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在溶液内,利用聚丙烯酰胺为还原剂制备出了聚丙烯酰胺保护下的Au纳米粒子。聚丙烯酰胺起到双重作用,它是制备金纳米粒子的还原剂;另外,它也是一种很好的金纳米粒子的稳定剂。紫外-可见光谱测试证实了溶液内金纳米粒子的存在,透射电镜观察到制得的纳米纤维内含有金纳米粒子。这种新的路线对于制备其他功能性复合纤维有很好的借鉴作用。 相似文献
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在乙醇和碱性环境下合成了金纳米粒子,并通过电子显微镜进行表征。紫外可见光谱计研究了胶体金吸收的吸收光谱及其不同的影响因子对合成过程的影响,氢氧化钠的量对于最终胶体产物的形成是重要的影响因子。通过X射线衍射分析表明,该金纳米粒子的晶体结构是面心立方结构。另外,讨论了该反应的机理及其氢氧化钠在还原反应中的作用,对于室温下仅仅几分钟内就产生金纳米粒子,乙醇和氢氧根离子是缺一不可的 相似文献
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本文以芦荟叶提取液为还原剂和稳定剂,成功地制备了小粒径、球状的金纳米粒子。在这种方法中,简单的芦荟叶提取液和金源混合,没有使用有毒试剂,因此该方法是一种生态友好的合成纳米金的方法。混合溶液的颜色从浅黄色变到紫色,表明生成了纳米金粒子。采用紫外-可见吸收光谱(UV-vis)、激光粒径分析仪(DLS)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱(FT-IR)、X-射线衍射(XRD)等方法对合成的纳米金粒子进行了表征和性能测试。紫外-可见光谱的吸收峰再次表明金纳米颗粒的形成。XRD分析表明所生成的纳米我金具有高度结晶性。TEM和SEM表明纳米金颗粒呈球形,粒径分布在20 nm到60 nm之间。FT-IR证实了金纳米粒子提取物所保护,使其不发生团聚和氧化。论文研究了反应温度、氯金酸溶液和提取物的用量对纳米金粒径的影响。结果表明,这些参数在金纳米粒子的合成中起着重要的作用。 相似文献
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在生物相容性的葡萄糖-柠檬酸盐溶液体系中,研究了Au(III)离子的化学还原和金纳米粒子的各向异性生长;借助VIS/NIR光谱和透射电子显微镜的表征以及梯度离心分离技术,获得了具有多重孪晶、形状类似于马铃薯的链状金纳米粒子结构,其溶液具有2个表面等离子体共振吸收峰,分别呈现在光谱曲线较短和较长波长方向;研究了在含有球形和椭圆形金纳米粒子的溶液中由NaOH诱导所产生的自组装行为,获得了具有类似于金纳米棒光谱性质的金纳米链,其纵向共振吸收光谱峰位于大约800 nm波长处。简要讨论了在溶液体系中链状金纳米结构的形成和纳米粒子的自组装机理。 相似文献
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在含有高浓度的 HAuCl4单组份表面活性剂的溶液体系中,研究了由丙酮促进的金纳米棒晶种媒介的光化学生长和溶解。结果表明,在晶种媒介的生长溶液中,当丙酮/生长溶液之比高于0.1/25(V/V)时,高产率的金纳米棒(长径比为3.5,平均直径14 nm)能够快速形成;当丙酮/生长溶液之比等于或低于这一临界值时,在化学陈化阶段已形成的金纳米棒则在紫外光照射下溶解。在溶解过程中,金纳米棒发生一系列的形态变化,包括缩短,形成纳米球和完全溶解。进一步的紫外照射最终使溶液成为无色的初始Au(I)-CTAB络合物溶液状态。 相似文献
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研究了晶种媒介的金纳米棒光化学二次生长及其长径比的精细调控。在单一组份的表面活性剂生长溶液中,以十六烷基三甲基溴化铵(CTAB)封端的带正电荷的金纳米粒子作晶种,形貌均一的金纳米棒通过二次生长获得,其二次生长是在晶种媒介的化学生长反应达到平衡后于丙酮存在下用300 nm的紫外光照射来实现。通过改变银离子的加入量,具有约10 nm直径金纳米棒的长径比被精细调控在2.3~4.0范围内,相应的纵向等离子体带最大在730~840 nm之间。另外,纵向等离子体带达到最大之后,进一步的紫外光照射使金纳米棒变短。通过这一途径,金纳米棒的长径比也能 相似文献
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在AOT/正庚烷/氯金酸反相微乳液中,用水合肼作为还原剂制备了纳米金粒子, 用紫外-可见光谱和透射电镜进行分析,系统地研究了水和表面活性剂摩尔比 (ω=nH2O/nAOT)以及氯金酸浓度对粒径的影响。结果表明, 制备的纳米金粒子粒径在4~12 nm、单分散性好。纳米金粒径与ω值存在线性关系。氯金酸的浓度对粒径的影响比较复杂, 随着浓度增大, 粒径先减小后增大。用FT-IR红外光谱解释了AOT的磺酸基对纳米金粒子表面有强烈的吸附作用,从而对合成的纳米金粒子有着很强的保护作用 相似文献
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在超声场作用下,以氯金酸为前驱物,经柠檬酸钠和单宁酸还原,在云母基底上组装分散均匀的金纳米粒子单层膜。利用扫描探针显微镜、扫描电子显微镜和X射线衍射等技术对制备的金胶体进行表征。结果表明:超声场分布和超声功率对金纳米粒子形貌影响较大,驻波场下制备的金粒子为纺锤形,而且随超声波功率的增大,纺锤形金粒子的平均长径比减小;而在扩散场中得到单分散的球形金纳米颗粒,XRD和SEM测试表明金的平均晶粒尺寸为25 nm。金纳米粒子在处理前后的云母表面均能组装成膜,但在处理后的云母表面覆盖度更大 相似文献
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Kaushik Mallick Michael J Witcomb Michael S Scurrell Andre M Strydom 《Gold bulletin》2008,41(3):246-250
A facile synthesis route is described for the preparation of a gold-polyaniline nanocomposite material by polymerization of
aniline hydrochloride using HAuCl4 as the oxidant. It was found that the oxidative polymerization of aniline hydrochloride
leads to the formation of polyaniline with a fiber-like morphology, while the concomitant reduction of HAuCl4 results in the formation of gold nanoparticles of diameter 2–7 nm. The gold nanoparticles were highly dispersed and stabilized
