The synergistic effect of the PEO–PVA–PESf composite polymer electrolyte for all-solid-state lithium-ion batteries

Blending with poly(vinyl alcohol) (PVA) and poly(oxyphenylene sulfone) (PESf) has been investigated to improve the properties of a polymer electrolyte based on a poly(ethylene oxide) (PEO) matrix. The composite electrolyte shows a high ionic conductivity of 0.83 × 10⁻³ S cm⁻¹ at 60 °C due to the significant inhibition of crystallization caused by the synergistic effects of PVA and PESf. The symmetrical cell Li/CPE/Li is continuously operated for at least 200 hours at a current density of 0.1 mA cm⁻² without the enhancement in the polarization potential. In addition, the all-solid-state LiFePO₄/CPE/Li cells exhibit small hysteresis potential (about 0.10 V), good cycle stability and excellent reversible capacity (126 mA h g⁻¹ after 100 cycles).

PVA and PESf have synergistic effects for CPE, resulting in a wider electrochemical window, higher ionic conductivity and better cyclic performance.     

Influence of Moringa oleifera biodiesel–diesel–hexanol and biodiesel–diesel–ethanol blends on compression ignition engine performance,combustion and emission characteristics

In the current work, the influences of Moringa oleifera biodiesel–diesel–hexanol and Moringa oleifera biodiesel–diesel–ethanol blends on compression ignition engine characteristics were experimentally investigated. Experiments were conducted on a diesel engine at 0%, 25%, 50%, 75% and 100% load conditions run at a constant speed of 1500 rpm. The results revealed that B90-D5-H5 acquired the lowest BSFC and maximum BTE of 0.375 kg kW⁻¹ h⁻¹ and 28.8%, respectively, and B100 had the highest BSFC of 0.425 kg kW⁻¹ h⁻¹. B90-D5-H5 had the highest cylinder peak pressure of 74 bar at 4°CA aTDC. The maximum heat release rate (HRR) and longer ignition delay (ID) period of 44 J per °CA and 14.4°CA, respectively, were attained in the B90-D5-H5 blend. At 100% load condition, the lowest amount of carbon monoxide (CO) of 0.32% vol. was acquired in the B80-D5-E15 blend. The maximum nitric oxide (NO) emission of 1090 ppm was also acquired in the B80-D5-E15 blend. B100 had the lowest NO of 846 ppm; B80-D5-E15 had the lowest unburned hydrocarbon (UBHC) emission of 34 ppm at 100% load and the lowest smoke opacity of 34%. Biodiesel–diesel–alcohol blends improve engine performance and decrease emissions compared to the conventional diesel. The utilization of biodiesel–diesel–alcohol blends reduces the consumption of diesel. Hence, ethanol and hexanol are recommended as potential alternative additives in biodiesel–diesel blends to improve engine performance and reduce emissions.

In the current work, the influences of Moringa oleifera biodiesel–diesel–hexanol and Moringa oleifera biodiesel–diesel–ethanol blends on compression ignition engine characteristics were experimentally investigated.     

High performance flexible supercapacitors based on secondary doped PEDOT–PSS–graphene nanocomposite films for large area solid state devices

In this work, we propose the development of high performance and flexible supercapacitors using reduced graphene oxide (rGO) incorporated poly(3,4 ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT–PSS) nanocomposites by secondary doping. The structural and morphological features of the composite film were analyzed in detail using SEM, AFM, FTIR, XPS and TGA. Secondary doping of ethylene glycol (EG) assisted by rGO incorporation significantly enhances the room temperature conductivity of PEDOT–PSS films from 3 S cm⁻¹ to nearly 1225 S cm⁻¹ for a 10 wt% composite. The secondary doped PEDOT–PSS:EG/rGO composite film demonstrated improved electrochemical performances with specific capacitance of 174 (F g⁻¹) and energy density of 810 (W h kg⁻¹) which is nearly 4 times greater than pristine PEDOT–PSS due to synergetic interactions between rGO and PEDOT–PSS. The prepared composite films show long term stability with capacitance retention of over 90% after 5000 cycles of charging–discharging. The nanocomposite films used in the present investigation demonstrates percolative behavior with a percolation threshold at 10 wt% of rGO in PEDOT–PSS. The assembled supercapacitor device could be bent and rolled-up without a decrease in electrochemical performance indicating the potential to be used in practical applications. To demonstrate the practical applicability, a rolled-up supercapacitor device was constructed that demonstrates operation of a red LED for 40 seconds when fully charged. This study will provide new dimensions towards designing cost effective, flexible and all solid-state supercapacitors with improved electrochemical performance using electrodes based on secondary doped PEDOT–PSS/rGO organic thin films.

