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
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
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
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
Novel bulk ZnO porous nanosolids were pre- pared by a unique solvothermal hot-press method, using ZnO nanoparticles and several kinds of solvents as the start- ing materials. It was found from the experiments that ZnO...Novel bulk ZnO porous nanosolids were pre- pared by a unique solvothermal hot-press method, using ZnO nanoparticles and several kinds of solvents as the start- ing materials. It was found from the experiments that ZnO nanoparticles underwent a “self-assembly process” under some specific hydrothermal hot-press conditions. As a result, some “nanoflowers” formed. The results showed that porous nanosolids with uniform pore diameters could be obtained when water distributed uniformly among the ZnO nanopar- ticles. On the contrary, if the uniformity of the distribution of water was poor, “nanoflowers” would appear in the wa- ter-rich region. It was also found that the photoluminescence of ZnO porous nanosolids was affected by the self-assembly phenomenon. In addition, the results also showed that, both the volume and diameters of the pores could be adjusted by changing either the hot-press temperature, pressure or the kinds of solvents.展开更多
The new nanosolid superacid catalyst SO42-/TiO2 is compounded with nanometer chemical technology. This catalyst SO42-/TiO2 has good catalytic effects on esterificational reactions of ethylic acid and ethyl alcohol. It...The new nanosolid superacid catalyst SO42-/TiO2 is compounded with nanometer chemical technology. This catalyst SO42-/TiO2 has good catalytic effects on esterificational reactions of ethylic acid and ethyl alcohol. It has many other advantages such as strong water proof quality, being able to be used repeatedly, being easy to be reclaimed, non corroding, non polluting. So it is a green industrial catalyst which is helpful to the environment and possesses wide prospect of applications. The crystallo process, specific surface area and sulphur content of the SO42-/TiO2 system have been studied with the method of XRD, XPS and the chemical analysis, the result of which indicates that catalytic activity and acid strength of SO42-/TiO2 is affected by the H2SO4 saturant concentration, baking temperature, precipitating condition, specific surface area and sulphur content. The best preparation conditions of SO42-/TiO2 are: ageing temperature at 0℃, 0.5mol·L-1 of H2SO4 concentration, baking temperature at 500℃and 3 hours of baking time.展开更多
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.
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.
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
基金supported by the National Natural Science Foundation of China(Grant Nos.50272036,90101016,20473048,and 90206042)the Key Project of Science and Technology Research Program of Ministry of Education(KPSTRP)the Specialized Research Fund for the Doctoral Program of Higher Education(SRFDP).
文摘Novel bulk ZnO porous nanosolids were pre- pared by a unique solvothermal hot-press method, using ZnO nanoparticles and several kinds of solvents as the start- ing materials. It was found from the experiments that ZnO nanoparticles underwent a “self-assembly process” under some specific hydrothermal hot-press conditions. As a result, some “nanoflowers” formed. The results showed that porous nanosolids with uniform pore diameters could be obtained when water distributed uniformly among the ZnO nanopar- ticles. On the contrary, if the uniformity of the distribution of water was poor, “nanoflowers” would appear in the wa- ter-rich region. It was also found that the photoluminescence of ZnO porous nanosolids was affected by the self-assembly phenomenon. In addition, the results also showed that, both the volume and diameters of the pores could be adjusted by changing either the hot-press temperature, pressure or the kinds of solvents.
文摘采用改性技术合成了新型的纳米固体超强酸催化剂S2O82-/ZrO2,该催化剂对醋酸和脂肪醇的酯化反应具有很好的催化作用,并且具有耐水性强、稳定性好、再生容易、可重复使用、不腐蚀设备、不污染环境等优点,是对环境友好的很有应用前景的绿色工业催化剂.用X射线衍射分析、X光电子能谱、TEM、红外光谱和化学分析等手段对S2O82-/ZrO2进行了表征.结果表明,浸渍液(NH4)2S2O8浓度、陈化温度、焙烧温度、沉淀条件、比表面积和含硫量均明显影响S2O82-/ZrO2的酸强度及催化活性.S2O82-/ZrO2最佳制备条件:陈化温度为-15℃,浸渍液(NH4)2S2O8浓度为0.5 mol/L,焙烧温度为600℃,焙烧时间为3 h.
文摘The new nanosolid superacid catalyst SO42-/TiO2 is compounded with nanometer chemical technology. This catalyst SO42-/TiO2 has good catalytic effects on esterificational reactions of ethylic acid and ethyl alcohol. It has many other advantages such as strong water proof quality, being able to be used repeatedly, being easy to be reclaimed, non corroding, non polluting. So it is a green industrial catalyst which is helpful to the environment and possesses wide prospect of applications. The crystallo process, specific surface area and sulphur content of the SO42-/TiO2 system have been studied with the method of XRD, XPS and the chemical analysis, the result of which indicates that catalytic activity and acid strength of SO42-/TiO2 is affected by the H2SO4 saturant concentration, baking temperature, precipitating condition, specific surface area and sulphur content. The best preparation conditions of SO42-/TiO2 are: ageing temperature at 0℃, 0.5mol·L-1 of H2SO4 concentration, baking temperature at 500℃and 3 hours of baking time.
