【作者】 王义华；

【导师】 徐红；

【作者基本信息】 太原理工大学 ， 化学工程， 2016， 硕士

【摘要】 沸石咪唑酯骨架材料(ZIFs)是一类新型的金属有机骨架材料,稳定的晶体结构和丰富的化学组成使其受到同行学者的关注。由于ZIFs材料具有大比表面积和孔径可调控的特点,因此其应用主要有气体吸附/分离、催化和药物缓释。基于ZIFs力学性能的特点及其亲油性的特征,课题组发现ZIF-8材料具有良好的固体润滑性能。因此,本文开展了代表性ZIFs材料(具有不同粒径和基团)的合成,并选用四球摩擦磨损试验机对所合成材料在不同油品中进行了摩擦学性能研究。主要研究内容及结论如下:1、采用溶剂热法,合成了不同粒径的ZIF-8材料,大粒径的平均粒径约为2μm,小粒径的平均粒径约为100 nm;采用溶剂热法,通过改变温度研究了ZIF-71材料的合成规律,获得了1~2μm大粒径的ZIF-71材料;通过加入甲酸作为调控剂,合成了约450 nm小粒径的ZIF-71材料。2、将制备的ZIFs材料作为固体润滑添加剂加入基础油液体石蜡中,首先,在承载力方面,添加不同粒径ZIF-8材料,承载能力PB值都从431 N提高到549 N;添加2.0–3.0 wt.%大粒径ZIF-71,承载能力PB值均从431 N提高到598 N;而添加同一质量分数的小粒径ZIF-71材料,PB值提高到549 N;显然,ZIF-8、ZIF-71都表现出良好的承载能力,含氯基团的ZIF-71效果更好。其次,在抗磨方面,添加0.05 wt.%小粒径ZIF-71材料,磨斑直径降低到0.54 mm;但添加不同粒径ZIF-8材料和大粒径ZIF-71材料,抗磨效果不明显。3、将制备的ZIFs材料作为固体润滑添加剂加入基础油聚乙二醇200中,在抗磨方面,添加0.25 wt.%大、小粒径ZIF-8材料,磨斑直径分别从0.50 mm减小到0.36 mm和0.41 mm;添加0.5 wt.%大、小粒径ZIF-71材料,磨斑直径分别从0.50 mm减小到0.44 mm和0.40mm;可见,ZIF-8和ZIF-71材料都表现出良好的抗磨效果。4、从不同粒径的ZIF-8材料(或ZIF-71材料)的钢球磨损表面SEM照片、EDS元素分析可以看出,SEM图片表明钢球的磨斑表面都有划痕;EDS钢球磨损表面元素分布表明只有钢球自身元素Fe、Cr分布,表明ZIF材料的元素存在。3D轮廓仪图片表明,不同粒径的ZIF-8(或ZIF-71)材料在液体石蜡中的钢球磨痕面积比在聚乙二醇200大,表明ZIF-8(或ZIF-71)材料在聚乙二醇200中的抗磨性能更好。5、为了进一步了解ZIFs材料的润滑性能,将大粒径ZIF-8材料作为固体润滑添加剂加入锂基脂中,在锂基脂中添加15.0 wt.%的ZIF-8材料,PB值从314 N提高到617 N;烧结负荷PD值从1235 N提高到1960 N;体积磨损量从4.80×10-4 mm3减低到2.48×10-4 mm3;表明在锂基脂中添加ZIF-8材料有良好的抗磨和承载能力。更多还原

【Abstract】 Zeolitic Imidazolate Frameworks(ZIFs) is a new kind of metal organic framework materials, owing to their stability of structure and diversified chemical composition, ZIFs are increasingly attracting the attention of the research community. ZIFs with large surface area and tunable pore sizes suited for a range of application such as gas storage / separation, catalysis and drug delivery. Based on the characteristics of mechanical properties of ZIFs and the characteristics of its lipophilic properties, the research group has found that the ZIF-8 material has good solid lubrication performance. Therefore, this paper has carried out the synthesis of representative ZIFs materials with different sizes and groups. The tribological properties of ZIFs crystals as additives in different oil were evaluated with a four-ball tester.The main research contents and conclusions are as follows :1. Using the solvent thermal method, the different particle sizes of ZIF-8 were synthesized. The average particle sizes were about 2 μm and 100 nm. And by varying temperature on the ZIF-71 synthesis rules, we obtained micrometer- sized ZIF-71, which were about 1 ~ 2 μm. The smaller particles size of ZIF-71 with 450 nm were obtained by adding formic acid.2. The preparation of ZIFs material were added into the base oil liquid paraffin as a solid lubricant additives. First, adding different particle sized ZIF-8, the maximum non-seizure load(PB value) increased from 431 N to 549 N. And adding 2.0- 3.0 wt.% of large particles ZIF-71, PB value increased from 431 N to 598 N; while adding with a mass fraction of small particles ZIF-71, the PB value only increased to 549 N. Of course, adding ZIF-8 or ZIF-71 have showed good carrying capacity. Adding 0.05 wt.% small sized ZIF-71 in liquid paraffin, the wear scar diameter was deceased to 0.54 mm, but there was no effect on the anti-wear property by adding ZIF-8 with different particle sizes.3. The preparation of ZIFs material were added into the base oil polyethylene glycol 200(PEG200) as a solid lubricant additives. Adding 0.25 wt.% larger or small sized ZIF-8, the wear scar diameter was decreased from 0.50 mm to 0.36 or 0.41 mm, respectively. Adding0.5 wt.% larger or small sized ZIF-71, the wear scar diameter was decreased from 0.50 mm to 0.44 or 0.40 mm, respectively.4. SEM images and EDS spectrum were used to investigate the worn steel ball surface lubricated by base oil and oil containing different sized ZIF-8(or ZIF-71). It can be seen that the steel ball surface had scratches, EDS elemental distribution map indicated that the worn surface only had Fe, Cr element, no ZIFs elemental distribution. 3D profiler images showed that the worn scar of different sized ZIF-8(or ZIF-71) in liquid paraffin is larger than their worn scar in PEG200.5. In order to further understand the lubrication properties of ZIFs materials, ZIF-8 with an average size of 2 μm were added in lithium grease as an additive. Adding 15.0 wt.% of ZIF-8 in grease, PB value increased from 314 N to 617 N; the sintering load PD value increased from 1235 N to 1960 N. So, it can be concluded that ZIF-8 crystals have good load-carrying capacity and extreme pressure property. The wear volume reduced from 4.80 × 10-4 mm3 to 2.48 ×10-4 mm3. ZIF-8 as an additive are effective in improving anti-wear ability of base grease.更多还原