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A variety of supramolecular structures of benzene-1,3,5-tricarboxamide derivatives (BTAs), such as helixes and nanosheets, have been fabricated. However, how to regulate the self-assembly behavior through molecular design and control of experimental conditions, and thus to form supramolecular structures with different morphologies is still a topic that needs to be further explored. In this paper, two kinds of BTAs with different end groups, i.e. terpyridine and carboxyl were synthesized, which are referred to as L and A, respectively. Their self-assembly behaviors in DMF/aqueous solution were investigated by adding the DMF solution of BTAs into the aqueous solution dropwise. It was found that the two BTAs exhibited different self-assembly behaviors. L self-assembled into helical nanowires and nanosheets in the mixed media at lower and higher metal ion concentrations. However, A formed multilayer vesicles and nanotubes at lower and higher concentrations of A molecules. Such a difference was ascribed to their different molecular structures and therefore the different amphiphilicity. The more hydrophobic L molecules could escape from DMF droplets and self-assembled with the help of supramolecular interactions. The more amphiphilic A molecules were prone to adsorb at the oil/water interface to form layered films. The relative strength of coordination interaction determined the self-assembly behavior of L and the formation of helical nanowires and nanosheets, and the packing mode of A molecules at the oil/water interface determined the formation of vesicles and nanotubes. In addition, the formed vesicles of A were responsive to pH. [Display omitted] • BTAs with end groups of terpyridine and carboxyl are referred to L and A molecules. • The self-assembly behaviors of L and A in mixed DMF/aqueous solutions were studied. • L self-assembled into helical nanofibers and nanosheets. • A self-assembled into multilayer vesicles and nanotubes. • The self-assembly behaviors are related to molecular structure and conditions. [ABSTRACT FROM AUTHOR]

Amphiphilic block copolymers can self-assemble into various aggregates in which functional inorganic nanoparticles and organic chromophores can be incorporated. A variety of fabrication methods have been developed. In this work, the liquid/liquid interface mass transfer-assisted self-assembly method was extended to fabricate composite organized structure of polystyrene-b-polyacrylic acid (PS-b-PAA) with small organic molecules, such as diamines, dopamine and dyes. It was found that long uniform nanowires, hollow spheres and foams were generated when using these organic molecules under different conditions, which correspond to worm-like micelles, vesicles and aggregates of microcapsules, respectively. The length of the nanowires reaches to several tens of micrometers. The influence of the molecular structure of the organic molecules, especially the diamines was investigated and discussed, and the formation mechanism of these aggregates was analyzed. This method may be developed to a facile and useful approach to fabricate functional composite structure of block copolymers and small molecules. [ABSTRACT FROM AUTHOR]

It is of great importance to explore the self-assembly behavior of amphiphilic block copolymers at the liquid/liquid interface for the construction of hierarchical nanostructures and evaluation of emulsifiers. In this work, the adsorption and self-assembly of PS- b -PEO, a typical amphiphilic and temperature-sensitive block copolymer with abundant coordination sites were investigated by using a liquid/liquid interfacial assembly method in which pure water covered a chloroform solution of PS- b -PEO to form a planar liquid/liquid interface first, and then the aqueous solution of copper acetate was added dropwise into the water. It was found that spontaneous interfacial emulsification occurred when Cu2+ aqueous solution was added into the water at 28 °C. The PS- b -PEOs with shorter PEO chains self-assembled into hollow spheres, hierarchical hollow spheres, and hollow spheres with layered walls, depending on the relative length of the PEO blocks; while the PS- b -PEO with a longer PEO chain formed Janus sheets. While, PS- b -PEOs self-assembled into Janus sheets with monolayer or stepped multilayer structures at 18 and 8 °C through interfacial adsorption and assembly, regulated by the molecular structures. In addition, the concentrations of PS- b -PEO and Cu2+ ions also affect the self-assembly behavior and the aggregate morphologies. [Display omitted] • The liquid/liquid interfacial self-assembly of PS- b -PEOs was investigated. • They self-assembled into various hollow spheres at higher temperature. • The formation of hollow spheres was attributed to spontaneous emulsification. • They self-assembled into monolayer or multilayer Janus sheets at lower temperature. • The self-assembly behavior also depends on molecular structure and metal ions. [ABSTRACT FROM AUTHOR]

