氟硅溶胶-气相纳米SiO2复合超疏水涂层的制备

以气相纳米SiO2和氟硅溶胶为原料,通过多层堆积法在玻璃表面制备复合超疏水涂层,涂层的表面形貌和疏水性分别通过扫描电镜和接触角测量仪进行表征,重点考察了氟硅溶胶与气相纳米SiO2质量比及涂装层数对涂层疏水性、附着力和硬度的影响.结果证明:氟硅溶胶可在无定型气相纳米SiO2表面形成团簇状微球结构,形成兼具低表面能和高粗糙...     

金纳米双锥体的制备及对食品污染物的快速检测

制备了一种新颖、可靠、快速的检测平台用于检测食品中多种化学污染物。通过种子两步生长法合成出金纳米双锥体,采用消耗诱导分离法获得纯度接近100%的金纳米双锥体,利用液-液界面自组装法制备出大面积致密的金纳米双锥体表面增强拉曼散射（SERS）活性基底。研究表明,以结晶紫（CV）作为拉曼探针分子,该基底具有较好的SERS灵敏性和重复性;而且对抗生素孔雀石绿（MG）、农药残留福美双（THR）和塑化剂邻苯二甲酸卞酯（BBP）的检测灵敏性较高,检测限分别达到10^-9、10^-9、10^-8 mol/L,对酒中BBP的检测限为1.3 mg/kg。     

沉积碳纳米微球制备超疏水表面

通过采用长链脂肪烃混合物在大气环境下的不完全燃烧,将其产生的碳纳米微球沉积在铝合金基底,制备一种具有稳定超疏水性能的表面。该方法简捷高效、所用原料廉价易得、操作简单、无需特殊设备。所制备的超疏水表面不仅对纯水具有很高的接触角,而且对于腐蚀性液滴也保持了很高的接触角。采用透射电镜和扫描电镜分别研究了所制备的超疏水表面的表面形貌以及碳纳米微球的微观结构,结果表明,碳纳米微球在微米尺度上的堆积和其50 nm的直径赋予了表面超疏水性能。     

基于聚苯乙烯微球阵列模板法制备有序纳米结构及表面增强拉曼应用

以规则排列聚苯乙烯微球阵列为模板,在平面衬底上获得了六角形排列的开口球腔结构,在微观曲面衬底上制备了3种不同纳米球腔结构。偏振紫外可见吸收光谱表明,开口纳米球腔阵列光学性质以π/3为周期。两种基底对4-巯基苯甲酸(4-MBA)表面增强拉曼散射(SERS)增强能力的差异证明球腔型纳米结构的拉曼增强能力来源于开口部分。利用球腔型SERS基底实现了对农药甲基对硫磷的检测,此类基底具有用于农药残留分析的潜力。     

介孔硅包金棒多聚体的制备及其对塑化剂的SERS检测

以种子生长法制备金纳米棒,用介孔硅包覆在金棒外,制备出高活性表面增强拉曼(SERS)基底。以乙醇和半胱氨酸诱导金纳米棒进行组装,再于金棒外包裹介孔硅壳层,制备出介孔硅包金棒多聚体SERS基底。以结晶紫(CV)为SERS探针,考察基底的灵敏性及重复性,并对邻苯二甲酸丁基苄酯(BBP)塑化剂进行SERS检测。结果表明,基底的灵敏性较高,重复性较好,对BBP塑化剂的检测限可达10^(-8) mol/L,且该基底在添加了中毒剂量(1.3 mg/kg)BBP的某在售白酒中可以检测出添加的塑化剂,因此该基底有望应用于实际食品检测中。     

纳米Pd／PEG复合材料棒状结构的制备与表征

在超声辐射作用下,以不同相对分子质量的PEG为还原剂和稳定剂,合成了纳米Pd／PEG复合材料。XRD和UV—Vis结果证明了氯化钯被完全还原成钯,TEM显示PEG600呈长约0．5Ixm,直径为50～80nln的棒状结构,并将部分纳米钯粒子包覆在其中;XPS表明PEG030中的c-0H中Cls结合能（287．5eV）比标准的Cls结合能（2s6．5eV）降低了1．0eV,说明聚合物中羟基上的氧原子和纳米钯之间形成了一定的相互作用。     

PVDF负载银纳米花SERS基底膜的制备及对阿霉素的高灵敏检测

利用聚偏氟乙烯(PVDF)的疏水特性结合表面增强拉曼光谱(SERS)技术对抗肿瘤药阿霉素(DOX)进行灵敏检测。首先，合成了形貌大小均一的花状银纳米颗粒(Ag NFs)，通过涂布将其负载至PVDF薄膜表面形成具有SERS活性的基底膜。选取结晶紫(CV)评估Ag NFs-PVDF基底膜的SERS性能，对不同浓度的阿霉素标准液进行检测，考察其检测限。最后结合有机相沉淀法去除蛋白质，在消除干扰的同时，提升人体血清中阿霉素检测灵敏度。结果表明，血清中DOX检测限为0.25μg·mL^-1。因此，该基底为未来临床药物浓度的监测提供了一种快速、便捷、低廉且高效的检测手段。     

