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1.
采用水相硅烷化方法,将γ-氨基丙基三乙氧基硅烷[H2N(CH2)3Si(OC2H5)3](APES)组装在石英表面,在基底表面修饰上氨基为末端的单层膜,并进一步在这种功能化的单层膜基底上组装金纳米粒子得到金纳米粒子/APES/石英的纳米复合结构.以制备的金纳米粒子自组装膜修饰石英为基底及DL-半胱胺酸为中介,利用桑色素(Morin)和DL-半胱胺酸的化学吸附作用,将桑色素间接组装在金纳米粒子自组装膜修饰石英基底表面,所构建的桑色素修饰金纳米粒子自组装膜对三苯基锡有灵敏的荧光识别作用.文章着重研究了桑色素修饰金纳米粒子自组装膜的制备以及组装条件对其荧光行为的影响,探讨了膜的响应特性及响应机理.  相似文献   

2.
用化学还原法制备了铂金属纳米微粒 ,透射电子显微镜 (TEM)表征纳米Pt微粒的平均直径为 2 5nm。通过二硫醇将Pt纳米微粒组装到多晶金电极表面。以Fe(CN) 4- 3-6 的氧化还原作为探针反应的电化学研究表明 ,Au表面组装二硫醇后抑制了电极 /溶液界面的电子传递过程 ,而在二硫醇上再组装铂纳米微粒后 ,电子传递又可进行。运用电化学FTIR反射光谱研究了Pt纳米微粒组装电极在酸性介质中CO的吸附 ,检测到CO的线型、桥式吸附态 ,分别在 2 0 30和 184 5cm- 1 附近给出红外吸收谱峰 ,并且有增强红外效应。此外 ,还观察到Pt纳米微粒上的CO孪生吸附态。红外吸收峰位于 2 10 0cm- 1 附近。  相似文献   

3.
纳米α-Al2O3磨料抛光单晶硅片光滑表面的形成机理   总被引:2,自引:0,他引:2  
"将纳米α-Al2O3粉体配制成抛光液并冷冻成冰结抛光垫对单晶硅片进行了抛光,用原子力显微镜观察了抛光表面的微观形貌并测量了其表面粗糙度,采用透射电镜观察了单晶硅片抛光后的断面形貌.为进一步分析抛光过程中的化学作用机理,采用X射线光电子能谱分析了单晶硅片抛光后表面的化学成分.利用纳米压痕仪的划痕附件对单晶硅片进行了划痕测试,研究了抛光过程中的机械作用机理.结果表明纳米α-Al2O3磨料冰冻抛光单晶硅片时,在1 mm£1 mm的范围内得到了微观表面粗糙度为0.367 nm的超光滑表面,亚表面没有任何损伤,材  相似文献   

4.
在氨基硅烷化的单晶硅片表面通过静电自组装技术组装上金和金核铂壳两种纳米粒子,通过改变基底浸泡在溶胶中的时间控制基底上纳米粒子的密度。用扫描电子显微镜(SEM)对基底表面上的形貌进行表征,结果表明纳米粒子呈亚单层二维阵列分布。以吡啶(Py)为探针分子,用波长为632.8 nm的激发光作为激发光源,研究纯金和金铂复合基底上的表面增强拉曼光谱(SERS)行为。数据显示在金纳米粒子之间引入金核铂壳纳米粒子后,Py的两个特征峰的频率没有明显变化,但谱峰的强度却变弱了,其SERS信号衰减最大可至原来的24%。这是由于引入的铂的d态电子使金的等离子体激发猝灭,从而破坏了电磁场增强,使金的SERS信号衰减。  相似文献   

5.
功能性硅烷在纳米氧化硅表面的自组装   总被引:9,自引:0,他引:9  
在分散体系中 ,两种功能性硅烷 ,甲基丙烯酰氧丙基三甲基硅烷 (MPTES)和氨丙基三甲基硅烷 (APTES)在纳米氧化硅表面形成自组装单分子层 ,用XPS和FTIR对所得自组装单分子层进行了表征 .元素分析结果表明 ,所得功能性纳米氧化硅中的功能基含量分别为 1.0 3mmol/g甲基丙烯酰氧基 /丙烯酰氧丙基纳米氧化硅 (MPSN)和 3.34mmol/g氨基 /氨丙基纳米氧化硅 (APSN) .LSS分析结果表明 ,未修饰纳米氧化硅、MPSN和APSN在甲苯分散体系中的平均流体力学直径大约分别为 2 4 0、4 5和 5 6 0nm .  相似文献   

