【作者】 周晓东；

【导师】 傅洵；

【作者基本信息】 青岛科技大学 ， 应用化学， 2007， 博士

【摘要】 咪唑啉型表面活性剂具有良好的去污、起泡和乳化性能，极低的毒性和良好的生物降解性，在日用化工、纺织、印染、缓蚀以及工业表面清洗等领域已经得到了广泛的应用。然而长期以来，人们忽略了拓展这类表面活性剂在其它领域的应用。咪唑啉型表面活性剂分子结构特殊，其中含有长链烷基构成了细长的疏水链段，而咪唑啉环及与其相连的侧链上含有多个S、N、O等杂原子，构成了体积较大的亲水链段，特殊的双亲性能使它们的分子结构类似于嵌段共聚物，在选择性溶剂中具有特殊的表面／界面性能，因此咪唑啉型表面活性剂在纳米材料制备及应用领域的修饰作用值得期待。而目前国内外未见这方面的研究报道。纳米材料由于其特殊的光学、电学、光化学、电化学、力学及催化性能，因此它们的制备及应用已经受到人们的广泛关注。然而在许多领域如纳米摩擦学和生物电化学分析领域，纳米材料自身较差的油溶性和分散稳定性限制了它们的应用，其优良性能也难以充分发挥，而利用有机表面活性剂对其进行表面改性是提高其应用效果的一种有效途径。咪唑啉型表面活性剂由于其特殊的两亲性能，非常适合应用于纳米材料的表面改性，它们在纳米材料的制备中充当表面修饰剂和分散稳定剂，对于拓展纳米材料的应用领域具有重要的意义。纳米材料的制备工艺路线对于它们的应用也非常重要，如何探索一种简便、方便、能耗低且环境友好的制备工艺仍面临巨大挑战。本文以咪唑啉型表面活性剂为表面修饰剂，采用多种方法制备了表面修饰的纳米材料，特别是常温制备具有特殊形貌纳米材料的工艺路线，对于纳米材料的规模化生产及其应用具有一定的意义，所制备的表面修饰的MoS₂微米实心球和纳米空心球以及表面修饰的ZnS空心球产品在液体石蜡、基础油500SN和中负荷齿轮油（GL-4）等润滑油体系中具有良好的摩擦学性能。本论文研究的目的在于首先合成具有特殊分子结构的咪唑啉型表面活性剂，在分析表征的基础上，系统研究它们的界面性能；然后将这种表面活性剂应用于纳米材料的制备中，对纳米材料进行表面改性；最后将所制备的表面修饰的MoS₂和ZnS产品作为润滑油添加剂应用于摩擦学领域，探讨这种咪唑啉型表面活性剂修饰的纳米材料在摩擦过程中的作用机理，从而为制备适用高效的工业润滑油添加剂提供了一种全新的思路，对于拓展表面修饰的纳米材料在工业润滑油领域的应用具有非常积极的意义。本论文的主要研究内容如下：（1）合成了2-十一（十七）烷基-1-二硫脲乙基咪唑啉季铵盐（SUDEI、SHDEI）和二（2-十一（十七）烷基-1-甲酰胺乙基咪唑啉）己二胺季铵盐（SUAEIHDI、SHAEIHDI）等四种咪唑啉型和咪唑啉双子表面活性剂，对它们进行了FT-IR、GC-MS和NMR表征，并系统研究了它们的界面性能，得到了临界胶束浓度CMC和胶团化热力学参数，探讨了烷基链长度、温度及溶剂极性对界面性能的影响，并用Langmuir单分子层吸附模型对界面性能进行了解释。（2）以7g／L SUDEI为表面活性剂，Na₂MoO₄·2H₂O为铝源，硫代氨基脲为硫源，水合肼为还原剂，在醇-水（1：1，v／v）介质中190℃溶剂热反应24 h得到粒径为0.5～2μm的实心球形2H-MoS₂。采用XRD、TEM、SEM、HRTEM和XPS等手段对MoS₂产品进行了表征，同时讨论了表面活性剂种类和浓度、反应时间及溶剂对MoS₂形貌的影响，并对MoS₂实心球的形成机理进行了探讨。（3）以酸性萃取剂Cyanex 301作为硫源和表面修饰剂，Na₂MoO₄·2H₂O为钼源，在醇-水混合溶剂（3：1，v／v）中190℃溶剂热反应24 h制备了粒径约200-300 nm的2H-MoS₂空心球，与文献比较此方法具有反应温度低、能耗小、条件温和易控制等优点；在DMF溶剂中采用上述类似的溶剂热法，制备了粒径约20 nm的花瓣状MoS₂。采用XRD、TEM、SEM和EDXA等手段对MoS₂产品进行了表征，讨论了萃取剂浓度、反应时间、反应温度等条件对MoS₂空心球及花瓣状MoS₂产品形貌的影响，并对空心球形及花瓣状结构的形成机理进行了探讨。（4）以0.05 mol／L SUDEI为表面活性剂，Pb（Ac）₂·3H₂O为铅源，Na₂SeSO₃为硒源，在醇-水混合溶剂（3：1，v／v）中150℃溶剂热反应12 h制备了分散均匀的四方形PbSe纳米晶；以4g·L^-1SUDEI为表面修饰剂，（K（SbO）C₄H₄O₆.1／2H₂O）为锑源，硒粉为硒源，150℃水热反应24 h制备了棒状Sb₂Se₃纳米晶。采用XRD、TEM和XPS等手段对PbSe和Sb₂Se₃产品进行表征，讨论了表面活性剂种类和浓度、反应温度及介质对产品形貌的影响，并对纳米晶形貌的形成机理进行了探讨。（5）以4g·L^-1SUAEIHDI为表面修饰剂，Zn（Ac）₂·2H₂O为锌源，硒粉为硒源，水合肼为还原剂，在水中150℃水热反应24 h，制得粒径约为100-300 nm的球形ZnSe纳米材料。采用XRD、TEM、SEM、FTolR和UV-vis等手段对ZnSe产品进行了表征，讨论了表面活性剂的浓度、种类、溶剂及温度等反应条件对ZnSe产品形貌的影响，并对球形ZnSe的形成机理进行了探讨。（6）以6g L^-1SUDEI为表面活性剂，CdCl₂·2.5H₂O为镉源，Na₂SeSO₃为硒源，在水中90℃恒温反应6 h制得粒径为0.5-1μm且分散均匀的CdSe实心球。采用XRD、EDXA、TEM、SEM、FT-IR和UV-vis等手段对CdSe产品进行了表征，讨论了表面活性剂浓度和种类、反应时间及溶剂对CdSe产品形貌的影响，并对球形CdSe的形成机理进行了探讨。初步的电化学性能测试表明，DNA分子很容易标记在CdSe纳米粒子上，DNA的检测限可达到pmol／L。（7）以6g L^-1SUDEI为表面活性剂，Zn（Ac）₂·2H₂O为锌源，硫代乙酰胺（TAA）为硫源，在无水乙醇中常温反应24h得到粒径为0.5～1μm的ZnS空心球，采用XRD、EDXA、TEM、SEM、FT-IR和UV-vis等手段对ZnS产品进行了表征，讨论了表面活性剂浓度和种类、反应时间及溶剂对ZnS产品形貌的影响，并对ZnS空心球形结构的形成机理进行了探讨。（8）以6gL^-1SUDEI为表面活性剂，Bi（NO₃）₃·5H₂O为铋源，硫代乙酰胺（TAA）为硫源，在DMF中常温反应24h得到粒径为200～400 nm的刺球形Bi₂S₃产品。采用XRD、EDXA、TEM、SEM、FT-IR和UV-vis等手段对Bi₂S₃产品进行了表征，讨论了表面活性剂浓度和种类、反应时间及溶剂对Bi₂S₃产品形貌的影响，并对Bi₂S₃刺球形结构的形成机理进行了探讨。（9）研究了本文制备的SUDEI表面修饰的MoS₂微米实心球（SU-MoS₂）、萃取剂Cyanex 301表面修饰的MoS₂纳米空心球（301-MoS₂）和Cyanex 302表面修饰的MoS2实心球（302-MOS₂）在液体石蜡、基础油500 SN和成品中负荷齿轮油GL-4中的摩擦学性能，并与商业级胶体MoS₂（CC-MoS₂）进行了对比，结果表明：三种自制的表面修饰的MoS₂产品在三种油品中具有良好的分散稳定性能、极压性能和抗磨减摩性能，与商业级胶体MoS₂（CC-MoS₂）相比是更好的润滑材料。另外研究了SUDEI表面修饰的ZnS空心球（SU-ZnS）在液体石蜡和基础油500 SN中的摩擦学性能，结果表明：表面修饰的ZnS空心球在两种油品中具有良好的分散稳定性能和抗磨减摩性能。利用SEM和XPS对磨斑表面进行观察分析，从而对摩擦过程中的润滑机理进行了初步探讨，结果表明，上述MoS₂及ZnS添加剂产品的摩擦机理可归因于由边界润滑条件下的化学吸附膜、化学反应膜和沉积膜组成的有效的表面复合膜以及滚动摩擦的存在。更多还原

