首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 125 毫秒
1.
李春发  刘广  王芹  刘征 《波谱学杂志》2018,35(3):363-373
通过多种核磁共振(NMR)技术(包括1H NMR、定量13C NMR、DEPT135、1H-1H COSY、1H-1H NOESY、1H-13C HSQC和1H-13C HMBC)技术,对季戊四醇硬脂酸酯润滑剂的组成进行了表征.结果表明:该润滑剂主要成分是单季戊四醇四硬脂酸酯,同时还含有少量的单季戊四醇三硬脂酸酯、单季戊四醇双硬脂酸酯、双季戊四醇硬脂酸酯和三季戊四醇硬脂酸酯,以及微量的多季戊四醇硬脂酸酯.  相似文献   

2.
硬脂酸稀土对PVC热稳定性的作用机理研究   总被引:2,自引:2,他引:0  
采用FTIR及XRD对硬脂酸稀土稳定剂进行结构表征 ,可知硬脂酸稀土中硬脂酸酸根与稀土离子间的作用主要是离子键性质的 ,且硬脂酸稀土具有层状晶体结构 ,晶层中稀土离子倾斜于基面。刚果红法测定结果表明 ,随着硬脂酸稀土用量增加 ,PVC的热稳定时间呈现增加的趋势 ,4种不同稀土硬脂酸盐稳定能力大小顺序为Last>Ndst>Yst>Dyst。通过FTIR对PVC稀土稳定体系稳定机理进行预测 ,结果表明Last和Ndst两种稀土稳定剂能取代不稳定的Cl原子 ,阻止PVC分子链上脱HCl反应 ,改变构象使其达到稳定的效果。Yst和Dyst在改变构象方面贡献较不明显。  相似文献   

3.
在钢铁表面获得了具有金属光泽和良好装饰效果的不溶性彩色Mo(W)-S-Fe族合物膜,采用加速化学腐蚀试验,LSV,XPS和AES研究了多种钝化剂处理簇合物膜前后的耐蚀性能,结果表明,硬脂酸钝化处理后,不仅保护和稳定了膜层的颜色,而且提高了钢铁的抗腐蚀能力,硬脂酸与彩色膜表面的Fe^2+反应形成了一层致密的不溶性配合物膜。  相似文献   

4.
伯胺结构碱性染料与亚硝酸根的反应机理及应用研究   总被引:2,自引:0,他引:2  
本文采用UV-Vis光谱法,电化学方法,FTIR光谱和NMR波谱法对含伯胺结构的碱性染料与亚硝酸根的反应进行了系统的研究,初步摸清了构效关系,提出伯胺结构染料与亚硝酸根之间进行的是重氮化偶合或重氮化反应,生成三氮烯类或重氮化合物的反应机理,对于完善,应用该类碱性染料,以及建立测定亚硝酸根的UV-Vis光谱,电化学分析新方法重要意义。  相似文献   

5.
 利用真空热蒸发的方法制备了厚度为0.28~0.40 μm的硬脂酸钠薄膜,并用光学显微镜和傅里叶红外光谱仪对硬脂酸钠薄膜进行了观察和分析,发现硬脂酸钠薄膜的红外光谱和固体的光谱具有相似性。在空气环境中硬脂酸钠薄膜不易潮解,在选择的无水脱膜溶液中,容易脱出无明显针孔的自支撑Al膜。用俄歇电子能谱测试,未发现脱出的Al膜上有残留的硬脂酸钠脱膜剂。  相似文献   

6.
红外光谱等方法对某未知样品的定性定量分析   总被引:1,自引:0,他引:1  
利用红外光谱,热分析及红外光谱-色谱联联用技术对某未知样品进行了分析。通过分析。可知该物质为丙三醇硬脂酸单脂。并含有少量的硬脂酸甲酸和十六烷基酸甲酯,这两种微量物物质的比为1:2。  相似文献   

7.
用红外光谱对合成季铵盐阳离子双子表面活性剂的反应机理进行研究,总结和归属了反应中间体以及产物的主要红外吸收谱带和特征,分析比较了反应过程中原料、中间体和产物之间红外光谱的变化,研究发现反应前后的红外光谱变化较大,可以作为鉴别产物是否生成的依据。  相似文献   

