Measuring grain rotation at the nanoscale

In this paper, we introduced a method to measure grain rotation of nanomaterials under external stress using a high pressure diamond anvil cell and the Laue microdiffraction technique at a synchrotron facility. We used tungsten carbide marker crystals to investigate grain rotation activities of 3 and 500?nm nickel media. Our results show that the grain rotation of 3 and 500?nm nickel nanocrystals increase with pressure and finally rotation of 500?nm nickel tends to stop at a lower pressure/stress level than 3?nm nickel. 3?nm nickel nanocrystals show a higher rotation magnitude than 500?nm nickel nanocrystals. Our measurements show an effective method to study the grain rotation of nanomaterials especially in ultrafine nanocrystals.     

卟啉单晶微纳米棒的合成及光电性能研究

通过相界面反应制备了一维卟啉微纳米棒,并通过紫外、红外和X衍射仪等多种表征方法对其进行了表征.结果表明,在无机酸的作用下,卟啉分子通过-,氢键和静电作用等多种相互作用聚集成有序的J-聚集体.将此一维卟啉微纳米棒构筑为微纳米器件,并测试其光电性能.该纳米器件在可见光照射下的光电流很大,关闭光源,电流在40 s内降到最低,再次打开光源,电流又在120 s内升到了最大.经过多次＂开＂、＂关＂光源,电导的光响应依旧没有降低.这种具有光电响应的卟啉微纳米棒有望成为微纳电子器件的光电元件.     

纳米颗粒透明分散体及其高性能有机无机复合材料

纳米颗粒分散是无机纳米材料在有机体系中应用的关键.本文提出了采用纳米颗粒液相分散体制备高度分散纳米透明有机无机复合材料的新方法,发明了超重力反应-萃取相转移方法制备纳米颗粒液相透明分散体技术,介绍了其制备原理和实施效果,以及其在纳米复合节能膜、纳米润滑油脂和高固含量光学材料等有机无机纳米复合材料中的最新研究进展.     

Small‐Peptide‐Based Organogel Kit: Towards the Development of Multicomponent Self‐Sorting Organogels

The results presented here highlight the extremely useful nature of ultra‐short peptides as building blocks in the development of smart multicomponent supramolecular devices. A facile bottom‐up strategy for the synthesis of a small library of stimuli‐responsive smart organogelators has been proposed based on the predictive self‐assembly of ultra‐short peptides. More importantly, the narcissistic self‐sorting of the gelators has been evaluated as a simple method for the efficient co‐assembly of a donor–acceptor dual‐component gel, allowing the investigation of possible future applications of similar systems in the development of a supramolecular photo‐conversion device. Interestingly, it was observed that the self‐organization of the components can lead to highly ordered systems in which discrimination between compatible and non‐compatible building blocks directs the effective organization of the chromophores and gives rise to the formation of an excited‐state complex with exciplex‐like emission. The current report may prove important in the development of organogel‐based multicomponent smart devices.     

Engineering of Supported Nanomaterials

This brief review analyzes the parameters that can be used to guide the generation of hierarchic systems that include inorganic and/or biological nanoscale objects. Importance of interface effects and geometrical factors are underlined. The mutual influence between the substrate and the deposited material is an important factor to determine the most appropriate set of parameters for the synthesis of nanomaterials with desirable properties for industrial applications.     

