膨润土有机改性的FTIR和XRD研究

研究内容是制备有机膨润土以提高膨润土与有机相的相容性,同时观察膨润土的层状结构在有机化前后的变化情况。以钠基膨润土为原料,并用十八胺试剂作为有机插层剂取代膨润土层间的Na^＋,制得有机膨润土,且对其结构进行表征。FTIR和DTA-TG都证明有机插层剂已进入膨润土的层间;XRD表明膨润土的层间距由1．4增大到4．3nm;从实验结果可知,钠化膨润土在各种指标上都比原钙基膨润土有显著的改善,如吸蓝量、膨胀容、胶质价、阳离子交换容量等。改性后的膨润土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,从而有利于制备综合性能较好的复合材料。     

膨润土的短碳链季铵盐改性研究

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。     

分光光度法研究插层膨润土对有机染料的脱色性能

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%。     

CTMAB和PDMDAAC有机改性膨润土的制备及其表征

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...     

有机膨润土制备及性能表征

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。     

有机膨润土负载ZnO/TiO2光降解催化剂的研制及性能

以六水硝酸锌、酞酸丁酯和有机膨润土为原料,采用沉淀法制备ZnO/TiO2膨润土复合光催化材料,用IR和XRD对光催化剂的组织构造和微观结构进行表征,实验了光催化剂对亚甲基蓝废水的降解性能。结果表明：ZnO/TiO2成功负载于膨润土片层表面,ZnO的含量为有机膨润土的8%,反应温度为70℃,焙烧温度为420℃,催化剂用量为12mg/L时,亚甲基蓝废水的降解率可达97%以上。     

十四烷基三甲基溴化铵对膨润土改性合成及其表征

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.     

吡嗪-2-羧酸在γ-改性磷酸锆中的插层组装及发光性能

采用直接沉淀法制备了层状框架γ-磷酸锆（γ-ZrP）及改性磷酸锆（γ-DDZrP）,通过插层化学法将吡嗪-2-羧酸生色团与改性磷酸锆进行杂化组装。X射线衍射结果显示,γ-DDZrP的层间距（3.70 nm）远远大于γ-ZrP（1.11 nm）,这有利于吡嗪-2-羧酸生色团的插入。组装后层状框架的层间距由3.70 nm减小为3.33~3.29 nm。 荧光光谱表明,最大发射峰位置发生了明显蓝移,由溶液中的373 nm蓝移至悬浮液的366 nm。研究发现,吡嗪-2-羧酸在水溶液中的荧光强度很低,但形成插层组装后,悬浮液的荧光强度有了很大程度的提高,当浓度为15 μmol/L时,荧光强度增大了6倍。这说明γ-DDZrP能够改善吡嗪-2-羧酸的荧光性能,有利于其在分子识别和荧光探针等领域的应用。     

有机层界面对双层有机发光二极管复合效率的影响

建立了双层有机发光二极管中载流子在有机层界面复合的无序跳跃理论模型.由于有机分子材料的空间及能带结构的无序性，采用刚体模型处理有机层界面问题是不恰当的，而采用无序跳跃模型比较合理.复合效率及复合电流由载流子跳跃距离、有机层界面的有效势垒高度及该界面处的电场强度分布所决定：在双层器件ITO/α-NPD/Alq₃/Al中，当所加电压小于19.5V时，复合效率随着载流子跳跃距离的增加而增加，而大于19.5V时，复合效率随着其距离的增加而减少；复合效率随着有机层界面有效势垒高度的增加而增加； 关键词： 有机层界面 双层有机发光二极管 复合效率 有效势垒高度 无序跳跃模型     

分子核间距对非时序双电离的影响

利用半经典再散射模型研究了激光强度在一定范围内时分子核间距对非时序双电离过程的影响.分别计算了非时序双电离率、两电子的电离能、两电子的动量相关、Coulomb和激光场的复合势随分子核间距的变化关系.研究表明,分子核间距在1.0—6.0 a.u.范围内时,非时序双电离率和两电子动量和为零的双电离事件数随着分子核间距的增大而增大.当分子核间距继续增大(大于6.0 a.u.)时,非时序双电离率和两电子动量和为零的双电离事件数却减小.     

Adsorption of Acetochlor Herbicide on Inorganic- and Organic-Modified Bentonite Monitored by Mid-Infrared Spectroscopy and Batch Adsorption

The results of sorption of acetochlor herbicide with different concentrations (1–15 µg/mL) in inorganic- and organic-modified bentonite are presented. Acetochlor sorption in both bentonite types was studied by attenuated total reflectance spectroscopy in the mid-infrared region and by batch equilibrium method. Infrared spectroscopy results suggest that the interaction of acetochlor with inorganic (or organic) bentonite takes place by mechanism involving the carbonyl stretching vibration and phenyl ring in the acetochlor molecule. The increase of the acetochlor concentration results in red shift of both corresponding band wavenumbers. Batch adsorption study pointed out more expressed sorption of acetochlor in organic bentonite.     