6.
通过简单的化学还原法在室温条件下成功的合成了三元的Ag-Cu2O/RGO纳米复合物,这种复合物结合了Ag,Cu2O以及石墨烯三者的特性,表现出了很高的SERS活性。Cu2O/RGO具有一定表面增强能力,复合了Ag纳米粒子后,Ag-Cu2O/RGO纳米复合物对探针分子PATP的检测可以达到10-9 mol·L-1,一方面由于石墨烯比表面积大并具有大π键结构对分子起到了很好的富集作用,另一方面是由于Cu2O和Ag共同的SERS增强作用提高了SERS信号。因此该基底在SERS检测上有潜在的应用。  相似文献   

7.
稀土纳米发光材料的燃烧法制备及光谱性质   总被引:7,自引:5,他引:2  
用燃烧法制备了不同粒径的La2O3:Eu3 纳米微粒,研究了影响La2O3:Eu3 纳米微粒大小的实验条件,发现粒径大小随甘氨酸(Gly)与稀土离子比例的增大而减小.制备的纳米微粒由谢乐公式计算的粒径尺寸为12~28 nm.测量了样品的高分辨光谱.运用激光选择激发,研究了光谱在不同发光中心上的变化,表面态对于这些变化起着主要作用.  相似文献   

8.
纳米Cu/Al_2O_3组装体模板合成与光吸收   总被引:2,自引:0,他引:2       下载免费PDF全文
以有序的多孔氧化铝为模板,利用交流电在孔洞中沉积金属铜得到纳米Cu粒子/Al2O3组装体系.透射电镜观察显示随着交流电沉积时间的延长,孔洞中纳米Cu粒子数量增加.测量了纳米Cu粒子/Al2O3组装体系的紫外可见光吸收光谱,发现随着孔洞中纳米Cu粒子数量增加,纳米Cu粒子/Al2O3组装体系的吸收带边大幅度红移;根据雷利散射引起的消光增强解释了组装体吸收带边红移的原因.同时发现Cu粒子的表面等离子共振吸收峰消失及组装体在吸收带边区光吸收值满足间接带隙半导体光吸收边的表达式.  相似文献   

9.
Ag-MgF2复合纳米金属陶瓷薄膜的微结构及吸收光谱特性研究   总被引:10,自引:2,他引:8  
对用真空蒸发技术制备的Ag-MgF2复合纳米金属陶瓷薄膜(Ag的质量分数为0.15、0.20、0.30)的微结构及吸收光谱特性进行了研究。微结构分析表明薄膜由平均粒径约18nm的fcc-Ag纳米晶粒嵌埋于主要呈非晶态的MgF2基体中所组成。对吸收光谱的研究表明,Ag纳米微粒的表面离子共振吸收峰出现在λ=412nm-417nm波段范围内。随着Ag组分增加,吸收峰强度下降,呈现轻微红移并且逐渐宽化。  相似文献   

10.
采用溶胶法,以硫脲为表面修饰剂,合成了长方体形CdS微粒,并用X射线粉末衍射、透射电子显微镜、红外光谱以及荧光光谱等手段进行了表征。实验结果表明,硫脲分子中的硫原子与CdS纳米晶表面的Cd2 离子存在配位作用;硫脲分子表面修饰的CdS纳米晶为立方闪锌矿结构,具有较好的荧光性质;长方体形CdS微粒可能是由硫脲分子表面修饰的CdS初级纳米晶粒自组装组成。该研究结果为硫脲分子表面修饰的CdS初级纳米晶粒在分子组装及作为新型发光材料方面的进一步研究奠定了基础。  相似文献   

11.
By dipping-lifting in sol-gel solution and reducing process, the graphene/TiO2 composite film on the glass plate was first prepared. Then, the Ag/graphene/TiO2 composite film was fabricated by interface reaction with AgNO3 and N2H4·H2O on the surface of graphene/TiO2 composite film. The characterization results show that the uniform porous TiO2 film is made up of the anatase crystal, and the Ag/graphene/TiO2 composite film is constructed by doping or depositing graphene sheets and Ag nanoparticles on the surface of TiO2 film. The photoelectrochemical measurement results indicate that the Ag/graphene/TiO2 composite film has an excellent photoelectrochemical conversion property.  相似文献   

