Rational engineering of one-dimensional (1D) self-assembled aggregates to produce desired materials for versatile functions remains a challenge. In this work, we report the noncovalent modulation of 1D aggregates at the micro/nanoscale using a coassembly protocol. Aromatic amino acids were employed as the model building blocks, and melamine (Mm) behaves as a modulator to form coassembly arrays with aromatic amino acids selectively. The selective self-assembly behavior between aromatic amino acids and Mm allows distinguishing and detecting Mm and aromatic amino acids from their analogues in macroscopic and microscopic scales. Dimensions and sizes of fibrous aggregates prepared from different amino acids show two opposite pathways from pristine assemblies to coassemblies induced by the addition of Mm. This pathway complexity could be controlled by the molecular conformation determined by α-positioned substituents. The developed hypothesis presents an excellent expansibility to other substrates, which may guide us to rationally design and screen 1D materials with different dimensions and sizes including the production of high-quality self-standing hydrogels.Keywords: aromatic amino acids; coassembly; hydrogen-bonding interaction; organic micro/nanofibers; pathway complexity;

Two novel cyclodextrin derivatives were synthesized that could self-assemble into a supramolecular polymer and gel in different solvent environments. Importantly, the obtained self-assemblies, including vesicles, micro-fibers and gels, could respond to various external stimuli efficiently.

Vesicles with dynamic membranes provide an ideal model system for investigating biological membrane activities, whereby vesicle aggregation behaviors including adhesion, fusion, fission, and membrane contraction/extension have attracted much attention. In this work we utilize an aromatic amino acid (pyrene-appended glutamic acid, PGlu) to prepare nanovesicles that aggregate to form vesicle clusters selectively induced by Fe3+ or Cu2+, and the vesicles transform into irregular nano-objects when interacting with Al3+. Vesicle clusters have better stability than pristine vesicles, which hinders the spontaneous morphological transformation from vesicles into lamellar nanosheets with long incubation period. The difference between complexation of Fe3+ and Al3+ with vesicles was studied by various techniques. On the basis of metal ion–vesicle interactions, this self-assembled nanovesicle system also behaves as an effective fluorescent sensor for Fe3+ and Al3+, which cause fluorescence quenching and enhanced excimer emission, respectively.

Structural matching of two organic building blocks bearing glutamate units and different luminophores assembled into unilamellar nanovesicles in aqueous media through a co-assembly process. Aggregation-induced energy transfer took place in the co-assembled system, leading to controllable generation of multiple luminescence colors including white light.

Cyanostilbene modified with dimethylaniline (CMD) could self-assemble into vesicles and fibrous morphologies depending on the solvophobic properties. Furthermore, morphology of well-defined nanostructures could be changed with enhanced emission triggered by the photo-isomerization of cyanostilbene. The present system has potential for building luminescent color conversion materials.

Gel formation by an N-fluorenyl-9-methoxycarbonyl (Fmoc)-based molecule was investigated and the chirality amplification observed during the self-assembly process could be switched on and off by controlling the solvent environment. The molecules could form gel in mixed solvents of water and dimethyl sulfoxide (DMSO) at either a high water fraction to afford flat nanofibers or a low water fraction to generate nanofibers with supramolecular chirality. At a moderate fraction of water, the molecules self-assemble into a precipitate composed of nanosheets. Furthermore, the gels showed different mechanical properties and thermal stabilities. Mechanism studies showed that π–π stacking interactions between the aromatic Fmoc groups and hydrogen bondings between the amide groups played important roles in the self-assembly process of the different gels. This study strives to shed light on the tuning of chiral gels with various nanostructures via controlled self-assembly, which might have potential use in smart materials.

Anthracen-9-ylmethyl octadecylcarbamate (A-9-YMOC) contains an anthracen headgroup, an imide group, and a long alkyl chain, which could show π–π stacking, hydrogen-bonding, and van der Waals interactions, respectively. The capability of A-9-YMOC to form well-ordered micro/nanostructures in different solvents was explored. And the influence of solvents with various polarities that can modulate the self-assembly behavior, including H-bond-forming solvents, π-stacking-forming solvents or van der Waals-type solvents was studied. In addition, different supramolecular architectures, including nanofibers and nanoflowers were observed during the solvent-polarity-tuned process, which were found to have different molecular arrangements. This work may provide a facile method to manipulate the morphology and properties of self-assembled low-molecular-weight organic building blocks.

The adaptive property of supramolecular building blocks facilitates noncovalent synthesis of soft materials. While it is still a challenging task, fine-tuning and precise control over topological nanostructures constructed from the self-assembly of low-molecular-weight building blocks are an important research direction to investigate the structure–property relationship. Herein, we report controlled self-assembly evolution of a low-molecular-weight building block bearing cholesterol and naphthalene-dicarboximide moieties, showing ultrasensitivity to solvent polarity. In low-polarity solvents (<4), it could form an M-type fiber-constituted organogel (supergel) with high solvent content, columnar molecular packing, and self-healing property. Highly polar solvents (>7.8) favor the formation of P-type helical nanostructures terminated by nanotoroids, having lamellar molecular packing. With a further increase in solvent polarity (up to 9.6), unilamellar and multilamellar vesicles were generated, which could undergo an aggregation-induced fusion process to form branched nanotubes tuned by the concentration. Self-attractive interactions between aggregates were found to be responsible for the formation of superstructures including helix–nanotoroid junctions as well as membrane-fused nanotubes.Keywords: adaptive dynamer; morphological evolution; self-assembly; superstructures; vesicles;

This paper reports an interesting type of self-assembly systems based on dynamic covalent bonds. The systems are pH-responsible and reversible, which could be utilized for controlling the morphology transformation of the assemblies. In alkaline conditions, the amine group of 11-aminoundecanoic acid (AUA) can connect with the aldehyde group of benzaldehyde (BA) or 1-naphthaledhyde (NA) by dynamic covalent bond to form a small organic building block accompanied by the morphological transformation from vesicles to fibers. When pH is lowered to a neutral value, the dynamic covalent bonds (imine bonds) can be hydrolyzed, leading to the dissociation of fibers and appearance of spherical aggregates. The transformation was confirmed reversible as fibers appeared again when the pH was changed back to alkaline value. In addition, a reversibly controlled gel was designed based on the nanofiber formation. NaCl, which is capable of greatly enhance the nanofiber density and cross-linking, was used to induce the growth of free-standing gel from free-flowing nanofiber system, and the resultant gel was proven to be pH-reversible.

A novel approach for preparation of graphitic carbon nitride nanosheets (CNNS) from stripping graphitic carbon nitride by strong acid and ultrasonic technology was demonstrated in this study for the first time. Transmission electron microscopy (TEM) was employed to characterize the surface morphology. Atomic force microscope (AFM) was carried out to characterize the thickness of nanosheets. X-Ray diffraction (XRD) was performed to estimate the lattice structure. X-Ray photoelectron spectroscopy (XPS) was carried out to characterize the surface composition and element analysis. Fourier transform infrared spectroscopy (FT-IR) was allowed to identify the functional groups. The as-synthesized CNNS exhibited excellent emission property as well as excitation-independent emission behavior, and fluorescence quantum yields could reach approximately 12.53%. Mercury ion (Hg2+) can make a result of quenching the significant intensity of fluorescence of CNNS by formation of a covalent bond between empty orbital of Hg2+ and the π electrons of N (turn-off). Moreover, the addition of the L-cysteine (L-Cys) can enhance the intensity of fluorescence of the CNNS– Hg2+ system through the thiol group of L-Cys anchored with Hg2+ and drag it from the surface of CNNS (turn-on). The CNNS was consequently functioned as a fluorescence probe towards “off–on” detection of Hg2+ and L-Cys with high sensitivity and selectivity. Moreover, the fluorescent probe was applied to detect tap water and well water with satisfactory results.

