热致变色化合物TiO[VO(SO_4)_2(H_2O)_3]·2H_2O的合成及其性能

热致变色示温材料具有操作方便,测温范围广和不需要复杂仪器等优点,因而广泛用于宇航事业、热记录材料及传感器等。钒为我国丰产元素,钒化合物的热致变色研究报导不多。本文报导氧钒(Ⅳ)化合物作为热致变色材料的探索。     

变色材料及其应用

受到光、电、热等外界激发原作用后可发生颜色变化的物质称为变色物质，本文介绍了光致变色，电致变色及热致变色材料的变色原理，应用及发前景前景。     

可控变色织物制备及颜色控制研究

基于聚苯胺电致变色高聚物、采用反射型电致变色器件结构模型,以柔性导电织物作为电极,构建了可控变色织物,可在-1.0～+1.0 V低电压范围内实现颜色变化显著的黄色和绿色的可逆响应.系统研究了变色织物在不同电压、不同弛豫时间及不同颜色工作电极下的L*a*b*,ΔE*值及反射率曲线,且讨论了透射型电致变色器件和电致变色织物的区别.随着正电压的增加,变色织物对应的a*b*依次减小,蓝绿色加深;随着负电压的增加,变色织物对应的a*b*依次增加,变色织物黄色加深.撤去电压后变色织物发生放电弛豫,慢慢回复到未加电压时的本征态.工作电极底色对电致变色织物也有显著的影响.变色织物的断电放电弛豫时间低于透射型电致变色器件.     

"元素化学实验"中的热致变色现象(二)——部分Cr(Ⅲ)化合物的热致变色现象及其变色机理探讨

在认识部分Co(Ⅱ)化合物的热致变色现象及变色机理的基础上,因势利导,创设问题“情境”,即再通过生动直观的演示实验,引导学生进一步认识一些Cr(Ⅲ)化合物的热致变色现象及其影响因素,引导和启发学生探讨和解释其热致变色的机理。进一步培养学生的观察、分析、判断、归纳、推理、总结和探索规律的能力以及“批判性”思维能力。     

四氯合镍酸三乙醇铵的固相合成及其热色性

可逆热变色材料作为感温防伪显示材料 ,它的应用已扩展到生产及日常生活的各个领域。例如 ,美国财政部已在新版的美元上使用了可逆热色性油墨[1 ] ;Nature公司生产了热色性釉料图案陶瓷杯 ,室温呈夜幕景色 ,倒入热水后显示白天景象 ,来显示水的冷热 ,给人以赏心悦目之感。在一些无法用常规仪器测温的场合 ,热色性示温涂料有着独特的优越性。本文通过固相反应合成了新化合物四氯合镍酸三乙醇铵 ,并借助光谱数据 ,探讨了该化合物的可逆热致变色机理。IFS 48FTIR傅立叶变换红外分光光度计 ,KBr压片 ;紫外 可见 近红外光谱采用UV 340 0分…     

BTF变色对其热安定性和与PVB等相容性的影响

通过光照制备了一定量的变色苯并三呋咱氧化物（BTF）,再分别采用差热（DTA）,差示扫描量热（DSC）,真空安定性试验（VST）等热分析方法,对变色前后的BTF进行了热安定性研究及与聚乙烯醇缩丁醛（PVB）等接触材料的相容性研究,并通过热重－红外等仪器分析手段,初步探讨了BTF与PVB之间的作用机理。     

导电聚合物基电致变色器件的研究进展

导电聚合物作为电致变色活性材料是目前最有应用前景的智能材料之一。本文概述了电致变色器件的基本结构和导电聚合物的电致变色机理,着重介绍了多种导电聚合物基电致变色器件的特点、组成及制备,并展望了未来电致变色器件的发展及应用趋势。     

旋转涂布法制备Si-Mo-W酸盐电致变色薄膜

本文采用旋转涂布制备了Si-Mo-W酸盐的电致变色薄膜。伴随着Li⁺的电化学注入，这些薄膜呈现出可逆的颜色变化。由于这类电致变色薄膜的变色幅度较小，故可用作为强变色材料的对电极。     

XPS和AES研究锡表面的防变色膜

通过比较多种防锡变色剂的防变色效果,发现乙二胺四甲叉膦酸(EDTMP)是一种优良的防锡变色剂。用XPS、AES及Raman光谱探讨了EDTMP的防变色机理,结果表明EDTMP在锡表面形成了一种耐蚀性保护膜。在深度剖析曲线的元素组成近似恒定区测得膜的相对原子浓度(A.C.％)为:O 48.0％;Sn 10.7％;N 7.7％;C 23.1％;P 10.5％。     

钛凝胶的光致变色和电致变色特性

过渡金属氧化物光致变色［１,２］和电致变色［３－７］材料在图象显示、信息存储以及做为调节光线强弱的“灵巧窗”等方面有着潜在的应用．国内外广大的科研工作者,在新型光电变色材料的寻找和光电变色机理等方面开展了较广泛而深入的研究．目前普遍认为变色机理为双注...     

