Raman spectra of gallium phosphide （GAP） nanosolids （unheated and heat-treated at 598 and 723 K, respectively） were investigated. It was observed that both the longitudinal optical mode （LO） and the transverse o...Raman spectra of gallium phosphide （GAP） nanosolids （unheated and heat-treated at 598 and 723 K, respectively） were investigated. It was observed that both the longitudinal optical mode （LO） and the transverse optical mode （TO） displayed an asymmetry on the low-wavenumber side. The scattering bands were fitted to a sum of four Lorentzians which were assigned to the LO mode, surface phonon mode, TO mode, and a combination of Ga-O-P symmetric bending and sum band formed from the X-point TA ＋ LA phonons, respectively. Analysis of the characteristic of surface phonon mode revealed that the surface phonon peak of the GaP nanosolids could be confirmed. In the infrared spectrum of the GaP nanoparticles, we observed the bands on account of symmetric stretching and bending of PO2, as well as stretching of Ga-O The Raman scattering intensity arising from the Ga-O-P linkages increased as increasing the heat-treatment temperature.展开更多
It is well known that the properties of material are determined by its structure and the interior atomic state. Nanosolid material is no exception either. Many unusual properties of nanosolid are indeed due to its par...It is well known that the properties of material are determined by its structure and the interior atomic state. Nanosolid material is no exception either. Many unusual properties of nanosolid are indeed due to its particular interfacial structuret. There are a large number of unsaturated coordination atoms located at the interface of nanosolids, and these atoms form a special interfacial structure with different types of bonds. As an展开更多
In the compacting process of the La 0.7Sr 0.3Mn 0.9Fe 0.1O 3 nanosolids under the pressure range of 0.0-4.5 GPa, the apparent pressure-induced crystallite breaking phenomenon in these nanosolids was observed. With inc...In the compacting process of the La 0.7Sr 0.3Mn 0.9Fe 0.1O 3 nanosolids under the pressure range of 0.0-4.5 GPa, the apparent pressure-induced crystallite breaking phenomenon in these nanosolids was observed. With increasing pressure up to 4.5 GPa, the average grain size decreases by 46% while the magnetization of nanosolids decrease by 40% and their coercive increases by 35%. This kind of breaking has a close relation to the existence of oxygen deficiency in La 0.7Sr 0.3Mn 0.9Fe 0.1O 3 nanoparticles. A simple and convenient method for preparing the bulk nanosolids with a large number of clean interfaces has been suggested.展开更多
Al2O3 porous nanosolid was prepared via solvothermal hot-press（SHP） method.The dielectric constant of Al2O3 porous nanosolid is as low as 2.34,while its compressive strength is very poor.In order to improve the comp...Al2O3 porous nanosolid was prepared via solvothermal hot-press（SHP） method.The dielectric constant of Al2O3 porous nanosolid is as low as 2.34,while its compressive strength is very poor.In order to improve the compressive strength and maitain low dielectric constant,polyimide was introduced to prepare Al2O3 /polyimide composite porous nanosolid.Compared to Al2O3 porous nanosolid,Al2O3 /polyimide composite porous nanosolid possesses much higher compressive strength,which reaches its saturation value when the mass loading of polyimide is 7.75%.In addition,the in situ Fourier transformation infrared（FTIR） monitoring result reveals that Al2O3 /polyimide composite porous nanosolid is stable up to 400 °C.展开更多
A better understanding of the bonding and aggregation processes occurring between carbon nanomaterials and metal oxide particles in aqueous solutions is important in the development of novel nanosolids for application...A better understanding of the bonding and aggregation processes occurring between carbon nanomaterials and metal oxide particles in aqueous solutions is important in the development of novel nanosolids for applications in the areas of sensor development,highly conductive paint,nanotube alignment,polymer composites,Li-ion batteries,and many other areas.The current investigation reviews these processes and presents a detailed description of the aggregation processes occurring between carbon nanomaterials and metal oxide particles(metals)in various aqueous solutions.The results indicate that the charge attraction between the particles results in a strong homogeneous bonding that occurs within the aqueous solution and for the first time demonstrate and describe the aggregation process of these nanoparticles.The relative importance of many parameters that impact the aggregation process is identified and discussed,and guidelines for controlling the aggregation process are presented.This is a simple and cost-effective process to manufacture a novel nano-solid based on carbon nanomaterial and metal oxide.In addition,the process is easy to scale up and optimize.The methodology could lead to many significant applications as well as commercialization.展开更多
文摘Raman spectra of gallium phosphide （GAP） nanosolids （unheated and heat-treated at 598 and 723 K, respectively） were investigated. It was observed that both the longitudinal optical mode （LO） and the transverse optical mode （TO） displayed an asymmetry on the low-wavenumber side. The scattering bands were fitted to a sum of four Lorentzians which were assigned to the LO mode, surface phonon mode, TO mode, and a combination of Ga-O-P symmetric bending and sum band formed from the X-point TA ＋ LA phonons, respectively. Analysis of the characteristic of surface phonon mode revealed that the surface phonon peak of the GaP nanosolids could be confirmed. In the infrared spectrum of the GaP nanoparticles, we observed the bands on account of symmetric stretching and bending of PO2, as well as stretching of Ga-O The Raman scattering intensity arising from the Ga-O-P linkages increased as increasing the heat-treatment temperature.