【Abstract】 Due to the excellent decontaminating, bubbling and emulsifying properties, verylow toxicity and good biological degradation, imidazoline-type surfactants have beenwidely used in industrial fields, such as domestic chemical engineering, textile, dying,corrosion inhibition and industrial surface washing, etc. However, people have ignoredto extend their application in other fields so far. Imidazoline-type surfactants are ofspecial molecular structure, in which the long slim hydrophobic chain segment iscomposed of long chain alkyl, while the hydrophilic chain segment with larger volumeis made up of imidazoline ring and the heteroatoms S, N and O located at the sidechain. The special amphiphilic properties make the molecular structure ofimidazoline-type surfactants similar to that of block copolymer, which are of specialsurface/interface properties in selective solvents. Thus, the excellent surface-modifyingeffects of this kind of surfactants in the preparation of nanomaterials are worthexpecting. However, no researches on this aspect have been reported home and abroad.Much more attention has been paid to the preparation and application ofnanomaterials due to their special optic, electrical, photochemical, electrochemical,mechanical and catalytic properties. However, in many fields such as nanotribologyand bioelectrochemical analysis, the poor oil-solubility, dispersion and stability ofnanomaterials in organic media limit their application, and their excellent propertiescan’t be exerted completely. Surface-modification with organic surfactants is aneffective way to improve the application effects of nanomaterials. Because of thespecial amphiphilic properties, the imidazoline-type surfactants are very suitable forthe surface-modification of nanomaterials, acting as the surface-modifying agent, dispersing and stabilizing agent and morphology-controlling agent, which is ofsignificant sense in expanding the application of nanomaterials.The synthesis processes of nanomaterials are very important for their application,and it still remains a great challenge to develop a facile, convenient, low-energy andenvironment-friendly route. In this paper, with imidazoline-type surfactants assurface-modifying agents, several methods are exploited to synthesize nanomaterials,especially the room temperature route to the fabrication of nanomaterials with specialmorphologies, which is significant to the manufacture production of nanomaterials in alarge scale. The as-prepared surface-modified MoS₂ micro-sized solid spheres andnano-sized hollow spheres, as well as the surface-modified ZnS hollow spheres are ofexcellent tribological properties in liquid paraffin, base oil 500 SN and medium-loadgear oil GL-4.The purpose of this paper is, the imidazoline-type surfactants with specialmolecular structure are firstly synthesized and characterized, and their interracialproperties are studied systematically; then the as-synthesized imidazoline surfactantsare applied into the preparation of nanomaterials to modify their surface; finally, thetribological properties of the as-prepared surface-modified MoS₂ and ZnS products arestudied as oil additives in lubricating oils, and the action mechanism of the imidazolinesurfactants-modified nanomateirals during the friction process are also investigated soas to provide a new route to the fabrication of practical and effective lubrication oiladditives, which is of active sense to expand the application of