A series of functionalized ionic liquids （ILs） containing ester-group were synthesized and their tribological prop- erties as lubricants for steel-steel contact were studied and compared with a non-functionalized io...A series of functionalized ionic liquids （ILs） containing ester-group were synthesized and their tribological prop- erties as lubricants for steel-steel contact were studied and compared with a non-functionalized ionic liquid and perfluo- ropolyethers （PFPE）. The morphology and chemical composition of the worn scars were analyzed by scanning electron mi- croscopy and X-ray photoelectron spectroscopy, respectively, and the possible lubrication mechanism of ILs was discussed. As a result, all ILs demonstrated a better lubricity and a much higher load-carrying capacity than PFPE used as lubricants for the steel-steel tribomates system. The functionalized ILs with ester-group showed slightly worse friction reducing abil- ity than their nonfunctionalized counterparts at relatively lower loads owing to their higher viscosity, but then exhibited better antiwear ability because the ester group they contained had not only physical but also strong chemical reactions with the freshly exposed steel surface and formed chemical adsorption boundary films on the worn surface during friction pro- cess. Under high loads, some triboehemical reactions took place between the active elements, such as fluorine which were released from the ILs, and fresh metal surfaces of rubbing pairs to form the admixture reaction films, which were mainly composed of ferric fluoride mixed with ferric oxide, leading to lower friction coefficients and good wear resistance.展开更多
文摘为研究多芳环烃(PAHs)在虾夷马粪海胆Strongylocentrotus intermedius体内的富集动力学,系统认识其动力学参数特征,应用半静态双箱动力学模型拟合虾夷马粪海胆(壳直径2.0 cm±0.3 cm)对3,4-苯并[a]芘、9,10-二甲基蒽、3-甲基菲3种PAHs的生物富集过程,通过非线性拟合获得海胆对3种多环芳烃的吸收速率常数(K_1)、释放速率常数(K_2)、生物富集因子(BCF),以及平衡状态下海胆体内3种多环芳烃的含量(C_(max))、生物学半衰期(t_(1/2))等动力学参数。结果表明:海胆对3,4-苯并[a]芘富集动力学参数K_1、K_2、BCF、C_(max)、t_(1/2)的平均值分别为59.1、0.152、136.5、11.788μg/g和6.36 d;海胆对9,10-二甲基蒽富集动力学参数K_1,K_2、BCF、C_(max)、t_(1/2)的平均值分别为12.3、0.228、54.05、4.383μg/g和6.32 d;海胆对3-甲基菲富集动力学参数K_1、K_2、BCF、C_(max)、t_(1/2)的平均值分别为18.16、0.113、88.1、12.407μg/g和7.6 d;在5μg/L浓度条件下,海胆对3种多环芳烃的富集能力进行比较,依次为3,4-苯并[a]芘(14 d BCF=220)>3-甲基菲(14 d BCF=128.4)>9,10-二甲基蒽(14 d BCF=84.0)。研究表明,海胆对浓度为1、5、20μg/L的3,4-苯并[a]芘、浓度为5、100μg/L的3-甲基菲、浓度为5、10、50μg/L的9,10-二甲基蒽的生物富集过程均符合双箱动力学模型。
基金the Natural Science Foundation Project of CQ CSTC, 2010BB0201
文摘A series of functionalized ionic liquids （ILs） containing ester-group were synthesized and their tribological prop- erties as lubricants for steel-steel contact were studied and compared with a non-functionalized ionic liquid and perfluo- ropolyethers （PFPE）. The morphology and chemical composition of the worn scars were analyzed by scanning electron mi- croscopy and X-ray photoelectron spectroscopy, respectively, and the possible lubrication mechanism of ILs was discussed. As a result, all ILs demonstrated a better lubricity and a much higher load-carrying capacity than PFPE used as lubricants for the steel-steel tribomates system. The functionalized ILs with ester-group showed slightly worse friction reducing abil- ity than their nonfunctionalized counterparts at relatively lower loads owing to their higher viscosity, but then exhibited better antiwear ability because the ester group they contained had not only physical but also strong chemical reactions with the freshly exposed steel surface and formed chemical adsorption boundary films on the worn surface during friction pro- cess. Under high loads, some triboehemical reactions took place between the active elements, such as fluorine which were released from the ILs, and fresh metal surfaces of rubbing pairs to form the admixture reaction films, which were mainly composed of ferric fluoride mixed with ferric oxide, leading to lower friction coefficients and good wear resistance.
