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Stable graphene oxide-based lyotropic liquid crystals for interfacial lubrication

Friction 2024年第5期12卷 954-967页

作者： Yumei GUO Hanglin li Jiusheng LI Xiangqiong ZENG Laboratory for Advanced Lubricating Materials Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China University of Chinese Academy of Sciences Beijing100049China

Lyotropic liquid crystals have lubricating properties due to their ordered assembly and fluidity,whose mesogens are often characterized by amphiphilic properties.Despite the attention that graphene oxide(GO)has been studied as a novel amphiphilic lyotropic mesogen this decade,and GO applied as a lubrication additive has been demonstrated in both oil and water-based systems,little research reveals the interfacial lubrication of GO liquid crystals yet.This work reports that GO aqueous dispersion can form lyotropic liquid crystals above a specific critical concentration of 5.00 mg/mL,providing a form of stable water-based lubricant,which can keep stable for several months and can reduce friction by 37.3%and wear by 25.24%.The liquid crystal phase was verified by polarizing microscope and synchrotron radiation small-angle X-ray scattering,and its rheological properties and viscoelasticity were studied by interfacial rheometer.The formation of lyotropic liquid crystals can enhance the stability of GO aqueous dispersions at high density,simultaneously ensuring friction decrease and anti-wear effect.It is attributed to the stable nematic network by the ordered GO sheets.The ordered assembly structure bears vertical shear force,therefore,reducing the wear.It is also assumed that the wide lateral size of graphene oxide promotes the nematic phase thus smoothes the graphene oxide film composed spontaneously under the coincidence of lamellar liquid crystal and 2D layered material.Through this work,the interlayer lubrication of GO was optimized,and the problem of GO dispersion sedimentation was solved by self-assembly.The range of interfacial lubrication of GO aqueous dispersion has been expanded and the synergistic effect is conducive to the environmentally friendly lubricants.

关键词： lyotropic liquid crystal graphene oxide aqueous lubrication tribological behavior

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Water lubrication of graphene oxide-based materials

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Friction 2022年第7期10卷 977-1004页

作者： Shaoqing XUE Hanglin li Yumei GUO Baohua ZHANG Jiusheng LI Xiangqiong ZENG Laboratory for Advanced Lubricating Materials Shanghai Advanced Research InstituteChinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghai 201210China School of Environmental and Chemical Engineering Shanghai UniversityShanghai 200444China Key Laboratory for Advanced Materials School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

Water is as an economic,eco-friendly,and efficient lubricant that has gained widespread attention for manufacturing.Using graphene oxide(GO)-based materials can improve the lubricant efficacy of water lubrication due to their outstanding mechanical properties,water dispersibility,and broad application scenarios.In this review,we offer a brief introduction about the background of water lubrication and GO.Subsequently,the synthesis,structure,and lubrication theory of GO are analyzed.Particular attention is focused on the relationship between pH,concentration,and lubrication efficacy when discussing the tribology behaviors of pristine GO.By compounding or reacting GO with various modifiers,amounts of GO-composites are synthesized and applied as lubricant additives or into frictional pairs for different usage scenarios.These various strategies of GO-composite generate interesting effects on the tribology behaviors.Several application cases of GO-based materials are described in water lubrication,including metal processing and bio-lubrication.The advantages and drawbacks of GO-composites are then discussed.The development of GO-based materials for water lubrication is described including some challenges.

关键词： tribology water lubrication graphene oxide(GO)

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Formulation of lyotropic liquid crystal emulsion based on natural sucrose ester and its tribological behavior as novel lubricant

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Friction 2022年第11期10卷 1879-1892页

作者： Yumei GUO Jiusheng LI Xiaojie ZHOU Yuzhao TANG Xiangqiong ZENG Laboratory for Advanced Lubricating Materials Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China University of Chinese Academy of Sciences Beijing 100049China National Facility for Protein Science in Shanghai Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China

