Soft materials of europium β-diketonate complexes constructed in lyotropic liquid crystals (LLCs) mediated by ionic liquids (ILs) are impressive for their excellent luminescence performance and stability. For the aim to further improve their mechanical processability and luminescent tunablility, the polyoxyethylene phytosterols (BPS-n) were introduced here as structure directing agents to prepare relatively “rigid” lamellar luminescent LLCs in 1-butyl-3-methyl-imidazolium hexafluorophosphate by doping europium β-diketonate complexes with different imidazolium counterions. As a result of the solvophobic sterol ring structure of BPS-n, the more effective isolation and confinement effects of europium complexes could be achieved. The longest fluorescence lifetime and the highest quantum efficiency reported so far for europium containing lyotropic organized soft materials were thus obtained. Changing the molecular structures of BPS-n with different oxyethylene chains or doped complexes with imidazolium counterions of different alkyl chain lengths, the spacings of lamellar LLC matrixes and position of dispersed complexes became tunable. The measured luminescent and rheological properties for such composite LLCs showed a dependence on the rigidity and isolation capability afforded by sterol molecules. It was also found that the increase of counterion alkyl chain length would weaken the LLC matrix’s confinement and isolation effects and therefore exhibit the deteriorated luminescence performance. The enhanced luminescence efficiency and stability of doped BPS-n LLCs reflected the excellent segregation of europium complexes from each other and therefore the reduced self-quenching process. The obtained results here present the designability of LLC matrixes and their great potential to promote achieving the luminescence tunability of soft materials.

The aggregation behavior of quaternary ammonium gemini surfactants (12-s-12) in a protic ionic liquid, ethanolammonium nitrate (EOAN), was investigated by small-angle X-ray scattering, freeze–fracture transmission electron microscopy, polarized optical microscopy, and rheological measurements. The rarely reported nonaqueous two phases in the ionic liquid were observed at lower 12-s-12 concentrations. The upper phase was composed of micelles, whereas only the surfactant unimers or multimers were detected in the low phase. At higher 12-s-12 concentrations, different aggregates were formed. The lamellar phase was observed in the 12-2-12/EOAN system, whereas the normal hexagonal phases in 12-s-12/EOAN (s = 3, 4, 5, 6, 8) systems and the micellar phase in the 12-10-12/EOAN system were observed. Such a dramatic phase transition induced by the spacer chain length was due to the unique solvent characteristics of EOAN compared to those of water and its counterpart ethylammonium nitrate.

The aggregation behaviors of a Gemini surfactant [C12H25(CH3)2N+(CH2)2N+(CH3)2C12H25]Br2– (12-2-12) in two protic ionic liquids (PILs), propylammonium nitrate (PAN) and butylammonium nitrate (BAN), were investigated by means of several experimental techniques including small and wide-angle X-ray scattering, the polarized optical microscopy and the rheological measurement. Compared to those in ethylammonium nitrate (EAN), the minor structural changes with only one or two methylene units (−CH2−) increase in cationic chain length of PIL, result in a dramatic phase transition of formed aggregates. The critical micellization concentration was increased in PAN, while no micelle formation was detected in BAN. A normal hexagonal phase was observed in the 12-2-12/PAN system, while the normal hexagonal, bicontinuous cubic, and lamellar phases were mapped in the 12-2-12/BAN system. Such aggregation behavior changes can be ascribed to the weaker solvophobic interactions of 12-2-12 in PAN and BAN. The unique molecular structure of 12-2-12 is also an important factor to highlight such a dramatic phase transition due to the PIL structure change.

The hydroxyl group in the spacer of a cationic Gemini surfactant (12-3OH-12) caused dramatic changes of the phase behaviors in a protic ionic liquid (EAN). Here, the effects of the hydroxyl group on micellization and lyotropic liquid crystal formation were investigated through the surface tension, small-angle X-ray scattering, polarized optical microscopy, and rheological measurements. With the hydroxyl group in the spacer, the critical micellization concentration of 12-3OH-12 was found to be lower than that of the homologue without hydroxyl (12-3-12) and the 12-3OH-12 molecules packed more densely at the air/EAN interface. It was then interesting to observe a coexistence of two separated phases at wide concentration and temperature ranges in this 12-3OH-12/EAN system. Such a micellar phase separation was rarely observed in the ionic surfactant binary system. With the increase of surfactant concentration, the reverse hexagonal and bicontinuous cubic phases appeared in sequence, whereas only a reverse hexagonal phase was found in 12-3-12/EAN system. But, the hexagonal phases formed with 12-3OH-12 exhibited lower viscoelasticity and thermostability than those observed in 12-3-12/EAN system. Such unique changes in phase behaviors of 12-3OH-12 were ascribed to their enhanced solvophilic interactions of 12-3OH-12 and relatively weak solvophobic interactions in EAN.

The unique and interesting aggregation behaviors of a novel surfactant-encapsulated complex (SEC), composed of a Keggin-type polyoxometalate (POM), phosphotungstic acid and a redox-responsive ferrocene-containing cationic surfactant, dimethyldioctadecylammonium bromide (BFDMA), have been investigated in N,N-dimethylformamide (DMF)/butanol mixed solvent. By carefully tuning the composition of the solvent, hollow spherical aggregates with multilayered shells were initially observed with a diameter of 55 ± 9 nm using transmission or scanning electron microscopes. Owing to the solvophobic effect and π–π stacking interaction between alkyl chains or ferrocene groups, these spherical aggregates were found to gradually fuse together into aggregates with flower-like and finally compartment-like morphologies with an average size of 120–150 nm. Based on X-ray diffraction measurements and the molecular configuration data of SEC, the multilayers in aggregates were composed of bilayers of SEC with the POM inside and three rearranged BFDMA molecules outside. The morphology of such aggregates was partially reversible under electrochemical modulation. Applying an anodic oxidation potential would induce the disassembling of compartment-like aggregates into irregular spheres with a size of about 200 nm, which could be turned back after applying a cathodic reduction potential. The obtained results here should shed light on the design of novel nanostructures from such inorganic/organic hybrid clusters.

