Synthesis and photochromic properties of WO<Subscript>3</Subscript> powder induced by oxalic acid

Tungsten trioxide powder with the novel morphology was prepared via the hydrothermal method with oxalic acid as the organic inducer, the structure and shape of which were detected by X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET. Furthermore, photochromic properties of the as-prepared powder samples were tested by an ultraviolet-visible spectrophotometer combined with a color difference meter. The corresponding results indicated that the induced product was still hexagonal WO₃, made up of regularly spindle particles with 200–300 nm in length and 30–50 nm in width. The ratio of the length and width was from 4 to 10. Moreover, the special morphology improved its absorptive capacity to the excitation light source, resulting in its high photochromic properties. Supported by the National Natural Science Foundation of China (Grant No. 50702052) and the Hubei Province Key Laboratory of Macromolecular Material     

草酸诱导合成WO3粉体与其光致变色性质

采用草酸有机诱导在水热条件下制备了形貌新颖的WO3粉体, 使用XRD, SEM, BET等手段进行结构和形貌表征, 并利用紫外-可见光谱仪(UV-Vis)及测色计对所制备的样品进行光致变色性能测试. 结果表明, 合成的WO₃粉体仍为六方相, 以草酸为诱导剂合成的粉体由大小及形状较为均匀的梭形组成, 颗粒长在200~300 nm之间, 宽在30~50 nm左右, 长宽比为4~10之间, 这种特殊的形貌改善了粉体对激发光源的吸收能力, 从而提高了合成的WO₃粉体的光致变色性能.     

甲醛诱导合成WO3粉体与光致变色性质研究

采用甲醛有机诱导在水热条件下制备了形貌新颖的WO3粉体, 使用XRD, SEM, TEM, BET等手段进行结构和形貌表征, 并利用测色计对所制备的样品进行光致变色性能测试. 结果表明, 合成的WO3粉体仍为六方相, 以甲醛为诱导剂合成的粉体是由WO3纳米立方体簇集成的大小均匀的微球团聚而成, 纳米立方体的边长为20～50 nm, 簇集形成的微球直径为500～800 nm, 这种特殊的形貌有利于光生质子的产生和传输, 从而提高了合成的WO3粉体的光致变色性能.     

正丙醇诱导合成WO3粉体与光致变色性质

采用正丙醇为有机诱导剂, 在水热条件下制备了形貌新颖的WO3粉体, 使用XRD, SEM和TEM等手段进行了结构和形貌表征, 并用紫外-可见(UV-Vis)光谱仪及测色计测试了光致变色性能. 结果表明, 正丙醇诱导合成的WO3粉体仍为六方相, 但形成了特殊的海胆状纳米结构, SEM和TEM测试结果表明, 海胆状WO3微球由大量的WO3纳米杆簇集形成. 该诱导产物的纳米杆簇集成的海胆状结构显著地改善了光生质子的传输过程, 提高了合成的WO3粉体的光致变色性能.     

草酸电还原制取乙醛酸的研究

研究了由草酸电解还原制备乙醛酸时，温度、草酸纯度、电解时间、电极状态和电解产物对电流效率和产率的影响。实验发现，除温度和原料纯度是重要的影响因素外，电极表面的有机物吸附和电解产物－乙醛酸的浓度具有更大的影响。     

Synthesis and properties of a novel photochromic luminophore

A photochemically bifunctional compound was obtained. Its molecule includes the spironaphthoxazine and dansylamino fragments. This compound exhibits both photochromic and luminescent properties. Its spectroscopic characteristics were studied in different solvents. The electronic systems of two constituent fragments do not interact with each other. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2802–2805, December, 2005.     

Synthesis, structures, and photochromic properties of N-aryl-3-indolylfulgides

New 3-indolylfulgides, viz., 3-[1-(1-aryl-5-methoxy-2-methyl-1H-indol-3-yl)ethylidene]-4-(1-methylethylidene)tetrahydro-2,5-furandiones, were synthesized. These compounds were obtained as E-isomers, as demonstrated by X-ray diffraction, electronic spectroscopy, and ¹H NMR spectroscopy. Fulgides exhibit photochromic properties in solution. The cyclic dihydrocarbazole photoisomers of indolylfulgides show fluorescence properties and are characterized by high thermal stability. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1417–1423, July, 2008.     

