Microcapsules with chlorpyrifos cores and polyurea walls were synthesized with 2,4-tolylene diisocyanate as an oil-soluble monomer and ethylenediamine as a water-soluble monomer via an interracial polycondensation rea...Microcapsules with chlorpyrifos cores and polyurea walls were synthesized with 2,4-tolylene diisocyanate as an oil-soluble monomer and ethylenediamine as a water-soluble monomer via an interracial polycondensation reaction. The products were characterized by means of Fourier transform infrared spectrometry, ^13C NMR spectrometry and ^31p NMR spectrometry. The morphology, the particle size and the particle size distribution, and the thermal properties were also evaluated. The prepared microcapsules exhibit clear and smooth surfaces and have a mean diameter of 28. 13 μm. These microcapsules also have a good thermal stability for long-term use, and have potential applications in minimizing the toxicity of chlorpyrifos through controlled release.展开更多
Zn2Al layered double hydroxide pillared with Dawson polyoxometalates,P2W17ZO8-61(Z=Mn2+,Co2+,Ni2+,Cu2+,Zn2+)was prepared.A basal space ofca.16 nm indicates the intercalated Dawson ions to be oriented with their C2 axi...Zn2Al layered double hydroxide pillared with Dawson polyoxometalates,P2W17ZO8-61(Z=Mn2+,Co2+,Ni2+,Cu2+,Zn2+)was prepared.A basal space ofca.16 nm indicates the intercalated Dawson ions to be oriented with their C2 axis perpendicular to the double hydroxide layers(with the exception of P2W17ZnLDH).The IR and^(13)P MASNMR spectral reveal that the Dawson ions retain their integrity in the interlayer space of LDH.A preliminary study shows that these compounds are highly active catalysts for the oxidation of cyclohexene with molecular oxygen.展开更多
Layered double hydroxides（LDHs） are a class of synthetic anion clays, characterized by the formula [MⅡ1-xMⅢx（OH）2]x＋（An-）x/n5yH2O（where M=metal and A=anion, usually carbonate）[1-3]. A large number of LDHs w...Layered double hydroxides（LDHs） are a class of synthetic anion clays, characterized by the formula [MⅡ1-xMⅢx（OH）2]x＋（An-）x/n5yH2O（where M=metal and A=anion, usually carbonate）[1-3]. A large number of LDHs with a wide variety of MⅡ-MⅢ cation pairs including MⅠ-MⅢ（e.g., Li-Al） and MⅡ-MⅣ（e.g., Co-Ti） have been reported. Thus the identities of the cations（MⅠ, MⅡ, MⅢ and MⅣ） and the interlayer anion（An-） together with the value of the stoichiometric coefficient（x） may vary widely, giving rise to a large class of isostructural materials. As a result,展开更多
文摘Microcapsules with chlorpyrifos cores and polyurea walls were synthesized with 2,4-tolylene diisocyanate as an oil-soluble monomer and ethylenediamine as a water-soluble monomer via an interracial polycondensation reaction. The products were characterized by means of Fourier transform infrared spectrometry, ^13C NMR spectrometry and ^31p NMR spectrometry. The morphology, the particle size and the particle size distribution, and the thermal properties were also evaluated. The prepared microcapsules exhibit clear and smooth surfaces and have a mean diameter of 28. 13 μm. These microcapsules also have a good thermal stability for long-term use, and have potential applications in minimizing the toxicity of chlorpyrifos through controlled release.
文摘Zn2Al layered double hydroxide pillared with Dawson polyoxometalates,P2W17ZO8-61(Z=Mn2+,Co2+,Ni2+,Cu2+,Zn2+)was prepared.A basal space ofca.16 nm indicates the intercalated Dawson ions to be oriented with their C2 axis perpendicular to the double hydroxide layers(with the exception of P2W17ZnLDH).The IR and^(13)P MASNMR spectral reveal that the Dawson ions retain their integrity in the interlayer space of LDH.A preliminary study shows that these compounds are highly active catalysts for the oxidation of cyclohexene with molecular oxygen.
基金Supported by Excellent Young Scholars Research Fund of Beijing Institute of Technology(No.000Y05-22)the Key Labora-tory of Beijing City on PreparationProcessing of Novel Polymer Materials(No.SYS100100420) in Beijing University of ChemicalTechnology.
文摘Layered double hydroxides（LDHs） are a class of synthetic anion clays, characterized by the formula [MⅡ1-xMⅢx（OH）2]x＋（An-）x/n5yH2O（where M=metal and A=anion, usually carbonate）[1-3]. A large number of LDHs with a wide variety of MⅡ-MⅢ cation pairs including MⅠ-MⅢ（e.g., Li-Al） and MⅡ-MⅣ（e.g., Co-Ti） have been reported. Thus the identities of the cations（MⅠ, MⅡ, MⅢ and MⅣ） and the interlayer anion（An-） together with the value of the stoichiometric coefficient（x） may vary widely, giving rise to a large class of isostructural materials. As a result,
