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Significant research has been focused on the synthesis of metal-organic frameworks (MOFs) with controllable compositions and structures, while much fewer works have been devoted to the construction of large micro-sized MOFs with uniform sizes and morphologies, which could be beneficial for practical applications. In this paper, a unique microfluidic jet spray drying technology has been adopted to reassemble nano-sized MIL-101 building blocks into hierarchical microparticles with uniform and large particle sizes. Specifically, suspension precursors of nano-sized MIL-101 building blocks are atomized into uniform droplets and then converted to microparticles on a one-to-one basis through a fast and scalable spray drying process. The particle size and morphology can be controlled by adjusting the solid concentration of the suspension and the drying temperature. The particle formation process with evolution of different morphologies are discussed. The resultant uniform MIL-101 microparticles possess hierarchical porosities and maintain the intrinsic crystal structure, microporosity and thermal stability of the nano-sized building blocks. They demonstrate a high efficiency toward benzene adsorption from n -octane solutions with high adsorption rates and very high adsorption capacities under batch conditions. Moreover, the large particle size and hierarchical structure make them applicable as filler of a fixed bed for dynamic flow separation of benzene from n -octane solutions with promising performance. The microfluidic jet spray drying technology can also be extended for the reassembly of other uniform MOF microparticles. [ABSTRACT FROM AUTHOR]

In this paper, conventional Ouali model for tensile modulus of composites is developed for polymer/carbon nanotubes (CNT) nanocomposites (PCNT) assuming the influences of filler network and dispersed nanoparticles above percolation threshold as well as the interphases between polymer host and nanoparticles which reinforce the nanocomposite and facilitate the networking. The developed model is simplified, because the characteristics of dispersed nanoparticles and surrounding interphase cannot significantly change the modulus of PCNT. The suggested model is compared to the experimentally measured modulus of some samples, which can calculate the percolation threshold of interphase regions and the possessions of interphase and filler network. The suggested model correctly predicts the influences of all parameters on the modulus. Thinner and longer CNT in addition to thicker interphase enhance the volume fraction of interphase which shifts the connectivity of interphase regions to smaller nanoparticle fraction and improves the modulus of PCNT. A very low level of percolation threshold significantly develops the modulus, but its high ranges have not any role. Among the studied parameters, the thickness and modulus of interphase between polymer host and networked nanoparticles play the most important roles in the modulus of PCNT. [ABSTRACT FROM AUTHOR]

Kolarik proposed a model for tensile strength of polymer particulate composites based on the cubic orthogonal skeleton or three perpendicular plates (3PP) system. In this paper, Kolarik model is expanded for tensile strength of polymer nanocomposites containing spherical nanoparticles assuming the interphase properties. This model expresses the strength as a function of interphase properties. This development is performed using some models such as Pukanszky and Nicolais-Narkis. The expanded model is applied to calculate the thickness and strength of interphase by the experimental results. Furthermore, the strength of polymer nanocomposites is evaluated at different levels of material and interphase properties. The experimental data show good agreement with the predictions of the developed model. [ABSTRACT FROM AUTHOR]

The application of fluorescent nanoparticles to the detection of inorganic ions and organic compounds has been attracted wide attention recently. In this paper, an “off-on” method for highly sensitive and selective detection of Hg 2+ and l -cysteine ( l -Cys) or Hg 2+ and I − using home-made nitrogen-doped carbon quantum dots (N-CQDs) as fluorescent probe was reported. The N-CQDs with a fluorescence quantum yield of 42.2% were prepared using tartaric acid, citric acid and ethanediamine as the precursors in the oleic acid media. The fluorescence of the obtained N-CQDs could be quenched selectively and sensitively by the addition of Hg 2+ (turn-off) with a detection limit of 83.5 nM. When l -Cys or I − was added into the N-CQDs-Hg 2+ system, the fluorescence was recovered effectively (turn-on). This process could be used to the detection of l -Cys or I − with a detection limit of 45.8 and 92.3 nM, respectively. [ABSTRACT FROM AUTHOR]

In this paper, the influence of 3 -glycidoxypropyltriethoxysilane (GPTES) based organic-inorganic coatings on the properties of treated textile fabrics was studied. All experimental results were deeply analyzed and thereafter correlated with the employed silica precursor concentration and with the presence of the BF 3 OEt 2 (Boron trifluoride diethyl etherate), used as epoxy ring opening catalyst. SEM analysis, FT-IR spectroscopy, X-ray Photoelectron Spectroscopy (XPS), thermogravimetric analysis (TGA) and washing fastness tests of the sol-gel treated cotton fabric samples were firstly exploited in order to characterize the morphological and structural features of the achieved coatings. Finally, the influence of the resulting nanohybrid coatings was explored in terms of abrasion resistance, tensile strength and elongation properties of treated cotton, polyester and silk fabrics. The catalyst amounts seem to strongly improve the formation of coatings, but still they do not influence the wear resistance of treated textile fabrics to the same extent. Indeed, it was found that increasing catalyst/GPTES ratio leads to a more cross linked inorganic 3D-network. GPTES itself was not found to affect the bulk properties of the selected textile and the resulting coatings were not so rigid to hardly modify the mechanical properties of the treated samples. Finally, it is worth mentioning that in all case the obtained 3 -glycidoxypropyltriethoxysilane-based chemical finishing have shown no cytotoxic effects on human skin cells. [ABSTRACT FROM AUTHOR]

Low dimensional nanomaterials have emerged as candidates for gas sensors owing to their unique size-dependent properties. In this paper, Bi 2 S 3 nanobelts were synthesized via a facile solvothermal process and spin-coated onto alumina substrates at room temperature. The conductometric devices can even sensitively response to the relatively low concentrations of NO 2 at room temperature, and their sensing performance can be effectively enhanced by the ligand exchange treatment with inorganic salts. The Pb(NO 3 ) 2 -treated device exhibited superior sensing performance of 58.8 under 5 ppm NO 2 at room-temperature, with the response and recovery time of 28 and 106 s. The competitive adsorption of NO 2 against O 2 on Bi 2 S 3 nanobelts, with the enhancement both in gas adsorption and charge transfer caused by the porous network of the very thin Bi 2 S 3 nanobelts, can be a reasonable explanation for the improved performance at room temperature. Their sensitive room-temperature response behaviors combined with the excellent solution processability, made Bi 2 S 3 nanobelts very attractive for the construction of low-cost gas sensors with lower power consumption. [ABSTRACT FROM AUTHOR]

We developed an interesting route for preparing a poly (acrylamide- co -acrylic acid) (P(AAm- co -AA)) hydrogel microsphere with a coating of Au nanospheres (hydrogel microsphere @ Au nanospheres) through self-assembly based on electrostatic interaction. The fabricated composites could be used as highly sensitive enhanced Raman scattering substrates. The nanogaps between adjacent Au nanospheres were dynamically tuned by volume changes in the hydrogel microspheres in the semiwet state under different pH conditions. At pH 6, the hydrogel microsphere @ Au nanospheres demonstrated highly sensitive SERS with an enhancement factor of 10 9 . The product could detect very low concentrations of analytes up to 10 −12 M 4-aminothiophenol (4-ATP) molecules. This paper proposes a new method for detecting trace amounts of environmental organic pollutants by dynamically tuning the SERS enhancement in the semiwet testing state. [ABSTRACT FROM AUTHOR]

