机械力化学法制备有机改性蒙脱石粉体

采用机械力化学改性法,以十六烷基三甲基溴化铵、十二烷基磺酸钠、硬脂酸钠为改性剂,对钙基蒙脱石粉体进行单独或组合改性,制得不同类型的有机改性蒙脱石粉体;利用X射线衍射、红外光谱、表面接触角等测试手段对蒙脱石和所得样品进行分析和表征,研究和探索机械力化学法制备有机改性蒙脱石的机制。结果表明,机械力化学法改性与湿法改性机理之间存在差异;在机械力作用下,改性剂与蒙脱石片层结合,2个蒙脱石片层与改性剂组合形成1个新的单元,同时使蒙脱石片层之间剥离,最后实现整体改性。     

CO_2插层作用下有机蒙脱土膨胀/结构行为的分子模拟

运用蒙特卡洛分子模拟方法,依据能量最小原则,从微观水平研究了二氧化碳环境下钠蒙脱土及表面活性剂改性有机蒙脱土的膨胀性能和层间结构。模拟结果表明,蒙脱土晶面间距随着层间二氧化碳含量增加而膨胀增大,其中有机蒙脱土表现出更强烈的膨胀性能。通过结构分析,层间二氧化碳随着蒙脱土晶面间距的增大而出现明显的多层分布现象,其中层间表面活性剂随着二氧化碳含量的变化而形成不同的结构形态。     

阳-非离子型有机蒙脱石制备、表征和机理

利用阳离子改性剂十六烷基三甲基溴化铵(CTAB)和非离子改性剂烷基酚聚氧乙烯醚(OP-10)对钙基蒙脱石进行湿法改性制得阳-非离子型有机蒙脱石,采用X射线衍射、傅里叶变换红外光谱、扫描电子显微镜和热重分析等手段对制得的蒙脱石进行表征,并对机理进行讨论。结果表明:CTAB与OP-10可以同时嵌入到蒙脱石层间,阳-非离子型有机蒙脱石的片层膨胀程度和改性效果优于单阳离子型有机蒙脱石的,表现出更好的热稳定性;投料顺序对阳-非离子型有机蒙脱石的改性效果没有影响。     

有机与无机改性蒙脱石对鲑鱼精DNA吸附特征研究

利用聚羟基Fe/Al制备出无机柱撑蒙脱石,以阳离子表面活性剂HDTMA、阴离子型的表面活性剂SDS作为有机改性剂制备出有机改性蒙脱石,并且通过XRD、FT-IR、BET和zeta电位等表征手段对柱撑粘土进行表征,首次研究了具有不同层间结构的改性蒙脱石对鲑鱼精DNA的吸附特征。DNA吸附量大小顺序为HTDM-MMT>MMT>SDS-MMT-Fe/Al-MMT。HTDMA改性促进了蒙脱石的吸附,吸附量达61.04μg/mg。而SDS覆盖其表面后,吸附量减至26.88μg/mg。在pH值为5.0～9.0范围内,有机改性蒙脱石对DNA的吸附量随pH值下降幅度远小于原土。吸附动力学研究表明,控制改性蒙脱石吸附DNA的主要步骤是化学吸附。用NaOAc和NaH2PO4解吸DNA时,有机与无机蒙脱石解吸规律有明显差异。实验结果表明,结构、电负性及表面性质是影响不同改性蒙脱石吸附DNA分子的关键因素。     

蓖麻油酸钠改性蒙脱土的制备及其表征

采用常规酸碱反应制备了阴离子表面活性剂—蓖麻油酸钠,并以此表面活性剂对钠基蒙脱土进行有机改性。讨论了有机改性过程中改性剂用量,固液比,溶液pH,反应体系的温度对有机蒙脱土层间距的影响。对制得的阴离子有机蒙脱土(OMMT)进行了红外光谱(IR)、X射线衍射(XRD)和热重分析(TGA)测试。红外测试及X射线衍射结果均显示,蓖麻油酸钠已成功插层于蒙脱土片层中;热失重结果显示有机蒙脱土的热稳定性明显提高。     

聚苯乙烯/蒙脱土复合材料的制备及表征

用本体聚合法制备了聚苯乙烯/蒙脱土复合材料,通过FTIR对有机改性蒙脱土的结构进行了表征,用XRD表征了纳米复合材料的结构,用TGA、DTA袁征了纳米复合材料的热稳定性.结果表明,聚苯乙烯可插层于含双键的咪唑盐表面活性剂改性的蒙脱土中,复合材料的热稳定性得到了较大的提高.     

