Eco-Friendly Production of Boron Nitride Nanosheets via Deep Eutectic Solvents and Their Application in Enhancing Thermal Conductivity of PVDF Composites.

Boron nitride nanosheets (BNNS) are expected to be ideal fillers because of their high thermal conductivity and excellent electrical insulation. However, it is still an open challenge to produce BNNS on a large scale using ecofriendly solvents. Here, first, we demonstrate an effective liquid exfoliation method for producing BNNS via utilizing deep eutectic solvents (DES) composed of D,L-menthol and various acids with the assistance of ultrasonication.

Upconversion particle-assisted NIR polymerization enables microdomain gradient photopolymerization at inter-particulate length scale.

High crosslinking and low shrinkage stress are difficult to reconcile in the preparation of performance-enhancing photopolymer materials. Here we report the unique mechanism of upconversion particles-assisted NIR polymerization (UCAP) in reducing shrinkage stress and enhancing mechanical properties of cured materials. The excited upconversion particle emit UV-vis light with gradient intensity to the surroundings, forming a domain-limited gradient photopolymerization centered on the particle, and the photopolymer grows within this domain.

3D printing of unsupported multi-scale and large-span ceramic via near-infrared assisted direct ink writing.

In the three-dimensional printing process of ceramic with low-angle structures, additional supporting structures are usually employed to avoid collapse of overhanging parts. However, the extra supporting structures not only affect printing efficiency, but the problems caused by their removal are also a matter of concern. Herein, we present a ceramic printing method, which can realize printing of unsupported multi-scale and large-span ceramics through the combination of direct ink writing and near-infrared induced up-conversion particles-assisted photopolymerization.

Laser Induced Thermal Effect on the Polymerization Behavior in Upconversion Particle Assisted Near-Infrared Photopolymerization.

Laser induced thermal effect is inevitable in upconversion particle assisted near-infrared polymerization (UCAP). Herein, the influence of thermal effects on the polymerization behavior are investigated. The effects of up-conversion particles content and NIR laser intensity on the polymerization rate and surface oxygen inhibition were systematically investigated, and the temperature evolution and complex viscosity changes in the polymerization system during the polymerization process were also monitored.

High-efficient liquid exfoliation of 2D metal-organic framework using deep-eutectic solvents.

The exfoliation of bulk two-dimensional metal-organic framework (MOF) into few-layered nanosheets has attracted much attention recently. In this work, an environmental-friendly route has been developed for layered-MOF (MAMS-1) delamination using deep eutectic solvent (DES), which is more sustainable and efficient alternative than conventional organic solvents for MOF nanosheet preparation. Under sonication condition, DES as solvents, the highest exfoliation rate of MAMS-1 is up to 70% with two host layers via poly(vinylpyrrolidone) (PVP) surfactant-assisted method.

Interfacial growth of metal-organic framework on carboxyl-functionalized carbon nanotubes for efficient dye adsorption and separation.

Hybrid nanocomposites based on UiO-66-NH and carboxyl-functionalized carbon nanotubes were developed in this study via different synthetic pathways. Combining them through interfacial in situ growth was beneficial for the better dispersity of UiO-66-NH in the CNTs@UiO-66-NH composite than physically mixing CNTs/UiO-66-NH and chemically bonded CNTs-CONH-UiO-66. Coordination between carboxyl groups of CNTs and zirconium ions resulted in the interfacial growth of UiO-66-NH on CNTs.

Cobalt-Polypyrrole/Melamine-Derived Co-N@NC Catalysts for Efficient Base-Free Formic Acid Dehydrogenation and Formylation of Quinolines through Transfer Hydrogenation.

It is highly desired but remains a great challenge to develop non-noble metal heterogeneous catalysts to supersede noble metal catalysts for formic acid (FA) dehydrogenation and the corresponding transfer hydrogenation reactions. Herein, we developed a simple and feasible melamine-assisted pyrolysis strategy for the preparation of atomic cobalt-nitrogen (Co-N)-anchored mesoporous carbon with high metal loading (>6.8 wt %) and high specific surface area (750 m g).

Preparation and controlled drug release ability of the poly[N-isopropylacryamide-co-allyl poly(ethylene glycol)]-b-poly(γ-benzyl-l-glutamate) polymeric micelles.