The breakup process of aqueous droplet with surfactant suspended in oil under direct current (DC) electric field is investigated in this paper. The characteristics of the breakup process, stretching, necking and breakup, are discussed quantitatively with the electric capillary number Ca and the dimensionless surfactant concentration C ∗ which is the ratio of surfactant concentration to the critical micelle concentration. The results show that the presence of surfactant reduces the steady deformation of droplet and significantly decelerates the stretching process, resulting from the redistribution of surfactant molecules within the oil/water interface. The law of droplet stretching process when C ∗ ≥ 1 indicates that the exchange of surfactant molecules between the bulk phase and the interface could not catch up with the increase of oil/water interfacial area. Ca and C ∗ count a great deal to the necking position and the daughter droplet size. The daughter droplet size decreases with the increase of surfactant concentration. These results provide a mechanistic framework to promote the electrocoalescence efficiency of oil/water emulsion and to the application of electric emulsification. [ABSTRACT FROM AUTHOR]

In this paper, a novel strategy for the preparation of poly(levodopa) functionalized MgAl-layered double hydroxide (PDOPA- f -LDH) was developed based on the modified mussel inspired chemistry. The utilization of PDOPA- f -LDH for the removal of methylene blue (MB) from aqueous solution was also examined. Taken advantage of the self-polymerization of levodopa (DOPA) in alkaline solution and the strong affinity of catechol groups to the substrate surface, the LDH was covered homogeneously by a layer of polymer coating of DOPA, leading to the functionalization toward LDH. The structure, surface morphology, thermostability and elemental composition of as-prepared PDOPA- f -LDH were investigated by the transmission electron microscope, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Besides, the surface charge of the PDOPA- f -LDH was also investigated using zeta potential. The effects of various parameters, including contact time, initial MB concentration, solution pH and temperature, on the adsorption of MB onto PDOPA- f -LDH were systematically investigated. Results show that the adsorption capacity of functionalized LDH at 25 °C could reach up to 102 mg/g, which is much higher than that of pure LDH in the same experimental conditions. The adsorption kinetics and isotherm of MB adsorption were studied in batch experiments. The pseudo-second-order model is found to be the best to describe the adsorption kinetics. The isotherm result shows that the Freundlich isotherm is the better-fit-isotherm model to represent the equilibrium data. The values of thermodynamic parameters, including enthalpy change Δ H 0 , entropy change Δ S 0 and Gibbs free energy change Δ G 0 , were also determined. All the Δ G 0 values are negative; the Δ H 0 and Δ S 0 values of PDOPA- f -LDH were −7.824 kJ mol −1 and −0.01562 kJ mol −1 K −1 , respectively. And the activation energy of system ( E a ) is calculated as 24.69 kJ mol −1 . The fact suggests that the MB adsorption on PDOPA- f -LDH is a spontaneous and exothermic process. These obtained results indicate that the prepared PDOPA- f -LDH could be used as an interesting adsorbent with great potential to adsorb the cationic dyeing pollutants from aqueous media. [ABSTRACT FROM AUTHOR]

In this paper, a novel heterogeneous nanodendrimer with generation of G2.0 was prepared by individual grafting of diethylenetriamine, triazine and l -cysteine methyl ester on the modified aluminum–silicate mixed oxides as a potent adsorbent of Hg(II) ions from aqueous media. The prepared nanodendrimer was characterized by nuclear magnetic resonance spectrum ( 1 H NMR and 13 C NMR), Fourier transform infrared spectroscopy (FT-IR), Diffuse reflectance UV–Vis spectroscopy (DR UV–Vis), zeta potential (ζ), inductively coupled plasma atomic emission spectroscopy (ICP-AES), transmission electron microscopy (TEM), scanning electron microscopy (SEM), nitrogen adsorption experiments at −196 °C and elemental analysis. Equilibrium and kinetic models for Hg(II) ions removal were used by investigating the effect of the contact time, adsorbent dosage, initial Hg(II) ions concentrations, effect of solution’s temperature, interfering ions, and initial pH. The contact time to approach equilibrium for higher removal was 6 min (3232 mg g −1 ). The removal of Hg(II) ions has been assessed in terms of pseudo-first- and -second-order kinetics, and the Freundlich, Langmuir and Sips isotherms models have also been applied to the equilibrium removal data. The removal kinetics followed the mechanism of the pseudo-second order equation, where the chemical sorption is the rate-limiting step of removal process and not involving mass transfer in solution, which was further proved by several techniques such as zeta potential, FT-IR and DS UV–vis. The thermodynamic parameters (ΔG, ΔH and ΔS) implied that the removal of mercury ions was feasible, spontaneous and chemically exothermic in nature between 15 and 80 °C. The nanodendrimer indicated high reusability due to its high removal ability after 15 adsorption–desorption runs. The adsorption mechanisms of Hg(II) ions onto the nanodendrimer was further studied by diverse techniques such as FTIR, EDS, zeta potential, DR UV–Vis spectroscopy and SEM. The possible mechanism of the Hg(II) ions adsorption onto the nanodendrimer could be carried out through the various paths such as electrostatic interaction, complexation, toxic metal chelation and ionic exchange, which eventually resulted in the hydrolysis and precipitation of the adsorbed Hg(II). The l -cysteine methyl ester nanodendrimer could also remove the mercury ions from the Persian Gulf water even after five times of recycling. [ABSTRACT FROM AUTHOR]

Combined effects of nonlinear thermal radiation and cubic autocatalysis chemical reaction on the three dimensional flow of stretched nanofluid along a rotating sheet have been investigated in this paper. The flow field is assumed to be suspended with magnetic iron oxide nanoparticles (IONPs). Hamilton-Crosser model is applied to measure effective thermal conductivity of nanofluid. Rosseland approximation is employed to obtain the nonlinear radiative heat flux. For novelty and practical point of view, influence of fluctuating surface velocity and periodic surface temperature constraints are incorporated into the governing equations which in turn are made dimension free by employing suitable transformations. For numerical solutions, an explicit finite difference scheme has been proposed under the restrictions of derived stability conditions. [ABSTRACT FROM AUTHOR]