•Self-assembly of graphitic carbon nitride nanosheets-carbon nanotube composite.•CNNS-CNT show more stronger conductivity than CNNS and CNT.•CNNS-CNT has been performed for detection of catechol and hydroquinone.•The probe was applied to detect practical samples with satisfactory results.In this paper, three-dimensional (3D) graphitic carbon nitride nanosheets-carbon nanotube (CNNS-CNT) composite was synthesized via hydrothermal reaction of 2D CNNS and 1D CNT-COOH by π-π stacking and electrostatic interactions. This CNNS-CNT composite was characterized by transmission electron microscope, scanning electron microscope, x-ray diffraction and fourier-transform infrared. In addition, the CNNS-CNT composite displayed excellent conductivity comparing with CNNS and CNT-COOH monomer. This composite was applied for electrochemical simultaneous determination of catechol (CC) and hydroquinone (HQ) with good sensitivity, wide linear range and low detection limit. In addition, this CNNS-CNT composite modified electrode was also applied to detect practical samples with satisfactory results.Schematic diagram of hydrothermal synthesis graphitic carbon nitride nanosheets-carbon nanotube composite and theirs application for electrochemical sensing catechol and hydroquinone.

Vesicles were formed in aqueous solution using β-cyclodextrin (β-CD) complexes with a series of ultra-small aromatic molecules. The vesicles are easy to prepare without a complicated synthesis procedure and their structure was identified and characterized using various techniques, including transmission electron microscopy, atomic force microscopy and dynamic laser light scattering. Using the β-CD/L-phenylalanine system as a representative example, the structural factors that caused the self-assembly were revealed using proton nuclear magnetic resonance, Fourier transform infrared spectroscopy and X-ray diffraction. In addition, the vesicular architecture could be endowed with a diverse range of stimuli-responses, as a consequence of the selective addition of various guest molecules. It is anticipated that this novel assembly strategy could be further extended, and that it presents new opportunities for the development of nanocarriers and soft materials.

In this work, a novel sandwiched film of cadmium sulphide/reduced graphene oxide (CdS/r-GO) was synthesized via one step hydro-thermal reaction and electrodes modified with this composite were successfully used to simultaneously determine hydroquinone (HQ), catechol (CC) and resorcinol (RC). Additionally, some kinetic parameters, such as the charge transfer coefficient (α) and the electron transfer rate constant (ks) were calculated. Differential pulse voltammetry (DPV) was used for the simultaneous determination of HQ, CC and RC in their ternary mixture. The calibration curves of HQ, CC and RC were obtained in the ranges of 0.2 to 2300 μM, 0.5 to 1350 μM and 1.0 to 500 μM, respectively. The detection limits for HQ, CC and RC were 0.054 μM, 0.09 μM and 0.23 μM, respectively (S/N = 3). The modified electrode was then used to analyse tap water, well water and river water and the results show its significance for practical applications in the aquatic environment.

Sodium benzoate is an important and widely used food additive, however, its self-assembly properties in diverse solvents have been rarely studied. Here, we report different self-assembled aggregates, including sodium benzoate vesicles and sodium benzoate gel, in different solvent environments. Sodium benzoate vesicles and gel were identified by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and Dynamic Light Scattering (DLS). Ultraviolet-visible (UV-vis) spectroscopy, Fourier Transform Infrared (FT-IR) spectroscopy, Thermal Gravity Analysis (TGA), Differential Scanning Calorimetry (DSC) and Small-Angle X-ray Scattering (SAXS) were further employed to study the formation mechanism of the sodium benzoate gel. A possible gel formation mechanism was proposed. Furthermore, sodium benzoate gel has multiple stimulus responsiveness, the addition of hydrochloric acid and metal ions can all cause disaggregation of sodium benzoate gel. Finally, sodium benzoate aggregates were found in calf serum.

As a small molecule, N-(9-fluorenylmethoxy carbonyl)-glycine (FG) possesses a hydrophobic plane domain (π-conjugated section) and a hydrophilic domain (amino acid section), which can be designed into multi-dimensional self-assembly structures under dual tuning. Through controlling the concentration of T-shaped FG, the transformation between various morphologies has been achieved: vesicles are obtained at low concentrations (0.0025–0.005 wt%); helical fibers can be found at the concentration of 0.2 wt% though Gly has no stereocenter, resulting in the birth of chiral organization; fibrous bundles can accumulate into a three dimensional network to finally form a supramolecular gel. Taking gel as an example, we devised a variety of nanostructures including nanoparticles, microparticles, nanoribbons and membranes obtained by adding base. The mechanism of self-assembly formation has been investigated and this system is hoped to enrich the category of nanomaterials from amino acid or short peptides.

•The supramolecular vesicles constructed by β-cyclodextrin with camptothecin are reported.•The mechanism of the vesicle formation was studied by various methods.•The effect of competitive guest 1-hydroxyadmantane on the vesicles was discussed.•The antitumor activity of the camptothecin supramolecular vesicles on HeLa cells was studied in detail.Camptothecin, as an antitumor drug, has shown significant antitumor activity against various cancers through the inhibition of topoisomerase I. However, its poor solubility severely limits the clinical applications. Here, we report a camptothecin supramolecular vesicle based on the host–guest interactions, which can uniformly disperse camptothecin into water and greatly enhance camptothecin aqueous solubility. The camptothecin vesicles were identified by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and dynamic light scattering (DLS). X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–vis spectrum, 1H NMR and 2D NMR ROESY were further employed to study the formation mechanism of the vesicles. Furthermore, camptothecin could be controllably released when the competitive guests were added into the vesicles system. Finally, the camptothecin vesicles in aqueous solution exhibited comparable antitumor activity in vitro as natural camptothecin in DMSO to HeLa cells under the same conditions.Graphical abstract

Through a good/poor solvent strategy, native folic acid (FA) which behaves as a super-gelator in DMSO–water system can be successfully employed to construct supramolecular gels. The system exhibited morphological evolution with the increase of FA concentration; various phases such as vesicles, fiber/vesicles, fiber/nanoparticles, nanoparticles were probed. In the self-assembly process, L-glutamic acid moiety induced the formation of helical 1-dimensional (1-D) fibers which further self-assembled into a gel. Stimuli like heat, stress, pH and light which affect the molecular structure of FA or solubility in the mixed solvents had a pronounced influence on the properties of the gels, such as mechanical properties or bulk phases. A time-dependent oscillatory stress scan indicated that the supramolecular gel had a self-healing property. Without tedious modification routes and addition of alkali metal ions, native FA which served as an efficient building block and super-gelator to build up multi-responsive and self-recovery material was investigated for the first time.

The natural antitumor drug camptothecin was found to self-assemble into helical nanoribbons in aqueous solution. The helical nanoribbons showed good reversible pH-responsiveness. The formation and disappearance of the helical nanoribbons can be tuned reversibly through changing the pH value of the solution.

We report a hierarchical self-assembly shown by the complexation of folic acid and melamine in water. With the increase in folic acid (FA) concentration, 2D membranes, 0D spherulites and 3D networks with porous structures are constructed. H-bonds and π–π stacking interaction are proven to be the basic driving forces for the formation of membrane and plates with high inter-affinity, which further self-organize into anisotropic spherulites that show strong birefringence. When the concentration of FA increases further, cross-linked networks with high viscoelasticity are generated.