throughout the polyaniline fibers while being in intimate contact with the polymer. The combination formed a uniform metal-polymer
composite material. 相似文献
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Baskar Gurunathan Pranav Vasanthi Bathrinarayanan Vasanth Kumar Muthukumarasamy Dilliganesh Thangavelu 《金属学报(英文版)》2014,27(4):569-572
Greener synthesis of nanoparticle is a revolutionizing area in research field.Biological method of reduction of metal ions is often preferred because they are clean,safe,biocompatible,and environmentally acceptable than physical,chemical,and mechanical methods.The wet biomass of Aspergillus terreus(A.terreus) was utilized for the intracellular synthesis of gold nanoparticles.Gold nanoparticles were produced when an aqueous solution of chloroauric acid was reduced by A.terreus biomass as the reducing agent.Production of gold nanoparticles was confirmed by the color change of biomass from yellow to pinkish violet.The produced nanoparticles were then characterized by FT-IR,SEM,EDS,and XRD.The SEM images revealed that the nanoparticles were spherical,irregularly shaped with no definite morphology.Average size of the biosynthesized gold nanoparticles was 186 nm.The presence of the gold nanoparticle was confirmed by EDS analysis.Crystalline nature of synthesized gold nanoparticle was confirmed by XRD pattern. 相似文献
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In this study, gold nanoparticles were synthesized by electroless recovery of [AuCl4]− from an acidic aqueous solution using nano-structured conducting polymer, polypyrrole nanoparticles, as active surface. The formation of gold nanoparticles was confirmed by TEM, SEM and EDX measurements. The effects of the initial Au(III) concentration on the gold uptake was examined. The recovery capability and gold particle morphology prepared from polypyrrole nanoparticle were compared to that from cast PPy film counterpart. 相似文献
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研究了金纳米粒子对染料罗丹明6G(R6G)和荧光素(FL)光学性质的影响。表面有柠檬酸根保护层的金纳米粒子吸附带正电荷的罗丹明6G后,其表面等离子体共振红移;但吸附带负电荷的荧光素后,其表面等离子体共振几乎不受影响,这可能与粒子之间的静电作用有关。罗丹明6G的表面增强拉曼光谱表明其平躺吸附在金纳米粒子表面,非辐射能量转移的发生和不利的吸附取向导致罗丹明6G荧光信号强度减弱,相反,荧光素由于与金纳米粒子表层柠檬酸根之间有静电排斥作用,产生了一段距离,使得荧光信号增强。 相似文献
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P.M. KadamN.L. Tarwal P.S. ShindeS.S. Mali R.S. PatilA.K. Bhosale H.P. DeshmukhP.S. Patil 《Journal of Alloys and Compounds》2011,509(5):1729-1733
Surface plasmon resonance (SPR) phenomenon of metal-dielectric composite thin films formed by embedding the noble metal nanoparticles in a dielectric matrix offers a high degree of flexibility and enables many applications such as surface enhanced spectroscopes, numerous biological and chemical sensing fields. A remarkable enhancement in optical modulation after embedding the gold nanoparticles in a reticulated mesh like matrix of WO3 thin films was observed. WO3 films were prepared onto the conducting ITO coated glass substrates by a novel pulsed spray pyrolysis technique (PSPT). A reticulated mesh like morphology of WO3 was achieved by optimizing the deposition parameters of PSPT and the gold nanoparticles were embedded in the WO3 matrix by a drop casting method. Enhancements in electrochromic properties of WO3 in terms of optical modulation (ΔOD), coloration efficiency (η) and response times (tc and tb) were attributed to the assistance of SPR in gold nanoparticles during coloration and electric field induced quenching of SPR during bleaching. 相似文献