ZnO has had little consideration as an anode material in lithium-ion batteries compared with other transition-metal oxides due to its inherent poor electrical conductivity and large volume expansion upon cycling and pulverization of ZnO-based electrodes. A logical design and facile synthesis of ZnO with well-controlled particle sizes and a specific morphology is essential to improving the performance of ZnO in lithium-ion batteries. In this paper, a simple approach is reported that uses a cation surfactant and a chelating agent to synthesize three-dimensional hierarchical nanostructured carbon-coated ZnO mats, in which the ZnO mats are composed of stacked individual ZnO nanowires and form well-defined nanoporous structures with high surface areas. In order to improve the performance of lithium-ion batteries, HfO 2 is deposited on the carbon-coated ZnO mat electrode via atomic layer deposition. Lithium-ion battery devices based on the carbon-coated ZnO mat passivation by atomic layer deposited HfO 2 exhibit an excellent initial discharge and charge capacities of 2684.01 and 963.21 mA h g −1 , respectively, at a current density of 100 mA g −1 in the voltage range of 0.01–3 V. They also exhibit cycle stability after 125 cycles with a capacity of 740 mA h g −1 and a remarkable rate capability. [ABSTRACT FROM AUTHOR]

In this paper, the synergetic influence of various weight ratios of TiO 2 nanoparticles (NPs)/graphene oxide nanoplates (GONs) in the matrix of ion exchange membranes was examined in order to adapt their electrokinetic properties based on the combination of the high specific surface area of GONs and the antifouling ability of TiO 2 nanoparticles. The morphology, physico-chemical features and ionic transport behavior of prepared membranes was studied. Scanning optical microscopy (SOM) and scanning electron microscopy (SEM) images showed a uniform surface for the lab-made membranes relatively. It was found that surface hydrophilicity of the membrane was increased in the presence of GONs and TiO 2 NPs. All modified membranes showed a higher water uptake than unmodified membranes. Furthermore, a higher ion exchange capacity, fixed ionic concentration, ionic permeability and flux were observed for all modified membranes in comparison with unmodified membranes. The membrane potential, transport number and selectivity improved in NaCl solutions by using GONs and TiO 2 nanoparticles. Furthermore, the membrane ionic conductivity showed an increasing trend by utilizing TiO 2 -co-GONs NPs. As an overall conclusion, the modified membrane containing 3 wt% GONs and 1 wt% TiO 2 NPs with superior transport number and permselectivity (∼99%), highest current density and cation flux and the lowest areal electrical resistance (∼4–5 Ω cm 2 ) showed the best performance. [ABSTRACT FROM AUTHOR]

In this paper, a new and facile strategy has been demonstrated for the electrochemical determination of tryptophan (Trp), based on graphite-like carbon nitride (g-C 3 N 4 ) nanosheets modified glassy carbon (CNNS/GC) electrode. The g-C 3 N 4 nanosheets were obtained via exfoliating bulk graphitic carbon nitride (bg-C 3 N 4 ), which was synthesized using a thermal poly-condensation process. The obtained g-C 3 N 4 nanosheets were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM). The results confirmed graphite-like structure with thickness of about 6–8 nm. The as-synthesized g-C 3 N 4 nanosheets were closely attached to the surface of GC electrode to construct electrochemical sensor without needing any film-forming agents. The CNNS/GC electrode exhibited good electrocatalytic activity towards Trp, and hereby some parameters, including scan rate and pH effect on Trp determination were investigated. Under the optimum experimental conditions, the oxidation peak currents had good linear relationship with Trp concentrations in the range of 0.1–110 μM and a detection limit of 0.024 μM (S/N = 3) was achieved. In addition, the obtained sensor showed good sensitivity, favorable repeatability, and long-term stability. Finally, the proposed electrochemical sensor has been successfully applied for the determination of Trp concentration in real samples with satisfactory results. [ABSTRACT FROM AUTHOR]

Polysaccharides are known to modify binding of proteins at interfaces and this paper describes studies of these interactions and how they are modified by pH. Specifically, the adsorption of human serum albumin on to polystyrene latex and to silica is described, focusing on how this is affected by hyaluronan. Experiments were designed to test how such binding might be modified under relevant physiological conditions. Changes in adsorption of albumin alone and the co-adsorption of albumin and hyaluronan are driven by electrostatic interactions. Multilayer binding is found to be regulated by the pH of the solution and the molecular mass and concentration of hyaluronan. Highest adsorption was observed at pH below 4.8 and for low molecular mass hyaluronan (≤150 kDa) at concentrations above 2 mg ml −1 . On silica with grafted hyaluronan, albumin absorption is reversed by changes in solvent pH due to their strong electrostatic attraction. Albumin physisorbed on silica surfaces is also rinsed away with dilute hyaluronan solution at pH 4.8. The results demonstrate that the protein adsorption can be controlled both by changes of pH and by interaction with other biological macromolecules. [ABSTRACT FROM AUTHOR]

In this paper, CuCr 2 O 4 nanoparticles were decorated on the surface of g-C 3 N 4 nanosheets (g-C 3 N 4 -NS) by a facile refluxing process. The structure, composition, morphology, optical, textural, and thermal properties were characterized by XRD, EDX, SEM, TEM, UV–vis DRS, FT-IR, XPS, PL, BET, and TGA techniques. The photocatalytic performance of g-C 3 N 4 -NS/CuCr 2 O 4 nanocomposites was assessed by degrading RhB and MB dyes and phenol under visible-light illumination. When the loading amount of CuCr 2 O 4 was 10 wt%, the nanocomposite exhibited the highest activity. Activity of the g-C 3 N 4 -NS/CuCr 2 O 4 (10%) nanocomposite refluxed for 3 h and calcined at 520 °C for 4 h was almost 11.8 and 4.8 times greater than those of the bulk g-C 3 N 4 and g-C 3 N 4 -NS photocatalysts in degradation of RhB, respectively. In the prepared nanocomposites, nanosheets of g-C 3 N 4 act not only as CuCr 2 O 4 support, but also as co-catalyst. The novel visible-light-active photocatalyst has considerable stability and it can be reused for five times without obvious loss of its photocatalytic activity. [ABSTRACT FROM AUTHOR]

The structure and thickness of the chemiresistive thin films can significantly affect their gas sensing performances for the heating-typed sensors. Under light irradiation, however, their influences are still to be addressed. In present paper, the multilayered ZnO porous thin films with different (three types) micro/nanostructures and controllable thickness are fabricated via layer by layer construction of the self-assembled colloidal-layers. The structural and thickness effects of such films on the gas sensing performances to NO 2 under ultraviolet (UV) illumination are experimentally studied. It has been found that under UV irradiation, the responses of the ZnO porous thin films to NO 2 increase upto the maxima with the rising film thickness. Further increasing the thickness would lead to the insignificantly or gradually decreasing responses. The film thicknesses corresponding to the maximal responses are associated with the porous structures and the porosity of the thin films. The films with the higher porosity would lead to the higher maximal responses and the larger corresponding film-thicknesses, or vice versa. Such thickness and porous-structure dependences of the responses are attributed to the ever-decaying light intensity (and hence ever-decreasing photo-generated carrier concentration) in the films along the depth from the films’ surface. This study is of importance in design and development of the light illuminating-typed gas sensing devices with high performances. [ABSTRACT FROM AUTHOR]