12.
The growth process of silver on a Si(111) substrate has been studied in detail by low-energy ion-scattering spectroscopy (ISS) combined with LEED-AES. Neon ions of 500 eV were used as probe ions of ISS. The ISS experiments have revealed that the growth at room temperature and at high temperature are quite different from each other even in the submonolayer coverage range. The following growth models have been proposed for the respective temperatures. At room temperature, the deposited Ag forms a two-dimensional (2D) island at around 2/3 monolayer (ML) coverage, where the Ag atoms are packed commensurately with the Si(111)1 substrate. One third of the substrate Si surface remains uncovered there. Then it starts to develop into Ag crystal, and at a few ML coverage a 3D island of bulk Ag crystal grows directly on the substrate. An intermediate layer, which covers uniformly the whole surface before the growth of Ag crystal, does not exist. At high temperatures (>~200°C), the well-known Si(111)√3-Ag layer is formed as an intermediate layer, which consists of 2/3 ML of Ag atoms and covers the whole surface uniformly. These Ag atoms are embedded in the first double layer of the Si substrate. It is concluded that the formation of the √3 structure needs relatively high activation energy which may originate from the large displacement of Si atoms owing to the embedment of the Ag atoms, and does not proceed below about 200°C. The most stable state of the Ag atoms on the outermost Si layer is in the shape of an island, both for the Si(111) surface and for the Si(111)√3-Ag surface.  相似文献   

13.
一种新型硅基3C-SiC的生长方法及光谱学表征   总被引:2,自引:1,他引:1  
采用LPCVD技术, 以CH4和H2混合气体为反应源气, 在n-Si(111)衬底上生长3C-SiC晶体薄膜。H2在反应过程中作为稀释气体和运输气体, CH4作为碳源, 硅源有衬底硅来提供。利用X射线衍射分析仪、场发射扫描电子显微镜、激光拉曼光谱和傅里叶变换红外光谱分别研究3C-SiC薄膜的晶相结构、表面形貌及其光谱性质。结果表明此生长方法可以成功的成长出3C-SiC薄膜。  相似文献   

14.
ABSTRACT

Crystalline silicon oxy-nitride (SiON) composite films are deposited on Si substrate for multiple (5, 15, 25 and 50) focus shots (FS) by plasma focus device. The X-rays diffraction patterns reveal the development of various diffraction peaks related to Si, Si3N4, and SiO2 phases which confirms the formation of SiON composite film. The intensity of Si3N4 (1 0 2) plane is linearly increased with the increase of FS. The Si3N4 (1 0 2) phase does not nucleate for 5 FS. Raman analysis confirms the formation of β–Si–N phase. Raman and Fourier transform infrared spectroscopy analysis reveals that the strength of chemical bonds like Si–N, Si–O formed during the deposition process of SiON composite films is associated with the bonds intensity which in turn depends on the number of FS. The field emission scanning electron microscopic analysis reveals that the surface morphology like size, shape and distribution of micro/nano-dimensional particles, film compactness and the formation of micro-rods, micro-teethes and micro-tubes of SiON composite films is entirely associated with the rise in substrate surface transient temperature which in turn depends on the increasing number of FS. The EDX spectrum confirms the presence of Si (22.5?±?4.7 at. %), N (13.4?±?4.5 at. %) and O (54.7?±?11.3 at. %) in the SiON composite film. The thickness of SiON composite film deposited for 50 FS is found to ~15.47?µm.  相似文献   

15.
The variation in interfacial reaction between Au islands and Si substrates and the fabrication of a Au/Si heterojunction on a nanometer scale are described. Morphologies and elemental distribution were drastically changed around the interface between Au islands and the Si substrate on changing the surface conditions of the substrate. In particular, the Au/Si bilayer structure was formed on the clean Si surface by thermal annealing instead of the well-known interdiffusion of the two elements. This structure was fabricated through liquid phase epitaxy (LPE), in which migrating Si atoms on the surface play an important role. These results suggest that the kinetics of the interfacial reaction are variable and controllable even within the same material system. On the basis of this phenomenon, mushroom-shaped bilayer dots of Au/Si and Ag/Si were fabricated on a nanometer scale by employing metal particles as the transport medium for Si growth.  相似文献   

