聚醚氨酯的红外酰胺Ⅰ.谱带分析

通过对聚醚氨酯红外光谱酰胺-Ⅰ谱带的二级微商及傅里埃自解卷积处理,发现了位于1715cm~(-1)的新组分并可归属于无序的相间界面。应用差减光谱及曲线拟合对热处理试样的光谱谱带进行分析表明聚醚氨酯的加热/冷却过程是与可逆的无序/有序化过程及微相混合/分离过程有关的。新发现的1715cm(-1)组分强度的变化与无序/有序化过程是一致的。     

二钼酸铵晶体饱和水溶液Raman光谱的变异现象及其机理

记录了常温下二钼酸铵晶体饱和水溶液的Raman光谱，并分别与二钼酸铵晶体、仲钼酸铵晶体、仲钼酸铵晶体饱和水溶液、水溶液状态下单钼酸根离子的Raman光谱进行了比较研究。结果表明：二钼酸铵晶体饱和水溶液Raman光谱相对二钼酸铵晶体Raman光谱，明显地发生了变异现象。二钼酸铵晶体饱和水溶液Raman光谱其主要特征峰最高振动频率937.6 cm^-1与仲钼酸铵晶体饱和水溶液Raman光谱主要特征峰最高振动频率937.6 cm^-1完全吻合，而其次高振动频率893.9 cm^-1，恰好介于水溶液中单钼酸根离子Raman光谱主要特征峰最高振动频率895.1 cm^-1与仲钼酸铵晶体饱和水溶液Raman光谱主要特征次高峰振动频率891.0 cm^-1之间，而且三者彼此接近。二钼酸铵晶体饱和水溶液Raman光谱主、次特征峰强度之比值为2.1，与仲钼酸铵晶体饱和水溶液Raman光谱主、次特征峰强度之比值4.4相比，一半不足。提出了一种利用Raman光谱主要特征峰振动频率及其主、次特征峰强度之比值对二钼酸铵晶体饱和水溶液组分同时进行定性和半定量分析的新方法。发现了常温下二钼酸铵晶体饱和水溶液中二钼酸根离子Mo₂O₇^2-已经不复存在，完全转变成了优势组分仲钼酸根离子Mo₇O₂₄^6-和次要组分单钼酸根离子MoO₄^2-；证明了常温下含钼水溶液酸化过程中溶液Raman光谱离散性变化现象的存在。运用结构化学和物理化学原理同时讨论了二钼酸铵晶体饱和水溶液Raman光谱发生变异现象的机理。     

新型L-苯丙氨酸桥联双卟啉的合成与光谱表征

用L-苯丙氨酸和5-[对-(4-溴丁氧基、己氧基、辛氧基)苯基]-10,15,20-三苯基卟啉合成3种新型L-苯丙氨酸桥联双卟啉,并通过质谱、¹H核磁共振谱、元素分析、红外光谱、紫外光谱对其结构进行了表征。测试并研究了它们在4 000~400 cm^-1范围内的傅里叶变换红外光谱,对主要谱带进行了经验归属。     

聚醚氨酯红外N—H伸缩振动谱带分析

通过快速淬火实验,直接观察到聚醚氨酯中由硬段N—H基与软段—O—形成氢键的N—H伸缩振动谱带位于约3295cm~(-1),低于与硬段本身C=O形成氢键的N—H伸缩振动谱带(约3330cm~(-1))。这两种氢键键连的N—H伸缩振动谱带的位置从聚醚氨酯-四氢呋喃溶液的红外光谱得到证实。在此基础上讨论了三种聚醚氨酯试样的红外光谱中N—H伸缩振动谱带的差异。     