A novel photo-responsive anionic surfactant with a dimethylamino-substituted azobenzene located at the end of the hydrophobic chain, 6-(4-dimethylaminoazobenzene-4′-oxy)hexanoate sodium (DAH), has been designed. Through the host–guest interaction in aqueous solution, the trans-DAH could be spontaneously included by using two native α-cyclodextrin (α-CD) molecules. The formed hydrophilic inclusion complex (DAH@2α-CD), however, could act as a gelator to induce the formation of a supramolecular hydrogel, which is driven mainly by hydrogen bonds between neighboring α-CDs and also between the carboxylate in DAH and water. Compared with common hydrogels that consist of networks with fibres or discrete polymer chains, the hydrogel formed by DAH@2α-CD was composed of periodic lamellar structures possessing good shear-thinning behavior and much swollen water layers. The more interesting point for such a hydrogel was its visible-light responsibility for gel–sol reversible phase transition. This originated from the introduction of an electron-donating group (dimethylamino) to azobenzene, which noticeably red-shifted the responsive wavelength for its trans-to-cis isomerization. It was also worth noting that the host–guest interaction between azobenzene in DAH and α-CD significantly improved the photo-transition efficiency from trans to cis forms of azobenzene, which played a critical role in the visible-light responsibility of the hydrogel. This unique visible-light-responsive behavior combined with the inherent thermo-responsive property from α-CD should make the prepared hydrogel find more potential applications in biomedical systems.

•Phase behavior in a mixture of Gemini surfactants and SDC was investigated.•The obtained aggregates were responsive to both temperature and pH.•The Gemini surfactant structure has a great influence on mixture phase behavior.The phase behavior in a mixture of a cationic Gemini surfactant (12-2-12) and an anionic sodium deoxycholate (SDC) in the aqueous solution was reported here. The microstructures of formed aggregates have been investigated by rheology, small angle X-ray scattering and transmission electron microscopy. Mediated by the hydrophobic and electrostatic interactions of 12-2-12 and SDC, the wormlike micelles and lamellar aggregates were formed successively with increasing the SDC concentration. Due to the presence of hydroxyl and carboxylate groups on SDC, these aggregates were temperature and pH responsive. At low SDC concentrations, the wormlike micelles could be transformed into lamellar aggregates at lower pH. While at high SDC concentrations, the lamellar aggregates would be transformed into wormlike micelles at elevated temperatures. The Gemini surfactant structure also played an important role here on such environment-responsive phase transitions. The obtained results suggest the possibility to form smart aggregates by utilizing simple molecules with certain functional groups.

Luminescent materials from europium β-diketonate complex in ionic liquids (ILs) could achieve enhanced luminescence efficiencies and photostabilities. However, the question of how to provide a feasible and environmentally-friendly way to distribute these lanthanide complexes uniformly and stably within IL-based matrix remains a significant challenge. Here, a soft luminescent material from IL-mediated lyotropic liquid crystals (LLCs) doped with [Bmim][Eu(TTA)4] (Bmim = 1-butyl-3-methyl imidazolium, TTA = 2-thenoyltrifluoroacetone) has been constructed by a convenient self-assembling method. The hexagonal or lamellar LLC phases could be identified by small-angle X-ray scattering (SAXS) measurements. All LLC samples exhibited intense red luminescence upon exposure to ultraviolet radiation. The good dispersibility of the complexes in LLC matrices and their good photostability (as in ILs) was verified by steady-state luminescence spectroscopy. The isolated and unique characteristics of the microenvironment within the LLCs were noteworthy to decrease the nonradiative deactivation of the excited states, thereby allowing more efficient energy transfer and longer lifetimes than those in pure complex or IL solutions. Both the luminescent property and the stability of the LLC materials were different in different phase structures, the complexes behaving better in the lamellar phase than in the hexagonal one. The findings reported herein will not only present an easy way to design novel luminescent lanthanide β-diketonate soft materials, but also provide a useful reference to better understand the LLC phase structure effects on the luminescence properties.

As one type of biocompatible surfactant, phytosterol ethoxylates (BPS-n, n is the oxyethylene chain length) have attracted more and more attention for their characteristic molecular structure. In this paper, the aggregation behaviors of BPS-5 or BPS-10 with five or ten oxyethylene units were investigated in glycerol to explore the solvent molecular structure effect, especially at higher surfactant concentration regions. Surface tension measurements were adopted to analyze the thermodynamic process for micelle formation. Polarized optical microscopy and small-angle X-ray scattering were then used to identify and characterize the formed lyotropic lamellar liquid crystalline (LLC) phase structures. An interesting coexistence of two kinds of lamellar phases in the BPS-5/glycerol system was found, which was attributed to different hydrogen bonding interactions between BPS-5 and glycerol. More intermolecular interaction information was mapped through the rheological measurement and Fourier transformed infrared (FTIR) spectroscopy. The relatively high self-assembling capability of glycerol was recognized to result from its molecular structure with more hydroxyl groups. Its higher Gordon parameter benefitting from the stronger hydrogen-bonded networks made the glycerol exhibit obvious enhancement on the LLC phase formation of BPS-5 or BPS-10, compared to those in water or amide solvents (wider concentration range of LLC phase and higher viscoelasticity). Such a stronger organized solvent structure in glycerol might originate from the special three-dimensional hydrogen-bonding patterns and much higher lifetimes compared to those for water.

Edge effects are predicted to significantly impact the properties of low dimensional materials with layered structures. The synthesis of low dimensional materials with copious edges is desired for exploring the effects of edges on the band structure and properties of these materials. Here we developed an approach for synthesizing MoS2 nanobelts terminated with vertically aligned edges by sulfurizing hydrothermally synthesized MoO3 nanobelts in the gas phase through a kinetically driven process; we then investigated the electrical and magnetic properties of these metastable materials. These edge-terminated MoS2 nanobelts were found to be metallic and ferromagnetic, and thus dramatically different from the semiconducting and nonmagnetic two-dimensional (2D) and three-dimensional (3D) 2H-MoS2 materials. The transitions in electrical and magnetic properties elucidate the fact that edges can tune the properties of low dimensional materials. The unique structure and properties of this one-dimensional (1D) MoS2 material will enable its applications in electronics, spintronics, and catalysis.

Well-organized nanobelts from the complexes of p-aminoazobenzene hydrochloride (AzoHCl) and sodium bis(2-ethylhexyl) sulfosuccinate (AOT) have been constructed through the non-covalent forces such as electrostatic, hydrophobic, and π-π interactions. The nanobelt morphologies were characterized by optical microscope (OM) and scanning electronic microscope (SEM). The nanobelts with the length up to hundreds of micrometers were stacked layer by layer. Their crystal structures were analyzed by small-angle X-ray scattering (SAXS) and X-ray power diffraction (XRD) measurements. The obtained results indicated that the nanobelts of a hexagonal lattice were self-assembled from the columns of complex aggregates with azobenzene groups in the core and hydrocarbon tails of AOT outside. The H-type aggregation state of azobenzene groups here lead to a fluorescence quenching of AzoHCl. The differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) measurements demonstrated the thermostability and crystal nature for these nanobelts. Such a versatile route of self-assembly should shed light on ordered functional materials preparation, with the use of economical surfactants and organic functional molecules.