We reported a supramolecular system consisted of β-cyclodextrin, N,N-dimethylformamide and LiCl, which could exhibit different behaviors toward various alcohols. When some liquid monohydric alcohols were injected into the system at room temperature, a semitransparent organogel (the ambient temperature organogel) was formed. Compared with liquid monohydric alcohols, the addition of solid alcohols could induce the formation of a heat-set organogel, a solution, and an ice-like crystal at different temperatures. The xerogels and dried ice-like crystal were characterized by scanning electron microscope, Fourier transform infrared spectroscopy, X-ray powder diffraction, thermogravimetry and derivative thermogravimetry. The systems were also studied by 1H nuclear magnetic resonance and 2D rotating frame overhauser effect spectroscopy. The alcohol-responsive properties of this system could be further designed as molecule switches based on molecular recognition.

•β-CD showed gelation ability as gelator by oneself in DMF with heating.•Microstructures of the organogel were confirmed to be β-CD molecular clusters.•The process of the gel formation was studied in detail.•The approximate heat effect of the gel formation was obtained.β-Cyclodextrins (β-CDs), without the help of the guest molecules embedding in cavities, can self-assemble an organogel with a very small amount of lithium chloride (LiCl) in N,N-dimethylformamide (DMF). Microstructures of the organogel were confirmed to be β-CD molecular clusters composed of many channel-type β-CD fibers extending from a cage-type β-CD core in various directions. The process of the gel formation and the structure were suggested based on FTIR, TR-FTIR, 1H NMR and XRD results. The interactions of the various molecules in the system were discussed for gelation. The morphology of the organogel was characterized by OM and SEM. A molecular dynamics simulation of the gel structure was performed in agreement with the results. In addition, the concentration of β-CD for the gel formation ranged from 0.13 to 0.28 mol/L. The approximate heat effect of the phase transition was 28 kJ/mol. This investigation will be of great significance to develop new temperature-controlling materials with native β-CD of low cost in application.

•A fenspiride/β-CD complex was prepared and characterized in detail.•An enzyme-responsive assembly system was constructed.•The system included reversible control of formation and disruption of vesicles.Herein, we report a novel responsive assembly system consisting of an amphiphilic drug fenspiride and β-cyclodextrin in host–guest approach. Fenspiride molecules can self-assembled into vesicles in aqueous solution. The obtained vesicles were characterized in detail by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Furthermore, such a vesicular structure will be destroyed upon the addition of β-cyclodextrin due to the formation of inclusion complexes by host–guest interactions. In addition, amylase is a digestive enzyme which can catalyze the breakdown of starch into sugars. Adding α-amylase into the system could release fenspiride molecules, and trigger the self-assembly of fenspiride molecules again. It is anticipated that this research will provide widespread applications in the fields of responsive materials and biochemistry related to enzyme-responsive model system and host–guest chemistry.We present a host–guest approach to construct enzyme-triggered assembly system on the basis of drug–cyclodextrin complexes and α-amylase. The enzyme-responsive system included the reversible control of formation and disruption of vesicles.

•The supramolecular vesicles constructed by cyclodextrin–ftorafur supramolecular amphiphiles are reported.•The mechanism of the vesicles formation was studied by various methods.•The effect of copper ions on the vesicles was discussed.•The antitumor effects of the ftorafur-loaded vesicles on human colon carcinoma cell lines HT-29 were studied in detail.Vesicles directly prepared from cyclodextrin–ftorafur supramolecular amphiphiles were reported. Ftorafur can be efficiently encapsulated in the cyclodextrin cavities embedded in the vesicle membrane. The morphologies and diameters of the vesicles were identified in detail by transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and dynamic light scattering (DLS). X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–vis spectrum, 1H NMR and 2D NMR ROESY were further employed to study the formation mechanism of the vesicles. Various morphologies were detected when different host molecules were employed as the hydrophilic moieties of the vesicles’ building blocks. Copper ions could arouse the simultaneous release of ftorafur from the vesicles. The proliferation and cell cycle assay of colon carcinoma cell Line HT-29 were performed to evaluate the anticancer effects of the ftorafur-loaded vesicles and natural ftorafur, respectively. The ftorafur-loaded vesicle system exhibits a better anticancer effect than the sole ftorafur.The ftorafur vesicles constructed by cyclodextrin–ftorafur supramolecular amphiphile was firstly reported here, the morphology, size, formation mechanism, stimulus responsive property and antitumor effect of the vesicles were investigated.

•Gel–sol–gel′ evolution induced by formic acid was verified.•Differences of building blocks in the two β-CD gel networks existed.•Probable model on the gel–sol–gel′ evolution was given.•Required conditions to achieve such evolutions were explored.Supramolecular “gel A” based on β-cyclodextrin as the gelator and K2CO3 as the salt bridge can be activated by the addition of HCOOH to evolve into another “gel B”. In the process, the release of CO2 dissociated the network of the “gel A” bridged by K2CO3 and the new network of the “gel B” can be reorganized with the help of the newborn HCOOK. The two gels, “A and B”, were investigated by optical microcopy, scanning electron microscopy, small- and wide-angle X-ray scattering, Fourier transform-infrared spectroscopy and X-ray diffraction. The “gel B” with greater elastic modulus (G′, 1 × 105 Pa) could endure higher applied stress (the yield point 300 Pa) than the “gel A” (G′, 3 × 104 Pa; the yield point 180 Pa). The “gel B” also exhibited the higher phase transition temperature (161.75 °C) than that (34.4 °C) of the “gel A” in differential scanning calorimetry. The influence of analogous salts on the macroscopic aspect of the samples was also reported. The reason behind the gel–sol–gel′ phase transition was the salt bridge evolution. This work is the first report on gel evolution with phase reorganization triggered by chemical additive (HCOOH), which may be of great significance to develop drug controlled release materials, and other more complex stimuli-responsive materials.The gel–sol–gel′ evolution induced by formic acid was confirmed. There were differences of the building blocks in the two gel networks β-CD as gelator. The concentrations of β-CD, and variety of solvents and salts, and other conditions were explored for extension of the gel–sol–gel′ evolution.

•Simple supramolecular gel based on native β-cyclodextrin is sensitive to alkali salts.•The gel has phase transitions (gel–sol, gel–gel, gel–crystal) tuned by the concentrations or types of salts.•Alkali salts, especially NaOH and Na2CO3, have a selectively effect on the gel which exhibited noteworthy structures.Just as biological behaviors that can be tuned by salt ions, salt-containing soft materials are of great importance in various fields. Here we report a supramolecular cyclodextrin gel, of which properties including gelation behavior, fiber size, thermal stability as well as mechanical strength could be well tailored by inorganic salts. The concentrations, types of alkali salts were tested and had a profound impact on the gel properties. The formation/collapse behaviors and variations of gel fiber size were characterized through scanning electron microscopy (SEM), transmission electron microscopy (TEM) and optical microscopy (OM). Infrared spectroscopy (IR), differential scanning calorimetry (DSC) and small angle X-ray scattering (SAXS) revealed the mechanism of molecular arrangement and provided insight into the outstanding salt effects. This might have potential applications in designing novel smart materials and provide a new course of constructing multi-morphological gels by salts.