高岭石插层效率评价

用基于X射线衍射分析(XRD)的插层率、基于热重分析(TGA)的热失重率和基于红外光谱分析(FTIR)的3 600 cm^-1谱带与3 700 cm^-1谱带强度比值对高岭石/二甲基亚砜(DMSO)插层复合物和高岭石/N-甲基甲酰胺(NMF)插层复合物的插层效率进行了综合评价。结果表明,当插层反应进行到1、6和25 d,高岭石/DMSO的插层率分别为5%、52%和89%;而高岭石/NMF的插层率则分别为93%、94%和95%。与此同时,高岭石/DMSO的热失重率分别为1.06%、8.06%和17.46%;而高岭石/NMF的失重率分别为6%、6.5%和14.2%。在红外光谱图中,高岭石/DMSO复合物的3 600与3 700 cm^-1带强度比分别为1.03,1.141和1.628,而高岭石/NMF复合物分别为1.403,1.433和1.612。3种评价方法显示很好的一致性,相对而言,在插层作用的初期,XRD方法比较灵敏,而在插层作用的后期,TGA和FTIR方法则显得更为灵敏和有效。     

丁基黄药在CuO表面吸附的二维连续在线原位ATR-FTIR光谱研究

运用连续在线原位衰减全反射傅里叶变换红外光谱(ATR-FTIR)技术测定了纳米CuO表面对丁基黄药的吸附行为. 在FTIR 谱图中发现有峰的红移现象,吸收峰由1200 cm^-1偏移到1193 cm^-1,用超纯去离子水脱附,峰强度只有微小的变化,可判断丁基黄药在CuO表面发生了很强的化学吸附. 通过对吸附行为进行二维(2D)红外光谱分析,分辨出吸附过程中光谱强度的变化顺序. 二维异步相关光谱测定结果表明,1265 cm^-1处振动吸收峰最先引起光谱强度的变化,1265 cm^-1处吸收峰可归因为表面反应生成的双黄药和黄药分子聚集体的复合峰. 根据1200 cm^-1处黄药特征吸收峰强度的变化,进行吸附动力学模拟,得出CuO对丁基黄药的最大吸附量为529 mg·g^-1,且吸附符合拟二级吸附动力学过程.     

金纳米粒子组装体系中偶联单分子层膜结构的SERS光谱表征与分析

通过分子自组装方法制备4,4′-二硫联吡啶(PySSPy)单分子膜修饰的金电极. 利用所形成的对巯基吡啶自组装单分子膜(SAMs)作为偶联层进行金纳米粒子有序膜的组装. 对该纳米粒子组装体系进行Raman光谱测定, 得到了具有良好信噪比的对巯基吡啶单分子膜的表面增强拉曼散射(SERS)光谱. 在此基础上, 进一步采用电化学现场SERS光谱技术研究了该纳米粒子组装体系的SERS光谱随电位变化的规律. 在该体系稳定的电位范围内表征对巯基吡啶单分子膜的特征谱峰1011与1093 cm^-1、1575与1610 cm^-1以及1206与1215 cm^-1这三对谱峰其强度随着所施加电位的改变呈现出明显的规律性. 分析表明, 偶联单分子层中吡啶环芳香性随着所施加电位的改变而有规律地变化是SERS光谱特征改变的内在原因.     

尿素作为造孔剂对聚乙烯支撑的PAMS聚合物电解质性能的改进

采用乳液聚合法合成聚(丙烯腈-甲基丙烯酸甲酯-苯乙烯) (P(AN-MMA-ST)或者共聚物PAMS), 并利用尿素作为造孔剂制备了聚乙烯(PE)支撑的PAMS聚合物膜(PE-PAMS-U)及凝胶聚合物电解质(GPE). 利用傅里叶变换红外(FTIR)光谱、X射线衍射(XRD)、扫描电子显微镜(SEM)、热重(TG)分析、线性电位扫描(LSV)、电化学阻抗谱(EIS)以及充放电等方法对PAMS聚合物以及PE支撑的聚(丙烯腈-甲基丙烯酸甲酯-苯乙烯) (PE-PAMS)聚合物隔膜及凝胶聚合物电解质的性能进行了研究. 结果表明, 利用尿素作为造孔剂可以提高PE-PAMS凝胶聚合物的性能. 由于尿素的加入, 聚合物膜呈现均匀的微孔结构, 室温下的电导率从1.1×10^-3 S·cm^-1提高到2.15×10^-3 S·cm^-1. 同时, 锂电极/聚合物电解质界面上的电荷传递电阻也从480 Ω·cm²降低到 250 Ω·cm². 电化学稳定窗口为5.0 V. 电池(Li/PE支撑的GPE/LiCoO₂)的测试证明, 用尿素作为造孔剂的凝胶聚合物锂离子电池表现出优良的倍率性能和循环性能.     

