Nanocrystalline,single-phase undoped In 2O 3 was prepared by a polymer-network synthesis technique with indium nitrate as the starting material;several methods such as X-ray diffractometry (XRD) and transmission ele...Nanocrystalline,single-phase undoped In 2O 3 was prepared by a polymer-network synthesis technique with indium nitrate as the starting material;several methods such as X-ray diffractometry (XRD) and transmission electron microscopy (TEM) were employed to obtain detailed information on the crystallography and microstructual appearance of In 2O 3 superfine powders. The influence of the concentration of starting solution,calcination temperature and time on the particle size was also that investigated by means of the XRD patterns. Results indicate that the obtained powders are mostly crystalline single phase with uniform size and also that the size of the products can be controlled under proper condition.展开更多
In this study, the effect of combining different molecular domains on single platform has been reported that revealed a proper packing and interpenetration of fullerene spheres with the monomeric species. The fabricat...In this study, the effect of combining different molecular domains on single platform has been reported that revealed a proper packing and interpenetration of fullerene spheres with the monomeric species. The fabricated IPN system exhibits hydrophobic behavior in nature. An interpenetrating polymer network (IPN) of fullerene-based poly (methyl hydro siloxane) (PMHS) and polyacrylonitrile (PAN) was prepared. The synthesized polymer network was characterized using infrared (IR) spectroscopy, differential scanning calorimetric analysis (DSC), and scanning electron microscopic (SEM) technique. The IPN was analyzed by IR spectroscopy, which depicts presence of fullerene at 500 cm<sup>−1</sup> and 1632 cm<sup>−1</sup>, presence of PHMS at 1050 cm<sup>−1</sup>, 1250 cm<sup>−1</sup>, 2225 cm<sup>−1</sup>, and 3000 cm<sup>−1</sup> and presence of PAN at 3077 cm<sup>−1</sup>, 1299 cm<sup>−1</sup>, 1408 cm<sup>−1</sup> and 2083 cm<sup>−1</sup>. Shifting in band positions indicated the interpenetration of the reacting species. DSC endotherm showed crystalline peak (T<sub>c</sub>) at 117˚C, which indicated the crystalline nature of the synthesized IPN. The absence of T<sub>g</sub> peak and clear observable T<sub>c</sub> peak revealed crystalline behavior of polymeric network. The microstructure of the polymer network was observed by SEM technique, which revealed transparent and dual-phase morphology of the IPN surface. The fluorescent emission spectra of polymeric network were recorded on a spectrofluorometer which revealed fluorescent excitation and emission spectra of the IPN. The Emission spectra generated by radiative decay of excitations exhibit a maximal peak at 450 nm, suggesting that the synthesized IPN nanosheets were typically high-intensity blue light emitting materials. The FTIR investigations revealed multiple non-covalent interactions achieved by polymerization with physical anchoring on the polymeric network surfaces. Such interactions can be recognized as the driving force for the fabrication of hydrophobic flexible silicon-based materials with a self-cleansing action.展开更多
基金TheScientificResearchFoundationfortheReturnedOverseasChineseScholars ,StateEducationMinistry (No . [2 0 0 2 ]2 47)
文摘Nanocrystalline,single-phase undoped In 2O 3 was prepared by a polymer-network synthesis technique with indium nitrate as the starting material;several methods such as X-ray diffractometry (XRD) and transmission electron microscopy (TEM) were employed to obtain detailed information on the crystallography and microstructual appearance of In 2O 3 superfine powders. The influence of the concentration of starting solution,calcination temperature and time on the particle size was also that investigated by means of the XRD patterns. Results indicate that the obtained powders are mostly crystalline single phase with uniform size and also that the size of the products can be controlled under proper condition.
文摘In this study, the effect of combining different molecular domains on single platform has been reported that revealed a proper packing and interpenetration of fullerene spheres with the monomeric species. The fabricated IPN system exhibits hydrophobic behavior in nature. An interpenetrating polymer network (IPN) of fullerene-based poly (methyl hydro siloxane) (PMHS) and polyacrylonitrile (PAN) was prepared. The synthesized polymer network was characterized using infrared (IR) spectroscopy, differential scanning calorimetric analysis (DSC), and scanning electron microscopic (SEM) technique. The IPN was analyzed by IR spectroscopy, which depicts presence of fullerene at 500 cm<sup>−1</sup> and 1632 cm<sup>−1</sup>, presence of PHMS at 1050 cm<sup>−1</sup>, 1250 cm<sup>−1</sup>, 2225 cm<sup>−1</sup>, and 3000 cm<sup>−1</sup> and presence of PAN at 3077 cm<sup>−1</sup>, 1299 cm<sup>−1</sup>, 1408 cm<sup>−1</sup> and 2083 cm<sup>−1</sup>. Shifting in band positions indicated the interpenetration of the reacting species. DSC endotherm showed crystalline peak (T<sub>c</sub>) at 117˚C, which indicated the crystalline nature of the synthesized IPN. The absence of T<sub>g</sub> peak and clear observable T<sub>c</sub> peak revealed crystalline behavior of polymeric network. The microstructure of the polymer network was observed by SEM technique, which revealed transparent and dual-phase morphology of the IPN surface. The fluorescent emission spectra of polymeric network were recorded on a spectrofluorometer which revealed fluorescent excitation and emission spectra of the IPN. The Emission spectra generated by radiative decay of excitations exhibit a maximal peak at 450 nm, suggesting that the synthesized IPN nanosheets were typically high-intensity blue light emitting materials. The FTIR investigations revealed multiple non-covalent interactions achieved by polymerization with physical anchoring on the polymeric network surfaces. Such interactions can be recognized as the driving force for the fabrication of hydrophobic flexible silicon-based materials with a self-cleansing action.