雪花钯纳米颗粒的合成及催化性能研究

以苯甲醇为溶剂和还原剂,氯钯酸为前躯体,在适量聚乙烯吡咯烷酮（ PVP）存在下,微波辐照加热150sec得到雪花状的钯纳米颗粒,并对制备的产物进行了TEM、 XRD表征。并以硝基苯为底物探讨了没有负载的雪花状Pd纳米颗粒的催化活性和选择性。     

应用表面增强拉曼光谱检测儿童化妆品中二噁烷的研究

文章以金纳米粒子作为表面增强拉曼散射(SERS)基底,用SERS法检测儿童化妆品中的二噁烷含量。探讨了儿童化妆品中其它物质和金纳米粒子作为SERS基底对儿童化妆品中二噁烷SERS特征峰的影响。     

单分散纳米二氧化硅微球表面化学修饰与表征

通过溶胶-凝胶法制备纳米二氧化硅微球,以乙醇作为分散介质,用硅烷偶联剂采用一步法对纳米二氧化硅进行了表面化学修饰。通过X-射线光电子能谱（XPS）、透射电子显微镜（TEM）和傅立叶红外光谱仪（FT-IR）等手段对其改性前后效果进行了分析。研究发现修饰后的纳米二氧化硅微球的疏水性增强;硅烷偶联剂与纳米二氧化硅表面羟基发生了化学反应。     

A Rapid Synthesis of Oriented Palladium Nanoparticles by UV Irradiation

Palladium nanoparticles of average size around 8 nm have been synthesized rapidly by UV irradiation of mixture of palladium chloride and potassium oxalate solutions. A rod-shaped palladium oxalate complex has been observed as an intermediate. In the absence of potassium oxalate, no Pd nanoparticles have been observed. The synthesized Pd nanoparticles have been characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selective area electron diffraction and energy dispersive analysis by X-rays (EDAX) analyses. XRD analysis indicates the preferential orientation of catalytically active {111} planes in Pd nanoparticles. A plausible mechanism has been proposed for the formation of anisotropic Pd nanoparticles.     

Formation of Pd nanoparticles in surfactant-mesoporous silica composites and surfactant solutions

Highly dispersed palladium nanoparticles containing mesoporous silicas MCM-41 and MCM-48 were prepared by one-pot synthesis. The method consists of the simultaneous formation of CTA⁺ surfactant templating MCM-41 mesophase and CTA⁺ micelle-capped PdO, which was reduced by hydrogen to Pd metal with particle size ≈ 2 nm and was observed to stay inside the mesochannels of MCM-41 (pore size ≈ 3.8 nm) by TEM, XAS, and PXRD. During hydrothermal synthesis of Pd/MCM-48, Pd nanoparticles of average size ≈ 6–7 nm were deposited on the MCM-48 of pore size = 4 nm. The deposition is probably derived from ethanol reduction of Pd(II) complex generated from PdCl₂ precursor by hydrolysis of TEOS and C₁₂H₂₅(OCH₂CH₂)₄OH surfactant. The formation of Pd(0) from Pd(II) species in solid mesoporous silicas by hydrogen reduction was monitored by in situ XAS, and compared with the formation of Pd(0) from [PdCl₄]²⁻, [PdCl₃(H₂O)], and Pd(OH)₂ by sodium dodecyl sulfate surfactant and alcohol reduction in aqueous solutions.     

A facile approach to preparing palladium nanoparticles-embedded polyvinylpyrrolidone (PVP) heterogeneous hybrid nanofibers mats by electrospinning

Well-dispersed palladium nanoparticles (Pd NPs) were prepared under the condition that trisodium citrate was the reduction agent and polyvinylpyrrolidone (PVP) was the stabilizing agent via sol-gel process. By making good use of the advanced electrospinning technology we obtained Pd NPs/PVP composite nanofibers films. Optical properties were examined by UV-visible absorbance spectra (UV-vis) and Fourier transform infrared spectroscopy (FTIR). The morphology and distribution of Pd NPs in/on PVP matrix were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that Pd NPs presented as spherical spots and distributed in/on PVP nanofibers uniformly; their diameter was 4–10 nm and decreased with the increase of PVP. The as-prepared Pd NPs/PVP hybrid mats possess catalytic activity, stability and reusability, as verified by performance in Heck reaction.     

