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1.
以自制的钠基膨润土为原料、用四甲基氯化铵和四丁基氯化铵作为有机插层剂与膨润土层间的Na^+交换,制备出有机膨润土,并经红外光谱分析(IR)、差热分析(DTA)和X-ray衍射分析(XRD)等测试手段对其结构进行表征。讨论了不同的季铵盐对有机膨润土性能的影响。实验表明,表面活性剂离子进入膨润土晶片层间,使其晶片层间的亲水环境改变为疏水环境以及增大晶片层间距离,增加膨润土与有机相的相容性,为制备高聚物/膨润土纳米复合材料奠定基础。  相似文献   

2.
有机膨润土制备及性能表征   总被引:15,自引:0,他引:15  
采用湿法工艺,分别用十六烷基三甲基氯化铵、十八烷基二甲基苄基氯化铵、十八烷基三甲基氯化铵与钠基膨润土,进行离子交换反应合成了有机膨润土。以红外光谱、X-ray衍射和差热分析等手段对改性膨润土进行了结构表征,讨论了不同的季铵盐对有机膨润土性能的影响。实验表明,表面活性剂离子进入膨润土晶片层间,使其晶片层间的亲水环境改变为疏水环境并增大晶片层间距离,为制备高聚物/膨润土纳米复合材料奠定基础。  相似文献   

3.
CTMAB和PDMDAAC有机改性膨润土的制备及其表征   总被引:2,自引:0,他引:2  
Yu HQ  Yan LG  Xin XD  Du B  Wei Q  Fan YH  Bi CF 《光谱学与光谱分析》2011,31(5):1393-1397
以天然膨润土为原料,进行提纯钠化,得到钠化膨润土,测定了其膨胀容、膨润值、胶质价、吸蓝量、阳离子交换容量等指标,使提纯钠化后的膨润土性能更加优越.分别以溴化十六烷基三甲基铵(CT-MAB)和聚二甲基二烯丙基氯化铵(PDMDAAC)作为有机插层剂制备了两种有机改性膨润土,通过傅里叶变换红外光谱(FTIR)、X射线衍射(X...  相似文献   

4.
以木薯淀粉为主要原料,自行研制的有机膨润土为改性剂,经过熔融和溶液插层等工艺制备木薯淀粉/膨润土复合粘结剂.采用FTIR和XRD手段表征及力学性能测试.结果表明,PVA插层改性后的有机膨润土的层间距大于有机膨润土的层间距大于Na基膨润土的层间距,膨润土的层间距越大,越有利于淀粉与膨润土的插层反应,得到的复合粘结剂的干强度也越高.该复合粘结剂具有粘结强度高、抗吸潮性好,且成本低、工艺简单和环境友好.  相似文献   

5.
插层复合体系中,有机插层剂在插层的同时也可能吸附在复合物的表面或以自由态存在,对插层分子的表征将会产生较大的影响。以丙酮作淋洗剂,用FT IR及XRD技术对淋洗前后的插层复合体系监控,插层剂分子在复合体系中的可能存在形式,探讨水的作用及复合物微观结构的变化。结果显示:甲酰胺有插层、游离和吸附在复合物表面三种存在形态。3355和3462 cm -1处的红外振动峰归属于表面吸附的插层剂分子,3626 cm-1的峰归属于插层的 H2 O分子,在干燥后均消失。H2 O作为填充空间的分子参预了插层过程,且插入到层间,并在干燥后脱嵌。3534 cm -1处的振动峰在淋洗前后一直存在,是由于插层的甲酰胺分子与高岭石层间形成氢键作用的结果。以丙酮作为淋洗剂,可以选择性的消除表面吸附的甲酰胺而不影响复合物的结构。插层的甲酰胺分子以C-N键垂直于层片呈单分子层排列,并通过氨基与高岭石铝氧八面体层的内表面羟基和硅氧四面体层的氧形成了两种氢键作用。  相似文献   