侧链型磺化聚芳醚酮/磺化聚乙烯醇复合型直接甲醇燃料电池用质子交换膜

通过溶液共混法制备了不同磺化聚乙烯醇(SPVA)含量的侧链型磺化聚芳醚酮/磺化聚乙烯醇(S-SPAEK/SPVA)复合膜. 应用红外光谱(FTIR)对复合膜进行了表征, 扫描电镜(SEM)显示SPVA均匀分布在复合膜中. 通过对复合膜的性能测试发现该系列复合膜具有良好的热性能、较高的吸水率和保水能力. SPVA中的羟基能有效地阻碍甲醇的透过, 甲醇渗透系数从S-SPAEK/SPVA5 复合膜的7.9×10^-7 cm²·s^-1降低到S-SPAEK/SPVA30的1.3×10^-7 cm²·s^-1, 比S-SPAEK膜的11.5×10^-7 cm²·s^-1降低了一个数量级. SPVA的引入增加了亲水基团数量, 增加了复合膜的吸水和保水能力, 有利于质子按照“Vehicle”机理和“Grotthuss”机理进行传递, 柔软的SPVA链段与S-SPAEK侧链聚集成亲水相区, 形成连续的质子传输通道, 提高了复合膜的质子传导率. 在25 和80℃ 时, S-SPAEK/SPVA30 复合膜的质子传导率分别达到了0.071 和0.095 S·cm^-1. 可见,S-SPAEK/SPVA复合膜有望在直接甲醇燃料电池中得到应用.     

1,4-丁炔二醇与4,4′-二乙炔联苯共聚物的合成及表征研究

 本文用(Ph₃P)₂PdCl₂为催化剂,合成了1,4-丁炔二醇(BD)与4,4-二乙炔联苯(DEBP)共聚物。对用不同比例的两种单体得到的共聚物测定了比重(d₄²⁵、溶胀度(θ_D)、最良溶剂及相邻两交联点之间的平均分子量(M_c)。实验表明,在两种单体摩尔比中,DEBP用量越多,共聚物中泡状微孔越多,颜色越淡,溶胀度和比重越小,交联度越大;DEBP/BD(摩尔比)大于1/5时,共聚物的最良溶剂为苯,溶度参数为9.15卡^0.5·cm^-1.5,是1/10时,其最良溶剂为乙醇,溶度参数是12.7卡^0.5·cm^-1.5。对共聚物还做了红外光谱表征。     

In situ FTIR and generalized 2D IR correlation spectroscopic studies on the crystallization behavior of solution-cast PHB film

The crystallization behavior of biosynthesized poly(3-hydroxybutyrate) film cast from 1,1,2,2-tetrachloromethane was studied by in situ FTIR spectroscopy and two-dimensional (2D) correlation analysis. Time-dependent in situ FTIR spectral variations in the C=O stretching region (1,780–1,700 cm^-1) were monitored and analyzed by a series of data processing methods, including calculation of difference spectrum and second derivative spectrum, Fourier self-deconvolution, curve-fitting and 2D correlation analysis. Four bands have been resolved from the 2D correlation analysis, and the following overall sequential order among the intensity changes of the four bands has been obtained at 1,750 > 1,739 > 1,722 > 1,715 cm^-1. Combining with the other data processing methods, a curve-fitting approach has been employed to reveal that there are probably five component bands under the C=O band profile, centered at 1,746; 1,737; 1,728; 1,722; and 1,712 cm^-1. Detailed analysis on the in situ component band intensity variations in the C=O stretching region indicates that the crystalline and amorphous band intensities change simultaneously during the crystallization process, with no local sequential order. Further analysis on the relative area percentage changes of the five component bands suggests that the crystalline component only changes in a fully cooperative manner with part of the amorphous component at the initial crystallization period.     