In this work, we propose the development of high performance and flexible supercapacitors using reduced graphene oxide (rGO) incorporated poly(3,4 ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT–PSS) nanocomposites by secondary doping.     

High response photochromic films based on D–A diarylethenes and their application in holography

A set of photochromic dithienylethenes bearing amino and nitro groups are synthesised and embedded at high concentrations in a polymer matrix (Cellulose Acetate Butyrate, CAB) to produce films showing a large reversible modulation of the complex refractive index in the Vis-NIR spectral range, thanks to an interesting combination of remarkable response at the molecular level and very high load capability in the chosen matrix. The photochromic derivatives are characterized in solution and in CAB films by means of electronic and vibrational spectroscopy, complemented by DFT calculations. Both the real and imaginary part of the refractive index are determined by spectroscopic ellipsometry. The modulation of the refractive index in the near infrared is in the range 0.02–0.04. These are very large values for such kinds of systems and they are due to a favourable combination of very large solubility of the derivatives in CAB and a high polarisability change. As for the change in transparency in the visible, contrast values larger than 10³ are easily achieved. Based on such films, holograms are written and reconstructed with a very high fidelity and efficiency.

Photochromic diarylethenes with D–A structure are good candidates in holography thanks to their very large modulation of the complex refractive index.     

Multiple-responsive supramolecular vesicle based on azobenzene–cyclodextrin host–guest interaction

Multiple-responsive supramolecular vesicles have been successfully fabricated by the complexation between β-cyclodextrin (β-CD) and a pH/photo dual-responsive amphiphile 4-(4-(hexyloxy)phenylazo)benzoate sodium (HPB) with azobenzene and carboxylate groups. When mixing β-CD with HPB to reach a host/guest molar ratio of 1 : 1, the azobenzene group of HPB could be spontaneously included by β-CD molecules. Then, the formed inclusion complexes (HPB@β-CD) could self-assemble into vesicles, which was driven by the hydrophobic interaction of the alkyl chain of HPB and the hydrogen bonds between neighboring β-CDs. The reversible assembly/disassembly of the vesicles could be simply regulated under UV or visible light irradiation. The reversible phase transformation between vesicles and microbelts could also be realized by adjusting the pH values of the sample. Adding both competitive guest molecules (1-adamantane carboxylic acid sodium (ADA)) and α-amylase would result in the phase transformation from vesicles to micelles. Moreover, the vesicles would be destroyed when β-CD was continuously added until the ratio of host/guest reached 2 : 1. Such an interesting quintuple-responsive vesicle system reported here not only has potential applications in various fields such as controlled release or drug delivery, but also provides a reference for the design and construction of multiple responsive systems.

A quintuple-responsive vesicle system was successfully fabricated by simply mixing HPB with an equal amount of β-CD.     

Hydrogen-driven dramatically improved mechanical properties of amorphized ITO–Ag–ITO thin films

An oxide/metal/oxide (OMO) multi-structure, which has good electrical, optical, and mechanical stability, was studied as a potential replacement of polycrystalline In–Sn–O (ITO). However, the degradation of mechanical properties caused by the polycrystalline structure of the top layer forming on the polycrystalline metal layer needs to be improved. To address this issue, we introduced hydrogen in the oxide layers to form a stabilized amorphous oxide structure despite it being deposited on the polycrystalline layer. An ITO/Ag/ITO (IAI) structure was used in this work, and we confirmed that the correct amount of hydrogen introduction can improve mechanical stability without any deterioration in optical and electrical properties. The hydrogen presence in the IAI as intended was confirmed, and the assumption was that the hydrogen suppressed the formation of microcracks on the ITO surface due to low residual stress that came from decreased subgap level defects. This assumption was clearly confirmed with the electrical properties before and after dynamic bending testing. The results imply that we can adjust not only IAI structures with high mechanical stability due to the right amount of hydrogen introduction to make stabilized amorphous oxide but also almost all oxide/metal/oxide structures that contain unintended polycrystalline structures.

An oxide/metal/oxide (OMO) multi-structure, which has good electrical, optical, and mechanical stability, was studied as a potential replacement of polycrystalline In–Sn–O (ITO).     

