It had very long been a dream in polymer science to synthesize long multi-block polymer chains with an orderedchain sequence and controllable block lengths. Using ionic or living free radical polymerization or furnish...It had very long been a dream in polymer science to synthesize long multi-block polymer chains with an orderedchain sequence and controllable block lengths. Using ionic or living free radical polymerization or furnishing each end ofpolymer blocks with a reactive functional group, one can only prepare heteropolymer chains with few long blocks, such asdiblock and triblock copolymers. The most plausible result so far was a pentablock copolymer. Recently, using a combinationof polymer physics and synthetic chemistry, we have invented self-assembly assisted polycondensation (SAAP). Thiscommunication reports the results of using this novel. method to connect 10-100 triblock polymer chains together to formlong multi-block heteropolymer chains with an ordered sequence and controllable block lengths.展开更多
The uniform zirconia nanoparticle multilayers/micrometer-sized silica particle(ZrO 2/SiO 2) was prepared for HPLC support material by layer-by-layer(LbL) self-assembly technique. XRD pattern shows that the crystalline...The uniform zirconia nanoparticle multilayers/micrometer-sized silica particle(ZrO 2/SiO 2) was prepared for HPLC support material by layer-by-layer(LbL) self-assembly technique. XRD pattern shows that the crystalline of nanometer particles on the surface is pure tetragonal zirconia, with a diameter of 13^9 nm. The specific surface area, pore volume and pore size of the material are 172.53 m 2/g, 0.378 4 cm 3/g, and 8.5 nm, respectively. The novel support not only has the mechanical strength and chemical stability of zirconia, but also has the good chromatographic features such as larger surface area, better permeability, less background pressure.展开更多
基金Financial support of the Research Grants Council of the Hong Kong Special Administration Region Earmarked Grant (CUHK4267/00P, CUHK 4209/99P, 2160122) and NNSFC 29974027 is gratefully acknowledged.
文摘It had very long been a dream in polymer science to synthesize long multi-block polymer chains with an orderedchain sequence and controllable block lengths. Using ionic or living free radical polymerization or furnishing each end ofpolymer blocks with a reactive functional group, one can only prepare heteropolymer chains with few long blocks, such asdiblock and triblock copolymers. The most plausible result so far was a pentablock copolymer. Recently, using a combinationof polymer physics and synthetic chemistry, we have invented self-assembly assisted polycondensation (SAAP). Thiscommunication reports the results of using this novel. method to connect 10-100 triblock polymer chains together to formlong multi-block heteropolymer chains with an ordered sequence and controllable block lengths.
文摘The uniform zirconia nanoparticle multilayers/micrometer-sized silica particle(ZrO 2/SiO 2) was prepared for HPLC support material by layer-by-layer(LbL) self-assembly technique. XRD pattern shows that the crystalline of nanometer particles on the surface is pure tetragonal zirconia, with a diameter of 13^9 nm. The specific surface area, pore volume and pore size of the material are 172.53 m 2/g, 0.378 4 cm 3/g, and 8.5 nm, respectively. The novel support not only has the mechanical strength and chemical stability of zirconia, but also has the good chromatographic features such as larger surface area, better permeability, less background pressure.