水镁石粉体表面改性及表面能测算

水镁石粉体是聚合物的常用填料,但水镁石极性较大,与基材的相容性也较差,因此必须通过表面改性,降低水镁石粉体表面能,增强亲油疏水性,从而增加与聚合物之间的相容性,而阴离子表面活性剂是合适的改性剂之一。水镁石粉体改性后的表面性能,可以用固体表面能数值的变化来表征,本文选择丙三醇、水、1-溴代萘为探针液体,用直接测定法与Washburn方程间接计算法获得了改性前后水镁石的接触角,通过Lifshitz-van der Waals acid base三参数法计算其表面能。研究结果表明,不同的阴离子基团中,羧酸类、磷酸较之磺酸类硫酸类改性效果有明显优势,表面能的碱分量γ-S和酸分量γ＋S降为0;随着改性剂中非极性链烃的碳原子个数增加,表面能非极性分量γLSW下降很多,最终导致总表面能下降,接触角增加,疏水性增强。     

不同表面活性剂对铟锡氧化物纳米悬浮液稳定性的影响

在纳米铟锡氧化物纳米粉体应用中悬浮液分散稳定是一个十分重要的问题。本文采用化学改性的方法,分别用阴离子表面活性剂、阳离子表面活性剂、非离子表面活性剂和硅表面活性剂对铟锡氧化物进行表面修饰以改进其悬浮液的稳定性。结果表明,除阳离子表面活性剂外,其他表面活性剂均可以使纳米铟锡氧化物在特定的分散体系中得到很好的分散,纳米铟锡氧化物悬浮液稳定性良好。     

表面活性剂助剂对水性基墨性能的影响

目的通过研究表面活性剂对水性基墨干燥性能、颜色性能和流变性的影响规律,得到选择表面活性剂助剂的理论基础。方法选用阴离子、非离子和阴/非三类6种表面活性剂助剂,利用流变仪和表面张力仪等测量助剂加入前后水性基墨粘度、表面张力、接触角、色密度、光泽度等的变化规律。结果6种助剂加入后对水性基墨在薄膜上的润湿性影响较小;阴离子表面活性剂能够降低水性基墨的动态表面张力和粘度,降低色密度,提高稳定性;非离子表面活性剂可以提高水性基墨的干燥速率;阴/非复合助剂和阴离子表面活性剂有利于提高水性基墨的综合性能。结论助剂对水性基墨性能影响复杂,要考虑综合效果选择使用。     

表面活性剂对Ni-SiC复合镀层性能的影响

表面活性剂能改善复合镀层的性能,过去对离子型和非离子型表面活性剂影响复合镀层性能的研究报道不多.为此,利用电子探针分析仪、电化学分析方法以及摩擦磨损试验,系统地研究了表面活性剂对Ni-SiC复合镀层性能的影响.结果表明:非离子表面活性剂不易使微粒与基体金属发生共沉积,对沉积速度有一定的抑制作用;阳离子表面活性剂能够增加镀层中SiC粒子的含量,当浓度为0.12 g/L时SiC粒子含量最高,随着镀层中SiC离子含量的增加镀层的硬度增加,耐磨性能提高,其中XCG阳离子表面活性剂效果最好;非离子表面活性剂与阳离子表面活剂的协同作用,进一步促进了镀层中SiC微粒的共沉积,改善了复合镀层的性能.     

聚磺酸甜菜碱与表面活性剂在水溶液中复合与相分离

通过浊点法研究了表面活性剂的结构与浓度对聚N、N-二甲基-N-甲基丙烯酰氧乙基-N-丁基磺酸铵（PDMABS）水溶液相分离温度的影响。选用的表面活性剂包括阴离子、阳离子和非离子型表面活性剂,以及大分子的聚丙烯酸、聚对乙烯基苯磺酸钠、聚甲基丙烯酰氧乙基二甲基苄基氯化铵。结果显示,各种表面活性剂对PDMABS有不同程度的增...     