A highly sensitive and selective chemosensor for Pb2+ based on quinoline–coumarin

In this study, a highly sensitive and selective fluorescent chemosensor, ethyl(E)-2-((2-((2-(7-(diethylamino)-2-oxo-2H-chromene-3-carbonyl)hydrazono)methyl)quinolin-8-yl)oxy)acetate (1), was synthesized and characterized by ¹H NMR, ¹³C NMR and ESI-MS. Sensor 1 showed an “on–off” fluorescence response to Pb²⁺ with a 1 : 1 binding stoichiometry in CH₃CN/HEPES buffer medium (9 : 1 v/v). The detection limit of sensor 1 to Pb²⁺ was determined to be 0.5 μM, and the stable pH range for Pb²⁺ detection was from 4 to 8.

A highly sensitive and selective fluorescent chemosensor 1 was synthesized and used for naked eye detection of Pb²⁺.     

The crystallization kinetics of Co doping on Ni–Mn–Sn magnetic shape memory alloy thin films

Co doping is an effective means to improve the performance of Ni–Mn–Sn alloy bulks and thin films. However, the Co doping effect on the crystallization process of the Ni–Mn–Sn alloy thin films is important but not clear. Therefore, we investigate the influence of Co doping on the crystallization kinetics for Ni₅₀Mn_37−xSn₁₃Co_x (x = 0, 0.5, 1.5, 4) magnetic shape memory alloy thin films by DSC analysis. For the non-isothermal process, each DSC curve has a single exothermic peak, which is asymmetrical. The crystallization peak temperatures and the activation energy of thin films both rise gradually with increasing Co content. Then, the activation energy of Ni₅₀Mn_37−xSn₁₃Co_x (x = 0, 0.5, 1.5, 4) thin films obtained by the Kissinger equation method is determined as 157.9 kJ mol⁻¹, 198.8 kJ mol⁻¹, 213 kJ mol⁻¹ and 253.6 kJ mol⁻¹, respectively. The local activation energy of thin films with different Co content show the different variation tendency. In the isothermal crystallization, the average of the Avrami exponent n for thin films of each Co content is approximately 1.5, suggesting that the mechanism of crystallization is two-dimensional diffusion-controlled growth for Ni₅₀Mn_37−xSn₁₃Co_x (x = 0, 0.5, 1.5, 4) thin films.

Co doping is an effective means to improve the performance of Ni–Mn–Sn alloy bulks and thin films.     

Self-supporting S@GO–FWCNTs composite films as positive electrodes for high-performance lithium–sulfur batteries

Although lithium–sulfur (Li–S) batteries are a promising secondary power source, it still faces many technical challenges, such as rapid capacity decay and low sulfur utilization. The loading of sulfur and the weight percentage of sulfur in the cathode usually have a significant influence on the energy density. Herein, we report an easy synthesis of a self-supporting sulfur@graphene oxide-few-wall carbon nanotube (S@GO–FWCNT) composite cathode film, wherein an aluminum foil current collector is replaced by FWCNTs and sulfur particles are uniformly wrapped by graphene oxide along with FWCNTs. The 10 wt% FWCNT matrix through ultrasonication not only provided self-supporting properties without the aid of metallic foil, but also increased the electrical conductivity. The resulting S@GO–FWCNT composite electrode showed high rate performance and cycle stability up to ∼385.7 mA h g_electrode⁻¹ after 500 cycles and close to ∼0.04% specific capacity degradation per cycle, which was better than a S@GO composite electrode (353.1 mA h g_electrode⁻¹). This S@GO–FWCNT composite self-supporting film is a promising cathode material for high energy density rechargeable Li–S batteries.

We report a synthesis of a self-supporting composite cathode film, wherein aluminum foil current collector is replaced by FWCNTs and sulfur particles are uniformly wrapped by graphene oxide along with FWCNTs.     

Ni–Al–Cr superalloy as high temperature cathode current collector for advanced thin film Li batteries

To obtain full advantage of state-of-the-art solid-state lithium-based batteries, produced by sequential deposition of high voltage cathodes and promising oxide-based electrolytes, the current collector must withstand high temperatures (>600 °C) in oxygen atmosphere. This imposes severe restrictions on the choice of materials for the first layer, usually the cathode current collector. It not only must be electrochemically stable at high voltage, but also remain conductive upon deposition and annealing of the subsequent layers without presenting a strong diffusion of its constituent elements into the cathode. A novel cathode current collector based on a Ni–Al–Cr superalloy with target composition Ni_0.72Al_0.18Cr_0.10 is presented here. The suitability of this superalloy as a high voltage current collector was verified by determining its electrochemical stability at high voltage by crystallizing and cycling of LiCoO₂ directly onto it.