Determination of 2-Acetyl-1-pyrroline via a Color-Change Reaction Using Chromium Hexacarbonyl

At present, there is no colorimetric method for the quantitation of the aroma compound 2-acetyl-1-pyrroline (2AP). A novel colorimetric method was developed for the determination of 2AP content using chromium hexacarbonyl (Cr(CO)₆) as a reagent. The reaction of synthetic 2AP with chromium hexacarbonyl reagent solution in the presence of light produced a green product with an absorption maximum (λ_max) at 623 nm. GC–MS was used to confirm the color-change reaction, which showed the loss of 2AP after the addition of Cr(CO)₆. This novel method enables facile and cost-effective determination of 2AP in fragrant rice. A comparative analysis of fragrant and nonfragrant rice grain extracts showed that no color-change reaction occurred with the nonfragrant rice sample. A limit of detection (LOD) of 2.00 mg L⁻¹ was determined by method validation with an effective linear concentration ranging from 5.00 to 60.00 mg L⁻¹ of 2AP. The results obtained using the developed colorimetric method were consistent with those obtained by automated static headspace gas chromatography with nitrogen-phosphorus detection (SHS-GC–NPD).     

Theoretical Limit of the Color-Change Sensitivity of a Composite Resin Dosimeter Film Based on Spiropyran/BaFCl : Eu2+/Polystyrene

The theoretical limit of the color-change sensitivity of a composite resin dosimeter film based on 6-nitro BIPS/BaFCl : Eu²⁺/polystyrene under X-ray exposure has been estimated. Each photophysical and photochemical process occurring inside the composite resin dosimeter was quantitatively determined, and the obtained values were used to estimate the theoretical limit of the color-change sensitivity for the composite resin dosimeter. The values obtained were 70.6 % for the X-ray absorption efficiency, 13 % for the fluorescence quantum yield, 73.5 % for the UV absorption efficiency and 37.6 % for the photochemical quantum yield. Assuming that the figure-of-merit is their product, its value is estimated to be 2.5 %, which contributes to the chromaticity difference and leads to a color-change sensitivity of 100 mGy. The figure-of-merit of a structurally optimized composite dosimeter was estimated to be 1.9 times that of the dosimeter without structural optimization, which showed a sensitivity of 100 mGy. We predicted that the structurally optimized composite resin dosimeter film, which eliminates optical losses due to the structure, will be able to detect X-ray exposure doses on the order of approximately 28 mGy.     

Horning-crown macrocycles: novel hybrids of calixarenes and crown ethers

[reaction: see text] Novel macrocycles possessing ether linkages and 2,6-disubstituted phenolics were produced in one step and with 100% atom economy by isoaromatization of chameleon macrocyclic precursors possessing 2,6-diarylidenecyclohexanone moieties. Intramolecular hydrogen bonding of the phenolic hydrogen atoms influenced the shape of the macrocycles and dictated host-guest behavior.     

Characterization of the main causes of deterioration of grisaille paint layers in 19th century stained-glass windows by J.-B. Capronnier

Twenty-seven glass fragments containing dark coloured grisaille paint layers of different qualities were collected from ten windows of the cathedral St. Michael & St. Gudule in Brussels (Belgium). The windows were made by J.-B. Capronnier (1814–1891) and cover the period between 1843 and 1878. The samples were cross-sectioned and examined in an electron microscope. Grisaille paint layers are not homogeneous and therefore, it is not meaningful to characterize them in terms of their average composition. Instead, parameters such as granularity, the number of residual gas bubbles per running millimetre of paint, the type of pigments, and the thickness of the paint layer were used to characterize them. The microscopic morphology allows a classification of the grisaille paint layers in four groups, every group associated with a quality level. Moreover, the main causes of the accelerated degradation of some of these paint layers could be explained. The classification made it possible to distinguish two periods in the work of Capronnier: (1) the early period (1843–1848) is characterized by the presence of either single granular paint layers or of double-layered systems consisting of a granular paint layer on top of a well-melted paint layer. The granular grisaille paint layers tend to pulverize; (2) the later period (1848–1878) is characterized by the presence of only well-vitrified paint layers. No sign of deterioration was found on the well-vitrified paint layers.     