离子表面活性剂对膨化硝酸铵的改性

为了提高膨化硝酸铵的使用性能,研究了十二烷基苯磺酸钠(SDBS)和十八烷胺醋酸盐(OCTA·AC)两种离子表面活性剂以及两者的复配对膨化硝酸铵性能的影响,测试了改性前后膨化硝酸铵的吸湿性、吸油率、水溶性、抗结块性、微观结构以及热分解特性。实验结果表明,两种离子表面活性剂都可改善膨化硝酸铵的使用性能,尤其是将SDBS和OCTA·AC按照2∶3比例复配之后,对改善膨化硝酸铵的性能,效果最为明显,其测试结果为,在温度15℃和湿度90%环境中24 h的吸湿率为8%,比改性前的9.5%降低1.5%;吸油率为42.10%,比改性前的36.76%提高5.34%。SEM照片显示改性后的膨化硝酸铵微观结构的内表面比改性前光滑,表明离子表面活性剂吸附在膨化硝酸铵的内表面,形成单分子层或亚单分子层,降低了表面自由能。C80微热量热测试结果表明,离子表面活性剂对膨化硝酸铵的α斜方晶体转变为β斜方晶体有抑制作用。     

Characterization of sodium dodecyl sulfate modified iron pillared montmorillonite and its application for the removal of aqueous Cu(II) and Co(II)

Anionic surfactant modified Fe-pillared montmorillonites were prepared by Fe-hydrate solution and sodium dodecyl sulfate (SDS) solution. These organo–inorgano complex montmorillonites were divided into three types (CM1, CM2 and CM3) depending on different intercalation processes. X-ray diffraction spectra, the Fourier transform infrared (FTIR) spectra were used to analyze the structure of the raw and modified montmorillonites. X-ray photoelectron spectra of the simples have been studied to determine spectral characteristics to allow the identification of Fe(III) hydroxide. The specific surface area of the host montmorillonite (M0) is 73.2 m²/g, while for the modified montmorillonites it is 114.0 m²/g, 117.2 m²/g, and 115.8 m²/g, respectively. The mesopore volumes of the montmorillonites decrease after modification. Ions of copper and cobalt were selected as adsorbates to evaluate the adsorption performance of each montmorillonite. The adsorption data was analyzed by both Freundlich and Langmuir isotherm models and the data was well fit by the Langmuir isotherm model. The adsorption was efficient and significantly influenced by metal speciation, metal concentration, contact time, and pH. Higher adsorption capacity of the modified montmorillonites were obtained at pH 5–6. The results of desorption indicated that the metal ions were covalently bound to the modified montmorillonites.     

纳米碳纤维在水性体系中的分散性能及机理讨论

以十二烷基硫酸钠（SDS）、聚丙烯酸（PAA）复合曲拉通（Tx100）、分散助剂DISPERBYK-180（D-180）和十二炕基苯磺酸钠（SDBS）等4种表面活性剂作为分散剂,采用多种表面活性剂超声分散法分散纳米碳纤维（CNFs）．结合紫外／可见分光光度计法、透射电镜（TEM）及场发射扫描电镜（FESEM）观察、Zeta电位法、表面张力测试、静置及离心分离等测试方法,全面地表征了采用不同表面活性剂的CNFs悬浮液的分散状态,探讨了表面活性剂对CNFs在水性体系中分散性的影响．实验结果表明：4种表面活性剂中,SDS对CNFs的分散效果最好,其最佳掺量为1．6g／L：SDBS的分散效果次之,D．180效果再次,而PAA复合Tx100的分散效果最差．     

Study of the dispersion and electrical properties of carbon nanotubes treated by surfactants in dimethylacetamide

In this study, the effects of sodium dodecyl benzene sulfonate, polyvinylpyrrolidone, sodium dodecyl benzene sulfonate/polyvinylpyrrolidone, and Triton X-100 on the dispersion of 0.1 wt% carbon nanotubes in dimethylacetamide are reported. Sedimentation results show that except for sodium dodecyl benzene sulfonate, all the surfactant-assisted carbon nanotube solutions have visually-stable dispersions for at least two months, and even the samples without a surfactant gave no obvious deposition. UV-Vis spectra of the dispersions with and without acid-treatment proved that the carboxyl group attached to the carbon nanotubes positively improves the dispersion effect. The states of aggregation of carbon nanotubes treated by different surfactants are distinctive, and the electrical properties of carbon nanotubes are strongly related to these states of aggregation. The best dispersing and stabilizing effect was found in the sodium dodecyl benzene sulfonate/polyvinylpyrrolidone sample, which also gave the lowest resistance (2.15 x 10(4) omega at 20 V) among all the surfactant-treated stable suspensions.     

