Creation of diverse ordered nanostructures via self-assembly of macromolecules is a promising "bottom-up" approach towards next-generation nanofabrication technologies. It is therefore of critical importance...Creation of diverse ordered nanostructures via self-assembly of macromolecules is a promising "bottom-up" approach towards next-generation nanofabrication technologies. It is therefore of critical importance to explore the possibilities to form new self-assembled phases in soft matter systems. In this review, we summarized recent advances on the identification of several unconventional spherical phases in the self-assembly of functional macromolecules, including Frank-Kasper(F-K) phases and quasicrystals originally observed in metal alloys. We believe that these results provide a new strategy towards the rational design of novel functional materials with hierarchically ordered structures.展开更多
In the present investigation, the microstructures and growth morphology of Mg32（Al,Zn）49 Frank-Kasper phase in rapidly solidified Mg32Al17Zn32 temary alloys were studied in detail. The samples were characterised by ...In the present investigation, the microstructures and growth morphology of Mg32（Al,Zn）49 Frank-Kasper phase in rapidly solidified Mg32Al17Zn32 temary alloys were studied in detail. The samples were characterised by X-ray diffraction analysis （XRD）, scanning electron microscopy （SEM）, field-emission scanning electron microscopy （FE-SEM） and energy dispersive spectrum （EDS）. The results show that the microstructures mainly consist of Mg3e（Al,Zn）49 Frank-Kasper phase and interdendritic Mg-rich O-phase. Under rapid solidification condition, Mg32（Al,Zn）49 Frank-Kasper phase reveals a perfect faceted dendritic characteristic in the shape of a three-fold symmetric microstructure with doublet tips in the axes direction. Observations for fracture surfaces show that the growth morphology of Mg32（Al,Zn）49 grains was truncated cubic, and its growth mechanism was also discussed.展开更多
We report herein the precision synthesis and phase behaviors of multi-tailed B_(2)AB_(2)-type regio-isomeric giant surfactants consisting of a hydrophilic polyhedral oligomeric silsesquioxane(POSS)head tethered with f...We report herein the precision synthesis and phase behaviors of multi-tailed B_(2)AB_(2)-type regio-isomeric giant surfactants consisting of a hydrophilic polyhedral oligomeric silsesquioxane(POSS)head tethered with four hydrophobic polystyrene(PS)tails.The synthesis was accomplished through two sequential"click"reactions to give a series of regio-isomeric giant surfactants S2DS2(where S is short for PS tails and D for hydroxyl-functionalized POSS)in para-,meta-,and ortho-configurations.Their phase structures and phase be-haviors at the columnar-spherical boundary were investigated with a single PS tail molecular weight of 1.4 kDa.Specifically,the para-and meta-isomers show hexagonally packed cylinders phases with slightly different order-disorder transition temperatures(~120℃ and~130℃)and the ortho-isomer exhibits an order-order transition from a kinetically favored,metastable dodecagonal quasi-crystal phase to a thermodynamically stable sigma phase at~120℃,as well as a further transition into the disordered state at~140℃.The phase diagram was constructed and their differences were rationalized based on the calculated interfacial area per molecule.This work demonstrates that tiny structural disparity could not only lead to unconventional phase formation in single-component macro-molecules,but also render dynamic and rich phase behaviors in these macromolecular assemblies.展开更多
Naturally,subtle variations in the chemical structures of constituent molecules may significantly affect their multiscale spatial arrangements,properties,and functions.Deceptively simple spherical assemblies supply an...Naturally,subtle variations in the chemical structures of constituent molecules may significantly affect their multiscale spatial arrangements,properties,and functions.Deceptively simple spherical assemblies supply an ideal platform to investigate how subtle chemical differences affect hierarchically assembled structures.Here,the authors report two sets of nanosized shape amphiphiles,which were constructed by a triphenylene core and six polyhedral oligomeric silsesquioxane cages peripherally grafted through linkers.The slight differences in these samples are merely several methylene units in their linkers,including several pairs of constituent isomers.These nanosized shape amphiphiles self-assemble into a variety of unconventional spherical packing structures,which include the Frank-Kasperσphase and dodecagonal quasicrystal.Several types of unconventional phase transitions were systematically investigated.The authors alternated the conventional columnar phases of discotic molecules to unconventional spherical packing phases.These unconventional structures may shed light into discovering discotic mesogens-based materials with new properties and functions.展开更多
基金supported by the Pearl River Talents Scheme (2016ZT06C322)the National Key R&D Program of China (2017YFC11050003)the Fundamental Research Funds for the Central Universities (2017JQ001)
文摘Creation of diverse ordered nanostructures via self-assembly of macromolecules is a promising "bottom-up" approach towards next-generation nanofabrication technologies. It is therefore of critical importance to explore the possibilities to form new self-assembled phases in soft matter systems. In this review, we summarized recent advances on the identification of several unconventional spherical phases in the self-assembly of functional macromolecules, including Frank-Kasper(F-K) phases and quasicrystals originally observed in metal alloys. We believe that these results provide a new strategy towards the rational design of novel functional materials with hierarchically ordered structures.