In this paper, a novel, efficient and green method for the preparation of Naringin sulfuric acid (NSA) as a Brønsted acid organocatalyst and silver nanoparticles (Ag NPs) by using Gongronema latifolium leaf extract as a reducing and stabilizing agent is introduced. The catalysts were characterized using the powder XRD, SEM, EDS, TEM, UV–Vis and FT-IR spectroscopy. Afterward, the catalytic activity of synthesized NSA and Ag NPs were investigated for the synthesis of N-monosubstituted ureas via the hydration of cyanamides in aqueous medium. All products were obtained in good to excellent yields. These methods provided several advantages such as shorter reaction time, simpler work-up and higher yield. [ABSTRACT FROM AUTHOR]

The solid-state Z-scheme trinary/binary heterostructures show the advantage of utilizing the high-energy photogenerated charge carriers in photocatalysis. However, the key factors controlling such Z-scheme in the binary heterostructures are still unclear. In this paper, we showed that oxygen vacancies could act as an interface electron transfer mediator to promote the direct Z-scheme charge transfer process in binary semiconductor heterostructures of CdS/ZnS. Increasing the concentration of surface oxygen vacancies of ZnO crystal can greatly enhance photocatalytic hydrogen generation of CdS/ZnO heterostructure. This was attributed to the strengthened direct Z-scheme charge transfer process in CdS/ZnO, as evidenced by steady-state/time-resolved photoluminescence spectroscopy and selective photodeposition of metal particles on the heterostructure. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present a method for predicting the effect of temperature on contact angles and wetting transitions for n -alkanes on PTFE. The analysis is based on the effect of temperature on two closely related phenomena, which are critical in the determination of contact angles: intermolecular forces and the thickness of an adsorbed film in the region adjacent to the three-phase contact. Considering solely van der Waals forces, it is possible to reproduce the experimental temperature dependence of contact angles. At low temperature values, contact angles show a small and linear decrease with temperature. For higher temperature values, substantially larger decreases are exhibited by the more volatile alkanes. In the case of n -octane, a single transition from partial to total wetting is found at 443 K. This transition, which arises from the vanishing of the effective Hamaker constant at 430 K, is characterized by a surface specific heat exponent close to one, indicating the existence of a first order wetting transition. For the less volatile alkanes, the contact angle decrease is progressively less pronounced as the volatility decreases in such a way that for n -hexadecane the contact angle remains approximately constant throughout the temperature range under study. [ABSTRACT FROM AUTHOR]

In this paper we present experimental results on the electrokinetic behavior of planar gibbsite particles in concentrated suspensions. The dc electrophoretic mobility measurements are in this case of little significance, as they are scarcely informative. In the present investigation, we show that the dielectric dispersion and dynamic electrophoresis can in contrast provide such information. The complicating factors are of course the non-spherical shape and the finite particle concentration, as no complete theory of these phenomena exists for such systems. We propose to use first of all a model of dynamic electrophoresis of spheroids in which the effect of volume fraction is considered by means of an approximate theory previously obtained for spheres, based on the evaluation of electrical and hydrodynamic interactions between particles. In addition, the role of volume fraction on the high frequency inertial relaxation is also ascertained and used to obtain a volume fraction-independent radius of the gibbsite spheroids. A similar approach is used for the evaluation of dielectric dispersion data. Both the dynamic mobility and dielectric constant dependencies on frequency were obtained for gibbsite suspensions of different volume fractions in 0.5 mM KCl. The theoretical treatments elaborated were applied to these data, and a coherent picture of the geometrical and electrical characteristics of the particles was obtained. [ABSTRACT FROM AUTHOR]

In this paper, an anionic metal-organic framework Bio-MOF-1 (Zn 8 (ad) 4 (BPDC) 6 O·2Me 2 NH 2 ) and a luminescent complex (Sm 3+ doped TiO 2 , labeled as Sm 3+ @TiO 2 ) have both been prepared as previous reports and their photophysical properties are investigated. Subsequently, Tb 3+ is introduced to Bio-MOF-1 via cation exchange and the obtained Tb 3+ @Bio-MOF-1 can exhibit characteristic emission bands of Tb 3+ . Exposed to varying concentration of oxygen, the luminescent intensity of Tb 3+ decreased as increasing oxygen content. However, the luminescent intensity of as-prepared Sm 3+ @TiO 2 is enhancing with the increase of oxygen content. With the assistance of IPTES (3-Isocyanatopropyltriethoxysilane) and TTA (2-Thenoyltrifluoroacetone), Sm 3+ @TiO 2 was assembled with Tb 3+ @Bio-MOF-1 successfully. As we had expected, the hybrid shows a ratio-dependent oxygen sensing performance, which makes it a good candidate for sensing of oxygen. [ABSTRACT FROM AUTHOR]

Amalgamation of noble metal nanomaterials on graphene flakes potentially paves one way to improve their physicochemical properties. This paper deals with the simultaneous electrochemical deposition of gold and palladium nanoparticles on graphene flakes (Au/PdNPs-GRF) for the sensitive determination of caffeic acid (CA). The physiochemical properties of the prepared Au/PdNPs-GRF was characterized by using numerous analytical techniques such as scanning electron microscopy, electron dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction, Raman spectroscopy and electrochemical impedance spectroscopy. The enhanced electrochemical determination of CA at Au/PdNPs deposition on GRF were studied by using cyclic voltammetry and differential pulse voltammetry. In results, Au/PdNPs-GRF electrode exhibited an excellent electrocatalytic activity towards CA with wide linear range and low limit of detection of 0.03–938.97 µM and 6 nM, respectively. Eventually, the Au/PdNPs-GRF was found as a selective and stable active material for the sensing of CA. In addition, the proposed sensor showed the adequate results in real sample analysis. [ABSTRACT FROM AUTHOR]

The surface modification of nano-hydroxyapatite with polyamidoamine (PAMAM) dendrimer has potential for biomedical applications due to their unique and well-defined secondary structures. This paper presents a facile method to synthesize siloxane-cored PAMAM dendrons modified Hydroxyapatite nanoparticles. Firstly, the siloxane-cored PAMAM dendrons with different generations (G1 to G5, respectively) were synthesized using repetitive reactions between Michael addition and amidation starting from 3-aminopropyltriethoxysilane. Then, hydroxyapatite nanoparticles were synthesized by hydrothermal crystallization method and functionalized with siloxane-cored PAMAM dendrons. These synthesized materials were characterized by using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Thermogravimetric analysis (TGA). The results showed that the PAMAM dendrimer functionalization was carried out successfully and these materials may be applicable in biocomposite material and/or bone tissue engineering. [ABSTRACT FROM AUTHOR]