surface-modifiednanomaterials in industrial lubrication field.The main contents of this paper are as follows:（1） Four imidazoline-type surfactants quaternary ammonium salts of 2-undecyl（heptadecyl）-1-dithioureido-ethyl-imidazoline （SUDEI/SHDEI） and di （2-undecyl（heptadecyl）-1-formyl aminoethyl imidazoline） hexanediamine （SUAEIHDI/SHAEIHDI） were synthesized and characterized by the measurements of FT-IR,GC-MS and NMR, and their interracial properties were also studied systematically.The critical micelle concentration （CMC） values were obtained and the micellizationthermodynamic functions were calculated as well. The effects of the hydrophobicchain length, temperature and polarity of solvents on the surface properties were alsodiscussed. The Langmuir Monolayer Adsorption Model was employed to explain theinterfacial properties of the four obtained imidazoline-type surfactants.（2） With 7 g/L SUDEI as surface-modifying agent, Na₂MoO₄·2H₂O as Mo source, aminothiourea as S source and N₂H₄·H₂O as reducing agent, MoS₂ solid spheres withsize of 0.5～2μm were synthesized via a solvothermal route at 190℃for 24 h in themixed medium of ethanol-water （1:1, v/v）. XRD, TEM, SEM, HRTEM and XPSmeasurements were used to characterize the MoS₂ products, and the effects of varioussurfactants type and concentration, reaction time and solvent on the morphologies ofMoS₂ products were discussed. The formation mechanism of MoS₂ solid sphericalstructure was investigated as well.（3） With acidic extractant Cyanex 301 as S source and surface-modifying agentand Na₂MoO₄·2H₂O as Mo source, 2H-MoS₂ hollow spheres with size of 200～300 nmwere synthesized via a solvothermal route at 190℃for 24 h in the mixed medium ofethanol-water （3:1, v/v）. Compared with the literature, this approach has theadvantages of low reaction temperature, low cost, mild and easy control of the reactionprocess. Petal-like MoS₂ particles with size of about 20 nm were also obtained via thesimilar way mentioned above in DMF. XRD, TEM, SEM and EDXA measurementswere used to characterize the MoS₂ products, and the effects of extractantconcentration, reaction time and temperature on the morphologies of MoS₂ werediscussed. The formation mechanisms of MoS₂ hollow and petal-like structure wereinvestigated as well.（4） With 0.05 mol/L SUDEI as surface-modifying agent, Pb（Ac）₂·3H₂O as Pbsource and Na₂SeSO₃ as Se source, well-dispersed rectangular PbSe nanocrystal wasprepared via a solvothermal route at 150℃for 12 h. in the mixed medium ofethanol-water （3:1, v/v）; with 4 g·L^-1 SUDEI as surface-modifying agent,（K（SbO）C₄H₄O₆.1/2H₂O） as Sb source and Se powder as Se source, rod-like Sb₂Se₃nanocrystal was prepared via a hydrothermal route at 150℃for 24 h. XRD, TEM andXPS measurements were used to characterize the PbSe and Sb₂Se₃ products, and theeffects of various surfactants type and concentration, reaction temperature and mediumon their morphologies were discussed. The formation mechanisms of PbSe and Sb₂Se₃nanocrystals were investigated as well.（5） With 4 g/L SUAEIHDI as surface-modifying agent, Zn（Ac）₂·2H₂O as. Znsource, Se powder as Se source and N₂H₄·H₂O as reducing agent, ZnSe nanosphereswith size of 100-300 nm were synthesized via a hydrothermal route at 150℃for 24 h.XRD, TEM, SEM, FT-IR and UV-vis measurements were used to characterize theZnSe products, and the effects of various surfactants type and concentration, reactiontemperature and solvent on the morphologies of ZnSe were discussed. The formation mechanism of ZnSe spherical structure was investigated as well.