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雷霆 《中国有色金属学会会刊》2007,17(6):1343-1346
Nanostructural gold/polyaniline core/shell composite particles on conducting electrode ITO were successfully prepared via electrochemical polymerization of aniline based on 4-aminothiophenol (4-ATP) capped Au nanoparticles. The new approach to the fabrication included three steps: preparation of gold nanoparticles as core by pulse electrodeposition; formation of ATP monolayer on the gold particle surface, which served as a binder and an initiator; polymerization of aniline monomer initiated by ATP molecules under controlled voltage lower than the voltammetric threshold of aniline polymerization, which assured the formation of polyaniline shell film occurred on gold particles selectively Topographic images were also studied by AFM, which indicated the diameter of gold nanoparticles were around 250 run. Coulometry characterization confirmed the shell thickness of polyaniline film was about 30 nm A possible formation mechanism of the Au/polyaniline core-shell nanocomposites was also proposed. The novel as-prepared core-shell nanoparticles have potential application in constructing biosensor when bioactive enzymes are absorbed or embedded in polyaniline shell film. 相似文献
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In this study, gold nanoparticles for use in the production of nanofluids were synthesized with various gap distances of 1.0
mm to 16.0 mm between cathode and anode electrodes using Solution Plasma Processing (SPP). The size distribution and the shape
of gold nanoparticles in the nanofluids were investigated using a UV-vis nir spectrophotometer and transmission electron microscope
(TEM); the dispersion stability of the gold nanofluids was characterized using zeta-potential. The results demonstrate that
the distances between electrodes have a strong effect on the formation of Au nanoparticles in nanofluids. The gap distance
of 1.0 mm produced the smallest average particle size, 17.7 ± 6.0 nm in diameter, and the most uniform size distribution.
In addition, the zeta-potential of the gold nanoparticles synthesized with a gap distance of 1.0 mm was measured at −45.4
± 1.3 mV, which suggests excellent dispersion stability of nanoparticles in the nanofluids. Possible mechanisms for the formation
of nanoparticles in SPP are suggested. The electrons provided from the solution plasma are believed to play a vital role in
producing the Au nanoparticles. Also, increased electrical energy from the plasma is responsible not only for increasing the
surface areas of the nanoparticles in the solution by making the nanoparticles even smaller in size, but also for facilitating
good dispersion stability by negatively charging the nanoparticles. 相似文献