A novel solar responsive photocatalytic fuel cell (PFC) consisted of a WO 3 /FTO photoanode and an air-breathing cathode was successfully prepared for simultaneous pollutant degradation and power production. The as-prepared PFC system exhibited outstanding photocurrent performances, which were attributed to the combined effects of the large specific surface area and the improved oxygen transportation by air-breathing cathode design, as well as the enhanced light absorption by transparent FTO substrate. Oxytetracycline hydrochloride was used as the model compound in this paper, and parametric effects on the PFC performances were deeply investigated. Results showed that increasing electrolyte concentration and light density were effective approaches to enhance power outputs. In terms of oxytetracycline hydrochloride concentration, the maximum power density firstly enhanced when oxytetracycline hydrochloride concentration increased to 0.5 mmol/L, then dropped dramatically with further increasing of oxytetracycline hydrochloride concentration to 2.0 mmol/L. The highest short-circuit current density of 372.4 μA/cm 2 and maximum power density of 36.3 μW/cm 2 were obtained when the PFC operated at the optimum operation condition of 0.1 mol/l Na 2 SO 4 electrolyte, 200 mW/cm 2 light density and 0.5 mmol/L oxytetracycline hydrochloride. The PFC-assisted photocatalytic degradation experiments also suggested a promising application of the as-prepared PFC system in refractory wastewater treatment. [ABSTRACT FROM AUTHOR]

This paper describes the electrochemical preparation of highly electrochemically active and conductive activated graphene oxide (aGO). Afterwards, the electrochemical properties of aGO was studied towards the simultaneous determination of hydroquinone (HQ) and catechol (CC). This aGO is prepared by the electrochemical activation of GO by various potential treatments. The resultant aGOs are examined by various physical and electrochemical characterizations. The high potential activation (1.4 to −1.5) process results a highly active GO (aGO 1 ), which manifest a good electrochemical behavior towards the determination of HQ and CC. This aGO 1 modified screen printed carbon electrode (SPCE) was furnished the sensitive detection of HQ and CC with linear concentration range from 1 to 312 μM and 1 to 350 μM. The aGO 1 modified SPCE shows the lowest detection limit of 0.27 μM and 0.182 μM for the HQ and CC, respectively. The aGO 1 modified SPCE reveals an excellent selectivity towards the determination of HQ and CC in the presence of 100 fold of potential interferents. Moreover, the fabricated disposable aGO 1 /SPCE sensor was demonstrated the determination of HQ and CC in tap water and industrial waste water. [ABSTRACT FROM AUTHOR]

Nanofluids comprising nanoparticle suspensions in liquids have significant industrial applications. Prior work performed in our laboratory on the spreading of a nanofluid on a solid substrate has revealed that the structural disjoining pressure gradient caused by the layering of the nanoparticles normal to the confining plane of the film with the wedge profile is a new mechanism for oily soil detachment from the solid substrate. In the present work, we explore the application of this new mechanism for the solid particle detachment using latex particles on glass and a copper-coated wafer substrate using nanofluids. In the experiment, we employed the nanofluids to observe the detachment of the latex particles adhered to the glass substrate. We found that the structural disjoining pressure exerted by the nanoparticles can detach the solid particles on the glass substrate. A video depicting this mechanism is provided. Our results showed that the detachment of the particulate solid particles on the solid substrate was clearly enhanced by the nanofluids, compared to using only pure liquids (such as water). The detachment efficiency was increased with the increase in the nanoparticle volume fraction. Our nanofluids also showed a greater detachment efficiency for the particulate soil removal from the copper-coated wafer substrates compared to that of pure liquids. We found that the detachment efficiency is well correlated with the calculated structural disjoining energy. Our findings in this paper provide new insights for the novel application of the structural disjoining energy mechanism for cleaning hard surfaces. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis, characterization, and electrochemical performance of nickel-cobalt hydroxide nanosheets. The hydroxide nanosheets of approximately 0.7 nm thickness were prepared by delamination of layered nickel-cobalt hydroxide lactate in water and formed transparent colloids that were stable for months. The nanosheets were deposited on highly oriented pyrolytic graphite by spin coating, and their electrochemical behavior was investigated by cyclic voltammetry in potassium hydroxide electrolyte. Our method of electrode preparation allows for studying the electrochemistry of nanosheets where the majority of the active centers can participate in the charge transfer reaction. The observed electrochemical response was ascribed to mutual compensation of the cobalt and nickel response via electron sharing between these metals in the hydroxide nanosheets, a process that differentiates the behavior of nickel-cobalt hydroxide nanosheets from single nickel hydroxide or cobalt hydroxide nanosheets or their physical mixture. The presence of cobalt in the nickel-cobalt hydroxide nanosheets apparently decreases the time of electrochemical activation of the nanosheet layer, which for the nickel hydroxide nanosheets alone requires more potential sweeps. [ABSTRACT FROM AUTHOR]

There is an increasing worldwide demand for chemiresistive sensors for specific gas working at low temperature, in particular for standalone and mobile systems, which call for small and low power devices. In this paper, we successfully assemble highly sensitive triethylamine (TEA) gas sensors working at near-room temperature with gold (Au)-decorated ZnO nanorods. ZnO nanorods grow directly on flat Al 2 O 3 ceramic electrodes by a cost-effective hydrothermal method and Au nanoparticles are deposited onto ZnO nanorods by DC-sputtering. Au-loaded ZnO (Au/ZnO) nanorods sensor at working temperature of 40 °C and relative humidity of 30% exhibits high response (22–50 ppm TEA), low detection concentration (∼1 ppm), and short response/recovery time (11 s/15 s), which are all much better than the pristine ZnO nanorods sensor. When the relative humidity increases, the sensor response decreases due to the water molecules adsorption. Moreover, the enhanced sensing properties of the Au/ZnO sensors are discussed in detail with the semiconductor depletion layer model introduced by the Au/ZnO Schottky contact and the catalytic effect of noble gold nanoparticles. [ABSTRACT FROM AUTHOR]

Wrinkles exist widely in nature and our life. In this paper, wrinkles on polydopamine (PDA)/polystyrene (PS) bilayer films were formed by thermal annealing due to the different thermal coefficients of expansion of each layer. The factors that influenced the dimensions of wrinkles were studied. We found that oriented wrinkles could be formed if the bilayer films were patterned with micro-grooves, and the degree of the orientation depended on the thickness of the PDA and the dimensions of the grooves. Combined with the strong adhesion, biocompatibility and reactivity of PDA, the oriented wrinkles on PDA/PS patterned bilayers may find potential application in diffraction gratings, optical sensors and microfluidic devices. [ABSTRACT FROM AUTHOR]

