Papers by Keyword: Infrared Spectrum

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Authors: Chao Wang, Yu Peng Zhu, Mei Xu, Yu Qiao, Wei Hua Zhang
Abstract: The improvement of the preparation method for carboxy methylation of konjac glucomannan (KGM) was proposed in this paper according to molecular structural characteristics of KGM. Carboxymethyl konjac glucomannan (CMK) were yielded by first blending KGM with etherification agent and then basifying and catalyzing in ethanol. Through single factor and orthogonal experiments, the effects of reaction conditions on degree of substitution (DS) and apparent viscosity (η) were investigated, and the optimum reaction conditions were obtained as follow: 55°C, pH12 for 3 hours. The results indicate that the maximal value of DS and η were 0.5278 and 15.57Pa•s respectively. The reaction mechanism for carboxymethyl of KGM was proposed and checked by infrared spectra. Meanwhile, it is showed that the properties of CMK were rather good in terms of hydrated rate and hydrosol transmittance.
1340
Authors: Zheng Feng Zhu, Da Peng Qi, Jun Hua Wang, Qian Han, Li Li Cai
Abstract: PPTA fibers made by China ShenMa Group Co., Ltd and Kevlar49 fibers made by Dupont as experimental materials were used in this paper. The differences of molecule structures were contrasted through infrared spectrum and degree of polymerization-counting by the detections of viscosity. The PPTA fibers were put into distilled water and seawater made by ourselves respectively, then ultrasonication were used to deal with them. After this, using the SEM to observe, found that the cracks appear on the fibers surfaces, presented the fibrillation and plush-like microfine fibers. Meanwhile the strength weak-link increased and breaking strength and elongation at break of fibers lowered after ultrasonication. Molecular kinetic theory was used in this paper to study loss of fibers the mechanical property.
314
Authors: Gui Chun He, Jin Ni Feng, Mei Xin Mao, Yi Peng Wu
Abstract: Application of Combined Collectors in Flotation of Lepidolite were researched, and the object is the gravity concentration tailing of YiChun Tantalum&Niobium Mine. The experiments show: when LZ-00 dispensed by ourselves and mixed amine combined in two to one was used in lepidolite flotation, the flotation indexes is best,and the optimum dosage is 360g/t .The close circuit test can got the lepidolite concentrate with grade 4.12%, recovery 70.37% .It has a remarkable upgrading compared with the target of ore dressing plant . Infrared spectrum showed mineral surface existed chemical adsorption and physical adsorption and hydrogen bonding simultaneously when using LZ-00 and mixed amine to flotation lepidolite .
921
Authors: Yu Liu, Jing Li, Chuan Hai Wu
Abstract: The macroscopic performance of three kinds asphalt and its after aging were analyzed, and aging mechanism and characteristics were explored by. FT-IR.The results showed that the asphalt dynamic shear G*/sinδis very consistent with penetration ratio, moving wavenumber of carbonyl is a valid indicator for the evaluation of asphalt anti-aging ability.
1265
Authors: Yan Yan Liu, Zhong Wen Huang, Jian Jun Li
Abstract: This paper proposes a research work that characteristically analyzes the component differences between new and aged pavement asphalts. Both the new and aged pavement asphalts are sampled from the same type and separated into four components: saturate, aromatic, resin and asphaltine. Based on the comparative analysis regarding the masses, functional groups and structural features of each component, it is found that the aged asphalt has less saturate and aromatic but more asphaltine, lower mass ratio of resin to asphaltine, and decreased compatibility of asphatine with saturate and aromatic. Also, although there is little change in the infrared spectra of saturate and aromatic, the infrared spectra of asphaltine are different, with those oxides that contain C, N and S being significantly increased in the aged asphalt.
