,合成了金纳米颗粒/氧化石墨烯复合材料。利用透射电镜(TEM)和X-射线衍射(XRD)对复合材料进行了结构表征与形态分析,并研究了金纳米颗粒/氧化石墨烯复合材料对Suzuki-Miyaura偶联反应的催化效果。结果表明,通过调节氯金酸与氧化石墨烯的质量比,可以得到不同形状的金纳米颗粒;金纳米颗粒/氧化石墨烯复合材料对Suzuki-Miyaura偶联反应具有很高的催化活性,并且很容易从反应体系中回收。     

β——环糊精包裹的金纳米粒子的制备和表征

用β-环糊精作还原剂还原氯金酸合成了金纳米粒子;同时,β-环糊精作为金纳米粒子的保护剂,防止生成的金纳米粒子的聚集。UV数据表明,溶液内含有金纳米粒子。TEM实验表明,β-环糊精还原氯金酸能生成β-环糊精包裹的球形金纳米粒子。     

纳米金溶胶的合成及紫外-可见吸收光谱的研究

在弱酸性或近中性条件下,用化学还原剂还原较高浓度的氯金酸溶液,制得纳米金种子溶液,然后用晶种法制备金溶胶。通过透射电镜、激光粒度分布仪等测定了纳米颗粒的粒径和分布情况,并对纳米金溶胶的紫外可见吸收曲线进行了研究。结果表明,以硼氢化钠为还原剂可以得到粒径小且分布均匀的产品,采用不同大小的晶种制备的纳米金颗粒的粒径不同,且随粒径变大紫外-可见吸收曲线上的最大吸收波长红移也越大,分布变宽。     

液相化学还原法制备油溶性纳米铜的研究

采用液相化学还原法,以硫酸铜为原料,抗坏血酸作还原剂,吐温-80作修饰剂,用正交实验方法获得了油溶性纳米铜的最佳的合成条件：抗坏血酸为3 g,吐温-80为30 mL,正丁醇为70 mL,反应温度95℃。并利用X射线衍射仪对产品进行表征测试。     

以抗坏血酸为还原剂制备硒纳米晶

用合成的Na2SeSO3和还原剂抗坏血酸在水溶液中反应12 h,合成直径为50 nm的硒纳米晶,利用X射线粉末衍射(XRD)和透射电子显微镜(TEM)对其结构进行了表征,介绍了生长机理.     

磁性纳米颗粒的制备及表面改性

采用化学共沉淀法合成Fe3O4纳米颗粒,用葡萄糖酸对磁性纳米颗粒表面进行了修饰,并利用扫描电子显微镜(SEM)、傅立叶转变红外光谱仪(FT-IR)、X-射线衍射(XRD)对修饰前后的Fe3O4纳米颗粒进行了表征,实验结果表明:磁性纳米颗粒粒径分布均匀、单分散性好,改性后其表面具有相应的官能团。     

琥珀酸二异辛酯磺酸钠辅助作用下球形Pd纳米粒子的制备与表征

以琥珀酸二异辛酯磺酸钠(AOT)为表面活性剂,分别以抗坏血酸、硼氢化钠(NaBH4)、七水硫酸亚铁(FeSO4.7H2O)为还原剂,成功地制备了球状的钯纳米粒子。采用扫描电镜和X射线衍射仪对产物进行了表征,钯纳米颗粒的平均粒径约50～150nm。结果表明,当琥珀酸二异辛酯磺酸钠的浓度为15g/L,氯化钯的浓度为0.0025mol/L,抗坏血酸的浓度为0.05mol/L,40℃反应2h时,可制得大小均匀、粒径小、分散性好的钯纳米颗粒。     

One-pot synthesis of PdAu bimetallic composite nanoparticles and their catalytic activities for hydrogen peroxide generation

We report a facile one-pot aqueous-phase synthesis of PdAu bimetallic nanoparticles with different Pd/Au ratio. The synthesis was conducted by co-reduction of Pd and Au precursor using ascorbic acid as a reducing agent and in the presence of polyallylamine hydrochloride (PAH). By high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and energy-dispersive X-ray spectrometry (EDS) analyses, we found that the synthesized nanoparticles had an onion-like core/shell/shell/shell structure with Au-rich core, Pd-rich shell, Au-rich shell, and Pd shell, respectively. We also investigated the catalytic performance of the synthesized PdAu nanoparticles toward hydrogen peroxide generation reaction.     

化学清洗中还原剂作用的研究

化学清洗过程中常需加入还原剂以抑制因Ｆｅ３＋浓度的升高而引起的加速腐蚀．本文试验了几种常用的还原剂,发现其中一些还原剂不仅没有起到抑制腐蚀的作用,反面引起腐蚀速率上升和严重的点蚀．实验证明,氯化亚锡和抗坏血酸是酸性介质中安全可靠的还原剂,而亚硫酸钠和盐酸联氨等将引起严重点蚀．     

12-磷钨酸体系水热法制备金颗粒及其表征

利用Keggin结构的12-磷钨酸作为软模板,采用水热法还原氯金酸制备金颗粒. 考察了AuCl4-离子与12-磷钨酸的摩尔比、反应时间及反应温度对Au颗粒的影响. 用TEM, UV-Vis, FESEM, XPS, XRD等手段对所制金纳米颗粒的形貌、组分、粒径和结构进行了表征. 结果表明,HAuCl4与磷钨酸反应速率较快,可获得尺寸范围较大的球形、三角形、多孪晶和六边形等不同形貌的Au颗粒. 对Au颗粒的形成机理进行了探讨.     

