A shear induced ordered structure in an exfoliated polystyrene(PS)/clay nanocomposite is reported. Self\|assembly behavior was reported for the first time of a shear induced ordered structure in the nanocomposite. The...A shear induced ordered structure in an exfoliated polystyrene(PS)/clay nanocomposite is reported. Self\|assembly behavior was reported for the first time of a shear induced ordered structure in the nanocomposite. The self assembly behavior was measured by X ray diffraction(XRD) patterns, transmission electron microscopy(TEM), and FTIR dichroism technique. Compared with the broad amorphous peaks of the PS, a series of sharp XRD peaks were observed for the exturded PS/clay nanocomposite pellet sample, showing that an ordered sructure occurred under shear flow. The intensities of the four sharp XRD peaks of the ordered sructure decreased significantly with temperature. However, at 95 ℃, the XRD peaks increased significantly, the FTIR dichroism showing that and the phenyl ring of PS changed its orientation from parallel to perpendicular to the monmorillonite primary particles, whereas no obvious orientation of the alkyl chain of PS could be found. At 110 ℃, a disordered structure occurred for the phenyl ring. TEM images confirmed directly that the origin of the ordered structure was mainly due to the planar orientation of the primary particles of silicate layers as well as local ordered microsructure of the primary particles, induced by shear flow. Basd on these investigations, a possible mechanism was deduced for the formation of the ordered strucure induced by shear flow in the exfoliated PS/clay nanocomposite.展开更多
This paper mainly elaborated the recent developments of the studies on the new type zeohite molecular sieve host-nanoguest composite materials composing of molecular sieve chaimels or cages encapsulated nanoscale mate...This paper mainly elaborated the recent developments of the studies on the new type zeohite molecular sieve host-nanoguest composite materials composing of molecular sieve chaimels or cages encapsulated nanoscale materials from the point of nanochemistry and material science,and the trends of development in this field. As the research of the properties of this kind of materials are gomg on. it is possible that this kind of host-guest nanocomposite materials will be usd in some fields. such as science and high technology fields. as the new type of ptical. electrical and magnetic materials in the level of molecular assembly. This paper contains the following contents:hosts and guests; the sizes and shapes of guests; the optical, electrical and magnetic properties of the materials; the syntheses and characterizations of the materials; the applications of the materials and forecast.展开更多
The cationic polyurethane/CeO 2 nanocomposite dispersion has been synthesiz ed by adding ceria organosol to pre-polymer of polyurethane and then adding neutralization reagent and water to give an emulsion. FTIR analys...The cationic polyurethane/CeO 2 nanocomposite dispersion has been synthesiz ed by adding ceria organosol to pre-polymer of polyurethane and then adding neutralization reagent and water to give an emulsion. FTIR analysis shows blue shift of the absorpsion band of CeO 2 . TEM micrograph shows that CeO 2 nano- particles ar e uniformly dispersed in polyurethane. Polyurethane/CeO 2 nanocomposite has high absorption at the region lower 350 nm.展开更多
Porous silicon-zinc sulfide nanocomposite(PS-ZnS) was prepared by in situ synthesis of ZnS via a simple polyphase reaction on the base of nano-PS. The formation of the composite was confirmed by X-ray diffraction(XRD)...Porous silicon-zinc sulfide nanocomposite(PS-ZnS) was prepared by in situ synthesis of ZnS via a simple polyphase reaction on the base of nano-PS. The formation of the composite was confirmed by X-ray diffraction(XRD), field emission scanning electron microscopy(FE-SEM), energy dispersive spectroscopy(EDS) and photoluminescence(PL) measurements. Based on the XRD data and the Debye-Scherrer equation, the size of the formed ZnS particles both on the surface and in the holes of the PS was calculated to be nano-scaled, ca. 5—7 nm. FE-SEM observation showed agglomeration for the ZnS particles with an average crystallite size of 30—40 nm, and the hole diameter of the PS was below 100 nm. PL measurements and CIE diagram analysis for the PS-ZnS composite samples indicated that the emitted light color from the composites could be modulated and controlled by changing the annealing conditions, from orange to violet-blue, and finally, white-light emitter of the composite was obtained.展开更多
文摘A shear induced ordered structure in an exfoliated polystyrene(PS)/clay nanocomposite is reported. Self\|assembly behavior was reported for the first time of a shear induced ordered structure in the nanocomposite. The self assembly behavior was measured by X ray diffraction(XRD) patterns, transmission electron microscopy(TEM), and FTIR dichroism technique. Compared with the broad amorphous peaks of the PS, a series of sharp XRD peaks were observed for the exturded PS/clay nanocomposite pellet sample, showing that an ordered sructure occurred under shear flow. The intensities of the four sharp XRD peaks of the ordered sructure decreased significantly with temperature. However, at 95 ℃, the XRD peaks increased significantly, the FTIR dichroism showing that and the phenyl ring of PS changed its orientation from parallel to perpendicular to the monmorillonite primary particles, whereas no obvious orientation of the alkyl chain of PS could be found. At 110 ℃, a disordered structure occurred for the phenyl ring. TEM images confirmed directly that the origin of the ordered structure was mainly due to the planar orientation of the primary particles of silicate layers as well as local ordered microsructure of the primary particles, induced by shear flow. Basd on these investigations, a possible mechanism was deduced for the formation of the ordered strucure induced by shear flow in the exfoliated PS/clay nanocomposite.
文摘This paper mainly elaborated the recent developments of the studies on the new type zeohite molecular sieve host-nanoguest composite materials composing of molecular sieve chaimels or cages encapsulated nanoscale materials from the point of nanochemistry and material science,and the trends of development in this field. As the research of the properties of this kind of materials are gomg on. it is possible that this kind of host-guest nanocomposite materials will be usd in some fields. such as science and high technology fields. as the new type of ptical. electrical and magnetic materials in the level of molecular assembly. This paper contains the following contents:hosts and guests; the sizes and shapes of guests; the optical, electrical and magnetic properties of the materials; the syntheses and characterizations of the materials; the applications of the materials and forecast.
文摘The cationic polyurethane/CeO 2 nanocomposite dispersion has been synthesiz ed by adding ceria organosol to pre-polymer of polyurethane and then adding neutralization reagent and water to give an emulsion. FTIR analysis shows blue shift of the absorpsion band of CeO 2 . TEM micrograph shows that CeO 2 nano- particles ar e uniformly dispersed in polyurethane. Polyurethane/CeO 2 nanocomposite has high absorption at the region lower 350 nm.
文摘Porous silicon-zinc sulfide nanocomposite(PS-ZnS) was prepared by in situ synthesis of ZnS via a simple polyphase reaction on the base of nano-PS. The formation of the composite was confirmed by X-ray diffraction(XRD), field emission scanning electron microscopy(FE-SEM), energy dispersive spectroscopy(EDS) and photoluminescence(PL) measurements. Based on the XRD data and the Debye-Scherrer equation, the size of the formed ZnS particles both on the surface and in the holes of the PS was calculated to be nano-scaled, ca. 5—7 nm. FE-SEM observation showed agglomeration for the ZnS particles with an average crystallite size of 30—40 nm, and the hole diameter of the PS was below 100 nm. PL measurements and CIE diagram analysis for the PS-ZnS composite samples indicated that the emitted light color from the composites could be modulated and controlled by changing the annealing conditions, from orange to violet-blue, and finally, white-light emitter of the composite was obtained.