The achievement of uniform nanoparticles distribution in polymer matrix is still a major challenge in the design and fabrication of polymer nanocomposites with desired properties. In this paper we propose a novel approach for the preparation of homogeneous polystyrene/silver nanocomposites utilizing Nitroxide Mediated Radical Polymerization (NMRP). In the first step of the developed procedure, the polystyrene grafted silver nanoparticles (Ag@PS) with well-defined core-shell structure and exceptionally high grafting density (from 2 chains/nm 2 to 5.9 chains/nm 2 ) have been synthesized through late injection of nitroxide-coated silver nanoparticles (N-AgNPs) into a TEMPOL mediated styrene polymerization system. Afterwards, the synthesized Ag@PS have been used for the preparation of nanocomposites (PS/Ag@PS) by mixing them with narrow-dispersity polystyrenes and thermoforming at 140 °C. Due to the high flexibility of polymer chains attached to silver surface through nitroxide linker, free volume effect enables interpenetration of polystyrene molecules that provides excellent mutual miscibility of Ag@PS with polymer matrix. The synthesized nanohybrids (Ag@PS) and their nanocomposites (PS/Ag@PS) exhibit effective antibacterial activity with respect to pathogenic bacteria: Pseudomonas aeruginosa (Gram-negative representative) and Staphylococcus aureus (Gram-positive representative). [ABSTRACT FROM AUTHOR]

As one kind of important p-type semiconductors, Cr 2 O 3 has been widely used for optical and electronic devices due to its high electrical conductivity and special optoelectronic characteristics, as well as high chemical and thermal stability. In this paper, single-crystalline Cr 2 O 3 nanoplates embedded in carbon matrix were successfully synthesized through direct thermal decomposition of a trinuclear cluster complex of [Cr 3 O(CH 3 CO 2 ) 6 (H 2 O) 3 ]NO 3 ·CH 3 COOH ([Cr 3 O]) in Ar atmosphere. The synergetic effect of the plate-like structure and embedding in carbon matrix contributes to the enhanced electrochemical performance of the Cr 2 O 3 -C nanoplates. Owing to different crystallinity and composition, the obtained products at 400, 500, 600, and 700 °C with different carbon content of 12.52, 8.26, 5.35 and 3.27% exhibited enhanced battery-type electrode materials in three-electrode system with high specific capacitance (823.11, 781.65, 720.72, and 696.73 F g −1 at 1 A g −1 ) and remarkable cycling stability (about 0.3, 2.7, 4.5 and 5.6% loss of its initial capacitance after 5000 charge-discharge cycles at a current density of 5 A g −1 ). Furthermore, an assembled asymmetric device (Cr 2 O 3 -C nanoplates (positive electrode)//activated carbon (AC, negative one)) with an extended operating voltage window of 1.8 V achieves a specific capacitance of 58.06 F g −1 at the current density of 1 A g −1 and an energy density of 26.125 W h kg −1 at power density of 0.9 kW kg −1 , as well as superior cycling stability with 91.4% capacitance retention after 10,000 cycles. The results indicate that the Cr 2 O 3 nanoplates embedded in carbon matrix show promising potential to construct high-performance energy storage devices. [ABSTRACT FROM AUTHOR]

In this paper, CeO 2 microplates were synthesized by a sol-gel auto-combustion method. AgI nanoparticles (NPs) were then deposited onto the surface of CeO 2 via a facile deposition–precipitation method. The as-prepared AgI/CeO 2 samples were characterized by various analytical techniques. The composites exhibited superior photocatalytic activities for the organic dyes (RhB) and the refractory pollutant (tetracycline (TC), a typical antibiotic) degradation under visible light irradiation. The CA-19.03 sample exhibited the highest photocatalytic activity. The enhanced photocatalytic performance could be ascribed to the improved separation of photogenerated charge carriers due to well-matched band structure. [ABSTRACT FROM AUTHOR]

This study provides the first attempt to combine UiO-66(Zr) with Bi 2 MoO 6 for the preparation of composite via electrostatic interaction induced self-assembly process. Synthesized products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscope (FT-IR), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) surface area analyse and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). The photocatalytic activities of as-obtained Bi 2 MoO 6 /UiO-66(Zr) composites were assessed by degradation of Rhodamine B (Rh B) under the visible-light irradiation. Comparing to the pristine materials, the developed Bi 2 MoO 6 /UiO-66(Zr) composite with Bi:Zr molar ratio 2:1, labelled as BMUO-2, showed the best photocatalytic activity. It was supposed that the participation of Bi 2 MoO 6 increased the use of solar energy and the existence of UiO-66(Zr) restrained the recombination rate of photo-generated electron-hole pairs. Moreover, Bi 2 MoO 6 /UiO-66(Zr) composite showed excellent stability and recyclability during cycling experiment. The mechanism and plausible pathway of Rh B degradation were also discussed in this paper. [ABSTRACT FROM AUTHOR]

In catalytic systems, the support materials need to be both eco friendly and low cost as well as having high thermal and chemical stability. In this paper, a novel starch supported palladium catalyst, which had these outstanding properties, was designed and its catalytic activity was evaluated in a Suzuki coupling reaction under microwave heating with solvent-free and mild reaction conditions. The starch supported catalyst gave remarkable reaction yields after only 5 min as a result of the coupling reaction of the phenyl boronic acid with 23 different substrates, which are bearing aril bromide, iodide, and chloride. The longevity of the catalyst was also investigated, and the catalyst could be reused for 10 runs. The starch supported Pd(II) catalyst yielded remarkable TON (up to 25,000) and TOF (up to 312,500) values by using a simple, fast and eco-friendly method. In addition, the catalytic performance of the catalyst was tested against different commercial palladium catalysts, and the green starch supported catalyst had excellent selectivity. The catalytic tests showed that the novel starch based palladium catalyst proved to be an economical and practical catalyst for the synthesis of biaryl compounds. [ABSTRACT FROM AUTHOR]

In this paper, a series of catalysts about CeO 2 active sites prepared using reduced TiO 2 (TiR) as supports were firstly used for selective catalytic reduction (SCR) of NO by NH 3 . The catalytic performance evaluation results showed that the NO removal efficiency of CeO 2 /TiR (CeTiR) was much higher than that of CeO 2 /TiO 2 (CeTi). Hence, the aim of this study was to investigate the promotion mechanism of catalytic performance of CeTiR catalysts. The catalysts were characterized by XRD, BET, Raman, XPS, NH 3 -TPD and H 2 -TPR. The results of characterization revealed that CeO 2 had a strong interaction with oxygen vacancies of TiR supports. The strong interaction resulted in more Ce 3+ formation and better redox properties for CeTiR catalysts. In addition, it was confirmed that the better redox properties of CeTiR could be considered as the major reason of its high SCR activity via L-H mechanism but not acid properties. We expected that this study could shed some lights on the development of SCR catalysts for improving the interaction between Ti support and active species for enhancing SCR reaction. [ABSTRACT FROM AUTHOR]

Olivine is a relatively common family of silicate minerals in many terrestrial and extraterrestrial environments, and is also useful as a refractory ceramic. A capability to synthesize fine particles of olivine will enable additional studies on surface reactivity under geologically relevant conditions. This paper presents a method for the synthesis of nanocrystalline samples of the magnesium end-member, forsterite (Mg 2 SiO 4 ) in relatively large batches (15–20 g) using a sol-gel/surfactant approach. Magnesium methoxide and tetraethylorthosilicate (TEOS) are refluxed in a toluene/methanol mixture using dodecylamine as a surfactant and tert-butyl amine and water as hydrolysis agents. This material is then cleaned and dried, and fired at 800 °C. Post-firing reaction in hydrogen peroxide was used to remove residual organic surfactant. X-ray diffraction showed that a pure material resulted, with a BET surface area of up to 76.6 m 2 /g. The results of a preliminary attempt to use this approach to synthesize nano-scale orthopyroxene (MgSiO 3 ) are also reported. [ABSTRACT FROM AUTHOR]

