Study on the Tribological Behaviors of N,N-dioctyldithiocarbamate Monolayer-Stabilized Copper Nanoparticles in Liquid Paraffin

Copper nanoparticles surface-modified with self-assembled monolayers of N,N-dioctyldithiocarbamate (S₂CNR₂, R = n-octyl) have been prepared in the presence of cetyltrimethylammonium bromide (CTAB). The trobological behaviors of the S₂CNR₂-coated copper nanoparticles as an additive in liquid paraffin are investigated using a block-on-ring tribometer. The results indicate that copper nanoparticles as additive in liquid paraffin are capable to greatly reduce the friction coefficient and wear rate of the steels counterparts even at an extremely low concentration. The tribochemically reacted films with Cu, FeS, Fe₂O₃, and SO₄ ^2? formed during the friction process are contributed to the good tribological properties of the S₂CNR₂-coated copper nanoparticles as additive in liquid paraffin.     

表面修饰Ag_2S纳米微粒的合成及摩擦学行为研究

在水醇混合介质中,采用同阳离子共沉淀法合成了有机化合物表面修饰的Ａｇ２Ｓ纳米微粒,在高速钢基底上制备成膜,研究了它的摩擦学特性。结果表明：修饰后的Ａｇ２Ｓ纳米微粒粒径小,性能稳定,在有机介质中分散成透明溶液。ＡｇＤＤＰ膜和Ａｇ２Ｓ ＤＤＰ膜均可显著降低钢基底的摩擦系数。研究证实表面修饰Ａｇ２Ｓ纳米微粒的摩擦作用机制是在较低负荷下表面修饰层起主要作用,在较高负荷下Ａｇ２Ｓ纳米核起主要的承载和减摩抗磨作用。     

油溶性银纳米颗粒的制备及摩擦学行为

btdyta;银;纳米颗粒;摩擦学性能;表面修饰     

表面修饰中空LaF3纳米微粒的制备及其摩擦学性能

在油酸钠,十六烷基溴化铵乳液体系中合成了表面修饰中空LaF3纳米微粒.通过透射电子显微镜(TEM)、X射线衍射(XRD)、傅立叶变换红外光谱(FTIR)、热重分析(TG-DTG)、能谱分析(EDS)等测试手段对其结构和形貌进行了表征.同时在四球摩擦磨损试验机上考察了LaF3纳米微粒作为润滑油添加剂时,添加浓度和施加载荷对其执磨减摩性能的影响.结果表明,此纳米微粒的表面为油酸修饰,具有中空结构,平均粒径约17.5nm;表面修饰中空油酸/三氟化镧纳米微粒作为成品润滑油的添加剂,具有良好的抗磨性能.另外,对中空纳米微粒的形机理进行了分析.     

Li17Sb13S28: A New Lithium Ion Conductor and addition to the Phase Diagram Li2S–Sb2S3

Li₁₇Sb₁₃S₂₈ was synthesized by solid‐state reaction of stoichiometric amounts of anhydrous Li₂S and Sb₂S₃. The crystal structure of Li₁₇Sb₁₃S₂₈ was determined from dark‐red single crystals at room temperature. The title compound crystallizes in the monoclinic space group C2/m (no. 12) with a=12.765(2) Å, b=11.6195(8) Å, c=9.2564(9) Å, β=119.665(6)°, V=1193.0(2) ų, and Z=4 (data at 20 °C, lattice constants from powder diffraction). The crystal structure contains one cation site with a mixed occupation by Li and Sb, and one with an antimony split position. Antimony and sulfur form slightly distorted tetragonal bipyramidal [SbS₅E] units (E=free electron pair). Six of these units are arranged around a vacancy in the anion substructure. The lone electron pairs E of the antimony(III) cations are arranged around these vacancies. Thus, a variant of the rock salt structure type with ordered vacancies in the anionic substructure results. Impedance spectroscopic measurements of Li₁₇Sb₁₃S₂₈ show a specific conductivity of 2.9×10^?9 Ω^?1 cm^?1 at 323 K and of 7.9×10^?6 Ω^?1 cm^?1 at 563 K, the corresponding activation energy is E_A=0.4 eV below 403 K and E_A=0.6 eV above. Raman spectra are dominated by the Sb?S stretching modes of the [SbS₅] units at 315 and 341 cm^?1 at room temperature. Differential thermal analysis (DTA) measurements of Li₁₇Sb₁₃S₂₈ indicate peritectic melting at 854 K.     

