A simple, practical and economical procedure has been developed to prepare novel C18 ether-bond reversed phase packing. A soft and long C18 alkyl chain was coupled onto silica（Sinopak-S, particle size d=5 μm, pore d...A simple, practical and economical procedure has been developed to prepare novel C18 ether-bond reversed phase packing. A soft and long C18 alkyl chain was coupled onto silica（Sinopak-S, particle size d=5 μm, pore diameter Dp=11 nm; and surface area S=170 m2/g） with γ-glycidoxypropyltrimethoxysilane as coupling agent. Chromatographic evaluation indicate that its reversed phase behavior was similar to ordinary ODS.展开更多
In this work, the mesophase properties were tuned via mixing two discotic molecules with structural complementarity. Compared with the liquid crystalline hexakis（n-hexyloxy）triphenylene（H6TP）materials（columnar he...In this work, the mesophase properties were tuned via mixing two discotic molecules with structural complementarity. Compared with the liquid crystalline hexakis（n-hexyloxy）triphenylene（H6TP）materials（columnar hexagonal phase from 53 ℃ to 91 ℃）, mesophase types as well as phase transition temperatures varied with the introduction of crystalline hexaazatriphenylene derivative（PBH）molecules. The introduction of less than 33% amount of PBH disrupted the columnar hexagonal phase formed by H6 TP remarkably, followed by the decreased clearing temperatures of liquid crystals. As the PBH amount was further increased, the destroyed columnar hexagonal phase was turned into the columnar rectangular phase, in which H6 TP and PBH molecules together formed the columnar mesophase. The formation of new mesophase contributed to the enlarged mesophase temperature（from44 ℃ to 144 ℃）. We speculated that the alkyl chains interaction induced by the PBH component competed with the strong p–p stacking between H6 TP molecules, thus altering the liquid crystalline properties including mesophase types and phase transition temperatures.展开更多
文摘A simple, practical and economical procedure has been developed to prepare novel C18 ether-bond reversed phase packing. A soft and long C18 alkyl chain was coupled onto silica（Sinopak-S, particle size d=5 μm, pore diameter Dp=11 nm; and surface area S=170 m2/g） with γ-glycidoxypropyltrimethoxysilane as coupling agent. Chromatographic evaluation indicate that its reversed phase behavior was similar to ordinary ODS.
基金supported by the National Natural Science Foundation of China(No.51303177)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB12020300)
文摘In this work, the mesophase properties were tuned via mixing two discotic molecules with structural complementarity. Compared with the liquid crystalline hexakis（n-hexyloxy）triphenylene（H6TP）materials（columnar hexagonal phase from 53 ℃ to 91 ℃）, mesophase types as well as phase transition temperatures varied with the introduction of crystalline hexaazatriphenylene derivative（PBH）molecules. The introduction of less than 33% amount of PBH disrupted the columnar hexagonal phase formed by H6 TP remarkably, followed by the decreased clearing temperatures of liquid crystals. As the PBH amount was further increased, the destroyed columnar hexagonal phase was turned into the columnar rectangular phase, in which H6 TP and PBH molecules together formed the columnar mesophase. The formation of new mesophase contributed to the enlarged mesophase temperature（from44 ℃ to 144 ℃）. We speculated that the alkyl chains interaction induced by the PBH component competed with the strong p–p stacking between H6 TP molecules, thus altering the liquid crystalline properties including mesophase types and phase transition temperatures.