•A supramolecular curcumin vesicle, which can greatly enhance curcumin solubility, is prepared by different cyclodextrins and curcumin in aqueous solution.•The morphologies and sizes of the vesicles were identified by TEM, SEM, AFM and DLS.•The mechanism of the vesicle formation was studied with various methods.•Curcumin could be controllably released by the addition of external stimuli into the vesicle solution.Curcumin is a safe and nontoxic natural potential antitumor drug. However, its extremely low aqueous solubility severely limits its clinical application. We designed a supramolecular curcumin vesicle based on different curcumin-cyclodextrin amphiphiles, which could greatly enhance the aqueous solubility of curcumin up to 7000-fold. The vesicles can exist for about one month in aqueous solution at around 20 °C, showing a certain colloidal stability. The curcumin-β-cyclodextrin vesicles were identified by transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and dynamic light scattering (DLS). X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–vis spectrum and 1H NMR were further employed to study the formation mechanism of the vesicles. Curcumin vesicles were also prepared when different host molecules were employed as the hydrophilic heads of the supramolecular amphiphiles. Finally, curcumin could be controllably released with the disruption of the vesicles when the external stimuli, including competitive guest molecules, enzymes and copper ions were added into the vesicles system.We designed a supramolecular curcumin vesicle based on different curcumin-cyclodextrin amphiphiles, which could greatly enhance the aqueous solubility of curcumin up to 7000-fold. The vesicles existed for about one month in aqueous solution at around 20 °C, showing a certain colloidal stability. Curcumin vesicles were also prepared when different host molecules were employed as the hydrophilic heads of the supramolecular amphiphiles. Finally, curcumin could be controllably released with the disruption of the vesicles when the external stimuli, including competitive guest molecules, enzymes and copper ions were added into the vesicles system.

A unique transformation from a heat-set organogel to a room-temperature organogel induced by ethanol (EtOH) was reported here. When the system containing β-cyclodextrin, 4,4′-isopropylidenediphenol, N,N-dimethylacetamide and LiCl was heated to the gelling temperature (Tgel), a heat-set organogel would be formed. In contrast, a semitransparent organogel (room-temperature organogel) could be obtained by injecting EtOH into the system at ambient temperature. In this transformation process, EtOH played a role in the formation of hydrogen bonds, which was critical for the self-assembly. The influence of other guest molecules, solvents and alcohols on this transformation was also investigated. These organogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, thermal gravity analysis and differential thermal gravity. Further, the formation mechanism of the organogels was proposed based on the above measurements.

Here, we report a dual stimuli-responsive organogel which can stabilize graphene oxide (GO) in apolar solvents. The gelator 1-octadecyl-ureido-naphthalene (OUN) was synthesized, and it could form organogel in toluene and xylene. The resultant gels can respond to thermal and anion stimuli, bringing about fluorescent changes. Thin nanoribbons are entangled together to form three dimensional networks that can immobilize solvents in gel, providing large superficial area to interact with GO sheets. The addition of GO influences the gel properties, which are studied through rheological, fluorescent, and DSC measurements.

The controllable self-growth of a supramolecular hydrogel of folic acid (FA) was developed based on the conduction of transition metal ions. The growth behavior of the gel could be flexibly controlled by adjusting the ambient environmental factors such as gelator concentration, temperature and external chemical stimuli. The obtained gel was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and rheological measurements. Differential scanning calorimetry (DSC) showed that the gel possessed excellent thermal stability. A mechanism for the fibrous formation of the gel was suggested based on the experimental results of Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR) and UV-Vis spectroscopy. The gel exhibited multiple stimuli-responsive properties to changes in ligand and pH. Furthermore, the gel can be incorporated into multi-layer hydrogels in both artificial and spontaneous ways, showing the advantages of self-growth and flexible control of the gel system. This novel hydrogel and the preparation strategy may provide a new route to rationally design advanced materials for biomedical applications.

Supramolecular amphiphiles (SAs) refer to a class of amphiphiles based on non-covalent interactions, while vesicles are important self-assembled aggregates in solutions and represent simple model systems for biological membranes. Vesicles assembled by “supramolecular amphiphiles” are considered not only more effective but also more promising in acting as stimuli-responsive nano-carriers. In this review, we first give a brief account of the efforts on the fabrication of vesicles from SAs. Following the self-assembly of SA, vesicles are prepared by combining multiple components through non-covalent interactions, such as host-guest recognition, charge transfer, π–π stacking and electrostatic interactions. Then, the applications and functions of these vesicles derived from the controllable self-assembly–disassembly phenomenon are highlighted. Finally, prospects of vesicles from SA were proposed. The easy fabrication and functionalization properties, as well as the dynamic nature of the non-covalent interactions of vesicles from SA would definitely enrich the traditional colloid and interface chemistry and provide more references for advanced supramolecular materials.

Anisotropic and well-defined β-cyclodextrin (β-CD) and sodium laurate (SL) gel fibers, with tetragonal and lamellar packing modes respectively, were combined to generate orthogonal and switchable assemblies for the first time. Through controlling the inclusion–exclusion processes between β-CD and SL by changing external stimuli, β-CD gel fibers, SL gel fibers and their coexistence states can be easily tailored. Different assembled states exhibited versatile morphologies and microstructures, which were detected by microscopy and X-ray scattering measurements. Furthermore, controllable assemblies provide facile ways to control the mechanical properties of the hybrid gels. The orthogonal self-assembly with self-sorting properties would enable this system to attract interest in material science.

A multi-responsive cyclodextrin-based organogel with a crystalline-like structure is first reported. An amount of β-cyclodextrin (β-CD) and lithium chloride (LiCl) was added into N,N-dimethylformamide (DMF), and the system obtained could transform instantly from a transparent solution into a gel state by introducing ethylene diamine (EDA), and then the gel could turn into another precipitate-like gel by undergoing a heating–cooling process. Among a series of aliphatic amines, only EDA was found to be able to induce the gel formation. Both the gels possess crystalline-like structures in their morphology with sheet-like layers, in a highly-ordered channel-type packing mode, which were proved by OM, SEM, XRD, and FT-IR measurements. Furthermore, the gel could respond to H+ and Cu2+ by transforming into an amorphous precipitate. This research may pave the way for the design of novel smart materials.Graphical abstractHighlights► A novel organogel based on native β-cyclodextrin was prepared. ► The gel had multiple-stimulus responsive properties. ► Crystals could be observed in gel under cross-polarized light. ► The gel was in a crystalline-like structure.

A novel cinnamic acid-based dipeptide is designed and prepared from cinnamic acid and glycylglycine. In aqueous solution, the molecules can self-assemble into vesicular structures, which were characterized in detail by transmission electron microscopy, scanning electron microscopy, and dynamic light scattering. Aromatic stacking and intermolecular hydrogen bonding interactions are regarded as the driving force in the formation of the stable supramolecular structure. Subsequently, the stimuli-responsive property of the vesicles to UV irradiation was also studied. The vesicles were also found to be able to efficiently carry hydrophobic drugs. We believe that this study may provide more references in the fields of body-friendly smart materials with the hope of in vivo applications.

Vesicles constructed by supramolecular amphiphiles are considered as more promising stimuli-responsive vehicles for carrying and delivering targeted molecules. In this research, novel supramolecular amphiphiles are directly assembled from UR-144, a general neuropathic drug, and a class of mono-diaminoalkane substituted β-cyclodextrins. In the aqueous solution, the supramolecular amphiphiles can assemble into vesicular particles, which were characterized in detail by transmission electron microscopy (TEM), atomic force microscopy (AFM), scanning electron microscopy (SEM) and dynamic light scattering (DLS). The mechanism was also suggested based on the NMR, Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) experimental results. The vesicular particles tend to be damaged upon the addition of Cu2+ and meanwhile release UR-144.The king is also a royal-palanquin lifter.Highlights► The idea of directly using drugs to construct vesicular structures was posed. ► Vesicular particles were obtained from the complex of cyclodextrin/UR-144. ► The mechanism of the vesicular formation was proposed. ► Cu2+-triggered release of UR-144 was achieved.