8.
5-羟基色氨酸的光度分析   总被引:2,自引:0,他引:2  
在 K2 HPO4 - Na2 HPO4 (p H=8.0 4 )缓冲液中 ,5-羟基色氨酸与苯并戊三酮生成灰紫色络合物。最大吸收波长在 570 nm处 ,表观摩尔吸光系数为 4 .73× 10 4 L· mol-1· cm-1。符合比耳定律的范围为 1—2 5.0 μg/ 10 m L,本法准确、快速 ,可用于产品测定 ,结果令人满意。  相似文献   

9.
 本文在0~4 GPa范围内研究了预压力对硬脂酸晶体的相关场劈裂和固态-熔融态相变过程的影响。通过γCH2面内摇摆振动模和γ'CH2相关场模的强度和频率变化,发现预压力对晶体内的相关场合分子链取向有明显的影响。预压力对硬脂酸的熔点虽然没有影响,但对γ'CH2模有“硬化”作用。并且由此出发,对硬脂酸的预熔过程作了讨论。  相似文献   

10.
基于在酸性条件下,草甘膦铵盐与Fe^3+可生成稳定配合物,同时以孔雀石绿(MG)作为捕捉剂可提高该配合物在异辛醇等有机溶剂中的溶解度,据此建立了溶剂浮选-紫外分光光度法分析/富集草甘膦生产废水中的草甘膦铵盐的方法。同时考察了捕捉剂和螯合剂及其用量、pH、浮选时间、有机溶剂等因素对浮选效果的影响,并将溶剂浮选法与泡沫浮选法以及溶剂萃取法进行了比较,结果表明溶剂浮选法分离/富集效果最好,草甘膦铵盐回收率达91.2%。  相似文献   

11.
The present work reports a simple and time-saving method to fabricate cupric stearate film on zinc substrate by a solution-immersion process. Superhydrophobic surfaces are conventionally prepared employing two steps: roughening a surface and lowering its surface energy. The fabrication of superhydrophobic cupric stearate surface is reported using a one-step process by immersing a zinc plate coated with copper into the stearic acid solution, simplifying the complexity of two different steps involved in the conventional methods. The surface of the zinc plate coated with copper is found to be covered with low surface energy cupric stearate film providing the water contact angle of 160 ± 1° with the rolling off properties. In addition, the damaged superhydrophobic surface can restore superhydrophobicity property by immersing the surface into the stearic acid solution again.  相似文献   

12.
To better study possible solid-state interactions between captopril (CAP) and different types of lubricants at the surface, grinding process was applied to enhance the probability of reaction. Grinding process was carried out for 5 min at room temperature under 32±5% or 80±5% relative humidity (RH) condition. The physical and ground mixtures of CAP and each lubricant (weight ratio: 1:1) were examined by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) microspectroscopy equipped with or without micro hot stage. The results indicate that CAP did not interact with talc, Precirol or stearic acid even if the grinding process was applied. However, a mixture of CAP and each metallic stearate before and after grinding exhibited a different behavior. Although there was a lack of interaction between CAP and sodium stearate in the course of grinding process, this process could induce the trans–cis isomerization of CAP in the CAP–sodium stearate ground mixture. No evidence was observed to show the solid-state interaction between CAP and monoaluminum stearate, but the grinding process seemed to accelerate the solid-state interaction of CAP with magnesium stearate (MgSt). The fact that solid-state interaction occurred between CAP and MgSt was proven by the shifting of the IR spectral peak of νas (COO) of stearate from 1578 to 1541 cm−1, due to interaction of the OH group in carboxylic acid structure of CAP with bridging coordination of the COO group of MgSt via hydrogen bonding of water. The interaction occurred between CAP and MgSt was stopped at 60 °C, due to the dehydration of water from the ground mixture.  相似文献   

13.
Fabrication of a superhydrophobic surface on a wood substrate   总被引:2,自引:0,他引:2  
A layer of lamellar superhydrophobic coating was fabricated on a wood surface through a wet chemical process. The superhydrophobic property of the wood surface was measured by contact angle (CA) measurements. The microstructure and chemical composition of the superhydrophobic coating were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). An analytical characterization revealed that the microscale roughness of the lamellar particles was uniformly distributed on the wood surface and that a zinc stearate monolayer (with the hydrophobic groups oriented outward) formed on the ZnO surface as the result of the reaction between stearic acid and ZnO. This process transformed the wood surface from hydrophilic to superhydrophobic: the water contact angle of the surface was 151°, and the sliding angle was less than 5°.  相似文献   