A liquid droplet placed on a nonuniformly heated solid surface will migrate from a high temperature region to a low temperature region. The present study reports the results of an experimental investigation on the migration behavior of mineral oil droplets subjected to a thermal gradient on an inclined plane. A particular attention is paid to the relationship between the critical inclination angle and thermal gradients. It is shown that there exists a critical inclination angle at which the droplet migration is halted. This critical inclination angle can be readily predicted using analytical expressions derived in this paper. This study puts forward the understanding of the interface phenomenon of thermocapillary migration on an incline. The knowledge of the critical inclination is important in applications where the migration on an incline must be obstructed to retain adequate lubrication in the desired location. [ABSTRACT FROM AUTHOR]

Superhydrophobic materials have drawn great attention due to its’ remarkable non-wetting properties and applications in many fields. In this paper, we synthesize a hollow superhydrophobic SiO 2 powder by typical template method and self-assembly functionalization. Robustness of many superhydrophobic surfaces has become the development bottleneck for industrial applications. Aiming at this problem, the adhesive epoxy resin is specially taken to use as the binding layer between superhydrophobic SiO 2 powder and substrates to create robust superhydrophobic coating. The mechanical durability of the obtained superhydrophobic coating is evaluated by a cyclic sandpaper abrasion. Also, the chemical stability of this superhydrophobic coating is assessed by exposuring it to different pH conditions and UV irradiation, respectively. Significantly, because of the special structure and superhydrophobicity/superoleophilicity of the hollow microspheres, these hollow superhydrophobic SiO 2 powders manifest great oil-adsorbing capacity, which thus can be used to separate oil/water mixtures and remove oil from oil-in-water emulsions. [ABSTRACT FROM AUTHOR]

In this paper, a series of BiOI/ZnO photocatalysts containing various BiOI contents were prepared by a facile two-step synthetic method. The structure and crystal phase, morphology, surface element analysis, optical property of as-prepared samples are measured by X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV–Vis diffuse reflectance spectrometry (DRS). BiOI/ZnO photocatalytic activities of the prepared photocatalysts were evaluated by photocatalytic degradation of phenol under simulated light irradiation. The phenol degradation rate reached 99.9% within 2 h under simulated solar light irradiation. The probable photocatalytic mechanism of composites photocatalysts is discussed by active species trapping experiments, the surface photovoltage (SPV), the transient photovoltage (TPV) and photoluminescence (PL) measurements. The results manifest that the superior photocatalytic activity of BiOI/ZnO composites is derived from the strong internal electric field between BiOI and ZnO, which is beneficial for the effective separation and transfer of photogenerated charges in ZnO. Moreover, the loading of BiOI on the surface of ZnO inhibited the recombination of photogenerated charge carriers in ZnO, resulting in excellent photocatalytic activity. On the contrary, the effect of an extension of the light absorption range induced by the introduction of BiOI on the phenol degradation activity is not significant. [ABSTRACT FROM AUTHOR]

Recently, the photocatalytic applications of silver chloride have been paid closed attention for the excellent ability to photodegrade organic pollutants. Comparing with other catalysts, the silver chloride presents outstanding photocatalytic activity. However, it also suffers from the poor photocatalytic stability. This very paper is focusing on the one-step wet chemical process of preparing Ag/AgCl/GO photocatalyst with high photocatalytic activity and stability. The detailed characterizations were particularly carried out in order to investigate the photo-catalytic activity and stability. Meanwhile the morphology, chemical composition as well as crystalline structure were investigated. It is found that the as-prepared Ag/AgCl/GO composite exhibited an ultrahigh photocatalytic activity and stability in the process of photodegrading RhB. The unique catalytic activity has been discussed based on the SPR effect in Ag nanoparticles on AgCl surface and the separation of photo-generated electron-hole pairs, the primary benefit of the stability owes a great deal to GO which can capture the photo-generated electrons in case they reduce Ag + ion or recombine the excited holes. [ABSTRACT FROM AUTHOR]

This paper builds on previous literature showing the interesting adsorptive properties of TiO 2 nanotubes. It further explores the positive effect of β -cyclodextrin on these properties. Hence, β -cyclodextrin modified TiO 2 nanotubes were successfully prepared and characterized by XRD, N 2 physisorption at 77 K, Raman, FTIR-ATR, 1 H NMR, TEM and EPR. The adsorptive interaction of Cu(II) with materials was investigated in aqueous solution at pH 9.25 (NH 4 + /NH 3 ). The main conclusion is that copper(II)-ammonia complexation equilibria play an important role in the adsorption process. The β -cyclodextrin was found to improve the Cu(NH 3 ) 4 2+ adsorption mainly by retarding its precipitation to high concentrations values (>400 mg L −1 ). Adsorption experimental data showed good fit with the pseudo-second-order model and the Langmuir isotherm model. [ABSTRACT FROM AUTHOR]

In this paper, silver nanoparticles (Ag NPs) are synthesized using Achillea millefolium L. extract as reducing and stabilizing agents and peach kernel shell as an environmentally benign support. FT-IR spectroscopy, UV–Vis spectroscopy, X-ray Diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), Thermo gravimetric-differential thermal analysis (TG-DTA) and Transmission Electron Microscopy (TEM) were used to characterize peach kernel shell, Ag NPs, and Ag NPs/peach kernel shell. The catalytic activity of the Ag NPs/peach kernel shell was investigated for the reduction of 4-nitrophenol (4-NP), Methyl Orange (MO), and Methylene Blue (MB) at room temperature. Ag NPs/peach kernel shell was found to be a highly active catalyst. In addition, Ag NPs/peach kernel shell can be recovered and reused several times with no significant loss of its catalytic activity. [ABSTRACT FROM AUTHOR]

Phosphate (P) removal is significant for the prevention of eutrophication in natural waters. In this paper, a novel adsorbent for the removal of P from aqueous solution was synthesized by loading zirconium oxide and iron oxide onto activated carbon nanofiber (ACF-ZrFe) simultaneously. The adsorbent was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The results showed that P adsorption was highly pH dependent and the optimum pH was found to be 4.0. The isotherm of adsorption could be well described by the Langmuir model and the maximum P adsorption capacity was estimated to be 26.3 mg P/g at 25 °C. The kinetic data were well fitted to the pseudo-second-order equation, indicating that chemical sorption was the rate-limiting step. Moreover, co-existing ions including sulfate (SO 4 2− ), chloride (Cl − ), nitrate (NO 3 − ) and fluoride (F − ) exhibited a distinct effect on P adsorption with the order of F − > NO 3 − > Cl − > SO 4 2− . Further investigations by FT-IR spectroscopy and pH variations associated with the adsorption process revealed that ligands exchange and electrostatic interactions were the dominant mechanisms for P adsorption. The findings reported in this work highlight the potential of using ACF-ZrFe as an effective adsorbent for the removal of P in natural waters. [ABSTRACT FROM AUTHOR]