This paper describes an instant-formative organogel triggered by small organic molecules (cogelators) at a high temperature. The system was prepared by β-cyclodextrin (β-CD) and lithium chloride (LiCl) in N, N-dimethyl acetamide (DMAc). Under stirring, a clear solution is obtained at 120–130 °C and transformed into a gel phase within several seconds once the cogelators are injected. The gelling times (GT) distribution of more than 1 min to no more than 1 s, which can be mediated by the concentration of cogelators. When beyond the certain concentration, cogelators can gel the system instantly which GT even cannot be precisely observed (below 1 s). Numerous kinds of short alkyl chain aliphatic molecules were studied as cogelators for the first time, which cover a broad range including acid, ketone, alcohol etc. Scanning electron microscopy (SEM) measurements revealed that the three-dimensional micromorphology were diverse corresponding to different functional groups of cogelators. The X-ray diffraction (XRD) measurement proves that the self-assembled mode of gel was head-to-head channel-type. Fourier transform infrared spectroscopy (FT-IR) measurement evidences the formation of intermolecular hydrogen bonds. The molecular dynamics simulation was performed to obtain the mechanism of the formation of the gel, and the result is consistent with the experimental phenomenon. We believe the specific properties of the gel may bring up a novel application of the supramolecular gel.Instant-formative organogel induced by small organic molecules was firstly reported here, the properties and mechanism of the gel were investigated.Highlights► Simple organic molecules are used as organogelators with native β-cyclodextrin. ► The gel could be instantly constructed at relatively high temperature. ► Gelling behaviors are diverse response to functional groups and alkyl chain length of cogelators.

An enzymic method to protect selected amino group of lysine has been reported. This reaction proceeds smoothly under room temperature with high regioselectivity (up to 99%) and high yields (up to 90%). This work will pave the way for simple and selective protection of amino group of lysine in industry.

Methylated β-cyclodextrin and a class of phthalate esters were found to be able to form “supramolecular amphiphiles” with double-chains in aqueous solution and could further assemble into stable vesicles under variable conditions. The vesicles were fully characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS) and Cryo-transmission electron microscopy (Cryo-TEM). The mechanism of the vesicle-formation was suggested based on the UV–vis spectrum, 1H NMR, 2D NMR NOESY, FT-IR spectrum and X-ray diffraction (XRD) results and further simulated by molecular dynamic simulation. The vesicles’ responses to the stimuli were also studied.Graphical abstractStable vesicles prepared by “supramolecular amphiphiles” with double hydrophobic chains were firstly reported here. The mechanism was studied in detail.Highlights► Stable vesicles assembled by “supramolecular amphiphiles” with double hydrophobic chains are reported. ► The mechanism of the vesicle formation was studied in detail. ► The stable property was particularly studied by multi-methods.

This paper describes an interesting structure dependent thermo-reversible dissolution of organic molecules in the presence of β-cyclodextrin (β-CD) in N, N-dimethyllformamide (DMF). β-CD could influence the solubility of dissolved organic molecules, resulting in the precipitation of organic molecule–β-CD complex from the original transparent solution as the temperature is increasing, while the precipitate will be dissolved again upon cooling. Different organic molecule–β-CD complex precipitates corresponded to different turbid temperatures (Tt). No precipitates were observed solely for either organic molecules or β-CD in DMF when the temperature increased, indicating the structure dependent recognition of β-CD to organic molecules. This molecular recognition behavior had been successfully applied in the separation of xylene isomers in preparative scale.Graphical abstractVarieties of small organic molecules can be precipitated in DMF by β-CD in the form of inclusion complex at different temperatures by a molecular recognition thermo-reversible process. The finding was successfully applied for the separation of xylene isomer mixtures in a preparation-scale in DMF solution.Highlights► An unusual structure dependent thermo-reversible precipitation–dissolution behavior was reported. ► Varieties of small organic molecules could be precipitated/dissolved in the presence of β-CD by heating/cooling in DMF. ► They can form organic molecules–β-CD complex by heating. ► Different organic molecule–β-CD complex precipitates corresponded to different temperature. ► This behavior was successfully applied for the separation of xylene isomer mixtures in DMF solution.

A novel supramolecular organogel consisting of β-cyclodextrin (β-CD), 4,4′-isopropylidendiphenol (BPA), LiCl, N,N-dimethylformamide (DMF) and ethanol (EtOH) was prepared. The system without EtOH was a clear solution at ambient temperature and turned into an organogel upon the addition of ethanol (EtOH). The micro-morphologies of the organogel were various, such as ellipsoids, spheres, cuboids and cylinders, and they could be obtained in sequence by controlling the stirring time or the dosage of introduced EtOH. The organogel with multi-morphologies was characterized by optical microscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD) and rheology measurements. Further, the formation mechanism of the organogel was proposed. This organogel may cast new light on the area of functional material design and fabrication.Graphical abstractOptical microscope images of the organogel stirred for different times: A, ellipsoids, stirred for 7 min; B, spheres, stirred for 9 min; C, cuboids stirred for 11 min, D, larger cuboids, stirred for 13 min; and E, cylinders, stirred for 70 min; solution: Cβ-CD 0.167 mol/L, CBPA 0.167 mol/L, ωLiCl 0.5%; solution:ethanol = 1:1 (v/v) (scale bar = 1 μm in A–E). We found a novel organogel induced by ethanol. The micro-morphologies of this organogel were various and could be tuned by controlling the stirring time or the dosage of introduced ethanol.Highlights► A novel supramolecular organogel was prepared. ► It was induced by ethanol. ► The morphologies of this organogel were various. ► The morphologies could be obtained by tuning ethanol dosage or stirring time. ► The organogel can trap a large amount of ethanol.

Controlled self-assembly of amphiphilic cyclodextrin is always a challenging topic in the field of supramolecular chemistry, since it provides the spontaneous generation of well-defined aggregation with functional host sites with great potential applications in drug-carrier systems. β-Cyclodextrin modified with an anthraquinone moiety (1) was successfully synthesized. In the aqueous solution, 1 was found able to self-assemble into vesicles, which was characterized in detail by TEM, SEM, EFM, and DLS. The formation mechanism of the vesicles was suggested based on the 2D ROESY and UV–vis results, and further verified by the MD simulation. Subsequently, the stimuli response property of the vesicles, including to Cu2+ and H+, was also studied. The vesicles can efficiently load Paclitaxel inside the membrane with functional macrocyclic cavities available, which can further carry small molecules, such as ferrocene. The vesicles loading with Paclitaxel have remarkable anticancer effects. This work will provide new strategy in drug-carrier systems and tumor treatment methods.

This paper describes a novel double phase transforming organogel (gel–sol–gel′) composed of nontoxic β-cyclodextrin, potassium carbonate, and 1,2-propylene glycol. The gel–sol–gel′ transforming processes are followed by a reversible gel–sol transforming process and an irreversible sol–gel′ transforming process based on heating. The gel–sol–gel′ transformation is accompanied by microstructure changes from nanospheres to nanorods. K2CO3 plays a key role in associating supramolecular architectures of β-cyclodextrin into a three-dimensional network. This work may bring further applications in the areas of smart materials, drug delivery systems, and biomaterials.

A class of aza-arm modified β-cyclodextrins were found to be able to trap paclitaxel (PTX), an effective but strongly hydrophobic anticancer drug, to form novel “supramolecular amphiphiles”, which can further self-assemble into vesicular structures in aqueous solution. The obtained vesicles were characterized in detail by transmission electron microscopy (TEM), scanning electron microscopy (SEM), cryogenic transmission electron microscopy (cryo-TEM), and dynamic light scattering (DLS). The mechanism of the vesicular formation was suggested on the basis of the experimental results of nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermal analysis. The effects to the vesicular formation by changing the host molecules and solvents were also studied. The vesicles will disappear upon the introduction of Cu2+ into the vesicular system, during the procedure of which, PTX will be released meanwhile. We believe that our research will provide a new strategy of directly employing special drugs to construct microvehicles to carry other targeted molecules.