•The vesicular and lamellar aggregates could be constructed by BPS-30/β-CD mixture systems.•The β-CD does not act as a host molecule but as a cosurfactant.•The main driving force of aggregation is a synergistic effect of H-bonding and hydrophobic interactions.The self-assembling behavior of a nonionic phytosterol ethoxylate surfactant (BPS-30), mixed with β-cyclodextrin (β-CD) at a 1:1 molar ratio, has been investigated in aqueous solutions. The anisotropic and birefringent aggregates obtained with the mixtures present vesicle and lamellar morphologies, which are rarely found in other surfactant/β-CD mixture systems. The observed aggregate morphologies are determined mainly by the surfactant concentrations as evidenced through observations using scanning or cryo-transmission electron microscopy. The vesicle aggregates appear in solutions of low BPS-30 concentrations (<12 wt%), while the lamellar structures are observed in solutions of high BPS-30 concentrations (>12 wt%). Additional aggregate structural details are explored through small-angle X-ray scattering measurements. Different with other surfactant/β-CD mixture systems, β-CD appears to function as a cosurfactant in this research, as shown by the 1H–1H NOESY nuclear magnetic resonance spectroscopy and the surface tension measurements. Control experiments with urea molecules were conducted to demonstrate that the main driving force of aggregation is a synergistic effect of the H-bonding and hydrophobic interactions. The obtained results on the nonionic mixture of biosurfactant/β-CD in this paper further demonstrate the potential expanded applications of soft matter construction.

•Micro-scale Au nanoparticle sheet-like assemblies with uniform sizes and shapes were fabricated.•The crystallization of C16MMB was identified to induce the formation of the assemblies.•Sensitive and uniform SERS signals were obtained using the assemblies as substrates.Crystallization of the N-methyl-N-hexadecylmorpholinium bromide (C16MMB) surfactant in Au nanoparticles (Au NPs) sol could induce a large-scale production of uniform rectangular Au@C16MMB crystal sheets with uniform surface enhanced Raman scattering (SERS) activity. Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopic measurements have been adopted to characterize the crystal sheet morphology and structure. The island-like Au NPs aggregates were observed to distribute uniformly over the surface of C16MMB crystal, which provide sufficient SERS-active sites. Results from zeta potential measurement and molecular dynamic simulation indicated that the C16MMB molecules were electrostatically adsorbed on Au NPs to reverse the nanoparticle surface charge to be positive. The concentration and crystallization capability of C16MMB in solution play a key role to induce the formation of the self-organized Au@C16MMB crystal sheets. A surfactant crystallization induced assembling mechanism has been proposed. Raman tests of Au@C16MMB as an ideal SERS substrate exhibit the high enhancement factor and good uniformity. It is believed that this approach could provide a unique way to fabricate uniform noble metal nanoparticle-based SERS substrates.

The aggregation behaviors of a Gemini surfactant [C12H25(CH3)2N+(CH2)2N+(CH3)2C12H25]Br2– (12-2-12) in two protic ionic liquids (PILs), propylammonium nitrate (PAN) and butylammonium nitrate (BAN), were investigated by means of several experimental techniques including small and wide-angle X-ray scattering, the polarized optical microscopy and the rheological measurement. Compared to those in ethylammonium nitrate (EAN), the minor structural changes with only one or two methylene units (−CH2−) increase in cationic chain length of PIL, result in a dramatic phase transition of formed aggregates. The critical micellization concentration was increased in PAN, while no micelle formation was detected in BAN. A normal hexagonal phase was observed in the 12-2-12/PAN system, while the normal hexagonal, bicontinuous cubic, and lamellar phases were mapped in the 12-2-12/BAN system. Such aggregation behavior changes can be ascribed to the weaker solvophobic interactions of 12-2-12 in PAN and BAN. The unique molecular structure of 12-2-12 is also an important factor to highlight such a dramatic phase transition due to the PIL structure change.

Fabrication of lyotropic aggregates containing the lanthanide ions is becoming a preferable way to prepare novel functional materials. Here, the lyotropic liquid crystals (LLCs) of reverse hexagonal, reverse bicontinuous cubic, and lamellar phases have been constructed in sequence directly from the mixtures of Eu(NO3)3·6H2O and Pluronic P123 amphiphilc block copolymer with increasing the salt proportion. Their phase types and structural characteristics were analyzed using polarized optical microscopy (POM) and small-angle X-ray scattering (SAXS) measurements. The driving forces of reverse LLC phase formation were investigated using Fourier-transformed infrared spectroscopy (FTIR) and rheological measurements. The hydrated europium salt was found to act not only as a solvent here, but also as the bridge to form hydrogen bonding between coordinated water molecules and PEO blocks, which played a key role in the reverse LLCs formation. Compared to those in aqueous solutions and solid state, the enhanced luminescence quantum yields and prolonged excited state lifetimes were observed in two europium containing reverse mesophases. The luminescence quenching effect of lanthanide ions was efficiently suppressed, probably due to the substitution of coordinated water molecules by oxyethyl groups of P123 and ordered phase structures of LLCs, where the coordinated europium ions were confined and isolated by PEO blocks. The optimum luminescence performance was then found to exist in the reverse hexagonal phase. The obtained results on such lanthanide-induced reverse LLCs should be referable for designing new luminescent soft materials construction to expand their application fields.

The aggregation behavior of Gemini surfactants with hydroxyl groups in their headgroups, butane-1,4-bis(hydroxyethyl methylalkylammonium) bromides hereafter abbreviated as m-4-m MEA (m = 12, 14, 16), has been investigated in aqueous solution. Each formed a viscous fluid in water at low concentration in the absence of a salt. In solutions of 14-4-14 MEA, the formation of highly viscoelastic wormlike micelles could be detected using steady and dynamic rheological measurements. The existence of these long column micelles has also been confirmed using cryo-transmission electron microscopy (cryo-TEM) and small angle X-ray scattering (SAXS). Compared with conventional bis(dimethylalkylammonium) bromide Gemini molecules with the same spacer (14-4-14), 14-4-14 MEA demonstrated a better ability to fabricate wormlike micelles because of the change in the headgroup structure. As for 16-4-16 MEA, which has longer alkyl chains, its aqueous solutions behave more like elastic gels at a concentration of 80 mmol L−1. The unique viscoelastic behavior of m-4-m MEA in water can be attributed to the synergistic interactions of hydrophobic attraction and hydrogen bonding. The obtained results are believed to be an important addition to the effect that the headgroups of Gemini surfactants have on their aggregation behavior in dilute solutions.