16.
在Si(111)衬底上用聚苯乙烯溶胶凝胶甩膜并经950℃真空(10-3Pa)热解处理法,制备出晶态SiC薄膜.用FTIR,XRD,TEM,RamanXPS等方法研究了SiC薄膜的晶体结构、微结构、组成以及各元素的化学态等性质.结果表明制得的是沿(0001)高度择优取向的晶态6H-SiC薄膜.膜中SiC晶粒沿c轴柱状生长,其最大尺寸约150nm,膜厚约为0.3μm,SiC中的Si/C比约为1.表层有少许污染C(CH和CO)和少量O(Si2O3,CO态氧和吸附氧).从对比实验可知,在热解时将甩膜的Si片与另一空白Si片面面相贴可明显增加SiC的生成量. 关键词: 碳化硅 薄膜 溶胶凝胶  相似文献   

17.
张增院  郜小勇  冯红亮  马姣民  卢景霄 《物理学报》2011,60(1):16110-016110
利用直流磁控反应溅射技术,通过调节反应气压(RP),在250 ℃衬底温度下制备了一系列氧化银 (AgxO) 薄膜,并利用X射线衍射谱、能量色散谱和分光光度计重点研究了RP对AgxO薄膜的结构和光学性质的影响. 研究结果表明,随着RP从0.5 Pa升高到3.5 Pa,薄膜明显呈现了从两相(AgO+Ag2O)到单相(Ag2O)结构再到两相(Ag2O+AgO)结构的演变. 特 关键词: 氧化银薄膜 直流磁控反应溅射 X射线衍射谱 光学性质  相似文献   

18.
The effect of Ag nanoislands on the Raman of graphene was investigated in this work. Compared with that on the bare silicon wafer, Raman enhancement was observed in the graphene film that covered on Ag/Si surface with nanoscale Ag islands, which would be induced by the localized plasmon resonance in Ag nanostructures. The interaction between the graphene sheet and Ag/Si substrate was further studied. The peak shift and line shape of Raman spectroscopy indicated a nonuniform strain distribution in the Ag/Si supported graphene film.  相似文献   

19.
Considering for the potential application in tissue engineering, polyaniline (PANi) film was fabricated via a two-step route: a self-assembled monolayer of C6H5NHC3H6Si(OMe)3 was firstly formed on the single-crystal Si substrate; the conducting PANi film was then prepared through electroless surface polymerization of the aniline molecules on the aniline monolayer-bearing silane surface in an acidic aqueous solution. The formation of PANi film on Si surface was confirmed by characterizations of X-ray photoelectron spectroscope (XPS) and specular reflectance Fourier transform infrared (SR-FTIR) spectrum, etc. At last, the proliferation behaviors of PC-12 cells on the PANi film surface were studied by the [3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) colorimetric assays, acridine orange fluorometric staining, and scanning electron microscope (SEM) observation, etc. The results demonstrate that the as-prepared PANi film provides high ability for cell proliferation, exhibiting promising potentials as surface coating to cultivate neuronal cells for applications in the tissue engineering.  相似文献   

20.
Ag or Au was deposited on a clean Si substrate at room temperature. These systems, Ag/Si and Au/Si, were annealed at various temperatures or various heating times. Due to the annealing, Ag or Au diffused into Si and/or Si diffused into the metal. The changes of the surface composition are analyzed by a quantitative Auger Electron Spectroscopy (AES) method which is newly developed as a non-destructive method. In the case of Ag/Si, Ag migrated into the Si substrate and/or Si diffused into Ag. Then, Ag-Si solid solution was produced. After the annealing, the Ag/Si system is changed into Ag/(Ag-Si)/Si of the three-phase structure. In the case of Au/Si (Au film thickness < 15 Å), the Au film thickness became thinner by annealing. The Au/Si system always keeps the Au/Si phase after annealing, while there was no Au-Si solution area. The difference between the Ag/(Ag-Si)/Si and the Au/Si structure is attributed to the reason that Au diffuses more quickly than Ag into the Si substrate. AES results after annealing cannot be explained by the model of the formation of the three-dimensional island structure which is commonly referenced.  相似文献   

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