6.
分光光度法研究插层膨润土对有机染料的脱色性能   总被引:3,自引:0,他引:3  
以钠基膨润土为原料制备o-羧甲基壳聚糖插层膨润土,通过XRD、IR及SEM表征插层膨润土的表面性质及组织构造;用分光光度法分析插层膨润土对有机染料的脱色性能;同时探讨表面活性剂和o-羧甲基壳聚糖加料顺序、配比对脱色性能的影响。结果表明:当表面活性剂和o-羧甲基壳聚糖为2:1时,先加入表面活性剂反应一定时间再加入羧甲基壳聚糖所得的插层膨润土对亚甲基蓝和酸性蓝脱色性能最优,脱色率可达98.5%。  相似文献   

7.
以天然杭锦2#土为原料,进行酸化活化,得到酸化杭锦2#土,并进一步以十六烷基三甲基溴化铵作为有机插层剂制备了有机改性杭锦2#土。其FTIR谱图中出现—CH的振动峰,说明插层剂已进入到杭锦2#土层间。再经高温焙烧有机改性杭锦2#土制得介孔杭锦2#土,并应用X射线衍射和扫描电子显微镜对样品进行了晶相和形貌分析,用N2吸附脱附测定其比表面积和孔径,通过傅里叶变换红外光谱和紫外-可见漫反射光谱对样品进行了光谱表征。  相似文献   

8.
首先以CdCl2·2.5H2O、SeO2和NaBH4为反应物,制备巯基丁二酸稳定的CdSe量子点。然后将有机膨润土与CdSe量子点溶液混合并充分搅拌,制备负载CdSe量子点的膨润土发光材料,用荧光光谱、扫描电镜和X射线粉末衍射等分析测试手段对所得材料的光谱性能与微观结构进行表征。光谱分析表明,量子点膨润土复合材料的发光颜色与量子点溶液非常一致;X射线光电子能谱分析表明,复合后的材料中含有Cd 和 Se两种元素;此外,在量子点膨润土复合材料X射线粉末衍射谱中可见CdSe量子点(111)、(220)及(331)3个晶面的衍射峰,2θ=4.3°处出现膨润土(001)衍射峰。数据表明,在制备的CdSe量子点膨润土复合材料中,量子点和膨润土的结构都没有改变。  相似文献   

9.
曾宇 《光谱实验室》2007,24(5):872-876
用阳离子表面活性剂十四烷基三甲基溴化铵(C17H38NBr)对膨润土进行插层改性制备.配制浓度为2.35%十四烷基三甲基溴化铵溶液备用.在碘量瓶中称取3.04g膨润土,加入30mL超纯水、10mL十四烷基三甲基溴化铵溶液,制成土浆,放入微波炉中反应1min.产物经抽滤、洗涤、烘干、研磨,做FT-IR和DSC-TG分析.DSC曲线在500℃时有一明显的放热峰;TG曲线显示改性土的失重率有明显的增大.有机改性膨润土中确实含有大量有机物,改性成功.  相似文献   

10.
朱鹏飞  任静  罗凤琳  牛笛  曾静 《光谱实验室》2013,30(5):2521-2524
以酸化改性膨润土为载体,采用浸泡法制备了稀土La掺杂的La/酸化膨润土吸附剂.通过XRD和FTIR对其结构进行了表征,探讨了膨润土的改性机理,研究了该吸附剂对废水的除磷性能.结果表明:酸化过程洗掉了膨润土中的杂质和氧化铝,稀土镧的掺杂在膨润土层间及表面引入了一定数量的羟基化合物,改善了膨润土的层间结构并生成了新的La-O-Si键,实现了La与膨润土的复合,提高了膨润土的吸附性能.  相似文献   

