Determination of Carbon Dioxide in Refined Titanium Tetrachloride by Infrared Spectroscopy.

Refined TiCl4 is the key procedure in producing titanium sponge. Besides, the content of carbon and oxygen (C and O) impurities in titanium sponge and that of C and O impurities in refined TiCl4 presents the 4-times enrichment relationship. Therefore, the content control of the C and O impurities in refined TiCl4 becomes the key part for the quality control of titanium material. In order to control the oxygen and carbon, there is the need to analyze the source of C and O impurities so that strict control can be conducted over the impurities of refined TiCl4. Determination of CO2 in refined TiCl4 was significant for analysis of its impurities. CO2 could be determined by infrared spectroscopy due to its infrared characteristic spectrum line. However, normal infrared absorption cell was not fit for the sample analysis, because TiCl4 easily reacted with moisture in the air and immediately was hydrolyzed to form highly corrosive hydrochloric acid smoke. According to Lambert-Beer Law, which means the concentration (c(ξ)) and absorbance(A) - length (L) curve's slope have direct ratio. The infrared absorption cell with the window film of ZnSe (φ10 mm x 1 mm, wavenumers: 7 800 -440 cm(-1)) and the glass cell (optical path: 42, 22, 12, 7 and 4 mm) was assembled and utilized in determination of the CO2 in refined TiCl4 by standard addition method. The detection limit of CO2 was 0.92 mg x kg(-1), the regression equation was Y = 0.031 1X, R = 0.997 2; With standard addition method, the regression equation of CO2 was Y = 0.131 7X, R = 0.998 6, it's good in linearity relation, the CO2 content in refined TiCl4 is determined to be 1.53 mg x kg(-1) and SD up to 0.04 x mg x kg(-1). RSD of the method precision is between 0.53%-1.27%, while recovery rate is between 89.2%-96.8%. This infrared absorption device was safe, simple and convenient, easily removable and washable, and re-useable. The method could conduct the quantitative analysis over the CO2 content in refined TiCl4 through adding standard sample for one time, it could meet the requirement of determination of CO2 in refined TiCl4.

[A Set of Infrared Cells for the Determination of Titanium Oxychloride in Refined Titanium Tetrachloride].

The content control of the impurities in refined TiCl4 becomes the key part for the quality control of titanium material. Refined TiCl4 is the key procedure in producing titanium sponge. Besides, the content of the impurities in titanium sponge and that of the impurities in refined TiCl4 presents the 4-times enrichment relationship. Therefore, control the content of the oxygen, there is the need to analyze the source of oxygen impurities so that strict control can be conducted over the impurities of refined TiCl4. Determination of TiOCl2 in refined TiCl4 was significant for analysis of its impurities. TiOCl2 could be determined by infrared spectroscopy due to its infrared characteristic spectrum line. However, normal infrared absorption cell was not fit for the sample analysis, because TiCl4 easily reacted with moisture in the air and immediately was hydrolyzed to form highly corrosive hydrochloric acid smoke. According to Lambert-Beer Law, which means the concentration (c(x)) and absorbance (A)-length (L) curve's slope have direct ratio. The infrared absorption cell with the window film of ZnSe (Φ10 x 1 mm, wavenumers: 7800-440 cm⁻¹) and the glass cell (optical path: 22, 12, 7 and 4 mm) was assembled and utilized in determination of the TiOCl2 in refined TiCl4 by standard addition method. The detection limit of TiOCl2 was 17.8 mg · kg⁻¹, the regression equation was Y = 1.011 8X, R = 0.9963; With standard addition method, the regression equation of TiOCl2 was Y = 1.940 0X, R = 0.997 0, it' s good in linearity relation, the TiOCl2 content in refined TiCl4 is determined to be 833.8 mg · kg⁻¹ and SD up to 40.0 mg · kg⁻¹. RSD of the method precision is between 0.95%-1.94%, while recovery rate is between 88.5%-93.1%. This infrared absorption device was safe, simple and convenient, easily removable and washable, and re-useable. The method could conduct the quantitative analysis over the TiOCl2 content in refined TiCl4 through adding standard sample for one time, it could meet the requirement of determination of TiOCl2 in refined TiCl4.

3,4-Bis[1-(prop-2-yn-yl)-1H-indol-3-yl]-1H-pyrrole-2,5-dione.

In the title mol-ecule, C26H17N3O2, both indole ring systems are essentially planar, with maximum deviations of 0.019 (2) and 0.033 (1) Šfor the N atoms, and form dihedral angles of 34.40 (9) and 45.06 (8)° with the essentially planar pyrrole ring [maximum deviation = 0.020 (2) Å]. The dihedral angle between the two indole ring systems is 58.78 (6)°. In the crystal, mol-ecules are connected by pairs of N-H⋯O hydrogen bonds, forming inversion dimers and generating R 2 (2)(8) rings. Weak π-π stacking inter-actions, with a centroid-centroid distance of 3.983 (2) Å, are also observed.

[Study of photoluminesence property of CdS/PAMAM nanocomposites].

The photoluminescence property of CdS/PAMAM nanocomposites in water at different ratio of Cd2+ to PAMAM(r) was studied by fluorescence emission spectrum, and the according mechanism was explored. The results indicate that in the irradiation of UV light at the wavelength of 330 nm, two peaks were shown in the fluorescence emission spectrum of CdS/PAMAM nanocomposites. One peak was attributed to PAMAM dendrimers, and the another came from CdS QDs. The strength of the frontier fluorescence emission peak became weaker and weaker, and at last disappeared with the enhancement of the ratio of Cd2+ to PAMAM; the strength of the latter fluorescence emission peak became stronger, which indicates that the electron at valence band of N atom in amines of dendrimers was transferred to CdS QDs. Oil latent finger marks deposited on transparent adhesive tapes surface treated with pure PAMAM solution with blue photoluminescence was not clear enough because of the blue light emitted from the impurity in adhesive tapes; Latent finger marks emitted strong yellow light and were successfully detected with good resolving rate with CdS/dendrimer solution with r of 10, which shows good reference value for detecting finger marks on surfaces with impurities emitting different photoluminescence colors.

Application of photoluminescent CdS/PAMAM nanocomposites in fingerprint detection.

Uniform and well-dispersed photoluminescent semiconductor CdS (cadmium sulfide) QDs (quantum dots) were in situ prepared inside Generation 4.0-NH(2) PAMAM (polyamidoamine) dendrimers in methanol, methanol and water mixed solutions of volume ratio 1:9, respectively. The prepared solutions containing photoluminescent semiconductor CdS QDs were utilized for detection of cyanoacrylate ester fumed fingerprints on tinfoil. The results show that fumed latent fingerprints treated with prepared CdS/PAMAM nanocomposites in methanol, 1:9 methanol:water mixed solutions emit pale yellow-green and orange luminescence respectively under ultraviolet excitation of 365 nm from an UV LED. Fumed fingerprints were successfully detected with good resolving rate and the mechanism was studied in detail.