The polymeric micelles were prepared through a copolymerization of allyl polyethylene glycol (APEG) and N-isopropylacrylamide in the presence of 2-aminoethanethiol (AET), followed by a ring opening polymerization of γ-benzyl-l-glutamate N-carboxyanhydride (BLG-NCA). Doxorubicin (DOX) as a model drug was covalently conjugated into the core of micelles via hydrazone bonds. The drug loading capacity could reach up to 15% with drug encapsulation efficiency of 80%.

Preparation of pH/redox dual responsive polymeric micelles with enhanced stability and drug controlled release.

Stimuli-responsive polymeric micelles were prepared through self-assembly of amphiphilic copolymers poly(ethylene glycol)-poly(γ-benzyl l-glutamate), followed by a core-crosslinking reaction using cystamine as the crosslinking agent. The crosslinked micelles with spherical morphologies in nanometer size showed enhanced stability against dilution and concentrated salt solutions compared to the micelles before crosslinking. Doxorubicin (DOX) as a model drug was encapsulated into the core of micelles through electrostatic interactions between carboxylic acid and DOX.

Studies on the preparation and controlled release of redox/pH-responsive zwitterionic nanoparticles based on poly-L-glutamic acid and cystamine.

The enhancement of tumor intracellular drug uptake and resistance against nonspecific protein adsorption are essential for an injectable anticancer drug carrier. In the present study, a new type of redox/pH-responsive zwitterionic nanoparticles (NPs) was prepared using poly-L-glutamic acid and cystamine in aqueous solutions under mild conditions. The NPs showed surface charge convertible feature in response to pH change of the solutions.

Pickering emulsions stabilized by a metal-organic framework (MOF) and graphene oxide (GO) for producing MOF/GO composites.

Herein we demonstrate the formation of a novel kind of Pickering emulsion that is stabilized by a Zr-based metal-organic framework (Zr-MOF) and graphene oxide (GO). It was found that the Zr-BDC-NO and GO solids assembling at the oil/water interface can effectively stabilize the oil droplets that are dispersed in the water phase. Such a Pickering emulsion offers a facile route for fabricating Zr-MOF/GO composite materials.

Converting Metal-Organic Framework Particles from Hydrophilic to Hydrophobic by an Interfacial Assembling Route.

Here, we propose to modify the hydrophilicity of metal-organic framework (MOF) particles by an interfacial assembling route, which is based on the surface-active nature of MOF particles. It was found that hydrophilic UiO-66-NH particles can be converted to hydrophobic particles through an oil-water interfacial assembling route. The underlying mechanism for the conversion of UiO-66-NH was investigated by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy.

Ionic liquid accelerates the crystallization of Zr-based metal-organic frameworks.

The Zr-based metal-organic frameworks are generally prepared by solvothermal procedure. To overcome the slow kinetics of nucleation and crystallization of Zr-based metal-organic frameworks is of great interest and challenging. Here, we find that an ionic liquid as solvent can significantly accelerate the formation of Zr-based metal-organic frameworks at room temperature.

Preparations of hyperbranched polymer nano micelles and the pH/redox controlled drug release behaviors.

Hyperbranched polymer nano micelles (NMs) were prepared through a nucleophilic ring opening polymerization between cystamine and polyethylene glycol diglycidyl ether, followed by a reaction of amino groups and dimethyl maleic anhydride. The NMs showed spheric morphologies with hydrodynamic diameters of 106-120nm. Doxorubicin was loaded in the NMs with loading rate as high as 15.

Preparations and doxorubicin controlled release of amino-acid based redox/pH dual-responsive nanomicelles.

Terpolymers of poly (Lysine-co-N, N-Bis (acryloyl) cystamine-co-β-Phenethylamine) (PLBP) were synthesized in one-pot by Michael addition terpolymerization. The terpolymers self-assembled into nano-sized spherical micelles (84-123nm) with narrow distributions. The surface charge of the nanomicelles (NMs) was depended on solution's pH and showed negative values under physiological conditions (pH7.

CO/Water Emulsions Stabilized by Partially Reduced Graphene Oxide.

Using functional materials to stabilize emulsions of carbon dioxide (CO) and water is a promising way to expand the utility of CO and functional materials. Here we demonstrate for the first time that the partially reduced graphene oxide (rGO) can well stabilize the emulsion of CO and water without the aid of any additional emulsifier or surface modification for rGO. More interestingly, such a novel kind of emulsion provides a facile and versatile route for constructing highly porous three-dimensional rGO materials, including rGO, metal/rGO, and metal oxide/rGO networks.