A novel cathode current collector based on a Ni–Al–Cr superalloy is presented here. The suitability of this superalloy as a high voltage current collector was verified by crystallizing and cycling of LiCoO₂ directly onto it.     

Radiation-induced curcumin release from curcumin–chitosan polymer films

The probability of human exposure to damaging radiation is increased in activities associated with long-term space flight, medical radiation therapies, and responses to nuclear accidents. However, the development of responsive countermeasures to combat radiation damage to biological tissue is lagging behind rates of human exposure. Herein, we report a radiation-responsive drug delivery system that releases doses of curcumin from a chitosan polymer/film in response to low level gamma radiation exposure. As a fibrous chitosan–curcumin polymer, 1 Gy gamma irradiation (¹³⁷Cs) released 5 ± 1% of conjugated curcumin, while 6 Gy exposure releases 98 ± 1% of conjugated curcumin. The same polymer was formed into a film through solvent casting. The films showed similar, albeit attenuated behavior in water (100% released) and isopropyl alcohol (32% released) with statistically significant drug release following 2 Gy irradiation. ATR FT-IR studies confirmed glycosidic bond cleavage in the chitosan–curcumin polymer in response to gamma radiation exposure. Similar behavior was noted upon exposure of the polymer to 20 cGy (1 GeV amu⁻¹, at 20 cGy min⁻¹) high linear energy transfer (LET) ⁵⁶Fe radiation based on FTIR studies. Density Functional Theory calculations indicate homolytic bond scission as the primary mechanism for polymer disintegration upon radiation exposure. Films did not change in thickness during the course of radiation exposure. The successful demonstration of radiation-triggered drug release may lead to new classes of radio-protective platforms for developing countermeasures to biological damage from ionizing radiation.

The probability of human exposure to damaging radiation is increased in activities associated with long-term space flight, medical radiation therapies, and responses to nuclear accidents.     

Immobilization adjusted clock reaction in the urea–urease–H+ reaction system

The bell-shaped reactivity-pH curve is the fundamental reason that the temporal programmable kinetic switch in clock reactions can be obtained in bio-competitive enzymatic reactions. In this work, urease was loaded on small resin particles through ionic binding. Experimental results reveal that the immobilization not only increased the stability of the enzyme and the reproducibility of the clock reaction, but also shifted the bell-shaped activity curve to lower pHs. The latter change enables the clock reaction to occur from an initial pH of 2.3, where the free enzyme had already lost its activity. Two mechanisms explain the influence of the immobilization on the clock reaction. Immobilization modified the pH sensitive functional groups on the enzyme, shifting the activity curve to a more acidic region, and reduced diffusion alters the enzyme dynamics.

The reported immobilization shifts the bell-shaped reactivity-pH curve to lower pHs and enables the clock reaction to occur from a very low initial pH, where the free enzyme had already lost its activity.     

Spectroscopic analysis of Eu3+ doped silica–titania–polydimethylsiloxane hybrid ORMOSILs

Eu³⁺ doped silica–titania–polydimethylsiloxane hybrid ORMOSILs were synthesized via a non-hydrolytic sol–gel route. The structural and thermal analyses of the samples confirmed that the matrix structure remains unaffected by doping with different concentrations of Eu³⁺ ions. Photoluminescence (PL) studies performed at 394 nm on Eu³⁺ doped ORMOSILs imply that they emit broad blue host emission and the characteristic Eu³⁺ red emissions simultaneously. Also, the samples were excited at the charge transfer (CT) band and this confirmed the existence of an energy transfer path from the host to the Eu³⁺ ions via Ti⁴⁺–O²⁻–Eu³⁺ bonds. The phonon energy of the host matrix was estimated by phonon sideband (PSB) analysis and the results were substantiated by Raman analysis. Judd–Ofelt (JO) parameters were also evaluated which give details about the local surroundings of the Eu³⁺ ions in the system and these parameters were further used for predicting the radiative properties of ⁵D₀ → ⁷F_1,2,4 transitions of Eu³⁺ ions. Furthermore, the quantum efficiency and CIE co-ordinates were evaluated and it was found that Eu³⁺ doped silica–titania–polydimethylsiloxane ORMOSIL has an intense pinkish red emission with a quantum efficiency of 30.7%.