Dynamic rheo-optical characterization of uniaxially oriented polyamide 11

Dynamic mechanical analysis, coupled with polarized step-scan FTIR transmission spectroscopy, has been used to monitor the submolecular motional behavior of uniaxially oriented polyamide 11. The dynamic in-phase spectra depend upon the morphology of the samples as well as on the polarization direction of the infrared radiation. The lineshape features of the dynamic in-phase spectra and their relationship to sample deformation are analyzed on the basis of changes of the internal coordinates, the reorientation movement of several functional groups, and the thickness change of the film during the stretching cycle. Dynamic infrared spectra are helpful for deconvolution of overlapping bands on the basis of their different responses to the external perturbation, which sometimes cannot be resolved well by derivative spectroscopy or curve-fitting analysis. The lineshape features have been used to follow microstructural changes after isothermal heat treatment. Near the N H stretching frequency, two bands at 3270 cm⁻¹ and 3200 cm⁻¹ are resolved and analyzed in terms of Fermi resonance between the N H stretching fundamental mode and the overtone and combination modes of the amide I and II vibrations. The dynamic response of the N H stretching mode correlates with the modulation of hydrogen bond strength in uniaxially oriented PA-11. After thermal treatment at the highest temperature (190°C), the dynamic response in this region is mainly caused by the modulation of crystals. In amide I region, three bands at 1680 cm⁻¹, 1648 cm⁻¹, and 1638 cm⁻¹ are separated and assigned to hydrogen bond-free, hydrogen-bonded amorphous, and hydrogen-bonded crystalline regions, respectively. The dynamic responses of the hydrogen-bonded regions are more sensitive to external perturbation. Two components are found in the amide II region, and the band at 3080 cm⁻¹ is assigned to the overtone resonance of the component with perpendicular polarization. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 2895–2904, 1998     

Investigation of infrared calibration methods for application to the study of methyl methacrylate polymerization

Infrared spectroscopy has been used to monitor the polymerization of methyl methacrylate. Concentrations of methyl methacrylate in the reaction mixture were determined by use of three calibration methods. Classical quantitative analysis was used to measure the height of the stretching vibration bands of the vinyl group at 1639 cm^–1. A calibration procedure using the considerably higher intensity of the C = O stretching vibration band of the carbonyl ester group at 1725 cm^–1 seemed useful only for high concentrations of methyl methacrylate, i.e. at the beginning of reaction, because this band overlaps that of poly(methyl methacrylate). Use of second-derivative spectra and measuring their values at 1725 cm^–1 enabled estimation of ten times lower concentrations of methyl methacrylate the calibration using the band from the vinyl group.     

Physical and chemical properties of hydroxyflavones. IV. Infrared absorption spectra of dihydroxyflavones containing the 5-hydroxyl group

Solid state infrared curves (O-H and C-H stretching region) are given for 5, n-dihydroxyflavones, where n is 2′, 3′, 4′, 6, 7 and 8. In chloroform solution spectra of 3,5-dihydroxyflavone and 3-hydroxy-5-methoxyflavone, the 3-OH stretching band appears at 3400 and 3334 cm^?1, respectively, indicative of a stronger hydrogen bond in the latter substance. Solid state and solution carbonyl bands are presented for twenty-six flavone derivatives which contain a hydroxyl, methoxyl or acetoxyl group at the 5-position. The solution spectra (dioxane or carbon tetrachloride) of fourteen flavone derivatives containing a free 5-hydroxyl group show carbonyl bands at 1655±2 cm^?1. Eleven flavones in which the 5-hydroxyl is blocked (carbon tetrachloride solution) give spectra with flavone carbonyl bands at 1653±3 cm^?1. The high resolution chloroform solution spectrum of 3, 5-dihydroxyflavone possesses a multi-peaked carbonyl band with midpoint at 1641 cm^?1. The chloroform solution spectrum of 3-hydroxy-5-methoxyflavone has a very strong band at 1616 cm^?1, with shoulder at 1646 cm^?1. Spectral data of this and a previous paper support the postulate that in 4′-hydroxyflavone the flavone carbonyl oxygen is the donor atom in an intermolecular hydrogen bond. Certain details of synthesis, and analytical data, are given for 3, 5-dihydroxyflavone.     