14.
利用红外光谱鉴别饱和脂肪酸及其盐   总被引:7,自引:0,他引:7  
有人认为饱和脂肪酸及其盐是碳酸盐岩中的生烃母质,但将它们从天然沉积物中鉴别出来的方法尚不成熟,对分析评价它们在沉积物中的分布造成困难。文章对几种合成饱和脂肪酸及其盐进行红外光谱测试,获得它们的红外吸收光谱。对特征峰进行指认,分析了饱和脂肪酸及其盐红外光谱的区别。从基团推电子能力、分子折合质量、离子核外电子构型及碳链长度的角度,解释不同饱和脂肪酸以及不同阳离子形成的饱和脂肪酸盐的特征官能团吸收峰波数的变化规律。为地质体中此类物质的鉴别提供参考。  相似文献   

15.
In an effort to study the scope of microwave radiation for organic bromination reactions, some reactions were studied using a domestic microwave oven. Results reveal that these radiation-induced reactions are unique in their high yields and that they require extremely short reaction times compared with conventional room-temperature reactions. In these reactions tetrabutyl ammonium tribromide was used as an alternative brominating reagent in order to avoid the chemical hazards associated with liquid bromine (Br2). As all the reactions were successfully carried out in solid state under microwave conditions, the use of solvent was not required. All these aspects make the bromination protocol quite environment friendly.  相似文献   

16.
The behaviour of water molecules at liquid–vapour interfaces with a surfactant monolayer of either stearic acid molecules or anionic stearate ions is investigated by means of molecular dynamics simulations. The density and dipolar orientational profiles and also the dynamics of translational and rotational motion of interfacial water molecules are calculated in the present work and the results are compared with the bulk liquid water and also of liquid–vapour interface of surfactant-free water. The present simulation results are also compared with available experimental results of similar interfacial systems with a monolayer of either neutral or ionic surfactants.  相似文献   

17.
几种饱和脂肪酸及其盐的拉曼光谱研究   总被引:5,自引:2,他引:3  
饱和脂肪酸及其盐在自然界中广泛存在,它们也是重要的化工原料。但是有关此类物质拉曼光谱特征的研究尚属少见。为了进一步了解它们的拉曼光谱特征,对乙酸、硬脂酸及乙酸钙、乙酸镁、硬脂酸钙、硬脂酸镁进行了拉曼光谱研究。从指认这6种物质拉曼光谱的特征峰拉曼位移出发,对它们的相应谱峰进行比对与分析,探讨了阳离子的引入对饱和脂肪酸及其盐的拉曼光谱的影响,找出了它们拉曼光谱的差异。比较不同阳离子形成的饱和脂肪酸盐的特征峰拉曼位移的差别,从折合质量和核外电子构型角度解释了造成差异的原因。同时发现了长碳链可以减弱不同阳离子对饱和脂肪酸盐拉曼光谱造成的影响。  相似文献   

18.
The present work reports a novel and facile approach to fabricate stable superhydrophobic surfaces for universal applicability in practice. Poly(furfuryl alcohol)/copper composite coatings were prepared on substrates via a brush-painting method; after being immersed in a stearic acid solution, the superhydrophobic surfaces were obtained due to the formation of copper stearate on the substrates. These products were characterized by field-emission scanning electron microscopy, Fourier transform infrared spectrometry, X-ray powder diffraction and the X-ray photoelectron spectrum. Results demonstrate that the superhydrophobic surfaces formed originally on copper substrates can also be generated on other substrates without the copper element. Furthermore, this work will provide a simple and universal method to create large-scale superhydrophobic surfaces on various substrates.  相似文献   

19.
Ferric stearate (FeSt) Langmuir-Blodgett (LB) films have been reacted chemically with H2S gas for making iron sulphide within the organic matrix. Films, before and after the reaction with H2S, have been analyzed with the X-ray reflectivity (XRR), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) studies. After sulphidation, more ‘pinhole’ defects form which changes the film morphology and the number of layers increases due to the rearrangement of the molecules. Formation of less ordered iron sulphide within the stearic acid multilayers after sulphidation increases the interfacial roughness that decreases the reflectivity. XPS analysis shows that polysulphide forms within the microenvironment of the FeSt LB films after reaction with H2S whereas both mono and polysulphide are produced when the reaction occurs with FeSt in bulk.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号