Eu³⁺ doped silica–titania–polydimethylsiloxane ORMOSIL emits broad blue host band and characteristic Eu³⁺ emission peaks simultaneously when excited at 394 nm.     

Preparation of biomimetic non-iridescent structural color based on polystyrene–polycaffeic acid core–shell nanospheres

Caffeic acid (CA), as a natural plant-derived polyphenol, has been widely used in surface coating technology in recent years due to its excellent properties. In this work, caffeic acid was introduced into the preparation of photonic band gap materials. By controlling the variables, a reasonable preparation method of polystyrene (PS) @polycaffeic (PCA)–Cu(ii) core–shell microspheres was achieved: 1 mmol L⁻¹ cupric chloride anhydrous (CuCl₂), 3 mmol L⁻¹ sodium perborate tetrahydrate (NaBO₃·4H₂O), 2 mmol L⁻¹ CA and 2 g L⁻¹ polystyrene (PS) were reacted at 50 °C for 10 min to prepare PS@PCA–Cu(ii) core–shell microspheres through rapid oxidative polymerization of CA coated PS of different particle diameters. The amorphous photonic crystal structure was self-assembled through thermal assisted-gravity sedimentation, resulting in structural color nanomaterials with soft and uniform color, no angle dependence, stable mechanical fastness and excellent UV resistance.

Caffeic acid (CA), as a natural plant-derived polyphenol, has been widely used in surface coating technology in recent years due to its excellent properties.     

Formation kinetics of Sr0.25Ba0.75Nb2O6 and Li2B4O7 crystals from 0.25SrO–0.75BaO–Nb2O5–Li2O–2B2O3 glass

We have investigated the transition kinetics of Sr_0.25Ba_0.75Nb₂O₆ (SBN) and Li₂B₄O₇ (LBO) crystals from 0.25SrO–0.75BaO–Nb₂O₅–Li₂O–2B₂O₃ (SBNLBO) glass under isothermal and non-isothermal processes. With increasing temperature, there are two consecutive steps of crystallization of SBN and LBO from the glass. The Johnson–Mehl–Avrami function indicates that the crystallization mechanism of SBN belongs to an increasing nucleation rate with diffusion-controlled growth. The crystallite size of SBN ranges from 40 to 140 nm but it is confined to within 30–45 nm for LBO during the whole crystallization process. The relationship between the nano size and strain of SBN based on the Williamson–Hall method, and the change of activation energies of SBN and LBO crystallization analyzed by using the isoconversional model are discussed. A comparison of phonon modes between as-quenched glass and fully transformed crystals clearly shows that the low dimensional vibration modes in the structurally disordered glass change to highly dimensional network units with the formation of crystals.

We have investigated the transition kinetics of Sr_0.25Ba_0.75Nb₂O₆ (SBN) and Li₂B₄O₇ (LBO) crystals from 0.25SrO–0.75BaO–Nb₂O₅–Li₂O–2B₂O₃ (SBNLBO) glass under isothermal and non-isothermal processes.     

Cu–Cd–Zn–S/ZnS core/shell quantum dot/polyvinyl alcohol flexible films for white light-emitting diodes

We present a facile route for the synthesis of water-soluble Cu–Cd–Zn–S/ZnS core/shell quantum dots (QDs) by simple pH regulation. The PL spectra of Cu–Cd–Zn–S/ZnS core/shell quantum dots can cover the whole visible light region in the case of only two ratios of Cu/Cd/Zn. The emission wavelength of Cu–Cd–Zn–S/ZnS QDs can be conveniently tuned from 474 to 515 and 548 to 629 nm by adjusting the pH value when the ratios of Cu/Cd/Zn are fixed at 1 : 5 : 80 and 1 : 5 : 10, respectively. It is worth noting that under the condition of a constant Cu/Cd/Zn ratio, the UV-vis absorption spectra do not change with the fluorescence spectra, indicating that the band gap of QDs remains unchanged during the change of pH value. The photoluminescence (PL) quantum yield of the as-prepared QDs with yellow emission is up to 76%. The QDs also show excellent chemical stability after the deposition of the ZnS shell. Luminescent and flexible films are fabricated by combining Cu–Cd–Zn–S QDs with polyvinyl alcohol (PVA). The QD/PVA flexible hybrid films are successfully applied on top of a conventional blue InGaN chip for remote-type warm-white LEDs. As-fabricated warm-white LEDs exhibit a higher color rendering index (CRI) of about 89.2 and a correlated color temperature (CCT) of 4308 K.