表面修饰ZrO_2纳米微粒的合成及结构表征(英文)

在溶液中化学合成了硬脂酸修饰ZrO2 纳米微粒 ,采用XRD、TEM和EA表征了ZrO2 纳米微粒的结构 ,结果表明成功合成了表面包覆硬脂酸分子的ZrO2 纳米微粒。     

表面修饰中空LaF3纳米微粒的制备及其摩擦学性能

在油酸钠/十六烷基溴化铵乳液体系中合成了表面修饰中空LaF3纳米微粒. 通过透射电子显微镜(TEM)、X射线衍射(XRD)、傅立叶变换红外光谱(FTIR)、热重分析(TG-DTG)、能谱分析(EDS)等测试手段对其结构和形貌进行了表征. 同时在四球摩擦磨损试验机上考察了LaF3纳米微粒作为润滑油添加剂时, 添加浓度和施加载荷对其抗磨减摩性能的影响. 结果表明, 此纳米微粒的表面为油酸修饰, 具有中空结构, 平均粒径约17.5 nm; 表面修饰中空油酸/三氟化镧纳米微粒作为成品润滑油的添加剂, 具有良好的抗磨性能. 另外, 对中空纳米微粒的形成机理进行了分析.     

表面修饰ZrO_2纳米微粒的结构表征及摩擦学行为研究(英文)

采用XPS,FTIR,DSC,TGA等多种现代分析手段表征了硬脂酸修饰ZrO2 纳米微粒的结构.在四球摩擦磨损试验机上,首次评价了表面修饰ZrO2 纳米微粒用作润滑油添加剂的摩擦学性能,结果表明ZrO2 纳米微粒具有良好的抗磨减摩性     

生物分子辅助溶剂热合成硫化锑纳米棒

以SbCl3和L-胱氨酸为反应原料,采用溶剂热法在170℃反应12h,制得硫化锑(Sb2S3)纳米棒.X射线衍射(XRD)、能量分散光谱(EDS)和X射线光电子能谱(XPS)研究表明所得产物为典型的Sb2S3正交结构.场发射扫描电子显微镜(FESEM)和透射电子显微镜(TEM)研究显示,Sb2S3纳米棒长为3～6μm,平均直径约为150nm.讨论了不同反应时间对Sb2S3的形成及其形貌的影响,并根据实验结果对所合成的一维纳米棒可能的形成机理进行了简单的探讨.     

碳纳米管的化学修饰以及作为润滑油添加剂的摩擦学性能研究

采用硫酸和硝酸混合酸对催化裂解法(CVD法)制备的多壁碳纳米管(MWNNTs)进行纯化,然后运用硬脂酸对碳纳米管进行表面修饰,并研究了硬脂酸修饰后的碳纳米管的表面状况以及作为润滑油添加剂的摩擦学行为．实验结果表明,在硫酸催化剂作用下,通过酯化反应碳纳米管能够被硬脂酸包覆,并且硬脂酸修饰的碳纳米管作为润滑油添加剂能够显著提高基础油的减摩抗磨性能,当添加量为0．15％左右时,润滑油的减摩抗磨性能最佳,与基础油相比可以使摩擦系数下降10％左右,磨损量下降30％～60％．     