Preparation and photochromic properties of dye-doped aluminosilicate and ORMOCER gels and coatings

Aluminosilicate and ORMOCER gels and coatings containing photochromic dyes, 1, 3-dihydro-1, 3, 3-trimethylspiro-[2H-indole-2, 3-[3H]-naphth-[2, 1-b][1, 4]-oxazine] (SO) and 1, 8a-dihydro-2, 3-dimethoxycarbonyl-spiro [fluorene-9, 1-indolizine] (DHI), were prepared by the sol-gel method and the photochromic activity was monitored in the course of the sol-wetgel-xerogel transformation. The photochromic activity of the aluminosilicate gels decreases rapidly and even vanishes in the wetgel-xerogel stage while that of ORMOCER gels and coatings levels off in the early wetgel-xerogel stage at a reasonably high photochromic intensity with the colour-fading speed similar to that in ethanol and the photostability being considerably improved. The experimental results are discussed in terms of the matrix effect on photochromism of organic dyes.     

Structure and photochromic properties of molybdenumphosphoric acid/TiO_2 composite films

TiO_2 sol-gel composite films with dropping molybdenumphosphoric acid(PMoA) have been prepared by sol-gel method.The structure and constitute of composite thin films were studied with Fourier transforms infrared spectroscopy(FT-IR),atomic force microscopy(AFM),and X-ray diffraction(XRD) patterns,respectively.The photochromic behavior and mechanism of composite thin films were inves-tigated with ultraviolet-visible spectra(UV-vis) and electron spin resonance(ESR).FT-IR results showed that the Keggin geometry...     

Synthesis and photochromic properties of spiro (benzindoline-naphthoxazines)

A new photochromic compound belonging to the class of spiro(indoline-naphthoxazines) was synthesized. Nitration of this compound was carried out and the structures of two photochromic nitro-substituted products were determined. The photochromic properties of the products were studied in solvents of different polarity.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 732–736, April, 1995.     

Synthesis and spectral kinetic investigation of solutions of photochromic thienylfulgimides

A convenient method has been developed for the synthesis of previously unknown photochromic 1-amino-3-[1-(2,5-dimethyl-3-thienyl)ethylidene]-4-(1-methylethylidene)pyrrolidine-2,5-dione, from which photochromic Schiff’s bases were obtained. A spectral kinetic investigation of the photochromism of the thienylfulgimides obtained has been carried out. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1170–1175, August, 2006.     

草酸改性空气凤梨生物炭吸附甲醛的机理研究

探究草酸改性园林废弃物类生物炭对溶液中甲醛的吸附效率和固定的机理,为园林废弃物类生物炭在甲醛污染控制方面的应用提供科学依据.利用马弗炉在低氧条件下将空气凤梨原材料和草酸改性后的原材料制备成生物炭.然后利用实验室模拟法,研究不同反应时间、甲醛浓度、pH对生物炭吸附效果的影响,并分析草酸改性如何提高园林废弃物类生物炭对甲醛...     

WO3在不同担体上的程序升温硫化研究

利用ＴＰＳ方法考察了ＷＯ３在γ－Ａｌ２Ｏ３，ＴｉＯ２－Ａｌ２Ｏ３及活性碳上的硫化过程，结果发现，随着ＷＯ２担载量的增加，表面Ｗ物种硫化峰的数目增加，表明ＷＯ３的的担载量超过一定量后，在这三种担体表面，都有几种Ｗ物种同时存在：ＷＯ３／ＴｉＯ２－Ａｌ２Ｏ３与ＷＯ３／Ａｌ２Ｏ３相比，当ＷＯ３担载量低于一个单层分布时，硫化温度明显降低，而超过一个单层分布后，两者的硫化温度相接近，表明ＴｉＯ２的调变作用对低     

Y_(2-x)Ho_x(WO_4)_3的制备及其热膨胀性能研究

采用固相化学反应法制取Y2-xHox(WO4)3(x=0.0~0.8,1.5~2.0)系列固溶体,利用高、低温X射线衍射方法研究Y2-xHox(WO4)3系列固溶体的热膨胀性能,并用热重法分析Y2-xHox(WO4)3所带的结晶水分子数目。由TOPAS软件计算出的晶胞参数随温度的变化可以看出,Y2-xHox(WO4)3{x=0.2,1.8}的化合物沿着3个晶向都是呈负热膨胀变化的,表明Y2-xHox(WO4)3这一系列固溶体均有负热膨胀性。     

Conformers and intramolecular hydrogen bonding of the oxalic acid monomer and its anions