High internal ionic liquid phase emulsion stabilized by metal-organic frameworks.

The emulsification of metal-organic frameworks (MOFs) for the two immiscible phases of water and ionic liquid (IL) was investigated for the first time. It was found that Ni-BDC (BDC = 1,4-dicarboxybenzene) can emulsify water and ILs and favor the formation of high internal phase emulsions (HIPEs) under certain experimental conditions. The microstructures of the HIPEs were characterized by confocal laser scanning microscopy using a fluorescent dye Rhodamine B, which proves that the HIPEs are the IL-in-water type.

Water-in-Supercritical CO Microemulsion Stabilized by a Metal Complex.

Herein we propose for the first time the utilization of a metal complex for forming water-in-supercritical CO (scCO ) microemulsions. The water solubility in the metal-complex-stabilized microemulsion is significantly improved compared with the conventional water-in-scCO microemulsions stabilized by hydrocarbons. Such a microemulsion provides a promising route for the in situ CO reduction catalyzed by a metal complex at the water/scCO interface.

Metal-Organic Framework for Emulsifying Carbon Dioxide and Water.

Forming emulsions of carbon dioxide (CO2 ) and water can largely expand the utility of CO2 . Herein we propose for the first time the utilization of a metal-organic framework (MOF) for emulsifying CO2 and water. Owing to the hybrid composition, MOF particles can easily assemble at the CO2 /water interface to create a rigid protective barrier around the dispersed droplet.

Micellization of long-chain ionic liquids in deep eutectic solvents.

The aggregation behavior of the ionic liquid (IL) 1-alkyl-3-methylimidazolium chloride with different alkyl chain lengths in a deep eutectic solvent (DES, composed of choline chloride and glycerol in a 1 : 2 mole ratio) was studied for the first time. The critical micellar concentration, micellar size and intermolecular interactions in IL/DES solutions were investigated by different techniques including the fluorescence probe technique, small angle X-ray scattering and Fourier transform infrared spectroscopy. The solvophobic effect dominates the micellization of CnmimCl in DES and the intermolecular hydrogen-bond interaction plays a positive role to promote micelle formation.

Cellular graphene aerogel combines ultralow weight and high mechanical strength: A highly efficient reactor for catalytic hydrogenation.

The construction of three-dimensional graphene aerogels (GAs) is of great importance owing to their outstanding properties for various applications. Up to now, the combination of ultralow weight and super mechanical strength for GA remains a great challenge. Here we demonstrate the fabrication of cellular GAs by a facile, easily controlled and versatile route, i.

High-internal-phase emulsions stabilized by metal-organic frameworks and derivation of ultralight metal-organic aerogels.

To design high-internal-phase emulsion (HIPE) systems is of great interest from the viewpoints of both fundamental researches and practical applications. Here we demonstrate for the first time the utilization of metal-organic framework (MOF) for HIPE formation. By stirring the mixture of water, oil and MOF at room temperature, the HIPE stabilized by the assembly of MOF nanocrystals at oil-water interface could be formed.

Gas promotes the crystallization of nano-sized metal-organic frameworks in ionic liquid.

Herein it was found that gas can be utilized as an activator to promote metal-organic framework (MOF) crystallization in IL at room temperature. The ultra-small MOF nanoparticles were obtained, and their size and porosity properties can be easily modulated by controlling gas pressure. The as-synthesized nano-sized Cu-MOF is an excellent candidate catalyst for the solvent-free oxidation of cyclohexene with oxygen.

Assembly of Mesoporous Metal-Organic Framework Templated by an Ionic Liquid/Ethylene Glycol Interface.

We propose a facile room-temperature synthesis of a metal-organic framework (MOF) with a bimodal mesoporous structure (3.9 and 17-28 nm) in an ionic liquid (IL)/ethylene glycol (EG) mixture. The X-ray diffraction analysis reveals that MOF formation can be efficiently promoted by the presence of the EG/IL interface at room temperature.

Ultra-small gold nanoparticles immobilized on mesoporous silica/graphene oxide as highly active and stable heterogeneous catalysts.

Here we demonstrate the in situ formation of ultra-small gold nanoparticles (<2 nm) finely dispersed on a binary solid carrier, i.e. a mesoporous SiO2 coated graphene oxide (GO) nanosheet.