基于CoFe(Ⅲ)PBA/GO过氧化物模拟酶化学发光法检测H2O2和抗坏血酸

制备了一种具有过氧化物酶活性的类普鲁士蓝/氧化石墨烯复合纳米材料(CoFe(Ⅲ)PBA/GO)。将具有过氧化物酶活性的CoFe(Ⅲ)PBA/GO和化学发光法相结合,构建了一种用于检测H₂O₂和抗坏血酸(AA)的化学发光分析法。CoFe(Ⅲ)PBA/GO催化H₂O₂产生的O₂·^-,·OH,1O₂自由基氧化Luminol会产生很强的化学发光信号,通过检测化学发光强度可以实现对H₂O₂的检测。该方法检测H₂O₂的线性范围为0~0.8μmol/L,检测限为11 nmol/L。利用AA作为活性氧消除剂可以抑制化学发光反应的特点,实现了AA的检测。该方法测定AA的线性范围为0.02~0.8μmol/L,检测限为20 nmol/L。方法已应用于H₂O₂消毒水中H₂O₂和维生素C片中抗坏血酸的检测。     

Solid-phase extraction techniques based on nanomaterials for mycotoxin analysis: An overview for food and agricultural products

Mycotoxin contamination is a globally concerned problem for food and agricultural products since it may directly or indirectly induce severe threats to human health. Sensitive and selective screening is an efficient strategy to prevent or reduce human and animal exposure to mycotoxins. However, enormous challenges exist in the determination of mycotoxins, arising from complex sample matrices, trace-level analytes, and the co-occurrence of diverse mycotoxins. Appropriate sample preparation is essential to isolate, purify, and enrich mycotoxins from complicated matrices, thus decreasing sample matrix effects and lowering detection limits. With the cross-disciplinary development, new solid-phase extraction strategies have been exploited and integrated with nanotechnology to meet the challenges of mycotoxin analysis. This review summarizes the advance and progress of solid-phase extraction techniques as the methodological solutions for mycotoxin analysis. Emphases are paid on nanomaterials fabricated as trapping media of solid-phase extraction techniques, including carbonaceous nanoparticles, metal/metal oxide-based nanoparticles, and nanoporous materials. Advantages and limitations are discussed, along with the potential prospects.     

Simultaneous determination of four sedative-hypnotics in human urine based on dendritic structured magnetic nanomaterials

A magnetic solid-phase extraction technique based on magnetic dendritic structured nanoparticles (Fe₃O₄@SiO₂-NH₂-G5) as adsorbent coupled with ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) has been developed to detect diazepam, midazolam, zolpidem, and zaleplon in human urine. With Fe₃O₄@SiO₂-NH₂ as the central core, dendrimer (G5) grafted alternately with cyanuric chloride and imidazole were bonded to the surface of the core to synthesize Fe₃O₄@SiO₂-NH₂-G5. The morphology and structure of the magnetic materials were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and dynamic light scattering (DLS). The key parameters affecting the extraction efficiency were optimized. A satisfactory performance was obtained under the optimum extraction conditions. The proposed method was validated, and the limits of detection of zaleplon, diazepam, zolpidem, and midazolam were 0.05, 0.05, 0.02, and 0.02 ng mL^?1, respectively. The linear correlation coefficients r of the four analytes were > 0.996, the intra-day precision was between 2.4 % and 9.4 % with the recoveries between 88.3 % and 104.8 %, and the inter-day precision ranged from 3.9 % to 15.2 % with the recovery in the range of 94.1 %?108.3 %. The magnetic dendritic structure nanomaterial Fe₃O₄@SiO₂-NH₂-G5 was successfully used to extract sedative-hypnotic drugs from human urine samples. The Fe₃O₄@SiO₂-NH₂-G5-based magnetic solid-phase extraction method eliminates centrifugation and filtration steps as in conventional extraction. Only one step of vortex dispersion extraction could achieve the separation and purification of the target compounds. The proposed method was simple, rapid, environment-friendly, and suitable for the analysis of sedative-hypnotic drugs in human urine.     

稀世之宝—铂*

铂是一种化学性质极其稳定的贵金属,铂、铂合金以及铂配合物在催化剂、医药、传感器等领域具有重要应用。简要介绍铂的发现史、自然分布与资源现状、铂的应用等3个方面,其中铂的应用,重点从铂基催化剂、铂合金纳米材料、发光铂配合物、铂类抗癌药物等4个方面展开介绍。