Self-assembly behavior of amphiphilic block copolymers has attracted much attention recently. In this paper, a novel liquid/liquid interface-mediated self-assembly behavior of block copolymer is reported. An aqueous solution of HAuCl 4 and a chloroform solution of poly(2-vinylpyridine)- block -polycaprolactone (P2VP 199 -b-PCL 22) are employed as the upper phase and the bottom phase, respectively. Structural transitions from toroids and plate like structures to vesicles and large compound vesicles are observed in the bottom phase by using transmission electron microscopy (TEM). It is proved that vesicles and large compound vesicles are formed through adsorption and desorption of copolymers at the liquid/liquid interface, molecular aggregation and microphase separation in the bottom phase due to the amphiphilic property of protonated P2VP 199 -b-PCL 22. The well-dispersed Au nanoparticles are formed during the self-assembly process and embedded in the bilayers of the vesicles. The concentrations of HAuCl 4 and P2VP 199 -b-PCL 22 have an effect on the self-assembly behavior. A unique structure, "pearl necklace", is obtained at higher concentrations. In addition, it was found that P2VP 252 -b-PCL 44 also formed vesicles, while P2VP 195 -b-PCL 75 and P2VP 195 -b-PCL 307 formed spherical micelles in the bottom phase through the same approach. The dependence of the aggregate morphology and the molecular structure was discussed based on the critical packing parameter, p. Vesicles and large compound vesicles were generated through a liquid-liquid interface-mediated self-assembly process including adsorption, desorption, aggregation, and microphase separation steps. Unlabelled Image • Composite vesicles, compound vesicles and micelles of block copolymer/Au nanoparticles were generated. • These aggregates were formed through a liquid/liquid interface mediated process. • The block copolymer molecules adsorbed at the interface, combined with inorganic ions and returned to the organic phase. • The composite molecules formed aggregates in the organic phase through self-assembly and microphase separation. • The morphology of the aggregates depends on the critical packing parameters of the composite block copolymers. [ABSTRACT FROM AUTHOR]

Composite nanostructures of PS-b-PAA/Mn+ with various morphologies were fabricated in solutions, emulsions and at interfaces. • A DMF−CHCl 3 solution of PS-b-PAA/aqueous solution of salt interface was constructed. • O/W and W/O emulsions were generated through a spontaneous emulsification process. • PS-b-PAA self-assembled into various organized aggregates in these emulsions. • The molecular structure of PS-b-PAA greatly affects the self-assembly behavior. • The concentration and sort of the metal ions also affect the self-assembly behavior. Composite organized molecular assemblies of amphiphilic block copolymers exhibit various properties and functionalities and have attracted much attention recently. Many research studies have focused on adjusting these properties by varying the fabrication approach and by controlling the morphology of the aggregates. This work involved an investigation of the self-assembly behavior of a series of polystyrene-b-polyacrylic acid (PS-b-PAA) homologues with different block ratios in water-in-oil (W/O) and oil-in-water (O/W) emulsions. These emulsions simultaneously formed via a spontaneous emulsification process across the liquid/liquid interface. A variety of aggregates of the polymers with metal ions were obtained, including microcapsules, spherical micelles, rod-like and disc-like micelles, vesicles, and interior microphase-separated particles. These structures formed either in the emulsion droplets or in the continuous phase, and then proceeded to adsorb at the air/liquid interface or the planar liquid/liquid interface to form thin films. The influence of the molecular structure, the concentration of the metal ions, and the nature of the metal ion on the self-assembly behavior of the polymer molecules and the aggregate morphologies is discussed. In addition, these composite structures are shown to exhibit higher catalytic activity and good stability for the hydrogenation of nitroarenes in aqueous solutions. [ABSTRACT FROM AUTHOR]