•Introducing g-C3N4-ZnO hybrid in Cu/ZnO/Al2O3 promotes CO2 hydrogenation to methanol.•Cu/5 wt% g-C3N4-ZnO/Al2O3 has superior methanol yield than industrial catalyst.•Modifying ZnO with g-C3N4 increases the electron richness on ZnO.•Enhanced strong metal-support interaction accounts for higher catalytic activity.Replacing ZnO with g-C3N4-ZnO hybrid in Cu/ZnO/Al2O3 catalysts for CO2 hydrogenation leads to enhanced methanol yield and selectivity, which shows a volcano-type relationship with g-C3N4 amount (0–15 wt% in g-C3N4-ZnO) in Cu/g-C3N4-ZnO/Al2O3 catalysts with the highest improvement at 5 wt% g-C3N4. The methanol space-time yield reaches 5.73 mmol h−1 gCu− 1 (12 bar, 250 °C) for Cu/5 wt% g-C3N4-ZnO/Al2O3, superior to the highest methanol yield (5.45 mmol h− 1 gCu− 1) of industrial catalyst HiFUEL-R120 obtainable under the same pressure. Time-resolved photoluminescence, electronic spin resonance and temperature-programmed reduction characterizations support the promotion from enhanced strong metal-support interaction in modified catalysts caused by introduced electron-rich support.Download high-res image (247KB)Download full-size image

The study presented here reports the synthesis of a recently developed rheology-controlled acrylic latex used in waterborne metallic coatings, which was synthesized from methacrylic acid (MAA), methyl methacrylate (MMA), butyl acrylate (BA), hydroxypropyl methacrylate (HPMA) and divinylbenzene (DVB) via core/shell seed emulsion polymerization. Once the latex was neutralized with dimethylethanolamine (DMEA), it could be further thickened with an additional solvent, ethylene glycol butyl ether (EGBE); in this process the dispersion viscosity increased dramatically and the resin exhibited strong thixotropy. To clarify the thickening mechanism, the swelling behaviour and interfacial properties of the latex with DMEA and EGBE were intensively investigated. Dynamic light scattering (DLS) results revealed that DMEA swelled latex particles to some extent, whereas EGBE could not change the diameter of particles but precipitated the particles. Surface tension experiments demonstrated that EGBE decreased the latex surface tension, and we concluded that amphiphilic EGBE causes particles to flocculate in the latex system. Scanning electron microscopy (SEM) results showed that particles in a sample that were thickened with DMEA and EGBE retained their spherical structure and were arranged regularly. The combination of alkali-swellable properties and the flocculating effect of EGBE were the main factors responsible for thickening of the latex.

Palladium supported on different shaped iron oxides has been synthesized and tested in glycerol hydrogenolysis in order to investigate the morphological effect of the support on catalytic performance. The plate-like iron oxide support exhibits a much higher activity due to the presence of more basic sites (oxygen vacancies) on its predominant polar surface. Thus, by tailoring the shape of the crystallized support, we show that bifunctional metal-oxide catalysis at the interface, like in the present example, can be significantly manipulated.

In this work, alkylamine–polyol assemblies were used as “micro-reactors” for in situ preparation of gold nanoparticles, which in turn altered the gel structure and morphology significantly.

•Systematic rheological investigation on alkylamine-ethylene glycol organogel was conducted.•Scaling laws of elasticity vs concentration was used to infer the structural features.•Growth mechanism of newly born fibers is controlled by supersaturation.A systematic rheological study is undertaken to investigate the viscoelastic behaviors of alkylamine-ethylene glycol organogels. Microstructures and resulting mechanical properties are thus studied in the functions of temperature, chain length and concentration of the alkylamine. A model based on scaling laws of shear elasticity versus concentration is employed to describe the structural features of the gels. According to the supersaturation principle, a gradual structural change from lamellar/fibrillar to spherulitic/polyhedral network can be accounted when the chain length of alkylamine is increased from 12 to 18.Formation of the topological networks based on the styles of branching.

Using sodium caprylate as a model molecule, in the present work, we unraveled the gelation mechanism of sodium soaps in organic solvents from its correlation with the microstructure morphology. It is interesting to find that both the formation of organogels and radiation-like gel fibers are controlled by Na+ concentration in the system. As the gel-activator, the sodium ions not only accelerate the gelation process and enhance the gel networks, but also induce the morphology transformation from fibers to radiative nanoribbons. TEM and XRD characterization reveals that the Na+ enhanced effect should be ascribed to the structure transformation of sodium caprylate from layers to hexagonal packing, due to its reduced inter-separation after the addition of Na+. Based on these results, the gelation mechanism of sodium soaps has been also proposed.Graphical abstractHighlights► Sodium soaps can form radiation-like gel fibers in organic solvents. ► Na+ plays a key role in gel formation and microstructure morphology. ► Na+ induces structure transformation from fibers to nanoribbons. ► These are produced by Na+-inducing packing change of sodium soaps. ► Layer to hexagonal packing transformation is the reason of gel formation and morphology change.