•The supramolecular gel with a flower-like morphology structure has been prepared.•The Ag-Fe3O4 nanodimer and carboxylated cyclodextrin play a key role to the gel morphology.•The introduction of nanodimers to gel may bring potential applications from both Ag and Fe3O4.Being considered as building blocks, the inorganic nanodimer particles such as Ag-Fe3O4, Cd-Se and Pt-Fe3O4, have attracted much attention because of their capability of dual surface functionalization and potential applications in field-emission, data storage and photovoltaic devices. For these motivations and as a continuation of our previous study, a gel with flower-like morphology based on Ag-Fe3O4 nanodimers has been constructed with the carboxylated cyclodextrin (MAH-CD) and Pluronic F127 molecules in mixed solvent of cyclohexane and water. The morphology of Ag-Fe3O4 nanodimers and structure of MAH-CD were characterized by transmission electron microscopy (TEM) and nuclear magnetic resonance (NMR) respectively. The mechanism of gel formation is discussed along with the data obtained from rheological measurement, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transformation infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Each Ag-Fe3O4 particle was coated by lots of MAH-CD molecules, which were threaded by F127 chains. The gel fabrication is controlled by the inclusion of MAH-CD with F127, the interaction between the carboxyl group and the Fe3O4 surface. The cyclohexane molecules in gel were trapped with F127 by cyclodextrin, which may be packed orderly through hydrogen bond. Meanwhile, the Fe3O4 side of nanodimers provides the anchoring position for carboxyl group to induce the formation of gel. Such an Ag-Fe3O4 nanodimer initiated gel can be used either based on Ag side for catalytic and sensing properties, or based on superparamagnetism from Fe3O4 side.The inclusion between carboxylated cyclodextrin (MAH-CD) and block polymer F127 forms a column-like structure, which may be close-packed to produce a crystal flake. With the help of anchoring cyclodextrin through the carboxyl group on Ag-Fe3O4, a flower-like gel morphology could be built by the directionally arranged flakes. Without carboxyl, however, the inclusions with normal β-CD could only result in a gel with a bulk solid morphology.

•A novel acid-soap has been prepared from a nitrogen-containing heterocyclic compound, pyrrolidine, and fatty acid.•Two six-membered-ring interacted hydrogen bonds have been speculated to make complex stable.•The pyrrolidinium fatty acid-soap exhibits amphiphilicity and can construct lamellar LLC phase in waterThe hydrogen bond induced acid–soap like complex has been prepared from a nitrogen-containing heterocyclic compound, pyrrolidine, and the myristic acid (MA). The complex composition and the intermolecular actions between two component molecules have been characterized with techniques of nuclear magnetic resonance (NMR), X-ray diffraction (XRD) and Fourier transformation infra-red (FTIR) spectroscopy. The molar ratio between the soap (pyrrolidium myristate, PM) and the acid (MA) is identified as 1:1. As an important driving force of assembly, the existence of hydrogen bond is further confirmed by a molecular mechanics calculation. It is interesting that such an acid–soap complex (PM–MA) exhibits amphiphilicity and its lyotropic liquid crystal phase in water has been observed over a wide concentration range. A lamellar phase structure is established using the polarized optical microscopy (POM) and small-angle X-ray scattering (SAXS) measurements. The change of lattice spacing indicates a typical one-dimensional swelling scheme for the uptake of water by this lamellar phase. The frequency-independent storage and loss module could be found for these lamellar samples by rheological measurements, reflecting a highly viscoelastic nature. The obtained results should add new insights to better understand the structure and aqueous behavior of long-chain fatty acid–soaps with a large size nitrogen-heterocyclic counterion.The pyrrolidinium fatty acid soaps containing a large size nitrogen-heterocyclic counterion have been prepared. Such an acid–soap complex exhibits well self-assembling properties in water and a lamellar lyotropic liquid crystalline phase has been successfully constructed over a wide concentration range.

Materials exhibiting unique aggregation behavior in nonaqueous solvents have attracted attention due to their wide applications. Motivated by this recent interest, the aggregation properties of a phytosterol ethoxylate surfactant, BPS-10, in three organic amide compounds, formamide (FA), N-methylformamide (NMF), and N,N-dimethyl- formamide (DMF), have been studied. Polarized optical microscopy and small-angle X-ray scattering techniques were used to investigate the lyotropic liquid crystalline (LLC) phases formed in these binary systems. Herein, we discuss the relationship between subtle intermolecular interactions and the aggregation behavior of BPS-10. As good proton donors or acceptors to form hydrogen bonding, FA molecules allow BPS-10 to show a richer phase behavior. Compared with the systems formed in water and ionic liquids, the LLCs constructed in FA have higher thermal stability. In addition, two kinds of lamellar phases could coexist in a narrow region. With the methyl replacement in formamide, however, the ability to form hydrogen bonds is reduced and the solvent bulk phase structure becomes less ordered from FA to DMF. Consequently, the solvophobic interaction of BPS-10 becomes weaker, and the LLCs are more difficult to form. In addition, the extra strong interactions between the steroid rings of BPS-10 may provide enough driving force to produce the hexagonal phase (H1) directly in NMF and DMF without micelle formation, thereby creating a novel sequence (isotropic → H1 → Lα) of ordered phases with increasing surfactant concentration. The results discussed herein should prove to be a useful complement to the growing body of literature regarding steroid surfactant aggregation in polar organic solvents.

Two different room-temperature ionic liquids (ILs), the protic ethylammonium nitrate (EAN) and the aprotic 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4), have been employed to investigate the solvent protonation effect on aggregation behaviors of a phytosterol ethoxylate surfactant (BPS-10). The calculated thermodynamic parameters based on surface tension measurements present a stronger solvophobic interaction in EAN than that in [Bmim]BF4 and disclose different driving forces for micelle formation. In addition, the polarized optical microscopy and small-angle X-ray scattering techniques are used to characterize the phase structures formed in both systems at 25 °C. Due to the H-bonding networks in protic EAN, BPS-10 exhibits a lyotropic liquid-crystalline behavior different from that in [Bmim]BF4. Results obtained from the rheological measurements reflect a more viscoelastic nature of lyotropic liquid-crystalline phases in EAN. The obtained results indicate that the protic EAN behaves more effective than [Bmim]BF4 to promote the nonionic BPS-10 aggregation.