7—乙基—1H—吲哚的合成

以邻硝基乙苯为起始原料,经还原、与水合氯醛和盐酸羟胺形成肟基乙酰胺衍生物,环合、LiAlH_4还原四步反应制得7-乙基-1H-吲哚。四步总收率为30.61％。     

Synthesis,characterization and catalytic application of Au NPs-reduced graphene oxide composites material: an eco-friendly approach

In this paper, we have reported the synthesis of Au NPs-reduced graphene oxide (rGO) composites under microwave irradiation using ascorbic acid as eco-friendly reducing agent. The formation of Au NPs-rGO composites was confirmed by UV/Visible spectroscopy, DRIFT spectroscopy, TGA, XRD analysis, SAXS and HRTEM. HRTEM analysis results show that the particle size of the Au NPs formed on rGO nanosheets were in the range of 2-20 nm which is also supported by SAXS analysis results. The synthesized Au NPs-rGO composites were successfully utilized for the aerobic oxidation of benzyl alcohols to their corresponding aldehydes.     

Preparation and nanotribological properties of polyelectrolyte multilayers with in situ Au nanoparticles

Polyelectrolyte multilayers with in situ Au nanoparticles were prepared by alternate immersion of a substrate in poly(allylamine hydrochloride) (PAH)-AuCl₄⁻ complexes solution and poly(acrylic acid) solution for layer-by-layer self assemble process followed by reduction of the metal cations Au³⁺ through immersion into a fresh NaBH₄ solution. UV–vis spectrum, atomic force microscopy (AFM), X-ray photoelectron spectra (XPS), and transmission electron microscope (TEM) were used to confirm the construction of multilayers and synthesis of the Au nanoparticles. The nanotribological behaviors also have been studied using AFM. The polyelectrolyte multilayers with in situ Au nanoparticles exhibited a lower surface adhesion and friction force than the pure polyelectrolyte multilayers due to the nanoparticles improved the mutilayers surface structure and possess a good load-carrying capacity in nanoscale.     

Synthesis and stabilization of Au nanoparticles in colloidal solution using macroelectrolytes with sulfonic acid groups

Metal nanoparticles are obtained by different chemical reactions using reducing agents that are not environmentally friendly. This work report the synthesis of Au nanoparticles in colloidal solution using three monodisperse macroelectrolytes, with peripheral sulfonic acid groups bonded covalently, without toxic reducing agents. During the synthesis of Au nanoparticles were used the new macroelectrolytes as reducing and stabilizing agents in aqueous solution or ethylene glycol. The macroelectrolytes were synthesized using hexachlorocyclotriphosphazene as core, and o‐ or p‐aminobenzenesulfonic acid, obtaining acid macroelectrolytes with two and six sulfonic acid groups in ortho‐ position, and four sulfonic acid groups in para‐ position. The ultraviolet–visible (UV–vis) absorption spectroscopy and transmission electron microscopy study show that the macroelectrolytes with sulfonic acid groups in ortho‐ position are reducing agents for Au⁺⁺⁺ ions in colloidal solution and produced Au nanoparticles with anisotropic shapes, such as decahedrons and prisms. The macroelectrolyte with sulfonic acid groups in para‐ position is reducing agent for Au⁺⁺⁺ and produces quasispherical Au nanoparticles with sizes between 8 and 40 nm. The colloidal solutions with Au nanoparticles were stable by several months due to the protection of imine and sulfonic groups of macroelectrolytes on the Au nanoparticles. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45888.     

Rapid microwave-assisted synthesis of gold loaded hydroxyapatite collagen nano-bio materials for drug delivery and tissue engineering application

A rapid microwave assisted facile synthetic technique was adopted to load gold nanoparticles (Au) on hydroxyapatite (HAp) surface. HAp nanoparticles were primarily synthesized by wet precipitation technique and further used for gold loading and successive collagen coating for biomedical applications. The microwave-assisted controlled synthesis technique with three heating cycles allows the very fast growing of Au seeds over HAp facets. Different sophisticated analytical techniques and spectroscopic characterization were employed to confirm the structural, chemical, and morphological features. The synthesized different concentration “Au” loaded hetero nanostructures coated with collagen (Au–HAp–Col) optimized for drug (Doxorubicin: DOX) loading and releasing purposes for biomedical applications. The maximum drug-loading efficiency of ~58.22% and a pH responsive releasing of ~53% (at pH 4.5) was obtained for 0.1?wt% Au–HAp–Col nanoparticles. To study the cytotoxic effects from the hetero nanostructures, MG-63 osteoblast-like cells were exposed to different concentration ranges on Au–HAp, Au–HAp–Col, and DOX loaded Au–HAp–Col nanoparticles. The non-toxic and bioactive properties of the synthesized nanoparticle-fabricated scaffold promotes cellular attachment, growth, and proliferation. These results indicated that optimized Au–HAp–Col nanoparticles may be promising drug delivery and scaffold materials for multifunctional biomedical applications.     

丙酮肟法合成乙氧基胺盐酸盐

通过三步反应合成乙氧基胺盐酸盐,采用盐酸羟胺和丙酮反应制备丙酮肟,经硫酸二乙酯乙基化、盐酸水解合成乙氧基胺盐酸盐。实验考察了反应温度、催化剂量、反应时间对乙基化反应的影响。结果表明:在无催化剂条件下,25℃下反应6 h,O-乙基丙酮肟收率87.6%(以丙酮肟计),产品总收率为66.7%(以盐酸羟胺计)。