CdSe量子点膨润土复合材料的制备与表征

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。     

Preparation and characterization of “green” hybrid clay-dye nanopigments

We obtained a low cost and abundant nanopigment material composed of Rhodamine B (Rh-B) organic dye compound and Unye bentonite (UB) clay from Turkey. The characterization of the nanopigment was investigated using scanning electron microscopy (SEM), particle size distribution, powder X-ray diffraction (PXRD), Fourier transformed infra-red spectroscopy (FT-IR) and thermal analysis techniques. According to the result of texture analyses, we showed that the particle size distribution (d: 0.5-mean distribution) of Rh-B/UB nanopigment material was around 100 nm diameter. It was also demonstrated that the samples had a particle size around nm diameter in SEM images. As seen in the PXRD and thermal analysis, there is a difference in basal spacing by 1.46° (2θ) and a higher mass loss by 7.80% in the temperature range 200–500 °C compared to the raw bentonite.     

CdS/膨润土复合材料的制备及其光催化性能

以CdCl₂和硫代乙酰胺为反应物,通过湿化学法合成CdS/膨润土复合材料,采用X射线衍射(XRD)、红外光谱(FTIR)以及紫外可见光谱(UV-Vis)等分析技术对其结构及光学性能进行表征。以罗丹明B和亚甲基蓝为目标污染物,考察了CdS/膨润土复合材料对有机染料的降解性能。结果表明:在罗丹明B和亚甲基蓝的初始浓度为20 mg/L 时,光照3 h后,CdS/膨润土对它们的降解率分别为80.6%和88.3%,优于CdS及膨润土原土催化剂。     

Effect of Nafion dispersion solvent on the interfacial properties between the membrane and the electrode of a polymer electrolyte membrane-based fuel cell

A new Nafion binder solution was prepared using a different organic solvent, dimethylacetamide (DMAc), and applied to a polymer electrolyte membrane-based fuel cell. Wide angle X-ray diffraction (WAXD), electrochemical impedance spectroscopy (EIS), and polarization of the fuel cell were carried out to determine the crystallinity of the Nafion binder film, the cell resistance, and the fuel cell performance. This new Nafion binder film, which was created using a homemade Nafion solution containing DMAc, dissolved slower than a recast Nafion film that was made using a commercial Nafion solution in methanol (2 M). It was found that the slow dissolution of the homemade Nafion binder film was due to a more highly developed crystalline morphology, which can lead to good structural integrity in the catalyst layer for long-term operation of the fuel cell. The micellar structure of Nafion in the commercial Nafion binder solution is broken by new organic solvent, which leads to higher physical chain entanglement between the Nafion membrane and the Nafion binder during preparation of the membrane/electrode assembly (MEA), thereby improving the interfacial stability between the membrane and the electrode and providing long-term stability of the fuel cell.     

Continuous Rotary Drum Granulation of N-K Fertilizers

The aim of this study was to investigate the effect of operating variables on the continuous rotary drum granulation of fertilizers. The fertilizers, viz. urea and potassium chloride with bentonite as a binder, were taken as feed materials. The effects of moisture content and feed rate on continuous rotary drum granulation are discussed. Step response experiments with respect to the above two variables were also conducted to investigate the dynamic behaviour of the system, which will be of use in the control of the granulator.     

An NMR protocol for determining ice crystal size distributions during freezing and pore size distributions during freeze-drying

Nuclear magnetic resonance water proton relaxometry is widely used to investigate pore size distributions and pore connectivity in brine-saturated porous rocks and construction materials. In this paper we show that, by replacing water with acetone, a similar method can be used to probe the porous structure of freeze-dried starch gels and therefore the ice crystal size distribution in frozen starch gels. The method relies on the observation that the starch surface acts as a powerful relaxation sink for acetone proton transverse magnetization so that Brownstein-Tarr theory can be used to extract the pore size distribution from the relaxation data. In addition the relaxation time distribution is found to depend on the spectrometer frequency and the Carr-Purcell-Meiboom-Gill pulse spacing, consistent with the existence of large susceptibility-induced field gradients within the pores. The potential of this approach for noninvasively measuring ice crystal size distributions during freezing and pore size distributions during freeze-drying in other food systems is discussed.     

Effects on the field emission properties by variation in surface morphology of patterned photosensitive carbon nanotube paste using organic solvent

Photosensitive carbon nanotube (CNT) paste was prepared by 3-roll milling of multi-walled carbon nanotubes (MWNTs), UV-sensitive binder solution, and Ag as filler additives. Arrays of MWNT dots with a diode structure were fabricated by a combination of screen printing method and photolithography using these paste, and acetone utilized as the developer. The MWNT dots were well-defined and the organic binder materials in the dots were partially removed. The MWNT film without a heat treatment showed a high current density of 1.35 mA/cm² at 3.25 V/μm and low turn-on field of 2.2 V/μm at 100 μA/cm². Acetone can be used as an efficient developer to form patterns and to remove the organic residues in patterns, simultaneously.