The micelle formation by the surface active ionic liquids (ILs) N-alkyl-N-methylpiperidinium bromide CnPDB (n = 12, 14, 16) in aqueous solution has been investigated through the characterizations of surface tension, electrical conductivity and steady-state fluorescence measurements. From the curves of surface tension vs CnPDB concentration at 25 °C, the critical micelle concentration (cmc), the effectiveness of the surface tension reduction (Πcmc), the maximum surface excess concentration (Гmax) and the minimum area (Amin) occupied per surfactant molecule at the air/water interface are calculated. Through the electrical conductivity measurements, the cmc values at different temperatures and a series of thermodynamic parameters (ΔGm°, ΔHm° and ΔSm°) for the formation of micelles are evaluated in the temperature range of 25–45 °C. The steady-state fluorescence measurement is also employed to investigate the micelle formation of CnPDB.Graphical abstractThe micelle formation by the surface active ionic liquids (ILs) N-alkyl-N-methylpiperidinium bromide CnPDB (n = 12, 14, 16) in aqueous solution is investigated through the characterizations of surface tension, electrical conductivity, and steady-state fluorescence measurements.Highlights► Micelles are formed by N-alkyl-N-methylpiperidinium (CnPDB) bromides in aqueous solution. ► CnPDB surface activity is compared with other surfactants of N-heterocycle headgroups. ► Micelle formation is entropy- or enthalpy-driven at low or high temperatures.

The aggregation behaviors of three Gemini surfactants [(CsH2s-α,ω-(Me2N+CmH2m+1Br–)2, s = 2, m = 10, 12, 14] in a protic ionic liquid, ethylammonium nitrate (EAN), have been investigated. The polarized optical microscopy and small-angle X-ray scattering (SAXS) measurements are used to explore the lyotropic liquid crystal (LLC) formation. Compared to the LLCs formed in aqueous environment, the normal hexagonal and lamellar phases disappear. However, with increasing the surfactant concentration, a new reverse hexagonal phase (HII) can be mapped over a large temperature range except for other ordered aggregates including the isotropic solution phase and a two-phase coexistence region. The structural parameters of the HII are calculated from the corresponding SAXS patterns, showing the influence of surfactant amount, alkyl chain length, and temperature. Meanwhile, the rheological profiles indicate a typical Maxwell behavior of the LLC phases formed in EAN.

The aggregation behaviors of a series of dissymmetric cationic Gemini surfactants, [CmH2m+1(CH3)2N(CH2)2N(CH3)2CnH2n+1]Br2, designated as m-2-n (with a fixed m + n = 24, m = 16, 14, 12) have been investigated in a protic ionic liquid, ethylammonium nitrate (EAN). Surface tension, polarized optical microscopy (POM), small-angle X-ray scattering (SAXS), and rheological measurements are adopted to investigate the micellization and lyotropic liquid crystal (LLC) formation. The obtained results indicate that the structure dissymmetry plays an important role in aggregation process of m-2-n. With increasing degree of dissymmetry, the critical micellization concentration, the maximum reduction of solvent surface tension, and the minimum area occupied per surfactant molecule at the air/EAN interface all become smaller. The thermostability of formed LLCs is therefore improved because of the more compact molecules. These characteristics can be explained by the enhancement of solvophobic effect due to the increased structure dissymmetry of Gemini surfactants.

The tough stimuli-responsive vesicles were prepared via electrochemical oxidation on the mixture solution of ferrocenylmethyl-trimethylammonium iodide (FcMI) and sodium deoxycholate (NaDC). The vesicle structure and morphology are characterized respectively by transmission electron microscopy (TEM), dynamic light scattering (DLS) and atomic force microscopy (AFM). The vesicle shells can be clearly observed by TEM with the thickness ranging from several to several tens of nanometers and their outer diameters at the range of 50–200 nm. The formation of vesicular structures is also supported via AFM measurements. Such tough vesicles made up of ferrocene and deoxycholate blocks are redox-responsive, and their assembly or disassembly behaviors may be controlled by electrochemical methods through the change of ferrocene states between the neutral hydrophobic and the hydrophilic ferrocenium cation. In addition, the stimuli-responsive vesicles can also be formed from the supramolecular inclusion complex between the ferrocene blocks and the β-cyclodextrin hosts, which can then be transformed into nanotubes with time. The obtained results are significant for the preparation of smart supramolecular aggregates.Graphical abstractHighlights► The tough stimuli-responsive vesicles were prepared via electrochemical oxidation. ► The vesicles obtained by electro-oxidation possess redox responsive properties. ► The stimuli-responsive vesicles can be formed from the β-CD inclusion complex. ► The vesicles formed from the complex can be transformed into nanotubes with time.

The phase behaviors of four phytosterol ethoxylates surfactants (BPS-n, n = 5, 10, 20, and 30) with different oxyethylene units in room temperature ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4), have been studied. The polarized optical microscopy and small-angle X-ray scattering techniques are used to characterize the phase structures of these binary systems at 25 °C. The structure and ordering of the liquid crystalline (LC) phases in such BPS-n/[Bmim]BF4 systems are found to be influenced by BPS-n concentration and the temperature. Due to the bulky and rigid cholesterol group, the phytosterol ethoxylates surfactants exhibit different properties and interaction mechanism from the conventional CnEOm type nonionic surfactant systems. The rheological measurements indicate a highly viscoelastic nature of these lyotropic LC phases and disclose a lamellar phase characteristic with a rather strong rigidity at high surfactant concentrations. The control experiment with Brij 97(polyoxyethylene (10) oleyl ether)/[Bmim]BF4 system and the FTIR measurements help to recognize that the solvophobic interaction combining with the hydrogen bonding are the main driving forces for the LC phases formation.Graphical abstractHighlights► The phase diagrams of nonionic surfactant BPS-n in [Bmim]BF4 at 25 °C are mapped. ► The formed lyotropic liquid crystal (LLC) structure and ordering are influenced by BPS-n content and temperature. ► The interaction between steroid rings of BPS-n is the dominated factor to result in LLC. ► The LLC in such system exhibits highly apparent viscosity.