11.
In this study, the synthesis of zirconium-pillared bentonite modified with cerium was performed via two different methods by the application of conventional and ultrasonic treatments during the intercalation stage. To synthesise copper-impregnated pillared clays by wet impregnation, cerium-modified zirconium-pillared clays were used as supportive materials after being calcined at 300 °C. Ultrasonic treatment significantly decreased the required processing time compared with the conventional treatment of the synthesised pillared bentonites. Chemical analysis confirmed the incorporation of Zr4+, Ce4+ and Cu2+ species into the pillared bentonites. X-ray diffraction (XRD) patterns of zirconium- and cerium/zirconium-pillared bentonites prepared by conventional treatment show that one large d-spacing above 3.5 nm corresponds to the mesoporous delaminated part, and another small d-spacing above 1.7 nm is indicative of the microporous pillared part. Zirconium- and cerium/zirconium-pillared bentonites prepared via ultrasonic treatment exhibited similar results, with the same high d-spacing but with a second low-intensity d-spacing above 1.9 nm. The delaminated structures of the pillared bentonites synthesised by both methods were conserved after copper impregnation. Nitrogen-adsorption isotherm analysis showed that the textural characteristics of products synthesised by ultrasonic treatment were comparable to those of products synthesised by conventional treatment. Fourier-transform infrared spectroscopy (FTIR) analyses showed the presence of Brønsted- and Lewis-acid sites, and zirconium-pillared clays synthesised by conventional treatment exhibited increased numbers of Brønsted- and Lewis-acid sites after cerium addition and copper impregnation. However, the products synthesised by ultrasonic treatment exhibited an increased number of Brønsted- and Lewis-acid sites after cerium addition, but a decreased number of acid sites after copper impregnation.  相似文献   

12.
Choosing suitable solvent is the key technology for the electrochemical performance of energy storage device.Among them,vinylene carbonate(VC),fluoroethylene carbonate(FEC),and ethylene sulfite(ES)are the potential organic electrolyte solvents for lithium/sodium battery.However,the quantitative relation and the specific mechanism of these solvents are currently unclear.In this work,density functional theory(DFT)method is employed to study the lithium/sodium ion solvation in solvents of VC,ES,and FEC.We first find that 4VC-Li+,4VC-Na+,4ES-Li+,4ES-Na+,4FEC-Li+,and 4FEC-Na+are the maximum thermodynamic stable solvation complexes.Besides,it is indicated that the innermost solvation shells are consisted of 5VC-Li+/Na+,5ES-Li+/Na+,and 5FEC-Li+/Na+.It is also indicated that the Li+solvation complexes are more stable than Na+complexes.Moreover,infrared and Raman spectrum analysis indicates that the stretching vibration of O=C peak evidently shifts to high frequency with the Li+/Na+concentration reducing in nVC-Li+/Na+and nFEC-Li+/Na+solvation complexes,and the O=C vibration peak frequency in Na+solvation complexes is higher than that of Li+complexes.The S=O stretching vibration in nES-Li+/Na+solvation complexes moves to high frequency with the decrease of the Li+/Na+concentration,the S=O vibration in nES-Na+is higher than that in nES-Li+.The study is meaningful for the design of new-type Li/Na battery electrolytes.  相似文献   

13.
In this work the lamellar cluster model was found to be applicable to the explanation of the mechanical yield behavior in polypropylene materials. According to the lamellar clustering theory, a spherulite is composed of radiating arms, each arm is composed of lamellar clusters, and each lamellar cluster is an aggregate of structural units of the cluster, including several crystalline lamellae and amorphous layers. The intercluster links capable of supporting external force play a role in the destruction of lamellar clusters at the yield point. These morphological features were directly confirmed from TEM observation on two-dimensional polypropylene spherulites that were crystallized from mixtures of isotactic polypropylene and atactic polypropylene, with the latter being removed later by a solvent. In addition, the structural parameters, such as the distance between intercrystalline links and the lamellar cluster thickness, which were determined by applying the mechanical yielding data to the lamellar cluster theory, were confirmed to be in agreement with the quantitative estimations from the TEM images of the polypropylene spherulites.  相似文献   