A series of poly(methyl methacrylate)-graft-oligoamines (PMMA-g-oligoamines), including PMMA-g-DETA, PMMA-g-TETA and PMMA-g-TEPA, were synthesized through aminolysis of the PMMA with diethylenetriamine, triethylenetetramine and tetraethylenepentamine. Agarose gel retardation assay indicated that PMMA-g-oligoamines had good binding capability with plasmidDNA, and the binding capability increased with increasing length of oligoamines and content of nitrogen (N%). The results of particle size, zeta potential and morphology observation further showed that the PMMA-g-oligoamines could condense DNA efficiently and the PMMA-g-oligoamine/DNA complexes were uniform nanospheres. The in vitro cell viability indicated that PMMA-g-oligoamines were less toxic than 25 kDa PEI, though the cytotoxicity of PMMA-g-oligoamines increased slightly with increasing length of oligoamines as well as the N% of PMMA-g-oligoamines. The transfection efficiency of PMMA-g-oligoamines/DNA complexes in 293 T and HeLa cells demonstrated that PMMA-g-oligoamines could transfect cells efficiently with increasing the length of oligoamines, especially PMMA-g-TEPA with highest N%, and showed similar transfection capability as 25 kDa PEI. The cellular uptake study showed that the distribution of YOYO-1 labeled DNA in the cytoplasm and nuclei increased gradually with increasing length of oligoamines.

A ligand is a crucial element for atom transfer radical polymerization (ATRP). A new nitrogen-containing compound, 1,1’-(2,2’-(ethane-1,2-diylbis(butyl azanediyl)) -bis(ethane-2,1-diyl)) dipyrrolidin-2-one (DBBD), was synthesized and utilized as the ligand of copper halide for ATRP of methyl methacrylate (MMA) and methyl acrylate (MA). It was found that the CuBr/DBBD and Ethyl 2-bromoisobutyrate (EBIB) system could mediate the polymerization of MMA and the reaction was first-order kinetics, although the control of molecular weights was not perfect. When CuCl was used to replace CuBr, the molecular weights of obtained polymers were well controlled, which indicated the halide exchange could improve the controllability. In the polymerization of MA using Methyl 2-bromopropronate (MBP) or EBIB as initiator and CuCl/DBBD as catalyst, good control of the polymerization could be achieved and the molecular weights were very close to the predicted value.

Here, we report, for the first time, the formation of a new thermoreversible organogel based on self-assembly of oleic acid (OA) and hexadecylamine (HDA) in ethylene glycol (EG) with addition of NaOH; this gelator can act as a template and carbon source for synthesis of Sn nanoparticles encapsulated in carbon.

(N-R)3TEDP, 1,1′-(2,2′-(2,2′-(alkylazanediyl)bis(ethane-2,1-diyl)bis(alkylazanediyl))bis(ethane-2,1-diyl))dipyrrolidin-2-one, with central alkyl amine and peripheral pyrrolidin-2-one structure was successfully employed as ligand in copper-based ATRP. The polymerization followed the first order kinetic and the molecular weights of PMMA increased linearly with monomer conversion. Although the Mn of products obtained by SEC was higher than the theoretic ones, the distribution of molecular weight was narrow (<1.4). By introducing deactivator CuBr2, the polymerization rate of the ATRP catalyzed by CuBr/(N-butyl)3TEDP decreased dramatically, but the control was improved (Mw/Mn=1.22). Using mixed halide initiation system (CuCl/EBiB), the Mn of synthesized PMMA was more close to the calculated value with much lower molecular weight distribution (Mw/Mn=1.15). The effect of temperature was investigated and the low ΔHθeq value (21.38 kJ·mol−1) was derived from the Arrhenius plot. The alkyl substitute of (N-R)3TEDP had profound effect on the CuBr-catalyzed ATRP of MMA, due to the steric effect introduced by their bulky size. The activity of these ligands in the ATRP showed the following order: C12 << C4 ~ C6 ~ C8, in the abbreviate form of (N-R)3TEDP.

•A series of PdPt@Au nanoparticles with uniform size and structure are fabricated.•A correlation between CO electrocatalytic oxidation and ATR-IR peak is discovered.•The core@shell samples could be more active than alloy samples in CO electroxidation.A series of PdPt@Au core@shell nanopaticles (NPs) of similar size are synthesized with composition controlled cores and thickness controlled shells. Their CO electrocatalytic oxidation properties change with the composition of the cores, showing a volcano curve. A correlation between the properties of CO electrocatalytic oxidation and the location of adsorbed CO ATR-IR peak is discovered. Attenuated Total Reflection-Infrared Spectroscopy (ATR-IR) shows that samples which have the strongest monodentate CO are most active in CO electrocatalytic oxidation.Download high-res image (169KB)Download full-size image

Here, we report, for the first time, the formation of a new thermoreversible organogel based on self-assembly of oleic acid (OA) and hexadecylamine (HDA) in ethylene glycol (EG) with addition of NaOH; this gelator can act as a template and carbon source for synthesis of Sn nanoparticles encapsulated in carbon.