A novel series of protic tertiary pyrrolidinium surfactants were prepared and characterized by different techniques. These compounds show good conductivity and efficient ability to reduce surface tension. Thermogravimetric analysis proves their high thermal stability at decomposition temperatures over 250 °C. Their lyotropic and thermotropic liquid crystalline properties are also discussed.

Vesicles prepared in an aqueous solution through self-assembly of the oxidized form of N,N-dimethyl-aminomethylferrocene (Fc+M) and an anionic surfactant, sodium bis(2-ethyl-1-hexyl) sulfosuccinate (AOT), could be reversibly transformed by redox reactions. Adding the hydroquinone as a reducing agent will cause the dissociation of vesicles and change the solution into emulsion. Subsequent oxidization by adding Ce(SO4)2 will regenerate vesicles. The vesicle structure and morphology were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS), respectively and the mean particle size was about 200 nm. The mechanism of vesicle formation and disruption caused by redox reactions is discussed along with the data obtained from cyclic voltammetry (CV) and UV–vis spectroscopy measurements. The redox state changes of the ferrocenyl moiety may influence the noncovalent interactions between FcM and AOT. Meanwhile, the π–π stacking and amphiphilic hydrophobic association are also included during such a redox modulated process. These results provide guidance for the design of surfactant and small molecular systems that permit active control of self-assembly.

The aggregation behaviors of oleyl polyoxyethylene (10) ether, Brij 97, in room temperature ionic liquids, ethylammonium nitrate (EAN), pyrrolidinium nitrate ([Pyrr][NO3]), ethylammonium butyrate (EAB), 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]), and 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]), have been investigated. Only in the Brij 97/EAN binary system is the hexagonal liquid crystalline phase formed, and its ordering is found to decrease with increasing temperature. The lattice spacing values measured from the small-angle X-ray scattering (SAXS) shrink with reduction of ionic liquid content at room temperature. The general rules for aggregate formation in these ionic liquids are discussed and compared with that in water. A degraded ability to produce the ordered self-assembly of Brij 97 from H2O to EAN to [Bmim][PF6], [Bmim][BF4], [Pyrr][NO3], and EAB is found and analyzed based on the molecular packing and Gordon parameters and also hydrogen-bonding or solvophobic interactions. Steady-shear rheological measurements combined with the frequency sweep data indicate the highly viscoelastic nature of this liquid crystalline phase.

Wormlike nanowires have been successfully prepared via the ionic self-assembly (ISA) route from the cationic (ferrocenylmethyl)trimethylammonium iodide (FcMI) and the anionic sodium bis(2-ethyl-1-hexyl)sulfosuccinate (AOT). The formed FcM−AOT complexes have been proved to possess a composition of equal molar ratio and show good redox activity also due to the introduction of organic metal ferrocene. These complexes exhibit an ordered hexagonal columnar structure with the lattice spacing D of 2.49 nm. More interestingly, the wormlike nanowires interweave themselves together to form a net-like structure, and some of them are large enough to exhibit a high-order crystal structure. In addition, such an ISA organized aggregate can be changed into vesicles by including the Fc blocks into β-cyclodextrins to form another supramolecular complex. The supramolecular structure and morphology of the vesicles were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS), respectively. Both the complex fabrication and transition mechanisms are discussed and found to be controlled by the inclusion equilibrium and the cooperative binding of noncovalent interactions, including the electrostatic interactions, π−π stacking, and amphiphilic hydrophobic association.

Stable solid-like vesicles were prepared via a facile ionic self-assembly (ISA) route, through complexation between 1-naphthylammonium chloride (NA) and sodium deoxycholate (NaDC), and the vesicles could entrap hydrophilic quantum dots (QDs) to exhibit fluorescence microscopy images and transform to nanobelts with temperature.

The aggregation behavior of a surfactant-like ionic liquid, 1-hexadecyl-3-methylimidazolium chloride (C16mimCl), in a room temperature ionic liquid ethylammonium nitrate (EAN) has been investigated. With increasing C16mimCl concentration, a series of ordered aggregates including micelles, normal hexagonal (H1), lamellar (Lα), and reverse bicontinuous cubic (V2) liquid crystalline (LC) phases can be detected over a large temperature range by using polarized optical microscopy (POM) and small-angle X-ray scattering (SAXS) techniques. When comparing such a phase behavior with that of the C16mimCl/H2O binary system, an additional V2 phase is identified and could be attributed to the different affinities of C16mimCl to EAN and water. Higher temperatures induce smaller lattice spacing for the LC phases, which may be due to the softening of the solvophobic chains of C16mimCl molecules. Both the imidazolium ring structure and alkyl chain of C16mimCl molecule are proved to play important roles for the LC phase formation. Dissipative particle dynamic simulations are also carried out at room temperature, and the obtained intuitive three-dimensional (3D) models can help us better understand the self-assembled structures, which are considered to be supplements for the experimental results.

The phase behavior of a catanionic system composed by a cationic surfactive ionic liquid (IL), 1-hexadecyl-3-methylimidazolium chloride ([C16mim]Cl), an anionic sodium dodecyl sulfate (SDS), and water has been investigated. A novel gel phase with quite high water content can be fabricated showing similar rheological properties to vesicles usually formed in traditional catanionic systems. The lamellar structure could also be constructed in SDS-rich region. Both the hydrophobic interaction of alkyl chains and interactions between oppositely charged head groups play important roles for the gel formation. Such a facile method to form gels directly from the catanionic system at relative low surfactant concentrations is novel, which should be related to the specific molecular structure of imidazolium ILs. The obtained results are expected to be helpful for better understanding of catanionic systems.

Copper sulfide nanoparticles with mean diameter about 1 nm have been prepared in copper bromide-based perovskite organic–inorganic crystal hybrid templates (CnH2n+1NH3)2CuBr4 (abbreviated as CnCuBr, n = 10, 12, 16 and 18) by reacting their spin-casting films with H2S gas. X-ray powder diffraction (XRD) reveals the layered structure of CnCuBr templates. Transmission electron microscopy (TEM), UV–visible (UV–vis) absorption spectroscopy and photoluminescence spectroscopy (PL) are respectively adopted to characterize the products morphologies and optical properties. The obtained results indicate an important effect of template anions on size control of the formed particles. Such a preparation method also provides an effective way to incorporate the functional inorganic nanoparticles into the structured organic matrices.

