The coaggregating tendencies of five methyl esters of saturated or unsaturated single-chain carboxylic acids, namely octanoic (8-Me), dodecanoic (12-Me), stearic (18-Me), oleic (c18:1-Me) and elaidic (t-18:1-Me) acids...The coaggregating tendencies of five methyl esters of saturated or unsaturated single-chain carboxylic acids, namely octanoic (8-Me), dodecanoic (12-Me), stearic (18-Me), oleic (c18:1-Me) and elaidic (t-18:1-Me) acids, were investigated in five aquiorgano binary solvent systems, V/V DX-H2O (Phi=0.50, 0.45, 0.40, 0.30, 0.20), using naphthylethyl octyl (Np-8), dodecyl (Np-12), hexadecyl (Np-16) ether as fluorescent probes. The orders of their coaggregating tendencies changed in solvents of different Phi values. Our results could be rationalized by a chain-foldability effect without neighboring moiety participation.展开更多
Very recently,we have proposed that all culprit molecules of arteriosclerosis mightpossess a common and measurable inherent property,namely,a coaggregating ten-dency.Extensive kinetic measurements of these tendencies ...Very recently,we have proposed that all culprit molecules of arteriosclerosis mightpossess a common and measurable inherent property,namely,a coaggregating ten-dency.Extensive kinetic measurements of these tendencies in terms of △CAgC valueshave led to a new and surprising observation,i.e.,the cholesteryl ester with a longsaturated 18-carbon chain(CE-18)actually has a much smaller tendency towardcoaggregation than that of the ester with a“short”8-carbon chain(CE-8).Thisstate of affairs has been coined as the“chain-foldability effect”,i.e.,the 18-carbon展开更多
For side-chain liquid-crystalline polymers(SCLCPs)bearing calamitic mesogens,nematic and typical smectic(Sm)phases are expected.Here,using a precise polyethylene derivative with the biphenyl moiety tethered on every n...For side-chain liquid-crystalline polymers(SCLCPs)bearing calamitic mesogens,nematic and typical smectic(Sm)phases are expected.Here,using a precise polyethylene derivative with the biphenyl moiety tethered on every ninth carbon(P9,b),we demonstrated that an SCLCP could form a crystal(Cr)phase in addition to an Sm phase.Two opposing interrelations of main-and side-chains determined the molecular packings.While the side-chain inclined to be perpendicular to the main-chain in the Sm phase,they paralleled and coassembled in the Cr phase with an orthorhombic structure.The Sm phase of P9,b was new in SCLCPs.Within the mesogen sublayers,the biphenyls were tilted and had a type of two-dimensional positional order,making this Sm phase ordering higher than that of smectic C.The Sm phase was metastable and kinetically grew faster below its isotropic temperature.However,it could not convert to the stable Cr phase unless it transitioned into the melting state.Fantastically,P9,b rendered the lamellar crystal in the Cr phase.The lenticular lamellae resembled that found in linear polyethylene crystallized at low undercooling.Importantly,albeit having the large anisotropic pendants situated regularly in the backbone,P9,b could follow the principle of chain-folding crystallization.展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘The coaggregating tendencies of five methyl esters of saturated or unsaturated single-chain carboxylic acids, namely octanoic (8-Me), dodecanoic (12-Me), stearic (18-Me), oleic (c18:1-Me) and elaidic (t-18:1-Me) acids, were investigated in five aquiorgano binary solvent systems, V/V DX-H2O (Phi=0.50, 0.45, 0.40, 0.30, 0.20), using naphthylethyl octyl (Np-8), dodecyl (Np-12), hexadecyl (Np-16) ether as fluorescent probes. The orders of their coaggregating tendencies changed in solvents of different Phi values. Our results could be rationalized by a chain-foldability effect without neighboring moiety participation.
基金the National Natural Science Foundation of China Laboratory of Photochemistry and PhotophysicsInstitute of Photographic Chemistry,Chinese Academy of Sciences.
文摘Very recently,we have proposed that all culprit molecules of arteriosclerosis mightpossess a common and measurable inherent property,namely,a coaggregating ten-dency.Extensive kinetic measurements of these tendencies in terms of △CAgC valueshave led to a new and surprising observation,i.e.,the cholesteryl ester with a longsaturated 18-carbon chain(CE-18)actually has a much smaller tendency towardcoaggregation than that of the ester with a“short”8-carbon chain(CE-8).Thisstate of affairs has been coined as the“chain-foldability effect”,i.e.,the 18-carbon
基金supported by the National Natural Science Foundation of China(grant nos.21634001,21875157,and 51921002)the National Key R&D Program of China(no.2018YFB0703703)The TEM facility is made available by Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices(nos.2019B121203003 and 2016ZT06C322).
文摘For side-chain liquid-crystalline polymers(SCLCPs)bearing calamitic mesogens,nematic and typical smectic(Sm)phases are expected.Here,using a precise polyethylene derivative with the biphenyl moiety tethered on every ninth carbon(P9,b),we demonstrated that an SCLCP could form a crystal(Cr)phase in addition to an Sm phase.Two opposing interrelations of main-and side-chains determined the molecular packings.While the side-chain inclined to be perpendicular to the main-chain in the Sm phase,they paralleled and coassembled in the Cr phase with an orthorhombic structure.The Sm phase of P9,b was new in SCLCPs.Within the mesogen sublayers,the biphenyls were tilted and had a type of two-dimensional positional order,making this Sm phase ordering higher than that of smectic C.The Sm phase was metastable and kinetically grew faster below its isotropic temperature.However,it could not convert to the stable Cr phase unless it transitioned into the melting state.Fantastically,P9,b rendered the lamellar crystal in the Cr phase.The lenticular lamellae resembled that found in linear polyethylene crystallized at low undercooling.Importantly,albeit having the large anisotropic pendants situated regularly in the backbone,P9,b could follow the principle of chain-folding crystallization.