回流法合成硫化锑纳米棒及其光催化性能研究

以三氯化锑(SbCl₃)、硫粉(S)和硼氢化钠(NaBH₄)为原料, 1,2-丙二醇(C₃H₈O₂)作溶剂, 用回流法成功合成了Sb₂S₃纳米棒. 用XRD, EDS, SEM, TEM, HRTEM, SAED以及UV-Vis等手段对所制备产品的晶型、成分、形貌和光学特性进行了表征|以太阳光为光源、亚甲基蓝为目标降解物评价了Sb₂S₃纳米棒的光催化活性. 结果表明, 经186 ℃回流15 h可得到直径约为78～180 nm、长度达2～5 μm的正交晶系的Sb₂S₃单晶纳米棒. 经计算, 其晶胞参数a＝1.124 nm, b＝1.138 nm, c＝0.384 nm. UV-Vis分析表明, Sb₂S₃纳米棒为半导体材料, 其带隙能量为1.52 eV. 光催化性能测试表明, 所制备的Sb₂S₃纳米棒在太阳光下对亚甲基蓝具有较高的光催化降解率, 经20 min降解, 亚甲基蓝的降解率达84.31%, 表现出明显的可见光活性. 加入的PVP对控制Sb₂S₃的形貌有重要的作用. 另外, 还讨论了Sb₂S₃ 纳米棒可能的形成机理.     

Passively Mode-Locked Er-Doped Fiber Laser Based on Sb2S3-PVA Saturable Absorber

In this paper, antimony trisulfide (Sb₂S₃) was successfully prepared with the liquid phase exfoliation method and embedded into polyvinyl alcohol (PVA) as a saturable absorber (SA) in a passively mode-locked Er-doped fiber laser for the first time. Based on Sb₂S₃-PVA SA with a modulation depth of 4.0% and a saturable intensity of 1.545 GW/cm², a maximum average output power of 3.04 mW and maximum peak power of 325.6 W for the stable mode-locked pulses was achieved with slope a efficiency of 0.87% and maximum single pulse energy of 0.81 nJ at a repetition rate of 3.47 MHz under a pump power of 369 mW. A minimum pulse width value of 2.4 ps with a variation range less than 0.1 ps, and a maximum signal to noise ratio (SNR) of 54.3 dB indicated reliable stability of mode-locking, revealing promising potentials of Sb₂S₃ as a saturable absorber in ultrafast all-fiber lasers.     

离子液体中二氧化硅纳米微粒的制备及其摩擦学性能

以 1-甲基-3-丁基咪唑四氟硼酸盐离子液体为溶剂, 合成了二氧化硅纳米颗粒, 并以含有二氧化硅纳米颗粒的离子液体作为基础油,对其摩擦学性能进行研究; 用透射电子显微镜对二氧化硅的形貌进行分析, 用扫描电子显微镜对钢球磨斑表面的形貌进行了分析. 结果表明, 添加二氧化硅纳米颗粒的离子液体具有较好的润滑性能.     

分级微纳结构MoS_2空心球的制备及其摩擦性能

<正>0引言近年来,具有复杂分级结构的物质由于具有新颖的磁学和电学性能而被广泛用于生物技术[1],催化剂[2],光学器件[3],药物释放[4],光子晶体[5]中。利用各种物理和化学方法,研究者们在制备各种纳米/微米尺度的分级结构上取得了很大的进步,这其中包     

Observation of Sb2O3 Nanocrystals in SiO2 after Sb Ion Implantation

 Antimony nanocrystals were formed in thin SiO₂ films using low-energy ion implantation of Sb followed by annealing. Using Fourier transform laser microprobe mass spectrometry (FT LMMS), we observed for the first time the presence of antimony oxide in the intermediate phase (as-implanted layer of Sb) by means of signals referring to the intact Sb₂O₃ molecules. Only SbO⁺ fragments, but no adduct ions of Sb₂O₃ could be detected in annealed samples. The size and the distribution of the nanocrystals formed around the initial depth of implantation were studied in the as-implanted samples by high-resolution electron microscopy (HREM). The crystalline structure of these nanocrystals was also studied and the presence of antimony trioxide Sb₂O₃ in the form of valentinite was proven. After the annealing step, the implanted material had spread into a wider band. The method introduced here, based on combining TEM (transmission electron microscopy) and FT LMMS results, offers the possibility of studying the evolution of the phases in Sb nanocrystal formation.     