基金the National Natural Science Foundation of China (No. 50571081)the Aeronautical Science Foundation of China (No. 04G53042) for their financial support
文摘In the present investigation, the microstructures and growth morphology of Mg32（Al,Zn）49 Frank-Kasper phase in rapidly solidified Mg32Al17Zn32 temary alloys were studied in detail. The samples were characterised by X-ray diffraction analysis （XRD）, scanning electron microscopy （SEM）, field-emission scanning electron microscopy （FE-SEM） and energy dispersive spectrum （EDS）. The results show that the microstructures mainly consist of Mg3e（Al,Zn）49 Frank-Kasper phase and interdendritic Mg-rich O-phase. Under rapid solidification condition, Mg32（Al,Zn）49 Frank-Kasper phase reveals a perfect faceted dendritic characteristic in the shape of a three-fold symmetric microstructure with doublet tips in the axes direction. Observations for fracture surfaces show that the growth morphology of Mg32（Al,Zn）49 grains was truncated cubic, and its growth mechanism was also discussed.
基金W.-B.Z.thanks the financial support from the National Key R&D Program of China(No.2018YFB0703702)the National Natural Science Foundation of China(Nos.21674003,21925102,21991132,92056118)+7 种基金Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-202006)Y.S.thanks Peking University for the Boya Postdoctoral Fellowship,the BMS Junior Fellowship of Beijing National Laboratory for Molecular Sciences,and the support from China Postdoctoral Science Foundation(No.8206300240)Q.F.thanks the National Natural Science Foundation of China for financial support(No.51721091)D.H.thanks the financial support from the Fundamental Research Funds for the Central Universities(No.2021SCU12042)J.H.thanks the financial supports from the National Natural Science Foundation of China(No.21774081)the Major Program of the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.20KJA150009)We are grateful to the Shanghai Synchrotron Radiation Facility(the Beamline 16B1)the Beijing Synchrotron Radiation Facility(the Beamline 1W2A)for the assistance with the in situ SAXS/WAXD experiments.
文摘We report herein the precision synthesis and phase behaviors of multi-tailed B_(2)AB_(2)-type regio-isomeric giant surfactants consisting of a hydrophilic polyhedral oligomeric silsesquioxane(POSS)head tethered with four hydrophobic polystyrene(PS)tails.The synthesis was accomplished through two sequential"click"reactions to give a series of regio-isomeric giant surfactants S2DS2(where S is short for PS tails and D for hydroxyl-functionalized POSS)in para-,meta-,and ortho-configurations.Their phase structures and phase be-haviors at the columnar-spherical boundary were investigated with a single PS tail molecular weight of 1.4 kDa.Specifically,the para-and meta-isomers show hexagonally packed cylinders phases with slightly different order-disorder transition temperatures(~120℃ and~130℃)and the ortho-isomer exhibits an order-order transition from a kinetically favored,metastable dodecagonal quasi-crystal phase to a thermodynamically stable sigma phase at~120℃,as well as a further transition into the disordered state at~140℃.The phase diagram was constructed and their differences were rationalized based on the calculated interfacial area per molecule.This work demonstrates that tiny structural disparity could not only lead to unconventional phase formation in single-component macro-molecules,but also render dynamic and rich phase behaviors in these macromolecular assemblies.
基金This study was supported by the Key-Area Research and Development Program of Guangdong Province(nos.2019B010941002 and 2020B010182002)the National Natural Science Foundation of China(nos.71890871 and U1832220)+2 种基金the Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices(no.2019B121203003)Guangdong Project(no.2016ZT06C322)the Fundamental Research Funds for the Central Universities(no.2019JQ05).
文摘Naturally,subtle variations in the chemical structures of constituent molecules may significantly affect their multiscale spatial arrangements,properties,and functions.Deceptively simple spherical assemblies supply an ideal platform to investigate how subtle chemical differences affect hierarchically assembled structures.Here,the authors report two sets of nanosized shape amphiphiles,which were constructed by a triphenylene core and six polyhedral oligomeric silsesquioxane cages peripherally grafted through linkers.The slight differences in these samples are merely several methylene units in their linkers,including several pairs of constituent isomers.These nanosized shape amphiphiles self-assemble into a variety of unconventional spherical packing structures,which include the Frank-Kasperσphase and dodecagonal quasicrystal.Several types of unconventional phase transitions were systematically investigated.The authors alternated the conventional columnar phases of discotic molecules to unconventional spherical packing phases.These unconventional structures may shed light into discovering discotic mesogens-based materials with new properties and functions.