The tribological behavior of oil-in-water emulsions formulated with natural lyotropic liquid crystal(LLC)emulsifiers based on natural sucrose ester was studied for the first time.Polarized optical microscopy,synchrotron radiation small-angle X-ray scattering,wide-angle X-ray scattering,and synchrotron radiation infrared microspectroscopy demonstrated that LLC emulsifiers were tightly ordered at the oil–water interface with a distinct nematic texture.The viscosity of emulsion was observed to change over time.Moreover,the zeta potential and laser particle size distribution verified the emulsion’s satisfactory stability.The frictional shearing test proved that the coefficient of friction of the emulsion versus pure oil decreased by 34.2%.The coefficient of friction of the emulsion with liquid crystal decreased 10.1%versus that without liquid crystal.Although liquid crystal emulsion did not exhibit outstanding anti-wear performance compared with pure oil,its wear volume was 29.4%less than the emulsion without liquid crystal.X-ray photoelectron spectroscopy and scanning electron microscope–energy dispersive X-ray spectroscopy(SEM–EDS)proved that the tribo-film of the emulsion with liquid crystal was formed synergistically by the liquid crystal phase with the base oil.The formulation affecting the lubricant quality was further studied by orthogonal experiments.The resulting Stribeck curve behavior suggested that proper composition with a slightly higher viscosity can better reduce friction in both boundary lubrication and mixed lubrication regimes.The lubrication mechanism indicated that the periodically ordered liquid crystal was transported to the sliding asperity in the form of emulsion droplets,which bored the pressure and released the oil to form a tribo-film.This LLC emulsion is environmentally friendly and potentially non-irritant to the skin.Thus,it has promising application prospects as novel water-based and biological lubricants.

关键词： lyotropic liquid crystal(LLC) emulsion aqueous lubrication tribological behavior

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A mild phenoxysilyl linker for self-immolative release of antibody-drug conjugates

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Chinese Chemical Letters 2023年第5期34卷 494-498页

作者： Ding Wei Yurong Mao Huihui Wang Siqi Qu Jiakang Chen Jiusheng LI Biao Jiang Hongli Chen Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China Shanghai Institute for Advanced Immunochemical Studies ShanghaiTech UniversityShanghai 201210China University of Chinese Academy of Sciences Beijing 100049China

Self-immolative linkers have been widely used to construct prodrugs to improve their efficacy and safety.In this study,we report the use of phenoxysilyl linker as a self-immolative unit to prepare antibody-drug conjugates(ADCs).Phenoxysily based ADC Ate-PPS-CA4 was prepared and its release was systematically investigated by mass spectrometry.Biological evaluation showed that Ate-PPS-CA4 displayed the ability to target delivery and self-immolative release the active payload CA4 on PD-L1 positive cells MDA-MB-231.As the same with its payload CA4,it could arrest the cell cycle to the G2/M phase and induced changes in cell morphology at the dose of its IC_(50).The development of this linker with novel drug release mechanisms will expand the methodology to construct ADCs,especially for non-internalizing ADCs by extracellular cleavage.

关键词： Antibody-drug conjugates Self-immolative release Phenoxysilyl linker Combretastatin A4(CA4)

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Tribological behavior of nanocarbon materials with different dimensions in aqueous systems

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Friction 2020年第1期8卷 29-46页

作者： Hongmei YANG Jiusheng LI Xiangqiong ZENG Laboratory for Advanced Lubricating Materials Shanghai Advanced Research InstituteChinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghai 201210China

Due to the widespread use of nanocarbon materials(NCMs),more researchers are studying their tribological performances.In this work,the tribological behaviors of the following five types of NCMs with different geometric shapes were evaluated in a novel oil‐in‐water system:spherical fullerenes(C60,0D),tubular multi‐walled carbon nanotubes(MWCNT,1D),sheet graphene oxide(GO,2D),sheet graphene oxide derivative(Oct‐O‐GO,2D),and lamellar graphite(G,3D).Among these,GO with two types of oxidation degrees,i.e.,GO(1),GO(2),and Oct‐O‐GO(1)were synthesized and characterized using Fourier‐transform infrared spectroscopy,Raman spectroscopy,x‐ray diffraction,thermogravimetric analysis,scanning electron microscopy,and contact angle measurements.The load‐carrying capacity of the NCM emulsions were evaluated using a four‐ball test machine,and the lubrication performances were investigated using a high‐frequency reciprocating friction and wear tester with a sliding distance of 1,800 mm under different loads(50 N and 100 N)at 0.5 Hz.The results revealed that the Oct‐O‐GO(1)emulsion exhibited the best load‐carrying capacity,and the best friction‐reducing and anti‐wear properties compared to other emulsions.Moreover,the anti‐wear advantage was more prominent under high load conditions,whereas the other emulsions exhibited a certain degree of abrasive or adhesive wear.The lubrication mechanism was determined through the analysis of worn surfaces using scanning electron microscopy/energy‐dispersive x‐ray spectroscopy,micro‐Raman spectroscopy,and x‐ray photoelectron spectroscopy.The results revealed that during frictional sliding,the ingredients in the emulsion can absorb and react with the freshly exposed metal surface to form surface‐active films to protect the surfaces from abrasion.Moreover,it was found that the higher the amount of ingredients that contain alkyl and O‐H/C=O,the better was the lubrication performance in addition to an increase in the carbon residue in the tribofilm generated on the meal surface.