Synthesis of AuPd alloyed nanoparticles via room-temperature electron reduction with argon glow discharge as electron source

Argon glow discharge has been employed as a cheap, environmentally friendly, and convenient electron source for simultaneous reduction of HAuCl₄ and PdCl₂ on the anodic aluminum oxide (AAO) substrate. The thermal imaging confirms that the synthesis is operated at room temperature. The reduction is conducted with a short time (30 min) under the pressure of approximately 100 Pa. This room-temperature electron reduction operates in a dry way and requires neither hydrogen nor extra heating nor chemical reducing agent. The analyses using X-ray photoelectron spectroscopy (XPS) confirm all the metallic ions have been reduced. The characterization with X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) shows that AuPd alloyed nanoparticles are formed. There also exist some highly dispersed Au and Pd monometallic particles that cannot be detected by XRD and transmission electron microscopy (TEM) because of their small particle sizes. The observed AuPd alloyed nanoparticles are spherical with an average size of 14 nm. No core-shell structure can be observed. The room-temperature electron reduction can be operated in a larger scale. It is an easy way for the synthesis of AuPd alloyed nanoparticles.     

Electrocatalytic properties of Pd clusters on Au nanoparticles in formic acid electro-oxidation

Pd clusters were formed on highly dispersed Au nanoparticles (∼3.5 nm in diameter) using a seed-mediated growth process. The structural information and electrocatalytic activities of these Pd clusters on Au nanoparticles were confirmed by high-resolution-transmission-electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). The resulting nanoparticles, which had a uniform size (<5 nm in diameter), were highly dispersed on carbon particles, and Pd clusters (<0.44 nm in size, <2 atomic layers) were formed selectively on Au nanoparticles. XPS results show that the Pd 3d_5/2 peak shifted to lower binding energies and that the amount of surface oxide decreased as the Pd content was decreased on the Au nanoparticles. In formic acid electro-oxidation, these Pd clusters exhibit enhanced electrocatalytic activity relative to that of carbon-supported Pd nanoparticles. These results may be due to the modified electronic and geometric structure of the Pd clusters on the Au nanoparticle substrate.     

Pd nanoparticles prepared by “controlled colloidal synthesis” in solid/liquid interfacial layer on silica. I. Particle size regulation by reduction time

Controlled colloidal synthesis (CCS) was developed to prepare monodisperse palladium particles in the nano-scale range on suspended SiO₂ particles in an ethanol–toluene mixture. On colloidal SiO₂ an about 1 nm thick ethanol-rich adsorption layer was produced in adsorption equilibrium with the liquid mixture. Ethanol served as a reducing agent for the Pd(II) ions diffusing from a toluene-rich liquid solution into the interfacial layer. The low reduction rate ensures the dominancy of particle growth over the nucleation of palladium during the reduction process after the initial nucleation. The relation between the reduction time and the particle size produced was studied. XRF, XPS, TEM, CO chemisorption, and benzene hydrogenation as catalytic test were employed to characterize the samples prepared using different reduction time.     

Electrochemical reduction of oxygen on palladium nanocubes in acid and alkaline solutions

The electrocatalytic properties of cubic palladium nanoparticles towards the electrochemical reduction of oxygen were studied in acid and alkaline solutions and compared with those of spherical nanoparticles and bulk Pd. The synthesised Pd nanoparticles were characterised by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Electrooxidation of pre-adsorbed CO was employed for cleaning the palladium catalyst surface. Oxygen reduction was studied using the rotating disk electrode (RDE) method and enhanced electrocatalytic activity of Pd nanocubes was revealed both in acid and alkaline solutions, which was attributed to the prevalence of Pd(1 0 0) facets. The mechanism of oxygen reduction on Pd nanoparticles was similar to that on bulk Pd, the first electron transfer being the rate-limiting step, and the reaction predominantly followed a four-electron pathway in both solutions.     

Structure and Size of Poly-Domain Pd Nanoparticles Supported on Silica

A polydomain internal structure was evidenced by means of High Resolution Transmission Electron Microscopy (HRTEM) in palladium nanoparticles of two 5% Pd/SiO₂ catalysts prepared by impregnation technique. Such poly-domain structure biased the line broadening analysis of the XRPD patterns, from which highly underestimated average diameters were obtained in comparison to those measured by means of Transmission Electron Microscopy (TEM).In both the investigated catalysts, a Pd/CO average chemisorption stoichiometry close to 2 was found, in good agreement with previous results obtained for Pd/C and Pd/-Al₂O₃ catalysts. The consistency of this result, in cases with different particle sizes and different support materials, suggests that such average stoichiometry is of general validity for palladium, when chemisorption measurements of CO are made using pulse flow technique.     

电导率法研究W/O微乳液中Pd纳米微粒的化学破乳负载

利用水-Tween-80-Span-80-环己烷微乳液合成了粒径为5~10 nm、高度分散的Pd纳米微粒. 结果表明,随着破乳剂用量的增大,含Pd微乳液与破乳剂的混合体系依次呈现微乳液、分层、胶体或微乳液体系. 破乳剂的亲水性与分子结构是影响破乳行为的主要参数. 利用混合物体系分层与再均相的临界区域,在微乳液浸渍a-Al2O3载体的同时,使其中的Pd纳米微粒破乳沉积,实现了Pd在载体表面的均匀负载. TEM及XPS分析表明,Pd的微粒粒径为10~20 nm, 以单质形态结合于载体表面.     

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。