基金the National Natural Science Foundation of China.
文摘It is well known that the properties of material are determined by its structure and the interior atomic state. Nanosolid material is no exception either. Many unusual properties of nanosolid are indeed due to its particular interfacial structuret. There are a large number of unsaturated coordination atoms located at the interface of nanosolids, and these atoms form a special interfacial structure with different types of bonds. As an
文摘In the compacting process of the La 0.7Sr 0.3Mn 0.9Fe 0.1O 3 nanosolids under the pressure range of 0.0-4.5 GPa, the apparent pressure-induced crystallite breaking phenomenon in these nanosolids was observed. With increasing pressure up to 4.5 GPa, the average grain size decreases by 46% while the magnetization of nanosolids decrease by 40% and their coercive increases by 35%. This kind of breaking has a close relation to the existence of oxygen deficiency in La 0.7Sr 0.3Mn 0.9Fe 0.1O 3 nanoparticles. A simple and convenient method for preparing the bulk nanosolids with a large number of clean interfaces has been suggested.
基金Supported by the National Natural Science Foundation of China(Nos.50990061,51021062,21073107 and 51102151)the Postdoctoral Science Foundation of China(No.20100481245)+1 种基金the Natural Science Foundation(No.ZR2011EMQ002)the Postdoctoral Innovation Foundation(No.201003077) of shandong Province, China
文摘Al2O3 porous nanosolid was prepared via solvothermal hot-press（SHP） method.The dielectric constant of Al2O3 porous nanosolid is as low as 2.34,while its compressive strength is very poor.In order to improve the compressive strength and maitain low dielectric constant,polyimide was introduced to prepare Al2O3 /polyimide composite porous nanosolid.Compared to Al2O3 porous nanosolid,Al2O3 /polyimide composite porous nanosolid possesses much higher compressive strength,which reaches its saturation value when the mass loading of polyimide is 7.75%.In addition,the in situ Fourier transformation infrared（FTIR） monitoring result reveals that Al2O3 /polyimide composite porous nanosolid is stable up to 400 °C.
基金This research was funded by Army Research Lab(Cooperative agreement W91INF 15-2-0034-S)Georgia Tech IRAD funds(DE00005346).
文摘A better understanding of the bonding and aggregation processes occurring between carbon nanomaterials and metal oxide particles in aqueous solutions is important in the development of novel nanosolids for applications in the areas of sensor development,highly conductive paint,nanotube alignment,polymer composites,Li-ion batteries,and many other areas.The current investigation reviews these processes and presents a detailed description of the aggregation processes occurring between carbon nanomaterials and metal oxide particles(metals)in various aqueous solutions.The results indicate that the charge attraction between the particles results in a strong homogeneous bonding that occurs within the aqueous solution and for the first time demonstrate and describe the aggregation process of these nanoparticles.The relative importance of many parameters that impact the aggregation process is identified and discussed,and guidelines for controlling the aggregation process are presented.This is a simple and cost-effective process to manufacture a novel nano-solid based on carbon nanomaterial and metal oxide.In addition,the process is easy to scale up and optimize.The methodology could lead to many significant applications as well as commercialization.