6101
Authors: Ling Gao, Lai Jiu Zheng, Ju Wei, Bing Du, Peng Peng Yin
Abstract: Optional viscosity average molecular weight of chitosan 3 × 105, the nanophase change microcapsules were mixed in the preparation chitosan spinning dope. Viscometer was used to measure the rheological properties of blend spinning fluid, using infrared spectroscopy,scanning electron microscope (SEM) and the interactions between the studies of phase change fiber surface microstructure. The results show that, blend spinning fluid is generally the basic characteristics of non-Newtonian fluid, with concentration of spinning solution, viscosity increases; temperature rise, viscosity decreased; prolonged standing, viscosity decreased. Chemical changes occurred between chitosan and microencapsulated phase change,no new chemical bonds, for a simple physical blending. By scanning electron microscope, along with the increase in the amount of phase change nanomicrocapsule, fiber surface is obvious.
130
Authors: Peng Bai, Juan Zao Ji, Peng Liu, Dao Tian Geng
Abstract: As for the problem that component gas characteristic spectrum lines overlaps seriously in the identification of Mixed Gas, Support Vector Machine is introduced for the identification, and an one-by-one identification methods for Mixed Gas classification based on the binary category identification model based on the support vector machine is proposed in this article. One-by-one category identification is carried out for each mixed gas when the characteristic spectrum lines are overlapped seriously and is transformed in high dimensional space into linear by SVM kernel function transformation. In the experiment for gas component identification of a natural gas, we compare the recognition results affected by different kernel functions, data preprocessing, feature extraction, numbers of training samples and other conditions. The results show that the method has the correct recognition rate of over 97% for the natural gas whose concentration is over 1%, and it has a great promotional value both in theory and practical application.
557
Authors: Xiao Ping Ji, Xue Zhang Tan, Nan Xiang Zheng
Abstract: This paper discusses the ageing features of SBS modified asphalt and its assessment index. The performances for both host asphalt and modified asphalt after different RTFOT ageing times was tested and micro analysis was conducted with infrared spectrum. The quantitative analysis for the micro-changes of ageing process was carried out according to Lambert Beer law. The research results show that the longer the ageing time, the smaller the penetration and ductility of asphalt are, and the greater the softening point and viscosity. In comparison with the host asphalt, the absorption peak of SBS modified asphalt in stretching vibration (C=C) at 1600cm-1, the absorption peaks of polybutadiene in bending vibration at 966cm-1 and 911cm-1 , and the absorption peak of styrene in bending vibration at 697cm-1 are from SBS modifier. The oxygen reaction happens in ageing process of asphalt, producing carboxyl and subsulfoxide. Affected by the higher activity of SBS modifier, SBS modified asphalt can be easily oxidized.There is good correlation between its penetration, softening point, ductility with carboxyl and subsulfoxide , so the above three indexes can be adopted to assess the ageing of SBS modified asphalt.
1652
Authors: Fei Lu, An Xian Lu, G.F. Huang
Abstract: Glasses in the Bi2O3-B2O3-BaO-ZnO system were prepared using the normal melt quenching technology. The structure of the glasses was analyzed by using of the infrared spectra within the range 2000∼400cm-1. The relation among the properties such as density (D), thermal expansion coefficient (α) and transition temperature (Tg), Bi2O3 introducing content and structure of the glass have been discussed.
61
Authors: Takuro Tomita, M. Iwami, M. Yamamoto, M. Deki, Shigeki Matsuo, Shuichi Hashimoto, Y. Nakagawa, T. Kitada, T. Isu, S. Saito, K. Sakai, Shinobu Onoda, Takeshi Ohshima
Abstract: Femtosecond (fs) laser modification on single crystal silicon carbide (SiC) was studied from the viewpoints of electric conductivity. Fourier transform infrared (FTIR) spectroscopy was carried out on femtosecond laser modified area. The intensity decrease of reststrahlen band due to the modification was observed, and this decrease was explained by the degradation of crystallinity due to the laser irradiation. Polarization dependence of reststrahlen band was also observed on laser modified samples. Current-voltage characteristics and Hall measurements on fs-laser modified region were carried out by fabricating the metal contacts on the ion implanted areas. The specific resistance up to 5.9×10-2 m was obtained for fs-laser modified area.
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