关键词： nano‐carbon materials tribological behavior modified graphene oxide oil‐in‐water emulsion

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Modeling the effects of plastic film mulching on irrigated maize yield and water use efficiency in sub-humid Northeast China

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International Journal of Agricultural and Biological Engineering 2017年第5期10卷 69-84页

作者： liu Yang Yang Haishun li Yanfeng Yan Haijun li jiusheng College of Water Resources and Civil Engineering China Agricultural UniversityBeijing 100083China State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing 100048China Department of Agronomy and Horticulture University of Nebraska-LincolnLincoln 68503United States

In sub-humid Northeast China,plastic film mulching(PFM)is increasingly used with drip irrigation system in maize(Zea mays L.)to cope with seasonal droughts and low temperatures during seedling stage.Although there were several studies showing the benefits of PFM on maize production in the region,quantification of the effects of PFM in sub-humid Northeast China are still lacking.Hybrid-Maize model has a special version that can not only simulate the effects of PFM on reduction of soil evaporation and rise of topsoil temperature,but also simulate the effects of PFM on crop development and other physiological processes.This paper reports how to verify the Hybrid-Maize model against observations and then applying the model to quantify effects of PFM on grain yield and water use efficiency(WUE)under irrigated scenarios.The Hybrid-Maize model was added the heating effects of PFM on rising surface-soil temperature and promoting subsequent crop development by establishing equations between surface-soil temperature and air temperature before V6 stage.A 3-year field experiment including maize growth and yield data measured at a drip-irrigated field in Heilongjiang Province was used to serve the model calibration.The simulated results indicated that the Hybrid-Maize model performed well in simulation of seasonal soil water storage and in-season aboveground dry matter in three years,but overestimated the leaf area index(LAI)for both treatments and underestimated the final aboveground dry matter at maturity for mulched treatments.Although the Hybrid-Maize model overestimated the grain yield and WUE,it did still reflect the effects of PFM on increasing grain yield and WUE during the three growing seasons.The average simulated grain yield and WUE for mulched treatments were 8%and 13%greater compared to non-mulched treatments using 30 years weather data,which were in agreement with observations that average grain yield and WUE was 11%and 14%increased by PFM,respectively.For evapotranspiration(ET),the average simulated ET for mul

关键词： film mulch maize yield water use efficiency Hybrid-Maize model drip irrigation Northeast China

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双/三氮杂冠醚化合物的合成及其作为摩擦改进剂的性能研究

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化学学报 2022年第3期80卷 310-316页

作者：胡文敬李久盛中国科学院上海高等研究院先进润滑材料实验室上海201210

现代汽车工业的发展以及环保法规的日益严格对车用润滑油的性能提出了更高要求,摩擦改进剂在提高发动机油减摩性能及燃油经济性方面发挥着重要作用.有机钼化合物作为目前使用最为广泛的摩擦改进剂,会增加油品热氧化沉积物的生成,且油品... 详细信息

现代汽车工业的发展以及环保法规的日益严格对车用润滑油的性能提出了更高要求,摩擦改进剂在提高发动机油减摩性能及燃油经济性方面发挥着重要作用.有机钼化合物作为目前使用最为广泛的摩擦改进剂,会增加油品热氧化沉积物的生成,且油品氧化会导致其减摩性能下降.针对摩擦改进剂所存在的诸如有害元素、灰分及活性吸附位点有限等问题,设计并合成了两种双/三氮杂冠醚化合物,将活性氮原子及长链烷基引入冠醚结构中以提高吸附性能和油溶性,并研究其作为摩擦改进剂的减摩和抗磨性能.结果表明,所合成双/三氮杂冠醚能有效降低油品的摩擦系数和磨损率,其中含有吡啶结构的三氮杂冠醚表现出更优的摩擦学性能,可使摩擦系数和磨损率相对于基础油分别降低8.8%和42%.机理分析表明,所合成的双/三氮杂冠醚化合物能够在钢表面发生不同程度的吸附,并进一步发生摩擦化学反应形成润滑保护膜,防止滑动表面微凸体的直接接触进而改善摩擦学性能.