Density functional theory, B3LYP/6‐31G** and B3LYP/6‐311+G(2d,p), and ab initio MP2/6‐31G** calculations have been carried out to investigate the conformers, transition states, and energy barriers of the conformational processes of oxalic acid and its anions. QCISD/6‐31G** geometrical optimization is also performed in the stable forms. Its calculated energy differences between the two most stable conformers are very near to the related observed value at 7.0 kJ/mol. It is found that the structures and relative energies of oxalic acid conformers predicted by these methods show similar results, and that the conformer L1 (C_2h) with the double‐interfunctional‐groups hydrogen bonds is the most stable conformer. The magnitude of hydrogen bond energies depends on the energy differences of various optimized structures. The hydrogen bond energies will be about 32 kJ/mol for interfunctional groups, 17 kJ/mol for weak interfunctional groups, 24 kJ/mol for intra‐COOH in (COOH)₂, and 60 kJ/mol for interfunctional groups in (COOH)COO⁻¹ ion if calculated using the B3LYP/6‐311+G(2d,p) method. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 76: 541–551, 2000     

Merocyanine form of photochromic spirooxazines in acid solutions

Electronic absorption and NMR spectra of solutions of photochromic spironaphthoxazines (SNOs) were studied. The addition of an acid results in the formation of a salt of the colored form of SNO. For SNOs with nitrogen-containing electron-releasing substituents, the structure of the product that formed depends on the acid concentration being the salt of the mono- or dication.     

纳米WO3的制备及其光解水析氧性能研究

用溶胶凝胶法,灼烧法合成了纳米级WO3,采用X-射线衍射、紫外可见漫反射光谱对WO3进行表征.在Fe3 为电子受体、溶液酸度pH为2.0情况下,研究了纳米级WO3在365nm紫外辐射下光解水析氧的光催化活性,并讨论了不同方法制备的催化剂活性差异的原因.结果表明,结晶程度越高、尺寸越小、比表面积越大的纳米级WO3具有更高的光分解水析氧活性,电子受体的浓度、溶液的酸度对析氧活性有明显的影响.     

用以分解氟里昂-12的新型催化剂WO_3/Al_2O_3

氟里昂(CFCs)是破坏大气臭氧层的元凶,是仅次于CO2的第二大类温室气体;此外,它作为一类含氯挥发性有机物,对人体有一定潜在危害.为了禁止氟里昂的生产和使用,1987年签署了“蒙特利尔协定”,至今已有包括中国在内的163个缔约方.然而各国还存有几百万吨氟里昂,为此,探索分解氟里昂的技术已成当务之急.氟里昂能通过多种技术销毁,如:等离子体分解法、UV射线分解法、高能射线分解法、焚烧法、电化学分解法、超临界水法、超声辐照法等,而催化分解是最被看好的方法之一.所谓催化分解,即在催化剂的作用下,氟里昂与水蒸气反应生成CO2、HF和HCl,…     

Synthesis,photochromic mechanism and properties of a novel biindenylidenedione compound containing ferrocene units

A novel biindenylidenedione compound, [2,2′‐bi‐1H‐indene]‐3,3′‐bis [(4‐oxo‐4‐ferrocenylbutanoyloxy)propyl]‐3,3′‐ dihydroxy‐1,1′‐dione was synthesized and characterized fully by ¹H NMR, IR, MS and elemental analysis. The photochromic and photo‐induced radical properties were investigated by means of UV–vis and electron spin resonance spectroscopy, respectively. The results show that the title compound simultaneously exhibits photochromism in the solid state as well as generating stable free radicals under irradiation with 330 nm light. This fact provides evidence for the photochromic mechanism of this kind of compounds. Copyright © 2008 John Wiley & Sons, Ltd.     

Spectral and thermal characterization of polyaniline–oxalic acid salt

Polyaniline–oxalic acid salts were prepared at 5 and 30°C by chemical polymerization of aniline using different concentration of oxalic acid. Polyaniline base was obtained from the corresponding polyaniline salt by dedoping using aqueous ammonium hydroxide solution. Conductivity measurements, elemental analysis, Infrared, electronic absorption, electron paramagnetic resonance spectral, and thermogravimetric analysis were performed on the polyaniline salts and bases. Composition and the extent of dopant in polyaniline salt systems where determined. The value of composition of polyaniline: oxalic acid is 4: 1.6 and the polymer yield is around 66%. The value of conductivity, polymer yield and composition of polyaniline–oxalic acid salt is independent of concentration of oxalic acid used and also the synthesis temperature. The results are compared with polyaniline–hydrochloride salt prepared by chemical polymerization. The conductivity of polyaniline–oxalic acid salt is three orders of magnitude lower than that of polyaniline-hydrocholoride salt. © 1995 John Wiley & Sons, Inc.