Nanoparticle of cerium borate with a size of about 50 nm was synthesized via sol-gel precipitation method under micro-emulsion by oleic acid,using Na2B4O7 and Ce（NO3）3 aqueous solution as raw materials,and the morph...Nanoparticle of cerium borate with a size of about 50 nm was synthesized via sol-gel precipitation method under micro-emulsion by oleic acid,using Na2B4O7 and Ce（NO3）3 aqueous solution as raw materials,and the morphology and microstructure of as-prepared particles were characterized by means of scanning electron microscopy（SEM） equipped with an energy-dispersive X-ray spectrometer（EDS）,X-ray diffraction（XRD）,infrared spectroscopy（IR）,and thermogravimetric analysis（TGA）.Two methods to disperse the particles into base oil were employed,and the results derived from the four-ball tribotester indicated that the friction coefficient of the base oil by the addition of the nanoscale cerium borate particles diminished greatly,and the anti-wear properties also depended on the dispersion methods.展开更多
A new type of cerium borate glass-ceramic is prepared and studied. The microstructure and crystallization behaviors of the glass samples were investigated by X-ray diffraction (XRD), electron diffraction (ED), and <...A new type of cerium borate glass-ceramic is prepared and studied. The microstructure and crystallization behaviors of the glass samples were investigated by X-ray diffraction (XRD), electron diffraction (ED), and <sup><span style="font-size:12px;font-family:Verdana;">31</span></sup><span style="font-family:Verdana;">P NMR spectroscopy. The microstructures of samples contain <1 mol% CeO</span><sub><span style="font-size:12px;font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">are amorphous in nature. More addition of CeO</span><sub><span style="font-size:12px;font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> transforms the glass to glass-ceramics without thermal annealing. The morphological change of the microstructure of these materials was followed by transmission electron microscopy (TEM). The obtained results have revealed that the addition of more than 0.8 mol% CeO</span><sub><span style="font-size:12px;font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> can promote nucleation and crystallization routes that </span></span><span style="font-family:Verdana;">are </span><span style="font-family:;" "=""><span style="font-family:Verdana;">combined with the establishment of diverse crystalline phases. Glasses with lower contents of CeO</span><sub><span style="font-size:12px;font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">showed no tendency to crystallization. The crystals of CeO</span><sub><span style="font-size:12px;font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> containing glasses were spheroid like morphology that </span></span><span style="font-family:Verdana;">was </span><span style="font-family:Verdana;">assigned to the three-dimensional fast growth of the well-formed structural species in the boro-apatite phase. In addition, the cerium free glass is characterized by particle-like morphology. Then the growth of spheroid species展开更多
文摘Nanoparticle of cerium borate with a size of about 50 nm was synthesized via sol-gel precipitation method under micro-emulsion by oleic acid,using Na2B4O7 and Ce（NO3）3 aqueous solution as raw materials,and the morphology and microstructure of as-prepared particles were characterized by means of scanning electron microscopy（SEM） equipped with an energy-dispersive X-ray spectrometer（EDS）,X-ray diffraction（XRD）,infrared spectroscopy（IR）,and thermogravimetric analysis（TGA）.Two methods to disperse the particles into base oil were employed,and the results derived from the four-ball tribotester indicated that the friction coefficient of the base oil by the addition of the nanoscale cerium borate particles diminished greatly,and the anti-wear properties also depended on the dispersion methods.
文摘A new type of cerium borate glass-ceramic is prepared and studied. The microstructure and crystallization behaviors of the glass samples were investigated by X-ray diffraction (XRD), electron diffraction (ED), and <sup><span style="font-size:12px;font-family:Verdana;">31</span></sup><span style="font-family:Verdana;">P NMR spectroscopy. The microstructures of samples contain <1 mol% CeO</span><sub><span style="font-size:12px;font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">are amorphous in nature. More addition of CeO</span><sub><span style="font-size:12px;font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> transforms the glass to glass-ceramics without thermal annealing. The morphological change of the microstructure of these materials was followed by transmission electron microscopy (TEM). The obtained results have revealed that the addition of more than 0.8 mol% CeO</span><sub><span style="font-size:12px;font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> can promote nucleation and crystallization routes that </span></span><span style="font-family:Verdana;">are </span><span style="font-family:;" "=""><span style="font-family:Verdana;">combined with the establishment of diverse crystalline phases. Glasses with lower contents of CeO</span><sub><span style="font-size:12px;font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">showed no tendency to crystallization. The crystals of CeO</span><sub><span style="font-size:12px;font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> containing glasses were spheroid like morphology that </span></span><span style="font-family:Verdana;">was </span><span style="font-family:Verdana;">assigned to the three-dimensional fast growth of the well-formed structural species in the boro-apatite phase. In addition, the cerium free glass is characterized by particle-like morphology. Then the growth of spheroid species