We present a facile route for the synthesis of water-soluble Cu–Cd–Zn–S/ZnS core/shell quantum dots (QDs) by simple pH regulation.     

Deposition of Ag and Ag–Au nanocrystalline films with tunable conductivity at the water–toluene interface

Thin films of Au, Ag and Ag–Au alloy nanocrystals extending to areas of several square centimetres are obtained by deposition at the interface of water and toluene. Toluene containing chlorotris(triphenylphosphine)silver(i) and/or chlorotriphenylphosphine gold(i) is reacted with aqueous tetrakishydroxymethylphosphonium chloride to obtain nanocrystalline films adhered to the interfacial region. Alloying was induced by varying the composition of the toluene layer. The composition change results in regular and reproducible variation in the transport characteristics of the films, with the initially metallic deposits turning non-metallic with increased Au content. The films at the interface were transferred to different substrates and characterised using atomic force microscopy, UV-visible spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning and transmission electron microscopy.

Thin films of Au, Ag and Ag–Au alloy nanocrystals extending to areas of several square centimetres are obtained by deposition at the interface of water and toluene.     

Sealing effect of surface porosity of Ti–P composite films on tinplates

A novel chrome-free Ti–P composite film was prepared by casting a mixed solution containing titanium and phosphorus species, which is able to seal the pores on the tinplate surface. The obtained film was characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The surface porosity sealing effect on tinplates was verified by using a glow discharge spectrometer (GDS), porosity tests, and XPS. The results show that the film on the tinplates is composed of TiO₂, Ti₃(PO₄)₄·nH₂O, and FePO₄. Micropores on the tinplates are reduced apparently after film deposition, and the content of iron exposed in the pores is decreased significantly. An obvious concentration peak of phosphorus at a depth of around 0.75 μm infers that the film can penetrate into the micro-pores. The film lead to a 42.5% decrease in the surface porosity of the tinplates, exhibiting an outstanding surface porosity sealing effect in comparison with pure Ti or P films. Mechanistic analysis using XPS indicates that Ti₃(PO₄)₄·nH₂O and FePO₄ in the film play a role in sealing the surface porosity.

A novel chrome-free Ti–P composite film was coated on tinplates to seal the pores on the tinplate surface.     

Single-factor analysis of Ni–B–AC-catalyzed β-pinene hydrogenation based on hierarchical analysis

In the choice of catalysts for the hydrogenation of pinene, nickel-based catalysts show intriguing activity. Here, a Ni–B catalyst supported on activated carbon with Ni as an active component was synthesized by the titration reduction co-impregnation method. The mechanism of such heterogeneous systems has not yet been articulated, and the industrial applications of the potassium borohydride reduction of nickel-based catalysts are limited by their easy agglomeration and poor stability. The materials were analyzed by hierarchical and DFT studies, in situ XPS, BET, XRD, and SEM, which provided insights into the kind of signals in Ni²⁺ reduction to Ni⁰. The hierarchical analysis indicated that Ni/AC (0.4876) and reaction pressure (0.6066) influenced the catalyst preparation and process efficiency changes, respectively. Activated carbon was shown to provide a favorable basis for the stability of the Ni–B activity. In addition, the hierarchical analysis method provides new insights into the data analysis for chemical experiments.

In the choice of catalysts for the hydrogenation of pinene, nickel-based catalysts show intriguing activity.     

Smart edible coating films based on chitosan and beeswax–pollen grains for the postharvest preservation of Le Conte pear

Smart edible coating films can be used in food packaging. For this application, they must have good physical and mechanical properties. Herein, chitosan–beeswax based film is used to preserve Le Conte pears postharvest. The chitosan–beeswax films were characterized using XRD, FT-IR, and SEM analysis. Moreover, all films showed good self-healing aptitudes ranging from 86.7 to 96.3. The film treated with pollen grains showed an enhanced water contact angle compared with the chitosan film. The chitosan–beeswax/pollen grain film exhibited a two-fold lower WVTR value compared to the chitosan film, and showed the tendency to increase the stiffness of the film. The elongation% at break was reduced from 35.81 to 14.09. Fruit quality parameters were determined in cold storage for 105 days during shelf life after a simulated marketing period of 7 days. All coated fruits successfully showed decrease in weight loss, decay and rate of softening. Therefore, chitosan–beeswax/pollen grains can be considered safe and effective coating for the fruit preservation.

Smart edible coating films can be used in food packaging.