Identification of the chemical inventory of different paint types applied in nuclear facilities

The floors, concrete walls and many of the metal surfaces in nuclear power plant containments are coated with zinc primers or paint films to preserve the metal surfaces and simplify decontamination in the containment after the occurrence of a severe nuclear incident or accident. A chemical examination of paint films from different nuclear installations out of operation, as well as current operating ones, reveals that different types of paints are used whose composition can vary significantly. Results obtained for one type of paint at a certain nuclear site are in most cases unlikely to be comparable with sites painted with another type of paint. During normal operation and particularly during nuclear accidents, the paints will degrade under the high temperature, steam and irradiation influence. As paint and its degradation products can act as sources and depots for volatile iodine compounds, the type and aging conditions of the paint films will have a significant impact on the source term of the volatile fission product iodine. Thus, great care should be taken when extrapolating any results obtained for the interaction of radioactive iodine with one paint product to a different paint product. The main focus of the study is a comparison of the chemical profile of paint films applied in Swedish nuclear power plants. Teknopox Aqua V A, an epoxy paint recently used at Ringhals 2, and an emulsion paint used in the scrubber buildings of Ringhals 1–4 are compared with a paint film from Barsebäck nuclear power plant unit 1 that had been aged under real reactor conditions for 20 years. In addition, two paint films, an emulsion and a gloss paint, used in an international nuclear fuel reprocessing facility, are compared with the paints from the Swedish nuclear power plants.     

超耐候乳胶漆的研究

以常用工艺制备乳胶漆,严格按照国标GB／T9755～2001《合成树脂乳液外墙涂料》,测试了乳胶漆的耐水性、耐碱性、耐擦洗性和耐候性,研究了不同类型乳液、不同颜料体积分数（PVC）、不同粉体对乳胶漆的影响。结果表明,使用硅丙乳液、PVC为0．49％且颜料为金红石型钛白粉时,乳胶漆的耐候性最好。     

New silica and polystyrene nanoparticles labeled with longwave absorbing and fluorescent chameleon dyes

We are presenting new fluorescent nanoparticles (NPs) made from silica or polystyrene. Such NPs are potentially useful for purposes of cellular imaging and sensing. The NPs were surface-modified with amino groups, and longwave absorbing and emitting dyes were then conjugated, via their reactive chloro atoms, to the NPs. The reactions proceed at temperatures of around 65 °C and in predominantly aqueous solution, and are accompanied by a color change from typically green to blue. By analogy to other labels giving this effect, we refer to such dyes as chameleon labels. All NPs were characterized in terms of size, by absorption and emission spectroscopy, thermogravimetry and zeta potentials. The chameleon effect also was used to detect the presence of minute quantities of amino groups on the surface of NPs, both by absorptiometry and, with particular sensitivity, by fluorescence.

Nanoparticles made from silica, polystyrene or lanthanide-doped NaYF₄ are presented that have been labeled with a new class of longwave dyes that undergo a color change on reacting with surface amino groups (the so-called chameleon effect). This effect can also be used to detect the presence of amino groups on such particles.

     

Investigation of leaching of an antifouling agent from marine paint formulations using radiotracer technique

A radiotracer technique was used to investigate the leaching of an antifouling agent from different marine paint formulations with an objective to select the best paint formulation for bulk production. The antifouling agent (Diuron) itself was labeled with carbon-14 (half-life: 5,730?years, ??-energy: 156?keV) and used as a radiotracer. The different paint formulations added with radiolabeled Diuron were applied onto suitably selected substrates and measured for initial intensity of ??-radiation using a Geiger-Muller detector connected to a ratemeter. The painted substrates were subjected to shower tests for a pre-decided time and subsequently measured for ??-radiations. The comparison of intensity of ??-radiations in substrates prior and post shower tests provides information about leaching of antifouling agent Diuron from the paint formulation. The high leaching percentage of antifouling agent Diuron post shower tests indicates non-suitability of paint formulation for marine and civil structures. However, low leaching rate of Diuron will make a paint formulation more efficient and suitable. Based on the results of investigation, a paint formulation with minimum leaching rate was identified and selected for bulk production by a paint company.     

鱼类干货中过氧化氢(H2O2)残留的测定

利用过氧化氢与高锰酸钾发生定量氧化还原反应引起高锰酸钾溶液的吸光度下降,建立了用紫外-可见分光光度计测定鱼类干货(鱼鳞、鱼皮)中微量过氧化氢的方法。结果表明,回收率在87.7%~105.4%之间,该法可测定鱼类干货中的微量过氧化氢,方法简单、快速、准确度高。     

The certification of a new paint reference material

The use of paint as a coating for toys intended for sale on the European market is controlled by a European Standard (EN 71-3: 1994-European Standard for the Safety of Toys, Part 3—Migration of Elements). This work is the result of a preliminary study organised by the European Commission to produce a new paint reference material which can be used to validate the test methods given in the European Standard. The migration of elements from painted panels and comminuted paint produced by the Laboratory of the Government Chemist, (U.K.) was studied. Several methods were used in this certification exercise and this work reports the recults of neutron activation analysis and inductively coupled plasma mass spectrometry to determine the migration of As, Ba, Cd, Cr, Hg, Pb, Se and Sb into a simulated stomach environment. Replicate extracts obtained from paint samples gave a precision of within 10% for most elements by both analytical techniques for the paint panels and for the comminuted paint sample. This preliminary study has shown that the standard method can provide reproducible results for each of the paint materials studied and indicates that the study should be continued to produce a fully certified paint reference material.