Soft magnetic composites （SMCs） were prepared from three different ferromagnetic powder particles： iron powder ASC 100.29, spherical FeSi particles and vitroperm （Fe73CulNb3Si16B7） flakes. Two types of hybrid org...Soft magnetic composites （SMCs） were prepared from three different ferromagnetic powder particles： iron powder ASC 100.29, spherical FeSi particles and vitroperm （Fe73CulNb3Si16B7） flakes. Two types of hybrid organic-inorganic phenolic resins modified with either silica nanoparticles or boron were used to design a thin insulating layer perfect- ly covering the ferromagnetic particles. Fourier transform infrared （FTIR） spectrometry confirmed an incorporation of silica or boron into the polymer matrix, which manifested itself through an improved thermal stability of the hybrid resins verified by thermogravimetric-differential scanning calorimetry （TG-DSC） analysis. The core-shell particles prepared from the ferromagnetic powder particles and the modified hybrid resins were further compacted to the cylindrical and toroidal shapes for the mechanical, electrical and magnetic testing. A uniform distribution of the resin between the ferromagnetic particles was evidenced by scanning electron microscope （SEM） analysis, which was also reflected in a rather high value of the electrical resistivity. A low porosity and extraordinary high values of mechanical hardness and flexural strength were found in SMC consisting of the iron powder and phenolic resin modified with boron. The coercive fields of the prepared samples were comparable with the commercial SMCs.展开更多
Solvothermal reaction of Zn(NO_(3))_(2)·6H_(2)O with di-pyridin-2-yl-[4-(2-pyridin-4-yl-vinyl)-phenyl]-amine(ppvppa)and 1,4-naphthalenedicarboxylic acid(1,4-H_(2)NDC)in H_(2)O and MeCN at 150℃yielded a twodimens...Solvothermal reaction of Zn(NO_(3))_(2)·6H_(2)O with di-pyridin-2-yl-[4-(2-pyridin-4-yl-vinyl)-phenyl]-amine(ppvppa)and 1,4-naphthalenedicarboxylic acid(1,4-H_(2)NDC)in H_(2)O and MeCN at 150℃yielded a twodimensional(2D)coordination Zn(Ⅱ)polymer[Zn(ppvppa)(1,4-NDC)]_(n)(1).Compound 1 was characterized by elemental analysis,IR spectroscopy,powder X-ray diffraction,single-crystal X-ray diffraction and thermogravimetric analysis.Compound 1 consists of dimeric[Zn_(2)(ppvppa)_(2)]units linked by 1,4-NDC bridges to generate a 2D honeycomb network.Either compound 1 or ppvppa alone can detect Hg^(2+)or MeHgI selectively and with good sensitivity.Upon addition of Hg^(2+)ions to a MeCN solution of ppvppa,marked changes in the UV-vis and fluorescence spectra are observed,associated with colour changes,which are easily identified by the naked eye.The pyridinyl rings of ppvppa are coordinated to the Hg^(2+)ion.This motif in the presence of NO_(3)^(−)ions forms a binuclear complex[Hg_(2)(ppvppa)_(2)(NO_(3))_(4)](2),which has been characterized as the solvate[Hg_(2)(ppvppa)_(2)(NO_(3))_(4)]·H_(2)O·4MeCN(2·H_(2)O·4MeCN)by singlecrystal X-ray diffraction studies.In aqueous solution,compound 1 emits pale orange light at ambient temperature and the addition of Hg^(2+)or MeHgI induces an change of fluorescence color from pale orange to blue.Compound 1 is a promising candidate as a sensitive naked-eye indicator for Hg^(2+)or MeHgI in water under a UV lamp.展开更多
基金Supported by the Slovak Research and Development Agency under the contracts(APVV-0222-10)the Operational Program"Research and Development"financed through European Regional Development Fund(ITMS 26220220105)the Scientific Grant Agency of the Ministry of Education of Slovak Republic and the Slovak Academy of Sciences,projects(VEGA 1/0861/12,VEGA 1/0862/12,VEGA VEGA 2/0155/12)
文摘Soft magnetic composites （SMCs） were prepared from three different ferromagnetic powder particles： iron powder ASC 100.29, spherical FeSi particles and vitroperm （Fe73CulNb3Si16B7） flakes. Two types of hybrid organic-inorganic phenolic resins modified with either silica nanoparticles or boron were used to design a thin insulating layer perfect- ly covering the ferromagnetic particles. Fourier transform infrared （FTIR） spectrometry confirmed an incorporation of silica or boron into the polymer matrix, which manifested itself through an improved thermal stability of the hybrid resins verified by thermogravimetric-differential scanning calorimetry （TG-DSC） analysis. The core-shell particles prepared from the ferromagnetic powder particles and the modified hybrid resins were further compacted to the cylindrical and toroidal shapes for the mechanical, electrical and magnetic testing. A uniform distribution of the resin between the ferromagnetic particles was evidenced by scanning electron microscope （SEM） analysis, which was also reflected in a rather high value of the electrical resistivity. A low porosity and extraordinary high values of mechanical hardness and flexural strength were found in SMC consisting of the iron powder and phenolic resin modified with boron. The coercive fields of the prepared samples were comparable with the commercial SMCs.
基金financial support from the National Natural Science Foundation of China(Grant No.21373142,21531006,and 21471108)State Key Laboratory of Organometallic Chemistry,Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences(2015kf-07)+3 种基金the financial support from the Qing-Lan Projectthe“333”Project of Jiangsu Provincethe Priority Academic Program Development of Jiangsu Higher Education Institutionsthe“SooChow Scholar”Program of Soochow University.
文摘Solvothermal reaction of Zn(NO_(3))_(2)·6H_(2)O with di-pyridin-2-yl-[4-(2-pyridin-4-yl-vinyl)-phenyl]-amine(ppvppa)and 1,4-naphthalenedicarboxylic acid(1,4-H_(2)NDC)in H_(2)O and MeCN at 150℃yielded a twodimensional(2D)coordination Zn(Ⅱ)polymer[Zn(ppvppa)(1,4-NDC)]_(n)(1).Compound 1 was characterized by elemental analysis,IR spectroscopy,powder X-ray diffraction,single-crystal X-ray diffraction and thermogravimetric analysis.Compound 1 consists of dimeric[Zn_(2)(ppvppa)_(2)]units linked by 1,4-NDC bridges to generate a 2D honeycomb network.Either compound 1 or ppvppa alone can detect Hg^(2+)or MeHgI selectively and with good sensitivity.Upon addition of Hg^(2+)ions to a MeCN solution of ppvppa,marked changes in the UV-vis and fluorescence spectra are observed,associated with colour changes,which are easily identified by the naked eye.The pyridinyl rings of ppvppa are coordinated to the Hg^(2+)ion.This motif in the presence of NO_(3)^(−)ions forms a binuclear complex[Hg_(2)(ppvppa)_(2)(NO_(3))_(4)](2),which has been characterized as the solvate[Hg_(2)(ppvppa)_(2)(NO_(3))_(4)]·H_(2)O·4MeCN(2·H_(2)O·4MeCN)by singlecrystal X-ray diffraction studies.In aqueous solution,compound 1 emits pale orange light at ambient temperature and the addition of Hg^(2+)or MeHgI induces an change of fluorescence color from pale orange to blue.Compound 1 is a promising candidate as a sensitive naked-eye indicator for Hg^(2+)or MeHgI in water under a UV lamp.