In this paper, bismuth oxybromide (BiOBr) nanosquares photocatalysts were synthesized via a facile hydrothermal method with the double regulation of the ionic liquid (IL) 1-hexadecyl-3-methylimidazolium bromide and ammonium bismuth citrate (BCA). To the best of our knowledge, this report is the first to describe the BiOBr material with simultaneous bismuth and halogen bidirectional source regulation. The structures, components, morphologies, optical properties and photocatalytic properties of the as-prepared samples were specifically explored. The photocatalytic ability was assessed using the degradation of rhodamine B under visible light irradiation. The BiOBr-IL + BCA exhibited improved photocatalytic activity compared with the BiOBr materials without double regulation. The primary active species were determined to be holes (h + ) and superoxide radicals ( O 2 − ) using electron spin resonance (ESR) analysis and free radical trapping experiments. This enhanced activity was attributed to its larger specific surface, the superior electron transfer ability, and the increased negative conduction band position, which favors the photogenerated electrons to trap the molecular oxygen to produce O 2 − . The production of more O 2 − can benefit the removal of pollutants. [ABSTRACT FROM AUTHOR]

In this paper, novel polyimide/cellulose/TiO 2 bionanocomposites (PI/BNCs) were prepared via a simple and inexpensive ultrasonic irradiation process. PI was synthesized by direct polycondensation reaction of novel monomer dianhydride with 4-(2-(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropan-2-yl)benzenamine. Due to the high surface energy and tendency for agglomeration the surface of nanoparticles was modified with cellulose. PI/BNCs containing 5, 10, and 15% of cellulose/TiO 2 (BNCs) were successfully fabricated through ultrasonic irradiation technique. The obtained PI/BNCs were characterized by Fourier transform-infrared (FT-IR) spectroscopy, thermogravimetry analysis, X-ray powder diffraction, field emission-scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). Thermogravimetric analysis data indicated an increase thermal stability of the PI/BNC polymers in compared to the pure polymer. From TEM image of PI/BNCs it can be found that the surface modified TiO 2 with diametric size of less than 50 nm, uniformly dispersed in the obtained PI matrix. The results obtained from gas permeation experiments with a constant pressure setup indicated that adding cellulose/TiO 2 to the polymeric membrane structure increased the permeability of the membranes. [ABSTRACT FROM AUTHOR]

In this paper, a new synthetic strategy towards functionalized ZnO-HMD@ZnO-Fe/Cu core-shell using sol-gel process modified by chemical grafting of hexamethylenediamine (HMD) on the core and in-situ dispersion of Cu 0 /Fe 0 as metallic nanoparticles (M-NPs) on the shell. The as-prepared core-shell materials were fully characterized by transmission electron microscopy, X-ray powder diffractometry, diffuse reflectance and FT-IR spectrophotometery, photoluminescence, and complexes impedance spectroscopy measurements. The XRD patterns agreed with that of the ZnO typical wurtzite structure, indicating good crystallinity of ZnO-HMD@ZnO-Fe/Cu, with the presence of Fe 0 and Cu 0 phases. Hexamethylenediamine grafting and M-NPs insertion were highly activated and enhanced the core and shell interface by the physiochemical interaction. After functionalization, luminescence intensities and electrical properties of both core and core-shell nanoparticles are improved, indicating the effects of the surface groups on the charge transfer of ZnO-HMD@ZnO-Fe/Cu. The hydrogen capacity retention was depended strongly on the composition and structure of the obtained core-shell. Iron/Copper-loaded ZnO-HMD@ZnO materials exhibited the highest capacity for hydrogen storage. The excellent stability and performance of the ZnO-HMD@ZnO-Fe/Cu core-shell make it an efficient candidate for hydrogen storage. [ABSTRACT FROM AUTHOR]

This paper concerns experimental investigation of the sequenced flocculation of latex particles in a Taylor-Couette reactor. The aim of this work was to investigate the evolution of both the size and the shape of aggregates under sequenced hydrodynamics. A number of studies have focused on the evolution of the aggregate size or size distribution during steps of growth-breakage-regrowth, but aggregates generally experience steps of breakage-regrowth on repeated occasions in real operating conditions (passages near the impeller or during the transfer processes, for example). The experiments conducted in this work consisted thus of an alternation of six steps with alternately low and high shear rates under turbulent conditions. The particle size distributions were monitored throughout the sequencing, and the circularity and convexity (shape parameters) distributions were measured, enabling a more precise description of the entire floc population, rather than a fractal dimension. While the aggregate size distribution was clearly controlled by hydrodynamics, the shape distributions continuously evolved during the sequencing. The main new finding of our work notes the independence between the aggregate shape and hydrodynamics. Indeed, after multiples steps of breakage-regrowth, regardless of the aggregate size distribution and hydrodynamics, the aggregate shape seemed to reach a unique steady-state morphological distribution. [ABSTRACT FROM AUTHOR]

The interest in the use of nanoporous carbon materials in applications related to energy conversion and storage, either as catalysts or additives, has grown over recent decades in various disciplines. Since the early studies reporting the benefits of the use of nanoporous carbons as inert supports of semiconductors and as electron acceptors that enhance the splitting of the photogenerated excitons, many researchers have investigated the key role of carbon matrices coupled to all types of photoactive materials. More recently, our group has demonstrated the ability of semiconductor-free nanoporous carbons to convert the absorbed photons into chemical reactions (i.e. oxidation of pollutants, water splitting, reduction of surface groups) opening new opportunities beyond conventional applications in light energy conversion. The aim of this paper is to review the recent progress on the application of nanoporous carbons in photochemistry using varied illumination conditions (UV, simulated solar light) and covering their role as additives to semiconductors as well as their use as photocatalysts in various fields, describing the photochemical quantum yield of nanoporous carbons for different reactions, and discussing the mechanisms postulated for the carbon/light interactions in confined pore spaces. [ABSTRACT FROM AUTHOR]

In this paper firstly, 1-methyl-3-methylimidazolium bromide (MB) as a new high efficient ionic liquid was synthesized using chemical approach and then fabricated POAP/MB films by electro-polymerization of POAP in the presence of MB to serve as the active electrode for electrochemical supercapacitor. Theoretical study (AIM) and electrochemical analysis have been used for characterization of ionic liquid and POAP/MB composite film. Different electrochemical methods including galvanostatic charge–discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy are carried out in order to investigate the performance of the system. This work introduces new most efficient materials for electrochemical redox capacitors with advantages including ease synthesis, high active surface area and stability in an aqueous electrolyte. [ABSTRACT FROM AUTHOR]