（6） With 6 g/L SUDEI as surface-modifying agent, CdCl₂·2.5H₂O as Cd sourceand Na₂SeSO₃ as Se source, well-dispersed CdSe solid spheres with size of 0.5-1μmwere synthesized in water at 90℃for 6 h in air without stirring. XRD, EDXA, TEM,SEM, FT-IR and UV-vis measurements were used to characterize the CdSe products,and the effects of various surfactants type and concentration, reaction time and solventon the morphologies of CdSe were discussed. The formation mechanism of CdSespherical structure was investigated as well. The preliminary electrochemicalproperties indicate that the DNA molecules can be labeled easily on the CdSenanoparticles, and the detection limit of DNA is up to pmol/L.（7） With 6 g/L SUDEI as surface-modifying agent, Zn（Ac）₂·2H₂O as Zn sourceand TAA as S source, well-dispersed ZnS hollow spheres with size of 0.5-1μm weresynthesized in absolute ethanol at room temperature for 24 h in air. XRD, EDXA,TEM, SEM, FT-IR and UV-vis measurements were used to characterize the ZnSproducts, and the effects of various surfactants type and concentration, reaction timeand solvent on the morphologies of ZnS were discussed. The formation mechanism ofZnS hollow spherical structure was investigated as well.（8） With 6 g/L SUDEI as surface-modifying agent, Bi（NO₃）₃·5H₂O as Bi sourceand TAA as S source, well-dispersed urchin-like Bi₂S₃ products with size of 200～400nm were synthesized in DMF at room temperature for 24 h in air. XRD, EDXA, TEM,SEM, FT-IR and UV-vis measurements were used to characterize the Bi₂S₃ products,and the effects of various surfactants type and concentration, reaction time and solventon the morphologies of Bi₂S₃ were discussed. The formation mechanism of Bi₂S₃urchin-like structure was investigated as well.（9） The tribological properties of SUDEI-modified MoS₂ micro-sized solidspheres （SU-MoS₂）, Cyanex 301-modified MoS₂ nano-sized hollow spheres（301-MoS₂） and Cyanex 302-modified MoS₂ micro-sized solid spheres （302-MoS₂） inliquid paraffin （LP）, base oil 500 SN and medium-load gear oil GL-4 were studied andcompared with those of commercial colloidal MoS₂ （CC-MoS₂）. The results show thatthe three self-prepared surface-modified MoS₂ additives are of excellent dispersion andstability, extreme-pressure characteristics and anti-wear and friction-reducingproperties in the three base stocks mention above, which are much better lubricatingmaterials compared with commercial colloidal MoS₂ （CC-MoS₂）. Furthermore, thetribological properties of the as-prepared SUDEI-modified ZnS hollow spheres （SU-ZnS） in LP and base oil 500 SN were also studied, indicating that thesurface-modified ZnS hollow spheres are of excellent dispersion and stability,anti-wear and friction-reducing properties in the two base stocks. SEM and XPSmeasurements were used to observe the surfaces of the wear scars and the lubricationmechanisms of the systems lubricated with self-prepared surface-modified MoS₂ andZnS products in the friction process were investigated as well, which could be deducedas the effective surface composite film composed of chemical adsorption film,chemical reaction film and deposition film under boundary lubrication conditions, aswell as the existence of rolling friction.更多还原