Yongwei ZHU
金属学报(英文版)
The effect of nanodiamond content in electrolyte and rotational speed of the stirrer on the deposition rate of coatings, the nanodiamond content in coatings, the micro-structure and the micro-hardness of coatings were studied. A self-made pin-on-disk tribo-meter was employed to evaluate the wear resistance of prepared coatings. Results show that the thickness of composite coating decreases with the rotational speed, while the micro hardness of coating and the content of nanodiamond in coating increase with increasing its content in electrolyte. The wear resistance of the composite coating deposited in an electrolyte with 6 g/L nanodiamond increases by 50 % in contrast with the pure Ni-P coating.
关键词:
Nanodiamond
,
Composite electroless plating
,
Micro-hardness
,
Wear resistance
Yongwei ZHU
,
Xiangqian SHEN
,
Zhijing FENG
,
Xiangyang XU
,
Baichun WANG
材料科学技术（英文）
Several factors affecting the ζ-potential of nanodiamonds were studied. The Chemical Mechanical Modification (CMM) of surface, different surfactants and its dosage, and inorganic ions on the ζ-potential of nanodiamond sample L were studied using ZETASIZER3000HS and Nexus470. Results show that the ζ-potential changes with its parameters of detonation synthesis and purification. Results also suggest that CMM and subsequent treatments employed can alter apparently the ζ-potential and that some anionic surfactants increase the absolute value of the ζ-potential in the alkaline surrounding.
关键词:
Nanodiamond
,
null
,
null
,
null
Xiangyang XU
,
Yongwei ZHU
,
Baichun WANG
,
Zhiming YU
,
Shengzhong XIE
材料科学技术（英文）
A technology of mechanochemical treatment (MCT) is introduced to modify nanodiamond (ND) surface aiming to obtaining a stable suspension with well-dispersed ND particles in aqueous medium. ND investigated in this paper is a purified product of nanometer-sized diamond synthesized by explosive detonation. As obvious aggregation and sediment were observed when the sample was added into deionized water, it is crucial to conduct deaggregation and dispersion investigations. Amid a series of mechanical treatments, i.e. grinding, stirring, ultrasonic and classification, some reagents are introduced to modify the newly created surface during aggregates comminution. For the co-effects of mechanical forces and surfactants, the mean size of particles was reduced and a stable system containing ND with narrow size distribution was prepared. Mechanism of surface reaction and modification are discussed, while AFM, Zetasizer3000HS, XRD, XPS and FTIR are utilized for the analysis. The functional chemical structure of ND particle surface and surface electrical property changed during the modification processes, and the dispersion character and stability of suspension can consequently be improved.
关键词:
Aggregates
,
null
,
null
,
null
,
null
Yongwei ZHU
,
Feng XU
,
Jianliang SHEN
,
Baichun WANG
,
Xiangyang XU
,
Jianbin SHAO
材料科学技术（英文）
Fourier transform infrared spectroscopy (FT-IR) and ζ-potential were introduced to study the effect of different modification parameters on the surface properties of nanodiamond (ND). Results showed that under stirring grinding conditions, ND hard aggregates were smashed and some active spots on them reacted with surfactant molecules, which led to the increase in its ³-potential and stability. Different models of surface modification were also given in this study.
关键词:
Surface modification
,
null
,
null
,
null
杨玉东
,
徐菁华
,
杨林梅
新型炭材料
采用激光液相法,以爆轰纳米金刚石( PCD )为原料,在聚乙二醇( PEG200)溶液中得到单分散的纳米金刚石( LPCD)。利用TEM、XRD、FTIR、VSM和PL光谱等手段对LPCD的形貌、粒径、发光和磁性能进行表征。结果表明,混酸氧化处理的PCD能稳定分散在PEG200溶液中,但仍有一次团聚体。采用激光辐照得到的LPCD,具有较强的铁磁性,更大的比表面积和更多的表面悬键。激光辐照的同时发生了原位表面化学修饰,LPCD出现了特有的羟基( C-OH)峰和PEG200基团,粒子分散性好,没有一次和二次的团聚体,其平均粒径为5.5 nm。
关键词:
纳米金刚石
,
激光液相法
,
单分散
,
磁性能
楚亚卿
,
仝毅
,
黄风雷
,
张同来
新型炭材料
采用3种不同粒径的纳米金刚石与树脂基体、光固化剂和其他填料复合，合成光固化复合树脂。探讨纳米金刚石对光固化复合树脂挠曲强度、固化深度等性能的作用规律。结果表明，纳米金刚石可显著地增强树脂的挠曲强度、弹性模量等机械性能，但也会降低树脂的固化深度。发现纳米金刚石对光固化复合树脂的增强作用中存在逾渗现象，即当纳米金刚石含量达到一定数值后会导致树脂的机械性能明显降低。性能最佳的光固化复合树脂应该选择粒径为220 nm的纳米金刚石，其添加量在0.15%左右为宜。
关键词:
纳米金刚石
,
光固化
,
复合树脂
,
逾渗
,
增强