碳包覆WSe2纳米棒的制备及其摩擦学性能

以马来酸酐接枝乙烯-辛烯共聚物(POE-g-MA)为碳源,以一锅煮工艺即在800 ℃、密闭条件下,通过钨-硒的固相合成和碳源的热解碳化,成功地制备出碳包覆二硒化钨(WSe₂@C)纳米棒,并使用XRD、Raman、EDS、SEM和TEM对其组成、结构及形貌进行了表征。结果表明,WSe₂纳米棒的直径为20 nm,包覆层为无定形碳,厚度为40 nm。TG-DSC分析表明,该复合材料的热氧稳定性比纯WSe₂提高了约50 ℃。另外,将WSe₂@C作为润滑添加剂应用到基础油石蜡中,使用UMT-2球-盘模式摩擦磨损测试仪考察其摩擦学性能。结果发现,适量(比如0.5wt%)WSe₂@C纳米棒的加入,能有效地改善石蜡的减摩抗磨性能,显示出良好的润滑性能。     

Microwave-Assisted Preparation of CdS Nanoparticles in a Halide-Free Ionic Liquid and Their Photocatalytic Activities

A microwave-assisted (4-6 min) method was used for the preparation of CdS nanoparticles in 1-ethyl-3-methylimidazolium ethyl sulfate,a halide-free room-temperature ionic liquid (RTIL).The samples were characterized by powder X-ray diffraction,energy dispersive X-ray spectroscopy,and scanning electron microscopy.Diffuse reflectance spectra showed a 1.33 eV blue shift relative to bulk CdS.The photocatalytic activities of the nanoparticles for photodegradation of methylene blue (MB) using UV and visible light ...     

Sb2S3纳米丝的合成及杂化太阳电池研究

利用溶剂热方法制备出高质量的Sb₂S₃纳米丝, 并将其与聚(2-甲氧基-5-(2-乙基己氧基)-1,4-对苯乙炔)(MEH-PPV)共混制备成体型结构聚合物太阳电池.利用X射线衍射、扫描电子显微镜、透射电子显微镜和紫外-可见吸收光谱对Sb₂S₃纳米丝进行表征, 利用电流-电压(J-V)测试和电池的光电转换效率(IPCE)谱研究了Sb₂S₃纳米丝含量对Sb₂S₃/MEH-PPV共混体型结构太阳电池性能的影响.结果表明, 合成的Sb₂S₃纳米丝直径为60~70 nm, 长度为4~6 μm, 沿[001] 晶向生长, 在紫外-可见光区有较强的吸收, 光学带隙为1.57 eV.电池性能测试结果表明, Sb₂S₃纳米丝作为辅助光吸收材料及有效的电子传输材料, 提高了对可见光的利用率; Sb₂S₃的补充吸收作用使Sb₂S₃/MEH-PPV共混电池具有一定的宽谱响应特点; 与不含Sb₂S₃的电池相比, Sb₂S₃/MEH-PPV共混电池中增加的MEH-PPV/Sb₂S₃界面提高了光生激子分离效率, 从而提高了电池的效率.     

表面修饰Ag_2S纳米微粒的制备及其量子尺寸效应研究

采用同阳离子共沉淀法制备了DDP修饰的Ag2 S纳米微粒 ,其紫外—可见吸收光谱和荧光光谱表明DDP修饰的Ag2 S纳米微粒具有显著的量子尺寸效应 ,粒子尺寸分布较窄 ,粒子表面存在多种表面态能级。