(Silver-poly(4-vinylpyridine))(Ag-P4VP) hybrid microgels were synthesized by γ-irradiation and surfactant-free emulsion polymerization in a single step.The effects of dose rate and the concentrations of isopropanol,s...(Silver-poly(4-vinylpyridine))(Ag-P4VP) hybrid microgels were synthesized by γ-irradiation and surfactant-free emulsion polymerization in a single step.The effects of dose rate and the concentrations of isopropanol,silver ion,N,N′-methylenebisacrylamide(Bis) and 4-vinylpyridine(4-VP) on the hybrid microgels were studied in detail via transmission electron microscopy(TEM),powder X-ray diffraction(XRD) or dynamic light scattering(DLS).The results indicated that the size of Ag nanoparticles in the hybrid microgels increased with the increase of Ag^+ or Bis concentration and with the decrease of dose rate or isopropanol concentration.When the dose rate was decreased,the phase state of Ag nanoparticles was gradually transformed from amorphous state to cubic crystalline state.Although the variety of the P4VP microgels’ size was more complex,it could also be easily adjusted by the above-mentioned conditions.展开更多
Homopolymerization of 4-vinyl pyridine（4-VP） and copolymerization of 4-VP with styrene（St） were performed by catalyst systems composed of calix[4]arene-neodymium complex 2,di-n-butylmagnesium and hexamethyl phosph...Homopolymerization of 4-vinyl pyridine（4-VP） and copolymerization of 4-VP with styrene（St） were performed by catalyst systems composed of calix[4]arene-neodymium complex 2,di-n-butylmagnesium and hexamethyl phosphoramide. The molecular weight of P（4-VP） was greatly affected by adding calix[4]arene-neodymium complex,and high molecular weight of P（4-VP） was got by using calix[4]arene-neodymium complex.The highest molecular weight of P（4-VP） was as high as 4.65×106 obtained by using a catalyst system with 2.0×10-4?mol/L of calix[4]arene-neodymium complex,while the molecular weight of P（4-VP） was only 5.62×105 without calix[4]arene-neodymium complex. In addition,4-VP-St copolymers with different 4-VP contents were obtained in good yield.When styrene was polymerized first for a time period,and then 4-VP was added,4-VP-St copolymers with 4.85?mol%～23.3?mol% of 4-VP units were obtained,but when 4-VP and styrene were added at the same time the resultant 4-VP-St copolymers had 44.0?mol%～66.3?mol% of 4-VP units.展开更多
文摘(Silver-poly(4-vinylpyridine))(Ag-P4VP) hybrid microgels were synthesized by γ-irradiation and surfactant-free emulsion polymerization in a single step.The effects of dose rate and the concentrations of isopropanol,silver ion,N,N′-methylenebisacrylamide(Bis) and 4-vinylpyridine(4-VP) on the hybrid microgels were studied in detail via transmission electron microscopy(TEM),powder X-ray diffraction(XRD) or dynamic light scattering(DLS).The results indicated that the size of Ag nanoparticles in the hybrid microgels increased with the increase of Ag^+ or Bis concentration and with the decrease of dose rate or isopropanol concentration.When the dose rate was decreased,the phase state of Ag nanoparticles was gradually transformed from amorphous state to cubic crystalline state.Although the variety of the P4VP microgels’ size was more complex,it could also be easily adjusted by the above-mentioned conditions.
文摘Homopolymerization of 4-vinyl pyridine（4-VP） and copolymerization of 4-VP with styrene（St） were performed by catalyst systems composed of calix[4]arene-neodymium complex 2,di-n-butylmagnesium and hexamethyl phosphoramide. The molecular weight of P（4-VP） was greatly affected by adding calix[4]arene-neodymium complex,and high molecular weight of P（4-VP） was got by using calix[4]arene-neodymium complex.The highest molecular weight of P（4-VP） was as high as 4.65×106 obtained by using a catalyst system with 2.0×10-4?mol/L of calix[4]arene-neodymium complex,while the molecular weight of P（4-VP） was only 5.62×105 without calix[4]arene-neodymium complex. In addition,4-VP-St copolymers with different 4-VP contents were obtained in good yield.When styrene was polymerized first for a time period,and then 4-VP was added,4-VP-St copolymers with 4.85?mol%～23.3?mol% of 4-VP units were obtained,but when 4-VP and styrene were added at the same time the resultant 4-VP-St copolymers had 44.0?mol%～66.3?mol% of 4-VP units.