煤焦油的拉曼光谱表征和组分识别

用355 nm激光作为激发光源检测了煤焦油常温拉曼光谱;应用两种量子化学计算程序(Gaussian-DFT和ADF)模拟了占总量1%以上的15种煤焦油组分的拉曼光谱,模拟结果与实验光谱能较好匹配,并对振动模式进行了归属分析。研究表明,煤焦油组分主要由共轭六元环构成,其拉曼光谱特征谱带主要在1 660、1 420和1 265 cm^-1附近,当共轭六元环成链式结构时,1 420 cm^-1谱带特征明显;五元环嵌入共轭六元环链式结构会导致其拉曼光谱在1 265和1 660 cm^-1谱带相对强度增大;五元环、杂原子基团和甲基侧链依附在共轭六元环上,则对组分的拉曼光谱影响不显著。     

4-Hydroxycoumarin/2-hydroxychromone tautomerism: Infrared spectra of 3-substituted-2-13c-4-hydroxycoumarins

By isotopic replacement of the carbonyl carbon with ¹³C, the C?O stretching frequency was identified as the highest frequency strongly absorbing band in the 1550–1750 cm^?1 region of the infrared spectra of several 3-substituted 4-hydroxycoumarins and 3-substituted 4-alkoxycoumarins. The compounds selected for study were either known to crystallize as the coumarin tautomeric form by x-ray diffraction studies or were congeners of such compounds. The carbonyl band varied from 1664 cm^?1 in inter- or intramolecularly hydrogen bonded derivatives to 1718 cm^?1.     

Thermal decomposition of liebigite

Summary A combination of high resolution thermogravimetric analysis coupled to a gas evolution mass spectrometer has been used to study the thermal decomposition of liebigite. Water is lost in two steps at 44 and 302°C. Two mass loss steps are observed for carbon dioxide evolution at 456 and 686°C. The product of the thermal decomposition was found to be a mixture of CaUO₄ and Ca₃UO₆. The thermal decomposition of liebigite was followed by hot-stage Raman spectroscopy. Two Raman bands are observed in the 50°C spectrum at 3504 and 3318 cm^-1 and shift to higher wavenumbers upon thermal treatment; no intensity remains in the bands above 300°C. Three bands assigned to the υ₁ symmetric stretching modes of the (CO₃)^2- units are observed at 1094, 1087 and 1075 cm^-1 in agreement with three structurally distinct (CO₃)^2- units. At 100°C, two bands are found at 1089 and 1078 cm^-1. Thermogravimetric analysis is undertaken as dynamic experiment with a constant heating rate whereas the hot-stage Raman spectroscopic experiment occurs as a staged experiment. Hot stage Raman spectroscopy supports the changes in molecular structure of liebigite during the proposed stages of thermal decomposition as observed in the TG-MS experiment.     

Confirmation of the presence of imine bonds in thermally cured polyimides

Model compounds for imines formed during the thermal curing of short chain polyimides have been synthesized and characterized. These compounds have imine bonds (C?N) formed by the nucleophilic attack of primary amines on imide carbonyls. The C?N stretching mode appears at 1649–1664 cm^?1 in the Raman and infrared spectra of these compounds and the band assigned to the carbonyl mode in an imide ring with an imine bond appears near 1740 cm^?1. These compounds have been prepared and characterized to verify the conclusions of a previously reported study in which bands observed in thermally cured short chain polyimides at 1656 and 1742 cm^?1 were assigned as the C?N and associated C?O modes, respectively. It has also been confirmed that the C?N stretching mode in the imide model compounds is inherently IR weak and can only be seen if the concentration of imine species is high. © 1993 John Wiley & Sons, Inc.     

Infrared studies of the reversible stress-induced crystal-crystal phase transition of poly(tetramethylene terephthalate)

The reversible stress-induced crystal-crystal phase transition of poly(tetramethylene terephthalate) (PTMT) has been studied using infrared spectroscopy. Two spectral regions were used to study this transition: the 900–1000 cm^?1 methylene rocking region and the 1300–1550 cm^?1 methylene bending region. The bands at 917 and 1456 cm^?1 are assigned to the ∝ phase. The bands at 935 and 1388 cm^?1 have components from the α phase and the β phase. Dynamic stretching experiments performed above and below the glass-transition temperature indicated different mechanisms of the phase transition.