Novel vesicles assembled by ‘supramolecular amphiphiles’ based on the inclusion complexes between 1 and β-CDs (β-CD and HP-β-CD) were found to carry drugs and be successively-responsive to external stimuli for the first time. These vesicles were observed by TEM and SEM and confirmed by DLS. The formation patterns of ‘supramolecular amphiphiles’ characterized by UV and NMR can be controlled by choosing different hosts. Unlike traditional drug delivery and releasing systems, the ‘useless’ inclusion complexes 1·β-CDs in thinking formula can assemble into vesicles to carry both cytotoxic 1 and drugs (piroxicam and ampicillin) at one time, confirmed by TEM, UV, and NMR data. Also the vesicles assembled by 1·β-CDs can be successively-responsive to acidifying and oxidizing, and release drugs and cytotoxic compounds in order.Novel vesicles assembled by ‘supramolecular amphiphiles’ based on 1·β-CDs complexes can carry cytotoxic 1 and drugs at one time, be successively-responsive to acidifying and oxidizing, and release drugs and cytotoxic compounds in order. Also, the formation patterns of ‘supramolecular amphiphiles’ can be controlled by choosing different hosts.

A modified cyclomaltoheptaose (β-cyclodextrin) containing an anthraquinone moiety, mono[6-deoxy-N-n-hexylamino-(N′-1-anthraquinone)]-β-cyclodextrin (1), which can self-assemble into nanorods in aqueous solution, was synthesized. Interestingly, upon the addition of natural cyclodextrin, the nanorods could transform into bilayer vesicles, which were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), and epi-fluorescence microscopy (EFM). A transformation mechanism is suggested based on the results of 1H NMR, 2D NMR ROESY, FTIR, and UV–vis spectra. The response of the vesicles to changing pH and adding Cu2+ was also tested. Our research may pave the way to the development of new intelligent materials and biomaterials.

Although an important industrial catalyst for producing high density polyethylene, the SiO2-supported organosilyl chromate UCC S-2 catalyst has not been fully investigated compared with the SiO2-supported oxo chromium Phillips catalyst. In this work, gas phase ethylene polymerization by S-2 catalysts (Cat-1, Cat-2, and Cat-3) was carried out in a high-speed stirredautoclave reactor. The effects of temperature, time, and pressure on kinetics, activity, and product properties were studied. All kinetics were typical built-up types with slow decay. Compared to the simple physical mixtures of Cat-1 and Cat-2, Cat-3 showed higher activity and its product had a broader molecular weight distribution, indicating new active species induced during blending of Cat-1 and Cat-2 in n-hexane. The innovation by a simple catalyst technology created a new application to meet market demands.

Aggregates assembled by “supramolecular amphiphilies” are more promising in developing responsive materials. First pH-reversible vesicles based on “supramolecular amphiphilies” were prepared from the supramolecular inclusion of cyclodextrins (CDs) and anthraquinone derivate (1-((3-(dimethylamino)propyl)amino)anthracene-9,10-dione, 1). 1, as the guest molecule, was synthesized by the direct reaction of 1-nitroanthraquinone with N1,N1-dimethylpropane-1,3-diamine. The vesicles were characterized in detail by transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), and epi fluorescence microscope (EFM). 1H NMR, 2D NMR ROESY, UV–vis spectrum, and FT-IR were further employed to study the formation mechanism of the vesicles. The vesicles’ responsive property, especially the pH-responsive property was tested. We also tried to use the vesicle system as a new kind of fluorescence staining material for living cells and mouse prostate carcinoma cells (RM-1) were found to be stained effectively by the vesicles. Our research may provide new references in exploiting novel intelligence materials and biomaterials.Graphical abstractResearch highlights▶ We prepared a novel anthraquinone derivate by the direct reaction of 1-nitroanthraquinone with N1, N1-dimethylpropane-1,3-diamine without catalyst. ▶ We designed and prepared a novel pH-reversible vesicles based on the “supramolecular amphiphilies” formed by cyclodextrin and anthraquinone derivate and the vesicles were fully characterized. ▶ The novel pH-reversible vesicles were successfully applied in the staining of the living cells.

This paper describes a new class of heat-set organogels based on β-cyclodextrin (β-CD) and para-substituted anilines (ps-An) connected by supramolecular interactions. The organogel is prepared by mixing β-CD, ps-An and lithium chloride in N,N-dimethylformamide (DMF). The heat-set organogel is a thermo-reversible gel system which turns into a clear solution upon cooling to room temperature and is re-formed when heated to the gelling temperature (Tgel). It is very interesting that the ps-An gelator, as well as other gelators, can be gelated at high temperature but dissolved as the temperature in the system decreases. The organogel is a multi-component system, in which the gelators are small commercially available organic molecules that can self-assemble into fibrous structures based on supramolecular interactions. Further studies showed the Tgel can be influenced and controlled by the substituents of ps-An. The Tgel of the system is higher when the aniline is substituted with electron-donating substituents rather than electron-withdrawing substituents.Graphical abstractResearch highlights▶ The organogel is prepared by mixing β-CD, ps-An and lithium chloride in N,N-dimethylformamide. ▶ The organogel is a heat-set and thermo-reversible organogel. ▶ The organogel is a multi-component system. ▶ The gelators can be gelated at high temperature but dissolved as the temperature decreases. ▶ The Tgel can be influenced and controlled by the substituents of ps-An.

This paper describes a novel heat-set organogel transformation which could be triggered by lithium chloride (LiCl) from precipitate for the first time. The system was prepared with β-cyclodextrin (β-CD) and triphenylphosphine (Ph3P) in N,N-dimethylformamide (DMF). The system as an original transparent solution at room temperature could turn into precipitation by heating. Subsequently, the precipitation turned into organogel instantly based on the injection of LiCl into the system. SEM measurement revealed that the precipitate and gel systems have different microstructures. IR and XRD measurements revealed that the inclusion complexes formed by β-CDs and Ph3P were arranged in cage structures in the precipitate and channel structures in the gel. Molecular dynamics simulations were performed both on the formation of the precipitate and gel models in this system, which were consistent with the test results.Graphical abstractWe found a novel heat-set organogel based on β-cyclodextrin complexes which could transform from precipitate triggered by lithium chloride. There were great differences between precipitate and organogel in microstructure. The transformation mechanism was characterized.Highlights► The heat-set organogel can transform from precipitate induced by LiCl. ► The precipitates generate as temperature increases but dissolve in r. t.. ► There are great differences between precipitate and organogel in microstructure. ► The transformation temperature can be controlled by the amount of Ph3P.

The crystallographic study of a partially hydrated form of cyclomaltoheptaose (β-cyclodextrin, βCD) is reported. C42H70O35·7.5H2O; space group P21 with unit cell constants a = 15.1667(5), b = 10.1850(3), c = 20.9694(7) Å, β = 110.993(2)°; final discrepancy index R = 0.0760 for the 6181 observed reflections and 784 refined parameters. One water molecule is included in the cavity and distributed over two partially occupied positions, the other 6.5 waters distributed over eight positions are located as space-filler between the macrocycles. The crystal structure belongs to the cage-type, like that observed in Form I (βCD·12H2O; Lindner, K; Saenger, W. Carbohydr. Res. 1982, 99, 103–115) and Form II (βCD·11H2O; Betzel, C., et al. J. Am. Chem. Soc., 1984, 106, 7545–7567).The crystallographic study of a partially hydrated form of β-cyclodextrin (βCD) is reported. C42H70O35·7.5H2O; space group P21 with unit cell constants a = 15.1667(5), b = 10.1850(3), c = 20.9694(7) Å, β = 110.993(2)°; final discrepancy index R = 0.0760 for the 6181 observed reflections and 784 refined parameters. One water molecule is included in the cavity and distributed over two partially occupied positions, the other 6.5 water molecules distributed over eight positions are located as space-filler between the macrocycles. The crystal structure belongs to the cage-type, like that observed in Form I (βCD·12H2O) and Form II (βCD·11H2O).