14.
A new structural model of bivalve ligament from Solen grandis   总被引:1,自引:0,他引:1  
It is widely accepted that the structure of bivalve ligament contains two layers: outer organic lamellar and inner aragonite fibrous layer. However, by using scanning electron microscopy (SEM), X-ray diffraction (XRD), and infrared spectroscopy (FTIR), we found an additional protein fibrous layer in the Solen grandis ligament. The ligament consists of three layers: an outer layer (OL), middle layer (ML), and inner layer (IL). OL consists of lamellar protein, oriented normal to dorsal edge. ML has unique spring-like protein fibers (ca. 120 nm in diameter) structure, stretching continuously from the left to right valve. Interestingly, IL comprises of aragonite fibers (ca. 100 nm in diameter) oriented posteriorly and inclined at an angle about 26° to dorsal edge at dorsal part; then they turn gradually to ventral part, showing striking zigzag structure vertical to ventral surface (VS). The ligament presents a new three-layered structural model different from previous reports; it may inspire not only in materials synthesis and mechanical design, but also in bivalve classification and evolution.  相似文献   

15.
研究了Ce3+在碱金属-碱土金属硼酸盐体系LiCaBO3,LiSrBO3和LiBaBO3中的光谱特性,发现Ce3+在该体系中均呈现非对称的宽谱发射,对应的发射光谱主峰分别为428,436和440 nm;分别监测三个主发射峰,所得激发光谱主峰分别为364、369和370 nm。研究了电荷补偿剂Li+,Na+,K+对3种材料发射强度的影响,结果显示,材料的发射强度明显提高,其中以掺入Li+时效果最明显。  相似文献   

16.
We consider DNA-cationic lipid complexes that form lamellar stacks of lipid bilayers with parallel DNA strands intercalated in between. We calculate the electrostatically induced elastic deformations of the lipid bilayers. It is found that the membranes undulate with a periodicity that is set by the DNA interaxial distance. As a consequence the lamellar repeat distance changes resulting in a swelling or compression of the lamellar stack. Such undulations may be responsible for the intermembrane coupling between DNA strands in different layers as it is observed experimentally. Received 2 March 2001  相似文献   

17.
蒙脱土(MMT)作为一种天然矿物质,在树脂胶粘剂的增强改性方面应用前景广阔。为了探明蒙脱土增强作用机理,本文采用有机蒙脱土改性脲醛树脂,利用傅里叶红外光谱仪(FTIR)和X射线衍射仪(XRD)分析蒙脱土和改性树脂的化学和晶体结构;并制造木质复合材料,采用纳米压痕技术(NI)比较研究复合材料界面区域树脂的纳米力学性能,测定复合材料的宏观胶合强度。FTIR和XRD分析表明,经十六烷基三甲基溴化铵分析纯(CTAB)改性后的蒙脱土在2 929和2 855cm~(-1)附近出现新的吸收峰,蒙脱土原土中的金属阳离子和有机阳离子实现有效交换,其(001)面强衍射峰向小角度移动,蒙脱土原土纳米片层的间距从1.51nm增加至2.71nm,有助于蒙脱土均匀分散于树脂体系中,并与体系中聚合物分子基团发生化学反应。蒙脱土片层的物理填充、化学反应形成的弹性体结构使得胶粘剂在加载过程中可以有效地分散应力,从而有利于提高脲醛树脂的力学性能,有机蒙脱土改性脲醛树脂的微观弹性模量和硬度分别增加了66.9%和24.2%。改性后树脂的耐水性能得到明显改善,木质复合材料的湿胶合强度增加了约97%。  相似文献   

18.
Organic films fabrication offers the possibility of producing electronic devices of low weight, mechanical flexibility and low cost. One suitable material for organic film fabrigation which is the subject of the great interest is pentacene, because it is characterized by the large carrier mobility (∼1 cm2/Vs). In this work, the growth of pentacene layers using pulse laser deposition (PLD) on different substrates (glass/ITO, Si) is described and various processing parameters are investigated. Two pulsed YAG:Nd3+ laser wavelengths were used for the ablation of the PLD target: the first harmonic at 1064 nm aGn:dNdth3+e second at 532 nm. The structure of the layers formed was examined using SEM and RHEED methods. The results were compared with results of optical spectroscopy studies. It will be shown that layers deposed using second harmonics have a higher quality than those for first harmonic. The other PLD parametersalso have a strong influence on the structure quality of layers.   相似文献   

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