有机化试剂结构对粘弹性大分子插层蒙脱土的影响

以Gemini季铵盐、十六烷基二甲基甜菜碱和十二烷基三甲基溴化铵为有机化试剂对蒙脱土进行有机化处理和粘弹性大分子插层反应,通过XRD分析测试手段,研究了有机化试剂空间结构大小及可反应基团获得的有机化蒙脱土结构差异,以及粘弹性大分子对不同有机化结构蒙脱土的插层行为,结果表明Gemini季铵盐对蒙脱土进行有机化处理效果最好,粘弹性大分子插层Gemini季铵盐有机化蒙脱土的插层量大于含可反应基团的十六烷基二甲基甜菜碱有机化蒙脱土以及十二烷基三甲基溴化铵有机化蒙脱土的插层量。     

蒙脱土插层纳米复合材料改性涂料研究

采用双子季铵盐（GeminiC1）6表面活性剂和十六烷基三甲基溴化铵（CTAB）表面活性剂分别与钠基蒙脱土（Na-MMT）进行阳离子交换后,制备了新的有机蒙脱土（GeminiC16-MMT和CTAB-MMT）,通过X射线衍射（XRD）、透射电镜（TEM）等对有机蒙脱土进行表征并对其分散性做了测试。又用蒙脱土插层纳米复合材料改性水性涂料,并进行了性能测试表征,结果显示,经改性涂料的性能均有不同程度的提高。     

Novel Process to Prepare High-Performance Magnetorheological Fluid Based on Surfactants Compounding

To obtain high-performance magnetorheological fluid, first, the effectiveness of single surfactant including oleic acid, sodium dodecyl benzene sulfonate, OP4 emulsifier and Tween80 are analyzed by testing the sedimentation stability and viscosity. And then, according to the research results, a novel preparation process, that is the compounding of different surfactants, is proposed. Finally, the effect of surfactants compounding type and content on the properties of magnetorheological fluid are also researched. It is found that the properties of MR fluids can be improved effectively by compounding of oleic acid and sodium dodecyl benzene sulfonate, and the most appropriate compounding content relationship is 4.0 g: 4.0 g.     

Determination of trace levels of anionic surfactants in river water and wastewater by a flow injection analysis system with on-line preconcentration and potentiometric detection

The authors present an automated flow injection analysis (FIA) system for the determination of low levels of anionic surfactants in river water and wastewater. The system uses especially constructed tubular flow-through ion-selective electrodes (ISEs) as potentiometric sensors and on-line preconcentration techniques. The anionic surfactant ISEs employed are of the all-solid-state type with a plasticized PVC membrane. They show a general response to anionic surfactants with a lower limit of linear response of ～10(-)(5) M, when used in direct determinations. However, their specificity is limited, which hampers their direct use with environmental samples. Therefore, the FIA system presented here includes a solid-phase extraction procedure for purification and preconcentration of analytes. Breakthrough curves were constructed to characterize different sorbents and different eluents were tested to optimize the preconcentration process. The FIA system was first applied to the determination of different types of anionic surfactant standards. Potentially interfering substances such as chloride, nitrate, and nonionic surfactants were checked to verify that they did not interfere on the response of the system. Concentrations of ～10(-)(7) M (0.03 ppm) of sodium dodecyl sulfate could be detected in the nonlinear response region when 3 mL of sample was preconcentrated and eluted with 50 μL of a 75% acetonitrile/water (v/v) solution. Precision was 2% RSD (n = 31) for a 1 × 10(-)(6) M sodium dodecyl sulfate standard solution and the sample throughput was 10 h(-)(1). The FIA system was then used for the determination of total anionic surfactants in river water and wastewater.     

包覆双层表面活性剂Fe3O4纳米粒子的制备及性能研究

为制备稳定的水基磁流体,分别以月桂酸、油酸钠、十二烷基苯磺酸钠作为外层表面活性剂,对包油酸的Fe3O4粒子进行了再包覆.将得到的双层包覆的Fe3O4粒子分别分散在水中,发现以十二烷基苯磺酸钠为外层表面活性剂的磁粒子制成的水分散液的稳定性最佳.利用IR研究其吸附机理,结果显示:内层的油酸通过化学键合吸附在磁粒子表面,外层的十二烷基苯磺酸钠通过物理作用吸附在包油酸的Fe3O4粒子表面.