Redox-responsive vesicles self-assembled by supramolecular cyclodextrin amphiphiles, consisting of the guest (N-1-decyl-ferrocenylmethylamine, 1) and the host (2-O-carboxymethyl-β-cyclodextrin, CM-β-CD), were prepared. The morphologies and sizes of these novel vesicles in an aqueous solution were observed by transmission electron microscopy (TEM) and were confirmed by atomic force microscopy (AFM) and dynamic light scattering (DLS) measurements. The effects of the host–guest ratio, the concentration and the solvent composition of water and methanol on vesicles were investigated in detail. The interactions between the host and the guest, the complex stoichiometry, the stability constant and conformations of 1·CM-β-CD in aqueous solution were investigated by cyclic voltammetry (CV), UV and nuclear magnetic resonance (NMR) measurements. According to the complex stoichiometry and ‘tadpole-like’ spatial conformations, the supramolecular cyclodextrin amphiphiles made from 1·CM-β-CD were proposed to form the membranes of the vesicles. This kind of vesicle system was responsive to an oxidizing agent, which could pave the way to combine supramolecular host–guest chemistry and membrane chemistry for potentially functional applications.Redox-responsive vesicles self-assembled by ‘supramolecular cyclodextrins amphiphiles’, consisting of N-1-decyl-ferrocenylmethylamine (1) and 2-O-carboxymethyl-β-cyclodextrin (CM-β-CD), were prepared and investigated. The morphologies and sizes of these novel vesicles were characterized by TEM, AFM and DLS. The host–guest interactions of 1·CM-β-CD in water were investigated by CV, UV and NMR.

Reversible vesicles based on supramolecular inclusion of hydroxypropyl-β-CD (HPβCD) and N,N′-bis(ferrocenylmethylene)-diaminohexane (BFD) were prepared in water and methanol–water mixtures. The inclusion stoichiometry of HPβCD with BFD was in a molar ratio of 2:1, which could be named as ‘two head’ supramolecular amphiphile when the solvent was water. However, the inclusion stoichiometry of HPβCD with BFD would tend to be a molar ratio of 1:1 based on introduction of methanol to the solvent, especially when the volume ratio of methanol and water was more than 1:4, which could be named as ‘one head’ supramolecular amphiphile. The inclusion compounds could switch between ‘one head’ and ‘two head’ conformations by changing the methanol concentration of the solvents. The vesicles were also found to be responsive to the stimulus of external molecules. When the inclusion ability between HPβCD and an external guest was relatively stronger, the vesicles were easily destroyed. Furthermore, the vesicles disappeared after adding an oxidizing agent. NMR was used to confirm the conformation of the mixture of HPβCD and BFD in water. The structure and morphology of the vesicles were characterized by TEM and DLS. The vesicles may be used in smart materials, drug delivery and molecular recognition.The reversible vesicles based on the supramolecular inclusion of hydroxypropyl-β-CD (HPβCD) with N,N′-bis(ferrocenylmethylene)-diaminohexane (BDF) induced by methanol were prepared. The vesicles were also responsive to the stimuli of external guests as well as to an oxidizing agent.

This paper describes a triple-transforming gel system (gel–sol–gel′) for the first time, which is a thermo-responsive and multi-component organogel prepared by β-cyclodextrin (β-CD), diphenylamine (DPA) and lithium chloride (LiCl) in N,N-dimethylacetamide (DMAC) in a suitable proportion based on the supramolecular interactions. In the triple-transforming gel system, a gel (gel A) could be formed by β-CD, DPA and LiCl in DMAC at room temperature based on stirring, then the gel could transform into a clear solution based on heating, and then the other gel (gel B) can be formed at a relatively high temperature (Tgel, the gelation temperature by heating). The two gel states in the triple-transforming gel system have different microstructures. This gel system was characterized by OM, SEM, IR and rheology.

This paper describes the first reversible, heat-set organogel based on the supramolecular interactions of β-cyclodextrin (β-CD). The gel was prepared by interaction of diphenylamine (DPA) with β-CD and lithium chloride in N,N-dimethylformamide (DMF). In this gel system, DPA could be gelated in DMF as the temperature increased and then dissolved again as the temperature decreased. In the microscopic structure of gel, β-CDs play a key role in the formation of nanorods and microfibers. Some important features of the gel were observed. (1) The system is a multicomponent solution, in which each of the four components is required for the organogelation property. (2) The system is a reversible, thermo-responsive organogel composed of small organic molecules. When the temperature is lower than Tgel, the gel transforms back into a solution. The reversible thermo-transition was confirmed by differential scanning calorimetry (DSC). The gel system is responsive to the concentration of LiCl. No gel was formed without LiCl. The stimuli responses of the system with other salts such as KCl and NaCl were weaker than with LiCl. (4) The system is responsive to the addition of guest molecules. The structures and sizes of the guest molecules could influence the gel formation. Generally, Tgel decreased by adding guest molecules in the gel system, but some guest molecules, whose structures are exactly fitted to the cavity of CDs, could prevent gel formation. This work may provide new avenues in delivery of functional molecules as well as design of intelligent materials and biomaterials.

Vesicles, based on two-head inclusion model (2:1) and one-head inclusion model (1:1) of carboxymethyl-β-cyclodextrin (CM-β-CD) with N,N′-bis (ferrocenylmethylene) diaminohexane (BFD) were prepared in water as well as in mixed solvents (water/methanol, water/ethanol, water/isopropanol, water/tert-butanol and water/glycerol). Morphologies and sizes of the aggregates in water and mixed solvents were observed by TEM and confirmed by DLS. A gradual change was shown with increasing proportion of the organic component in the mixed solvents. The polarities and steric hindrances of the mixed solvents would play key roles in the morphological changes of aggregates. Moreover, two possible formation mechanisms in different solvents were proposed based on UV, CV and 1H-NMR data. The work in this paper may extend the applications of vesicles in biosimulation, drug-delivery and smart materials.

Micro-aggregates based on inclusion complexes between methyl orange (MO) and cyclodextrins (CDs) were investigated for the first time. The mixture of MO and γ-hydroxybutyric-β-cyclodextrin (γ-HB-β-CD) in water was observed to aggregate into vesicle-like particles by transmission electron microscopy (TEM), laser-confocal scanning microscopy (LCSM) and dynamic light scattering (DLS). Fluorescence measurements and NMR confirmed the existence of inclusion complexes between MO and γ-HB-β-CD. The formation mechanism and pH-responsive properties of the vesicle-like particles made by MO·γ-HB-β-CD have been investigated and discussed. This work is important reference for further investigating the vesicles and particles prepared based on host–guest interactions, and it is guide to understand the behavior of MO·β-CD complexes in fluorescent probes and bio-mimicking, etc.Micro-aggregates based on inclusion complexes between methyl orange (MO) and cyclodextrins were investigated for the first time. The mixture of MO and γ-hydroxybutyric-β-cyclodextrin in water was observed to aggregate into vesicle-like particles by TEM, LCSM and DLS. The formation mechanism and pH-responsive properties of these vesicle-like particles were also discussed.