The lamellar liquid crystalline phases composed of either imidazolium salt, the hydrophilic 1-butyl-3-methylimidazolium tetrafluoroborate (bmim-BF4) or the hydrophobic 1-butyl-3-methylimidazolium hexafluorophosphate (bmim-PF6), in aqueous solution of Brij-30 (tetraethylene glycol lauryl ether, C12E4) have been assembled at a constant temperature (T = 25 °C). Their elaborate structures such as the distribution of hydrophobic or hydrophilic parts of surfactant bilayer and water are revealed quantitatively by several structural parameters derived from small-angle X-ray scattering (SAXS) measurements. The effects of system composition and temperature on the lamellae are discussed with comparison to the corresponding Brij-30/water binary mixture. It concludes that the bmim-PF6 molecules tend to situate at the interface between polar and apolar regions and therefore cause a decrease of combined water amount around EO blocks. Bmim-BF4 molecules, however, like to locate themselves at water interlayers as well as in the polar domains. In addition, the pseudo-hexagonal columnar structures or micelles observed respectively at low or high temperatures are analyzed by SAXS and differential scanning calorimetry (DSC) methods.

Aggregation of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) triblock copolymer, Pluronic P123, is promoted in a room temperature ionic liquid, ethylammonium nitrate (EAN). A series of lyotropic mesophases including normal micellar cubic (I1), normal hexagonal (H1), lamellar (Lα), and reverse bicontinuous cubic (V2) are identified at 25 °C by using polarized optical microscopy and small-angle X-ray scattering techniques. Such self-assembly behavior of P123 in EAN is similar to those observed in H2O or 1-n-butyl-3-methylimidazolium hexafluorophosphate ([BMim+][PF6−]) systems except for the presence of the V2 phase in EAN and the absence of the I1 phase in [BMim+][PF6−]. This suggests that the ionic solvent of EAN plays similar roles as H2O and [BMim+][PF6−] during the aggregation process and solvates the PEO blocks through hydrogen-bond interaction. Furthermore, the hydrogen bonds are considered to form between the ethylammonium cations and oxygen atoms of the PEO blocks as confirmed by Fourier transform infrared spectra of P123−EAN assemblies. This deduction is also consistent with the results from differential scanning calorimetry and thermogravimetric analysis. The additional V2 phase appearing in the P123−EAN system is attributed to the higher affinity for the relatively hydrophobic PPO blocks to EAN than to water, which might reduce the effective area of the solvophilic headgroup and increase the volume of the solvophobic part. The obtained results may help us to better understand the self-assembly process for amphiphilic block copolymers in protic solvents.

The supramolecular ionic self-assembly (ISA) strategy has been used to construct the long-range ordered hierarchical aggregates from the complexes of 1-adamantanamine hydrochloride (AdCl) and sodium bis(2-ethyl-1-hexyl)sulfosuccinate (AOT). The formed AOT−Ad complexes have been proved to possess a composition of equal molar ratio and a hexagonal columnar structure with Ad blocks as the core and AOT outside. More interestingly, the length, width, and thickness of the aggregates are on the order of milli-, micro-, and nanometer, respectively, and can thus be taken as one type of organic nanobelt. Such nanobelts are plastic and stable to resist breakage even bent to a circle, which makes them useful in the fields of novel nanomaterial fabrication. In addition, the ISA process of this aggregate can be tuned by including Ad blocks in β-cyclodextrins to form a supramolecular complex, which is comparatively stable in the water and expected to self-assemble into some other ordered structures.

Single-crystalline gold nanoplates have been synthesized in a lamellar lyotropic liquid crystal (LLC) composed of a nonionic surfactant, C12E4 (tetraethylene glycol monododecyl ether) and the chloroauric acid (HAuCl4) solution. The sizes of gold nanoplates can be varied from several hundreds of nanometers to a few microns in width by changing reaction conditions. The factors which influence the product morphology, like LLC composition, capping agent and reaction temperature are studied by small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The mechanism analysis indicates that the LLC plays an important role for the consequent growth of single-crystal anisotropic plates by providing an ordered reaction medium and a limited growth space.

Lyotropic liquid crystals formed in a ternary system of 1-hexadecyl-3-methylimidazolium chloride ([C16mim]Cl), 1-decanol, and water at 25 °C are reported. The hexagonal and lamellar phases were characterized by small angle X-ray scattering and polarizing optical microscopy. In the phase diagram, the system shows two isotropic liquid phases, a hexagonal phase connected to the [C16mim]Cl–water axis, and a lamellar phase in the center. The formation of liquid crystalline phases is believed to arise from a hydrogen-bonded network comprised of an imidazolium ring, anion, 1-decanol, and water. In the liquid crystal, the intercalation of 1-decanol between neighboring [C16mim]Cl molecules favors the appearance of lamellar phases. The phase behavior of the present system is discussed in comparison with a similar ternary system of cetyltrimethylammonium bromide (CTAB).Hexagonal and lamellar lyotropic liquid crystals for 1-hexadecyl-3-methylimidazolium chloride with 1-decanol and water could be formed by H-bond network.

Single-crystalline gold nanoplates and also nanobelts, with {1 1 1} crystallographic facets and size length longer than 20 μm, are synthesized in large scale by reduction of HAuCl4 in lyotropic liquid crystal phases. Such flat products can be obtained from different systems including hexagonal or lamellar phases made of P123 (EO20PO70EO20) where different ionic liquid like additives play the crucial roles in the product formation. The results demonstrate that the product sizes and morphologies strongly depend on the balance among forces between different components and the adsorption of imidazolium cations on gold through controlling the reduction rates by their molar ratios.

The polypseudorotaxanes (PPRs) have been prepared by supramolecular self-assembly of β-cyclodextrins (β-CDs) threaded onto the triblock copolymers (Pluronic F127) in an ionic liquid [1-n-butyl-3-methylimidazolium hexafluorophosphate (bmimPF6)] with two different manners. Structural characterizations of the assembled PPRs are carried out in detail respectively with XRD, 13C CP/MAS NMR, 1H NMR and DSC techniques. The results obtained indicate a channel-type crystalline structure for such produced inclusion complexes (ICs). Which one will finally be included inside β-CD, F127 or bmimPF6, is related to the ethanol amount around the initially β-CD/bmimPF6 ICs. At higher ethanol concentration, F127 may squeeze bmimPF6 molecules out from β-CD and thread themselves instead into the cavity of β-CD and finally precipitate with more CDs being stacked.