关键词：氮杂冠醚合成减摩抗磨润滑作用机理

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COUPliNG EFFECTS OF VOID SHAPE AND VOID SIZE ON THE GROWTH OF AN ELliPTIC VOID IN A FIBER-REINFORCED HYPER-ELASTIC THIN PLATE

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Acta Mechanica Solida Sinica 2012年第3期25卷 312-320页

作者： jiusheng Ren Hanhai li Changjun Cheng Xuegang Yuan Department of Mechanics Shanghai UniversityShanghai 200444China Shanghai Key Laboratory of Mechanics in Energy and Environment Engineering Shanghai 200444China College of Science Dalian Nationalities UniversityDalian 116600China

The growth of a prolate or oblate elliptic micro-void in a fiber reinforced anisotropic incompressible hyper-elastic rectangular thin plate subjected to uniaxial extensions is studied within the framework of finite elasticity. Coupling effects of void shape and void size on the growth of the void are paid special attention to. The deformation function of the plate with an isolated elliptic void is given, which is expressed by two parameters to solve the differential equation. The solution is approximately obtained from the minimum potential energy principle. Deformation curves for the void with a wide range of void aspect ratios and the stress distributions on the surface of the void have been obtained by numerical computation. The growth behavior of the void and the characteristics of stress distributions on the surface of the void are captured. The combined effects of void size and void shape on the growth of the void in the thin plate are discussed. The maximum stresses for the void with different sizes and different void aspect ratios are compared.

关键词： fiber reinforced hyper-elastic material rectangular thin plate with void void shapeand void size potential energy principle growth of void

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Synthesis of Pillar[n]arene[5−n]quinines via Partial Oxidation of Pillar[5]arene

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中国化学:英文版 2015年第3期33卷 379-383页

作者： Changdong Xie Weibo Hu Wenjing Hu Yahu A.liu Jichuan Huo Jiusheng LI Biao Jiang Ke Wen School of Materials Science and Engineering Southwest University of Science and TechnologyMianyangSichuan 621010China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China Medicinal Chemistry ChemBridge Research Laboratories Inc.San DiegoCA 92127USA University of Chinese Academy of Sciences Beijing 100039China School of Physical Science and Technology Shanghai Tech UniversityShanghai 201210China

An improved partial oxidation of 1,4-dimethoxypillar[5]arene(DMP[5])was described,through which selected pillar[n]arene[5−n]quinones,such as pillar[4]arene[1]quinone,pillar[3]arene[2]quinone,pillar[2]arene[3]quinone and pillar[1]arene[4]quinone,were synthesized by manipulating the ratio of oxidative reagent(NH4)2[Ce(NO3)6]to DMP[5].

关键词： pillararene pillararene oxidation pillar[n]arene[5−n]quinones

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智能家居的伦理风险、成因透析及治理建议

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宁夏社会科学 2024年第1期 104-113页

作者：李猛谭九生湘潭大学公共管理学院湖南湘潭411105

随着物联网、人工智能和大数据等新兴技术的发展,家庭传统设备逐渐被赋予新的技术架构,使其能够感知周围环境和自动决策,智能家居产品快速发展并逐步进入寻常百姓家。智能设备逐步将家庭成员从繁重的家务劳动中解脱出来,同时也衍生出伦... 详细信息

随着物联网、人工智能和大数据等新兴技术的发展,家庭传统设备逐渐被赋予新的技术架构,使其能够感知周围环境和自动决策,智能家居产品快速发展并逐步进入寻常百姓家。智能设备逐步将家庭成员从繁重的家务劳动中解脱出来,同时也衍生出伦理风险,表现为技术剧本的性别歧视、机器神话的虚无主义、家庭时间的去休闲化、家庭空间的去秘密化、万物互联的数据殖民主义等风险样态。研究基于STS视角透析智能家居伦理风险的成因,既有智能技术自在的不确定性,也有技术营销、社会环境、技术受众的因素。智能家居技术的良性发展需要构建涵盖政府、市场和社会等多元主体的治理体系,实现智能家居从开发到使用的全过程治理,引导智能家居更好地为人类福祉服务。

关键词：智能家居伦理风险性别歧视媒介素养伦理审查

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