A practical and efficient multikilogram-scale preparation of 7-amino-3-vinylcephem-4-carboxylic acid (7-AVCA), a key intermediate used in the synthesis of cefixime and cefdinir, is described utilizing p-methoxybenzyl 7-phenylacetamido-3-chloromethylcephem-4-carboxylate (GCLE) as a starting material. Reaction conditions were optimized to simplify the process, to improve the quality and to increase the yield. The process has been demonstrated on a multikilogram scale in 77% overall yield with a purity of >99%.

A convenient one-step process for the preparation of methyl 2-benzamidomethyl-3-oxobutanoate (1), a raw material used in the synthesis of (2R,3R)-3-((R)-1-(tert-butyldimethylsilyloxy)ethyl)-2,3-dimethyl-4-oxoazetidin-2-yl acetate (2), a key intermediate for carbapenem synthesis is reported. The process is carried out under mild reaction conditions and is amenable to large-scale synthesis.

Vesicles were assembled from an unconventional inclusion complex between β-cyclodextrin (βCD), and N,N′-bis(ferrocenylmethylene)diaminohexane (1). The vesicles formed in water and in a mixed solvent (water/methanol) were observed by transmission electron microscopy. The peculiar inclusion effects of 1·βCD were characterized by UV and cyclic voltammetry. The structure of the complex was characterized by 1H- and 2D ROESY NMR spectroscopies. The size of the vesicles in water, methanol, and in mixtures of water and methanol was investigated by dynamic light scattering. The vesicles disappeared upon addition of an oxidizing agent. The structures of the inclusion complex and the vesicles formed via the complex are discussed according to the experimental data.Vesicles were assembled from an unconventional inclusion complex between the host, beta-cyclodextrin (βCD), and guest (1), N,N′-bis(ferrocenylmethylene)-diaminohexane. The vesicles formed in water and in a mixed solvent (water and methanol) were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The peculiar inclusion effects of 1·βCD were characterized by UV, cyclic voltammetry (CV), and NMR. The vesicles disappeared upon addition of an oxidizing agent.

Ethoxymethxoymethane (EMM) was conveniently prepared by acetalization of aqueous formaldehyde with methanol and ethanol in a batch reactive distillation mode using a cation-exchange resin catalyst for the first time. EMM was found to be a significant cosolvent of methanol/gasoline blends.

A new soluble cyclodextrin derivative 6-O-(2-hydroxybutyl)-β-cyclodextrin (6-HB-β-CD) was prepared. Its molecular binding and recognition ability were investigated with the comparison of β-cyclodextrin (β-CD), 2-O-(2-hydroxypropyl)-β-cyclodextrin (2-HP-β-CD), 6-O-(2-hydroxypropyl)-β-cyclodextrin (6-HP-β-CD), and 2-O-(2-hydroxybutyl)-β-cyclodextrin (2-HB-β-CD). The relationship between the complex stability constants and the possible structures of inclusion compounds was discussed with the interaction of hosts and guests, including the weak hydrophobic interactions, the size/shape matching, the steric hindrance, and the hydrophilic property.6-O-(2-Hydroxybutyl)-β-cyclodextrin was prepared and investigated with comparison of β-cyclodextrin, 2-O-(2-hydroxypropyl)-β-cyclodextrin, 6-O-(2-hydroxypropyl)- β-cyclodextrin, and 2-O-(2-hydroxybutyl)-β-cyclodextrin. The relationship between complex stability constants and possible structures of inclusion compounds was discussed with the interaction of hosts and guests, including the weak hydrophobic interaction, the size/shape matching, the steric hindrance, and the hydrophilic property.

A new cyclodextrin derivative 6-O-(2-hydroxyl-3-betainylpropyl)-β-cyclodextrin (6-HBP-β-CD) was prepared with a “synthesis-deprotection one pot” method and studied as an efficient chiral selector in the separation of racemic mixtures of drugs by capillary electrophoresis (CE). Compared with β-CD and 2-HP-β-CD, 6-HBP-β-CD could provide efficient separating capability about alkali racemic mixtures of drugs under suitable pH.

Synergistic effect for the mixtures of polyglycerol esters of fatty acids (PGEFs) [including triglycerol diisostearate (TGDIS), pentaglycerol distearate (PGDS), triglycerol monostearate (TGMS) and triglycerol monooleate (TGMO)] with sodium oleate solubilizing water in gasoline has been investigated. The effect of a series of alcohols on the water amounts solubilized in the microemulsion systems of TGDIS/sodium oleate/alcohol/gasoline/water has been studied. It was shown that the microemulsion system of TGDIS/sodium oleate/1-butanol/gasoline/water exhibited better behavior in solubilizing water than the other systems studied. The best weight ratio of TGDIS/sodium oleate was 6:4, in which the maximum solubilization capacity of water was 2.402 g at 16 °C, when the amount of the mixed surfactants and gasoline were 0.740 and 6.000 g respectively. In addition, the microemulsion system of TGDIS/sodium oleate/1-butanol/gasoline/water was more water soluble and less temperature sensitive, in comparison with the microemulsion system of TGDIS/lauryl polyoxyethylene (9) ether (AEO9)/gasoline/water.

An enzymic method to protect selected amino group of lysine has been reported. This reaction proceeds smoothly under room temperature with high regioselectivity (up to 99%) and high yields (up to 90%). This work will pave the way for simple and selective protection of amino group of lysine in industry.

Structural matching of two organic building blocks bearing glutamate units and different luminophores assembled into unilamellar nanovesicles in aqueous media through a co-assembly process. Aggregation-induced energy transfer took place in the co-assembled system, leading to controllable generation of multiple luminescence colors including white light.

A novel approach for preparation of graphitic carbon nitride nanosheets (CNNS) from stripping graphitic carbon nitride by strong acid and ultrasonic technology was demonstrated in this study for the first time. Transmission electron microscopy (TEM) was employed to characterize the surface morphology. Atomic force microscope (AFM) was carried out to characterize the thickness of nanosheets. X-Ray diffraction (XRD) was performed to estimate the lattice structure. X-Ray photoelectron spectroscopy (XPS) was carried out to characterize the surface composition and element analysis. Fourier transform infrared spectroscopy (FT-IR) was allowed to identify the functional groups. The as-synthesized CNNS exhibited excellent emission property as well as excitation-independent emission behavior, and fluorescence quantum yields could reach approximately 12.53%. Mercury ion (Hg2+) can make a result of quenching the significant intensity of fluorescence of CNNS by formation of a covalent bond between empty orbital of Hg2+ and the π electrons of N (turn-off). Moreover, the addition of the L-cysteine (L-Cys) can enhance the intensity of fluorescence of the CNNS– Hg2+ system through the thiol group of L-Cys anchored with Hg2+ and drag it from the surface of CNNS (turn-on). The CNNS was consequently functioned as a fluorescence probe towards “off–on” detection of Hg2+ and L-Cys with high sensitivity and selectivity. Moreover, the fluorescent probe was applied to detect tap water and well water with satisfactory results.

Through a good/poor solvent strategy, native folic acid (FA) which behaves as a super-gelator in DMSO–water system can be successfully employed to construct supramolecular gels. The system exhibited morphological evolution with the increase of FA concentration; various phases such as vesicles, fiber/vesicles, fiber/nanoparticles, nanoparticles were probed. In the self-assembly process, L-glutamic acid moiety induced the formation of helical 1-dimensional (1-D) fibers which further self-assembled into a gel. Stimuli like heat, stress, pH and light which affect the molecular structure of FA or solubility in the mixed solvents had a pronounced influence on the properties of the gels, such as mechanical properties or bulk phases. A time-dependent oscillatory stress scan indicated that the supramolecular gel had a self-healing property. Without tedious modification routes and addition of alkali metal ions, native FA which served as an efficient building block and super-gelator to build up multi-responsive and self-recovery material was investigated for the first time.