We report the electrophoretic deposition (EPD) of oleate-stabilized silver nanoparticles in lamellar lyotropic liquid crystal (LLC), composed of anionic surfactant sodium bis-(2-ethylhexyl) sulfosuccinate (AOT), isooctane, and water. Partly organized nanoparticle arrays are obtained. LLC template and the deposit are characterized respectively with small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Obtained results indicate that LLC template influences the array structure and nanoparticles have an additional aggregation effect under the electric field. Ag particles will assemble themselves more densely with increasing field strength and electrophoretic time. The possible description scheme on EPD of nanoparticles in lamellar LLC is discussed.

AbstractThe hydrophilic silver and hydrophobic gold nanoparticles are doped simultaneously or separately into different regions of a lyotropic liquid crystal (LLC) with long-range structural order built with the AOT/isooctane/ water ternary system. A stable lamellar hybrid is produced under suitable conditions. Polarized optical microscopy (POM) and small angle X-ray scattering (SAXS) are used to compare the phase changes upon various doping manners. The interactions between doped particles and surfactant bilayers are analyzed and compared in detail. Factors affecting the stability of inorganic/organic hybrids are also discussed. The doped hydrophobic particles affect the equilibrium of van der Waals and Helfrich interactions between them and the membranes. When hydrophilic particles are incorporated into LLC aqueous region, electrostatic force will be dominant. The results suggest that it is the balance of electrostatic, van der Waals, and Helfrich forces in the lyotropic liquid crystal that determines the hybrid structure.

A facial synthesis process of silver nanoparticles (NPs) capped by cetyltrimethylammonium bromide (CTAB) is reported with exploration for the capping effect of CTAB on particles’ stability and surface properties in aqueous medium. Multidisciplinary approaches including electrophoresis, UV-visible absorption spectroscopy, Fourier-transformed infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), thermal gravimetric analysis (TGA) and small angle X-ray scattering (SAXS) are conducted to systematically investigate surface charge and the adsorbed CTAB layer structure on Ag clusters. Obtained results indicate that CTAB molecules bind strongly to silver surface via their headgroups and form a bilayer shell. Detailed analysis of SAXS and NMR data and discussion on the interaction between CTAB molecules and NPs’ surface, provide a clearer model of capped molecules on Ag clusters.

ZnS semiconductor nanodisks are directly prepared from zinc chloride perovskite organic–inorganic layered crystals (CnH2n+1NH3)2ZnCl4 (n=10 and 12) by reacting their spin-casting films with H2S gas. The alkyl amine layers in the template act both for structure-direction and for surface-passivation during the formation of nanodisks. Transmission electron microscopy (TEM), UV–vis spectroscopy and small-angle X-ray diffractometry (SAXD) are used to characterize the product morphology and the matrix structure. Quartz Crystal Microbalance (QCM) is also applied to explore the kinetics of such gas–solid reaction. Obtained results indicate an effective way to prepare functional inorganic nanoparticles from structured hybrids.

Lyotropic liquid crystalline phases of an amphiphilic block copolymer are constructed and characterized in an ionic liquid with comparison of component and temperature effects.

Soft lanthanide luminescent materials are impressive because of their tunable and self-assembling characteristics, which make them an attractive emerging materials field of research. In this report, novel luminescent lyotropic liquid crystals (LLCs) with four different mesophases have been fabricated by a protic ionic liquid (IL) based europium β-diketonate complex EA[Eu(TTA)4] (EA = ethylammonium, TTA = 2-thenoyltrifluoro-acetone) and an amphiphilic block copolymer (Pluronic P123). The protic IL, ethylammonium nitrate (EAN), was used as both the solvent and linkage to stabilize the doped complexes. Analyses by single-crystal X-ray diffraction for EA[Eu(TTA)4] and Fourier transform infrared spectroscopy for the LLC materials reveal convincingly that the ethylammonium cations establish an effective connection with both the carbonyl group of the β-diketonate ligand and the EO blocks of the amphiphilic block copolymer P123 via strong hydrogen bonding interactions. Due to this, an extremely long decay time of the excited state is obtained in EA[Eu(TTA)4] and excellent photostability of the luminescent LLCs could be achieved. The long-period ordered structures of the luminescent LLCs have been investigated by small-angle X-ray scattering measurements and the best luminescence performance was found in the most organized mesophase. Noteworthy, the LLCs could yield an effective confining effect on the europium complex accompanied by a sizeable elongation of the excited-state lifetime and an enhancement of the energy transfer efficiency, which reaches a remarkably high value of 52.6%. More importantly, the modulated luminescence properties observed in the four mesophase structures offer the potential and powerful possibility for these unique composite LLCs to be used in the fabrication of soft luminescent materials with tunable functions.

Luminescent materials from europium β-diketonate complex in ionic liquids (ILs) could achieve enhanced luminescence efficiencies and photostabilities. However, the question of how to provide a feasible and environmentally-friendly way to distribute these lanthanide complexes uniformly and stably within IL-based matrix remains a significant challenge. Here, a soft luminescent material from IL-mediated lyotropic liquid crystals (LLCs) doped with [Bmim][Eu(TTA)4] (Bmim = 1-butyl-3-methyl imidazolium, TTA = 2-thenoyltrifluoroacetone) has been constructed by a convenient self-assembling method. The hexagonal or lamellar LLC phases could be identified by small-angle X-ray scattering (SAXS) measurements. All LLC samples exhibited intense red luminescence upon exposure to ultraviolet radiation. The good dispersibility of the complexes in LLC matrices and their good photostability (as in ILs) was verified by steady-state luminescence spectroscopy. The isolated and unique characteristics of the microenvironment within the LLCs were noteworthy to decrease the nonradiative deactivation of the excited states, thereby allowing more efficient energy transfer and longer lifetimes than those in pure complex or IL solutions. Both the luminescent property and the stability of the LLC materials were different in different phase structures, the complexes behaving better in the lamellar phase than in the hexagonal one. The findings reported herein will not only present an easy way to design novel luminescent lanthanide β-diketonate soft materials, but also provide a useful reference to better understand the LLC phase structure effects on the luminescence properties.

Stable solid-like vesicles were prepared via a facile ionic self-assembly (ISA) route, through complexation between 1-naphthylammonium chloride (NA) and sodium deoxycholate (NaDC), and the vesicles could entrap hydrophilic quantum dots (QDs) to exhibit fluorescence microscopy images and transform to nanobelts with temperature.