In Situ Transformation of Metal Molybdates into Polymetallic Sulfides with Enriched Edge Sites for High-Performance Supercapacitors.

An effective approach to synthesize polycrystalline Ni-Co-Mo sulfide (NiCoMoS) is developed through doping engineering coupled with chemical transformation. The polycrystalline NiCoMoS with enriched active edge sites is designed and fabricated on a Ni foam (NF) via a facile hydrothermal calcination and post-sulfidation approach, where the polycrystalline NiCoMoO4 precursor is elaborately prepared by doping Co ions into the NiMoO4 lattice and subsequently in-situ-converted into NiCoMoS with 3D architectures of ordered nanoneedle arrays. Benefiting from the unique 3D structure and synergistic effects of each component, the optimized needle-like NiCoMoS(2.0) arraying on a NF as a self-standing electrode exhibits superior electrochemical performances with a high specific charge (920.0 C g-1 at 1.0 A g-1), excellent rate capability, and good long-term stability. Furthermore, the assembled NiCoMoS//activated carbon hybrid device presents a satisfactory supercapacitor performance, affording an energy density of 35.2 W h kg-1 at a power density of 800.0 W kg-1 and competitive long-term stability (83.8% retention at 15 A g-1 after 10,000 cycles). Such a novel strategy may pave a new route for exploring other polymetallic sulfides with enriched, exposed active edge sites for energy-related applications.

Construction of Ultrafine Ag2S NPs Anchored onto 3D Network Rodlike Bi2SiO5 and Insight into the Photocatalytic Mechanism.

A novel three-dimensional (3D) network rodlike Ag2S/Bi2SiO5 photocatalyst with a p-n heterostructure composed of ultrafine Ag2S nanoparticles (NPs) and Bi2SiO5 nanosheets was prepared using an anionic self-regulation strategy by a two-step hydrothermal process. The architecture facilitated the efficient transfer and separation of photogenerated electron-hole pairs. The optimal Ag2S/Bi2SiO5 composite (ABSO0.10) exhibited an excellent reduction activity (93.5% Cr(VI) removal in wastewater containing 50 mg·L-1 Cr(VI) within 90 min under visible light), which was about 11.2 and 25.6 times higher than that of the pristine Ag2S and virgin Bi2SiO5, respectively. Assisted by experiments and density functional theory (DFT) calculations, a possible photocatalytic mechanism for Cr(VI) reduction over the Ag2S/Bi2SiO5 composite under visible-light irradiation was proposed.

Construction of NiCoZnS materials with controllable morphology for high-performance supercapacitors.

A facile two-step hydrothermal approach with post-sulfurization treatment was put forward to construct the mixed transition metal sulfide (NiCoZnS) with a high electrochemical performance. The different morphologies of NiCoZnS materials were successfully fabricated by adjusted the Ni/Co molar ratio of the NiCoZn(OH)F precursor. Moreover, thein situphase transformation from the NiCoZn(OH)F phase to Zn0.76Co0.24S and NiCo2S4phases and lattice defects via the S2-ion-exchange were determined by x-ray diffractometer, transmission electron microscopy and x-ray photoelectron spectroscopy techniques, which improved electric conductivity and interfacial active sites of the NiCoZnS, and so promoted the reaction kinetics. Significantly, the urchin-like NiCoZnS1/1prepared at the Ni/Co molar ratio of 1.0 exhibited promising electrochemical performances with high capacitance and excellent cycling stability. Furthermore, the asymmetric device (NiCoZnS//AC) using NiCoZnS1/1as the positive electrode had excellent supercapacitor performances with an energy density of 57.8 Wh·kg-1at a power density of 750 W·kg-1as well as a long cycle life (79.2% capacity retention after 10 000 cycles), indicating the potential application in high-performance supercapacitors.

Ag-Ag2O decorated multi-walled carbon nanotubes/NiCoAl hydrotalcite sensor for trace nitrite quantification.

Ag-Ag2O-decorated multiwall carbon nanotube/NiCoAl-hydrotalcite (CNT/LDH-Ag) composites were designed and synthesized for nitrite quantification. The materials were characterized by various techniques, and their electrochemical NO2- detection performances investigated using amperometric and differential pulse voltammetry (DPV) techniques. The Ag-Ag2O nanoparticles (NPs) were anchored on the surface of the CNT/LDH-Ag composites. At a suitable amount of the Ag-Ag2O loading, the Ag-Ag2O NPs with small particle size were distributed evenly on the CNT/LDH surface, increasing the surface area of the composites. The optimal CNT/LDH-Ag3 composite exhibited a high electrochemical activity for NO2- oxidation in pH 7.0. Furthermore, the optimal CNT/LDH-Ag3 composite was fabricated for trace NO2- quantification. The proposed sensor displayed a high sensitivity (0.0960 µA·µM-1·cm-2) and fast response (< 3 s) toward NO2- in a wide linear range from 0.250 µmol·L-1 to 4.00 mmol·L-1 with a low detection limit of 0.0590 µmol·L-1(S/N = 3). The sensor provided an outstanding analytical performance with a desirable recovery (95.3 ~ 107%, RSD < 1.05%) in real sample. As a result, the proposed sensor can be used for the real-time quantification of trace NO2- in the biological, food, and environmental fields.

High-sensitive sensor for the simultaneous determination of phenolics based on multi-walled carbon nanotube/NiCoAl hydrotalcite electrode material.

The ternary NiCoAl hydrotalcite (NiCoAl-LDH) was combined with carboxylic multi-walled carbon nanotube (MWCNT) to fabricate a novel electrochemical sensor for simultaneously determining the co-existing trace phenolic substances. The morphology, structure, and electrochemical behavior of the as-prepared materials were characterized by various techniques. Benefitting from the great conductivity of MWCNT and high electrocatalytic activity of NiCoAl-LDH for phenolic substances, the advanced MWCNT/NiCoAl-LDH sensor presented a fast response, high sensitivity, excellent stability, and satisfactory replicability. The sensor offered good linear responses in the ranges1.50~600 µM to hydroquinone (HQ), 5.00~1.03 × 103 µM to catechol (CC), and 6.00 × 10-2~250 µM to bisphenol A (BPA). The detection limits of HQ, CC, and BPA were 0.4, 0.8, and 6. × 10-3 µM (S/N = 3), respectively. In environmental water, the sensor achieved satisfactory recoveries for the simultaneous detection of HQ (98.6~101%), CC (98.0~101%), and BPA (97.5~101%), with relative standard deviations less than 4.4%.

[Study on the Analytical Method of Solid Phase Extraction-Ultra Performance Liquid Chromatography Tandem Quadrupole Linear Ion Trap Mass Spectrometry for 12 Perfluorinated Compounds in Human Urine].

OBJECTIVE: To establish a method for simultaneous determination of 12 kinds of perfluorinated compounds (PFCs) in human urine based on ultra performance liquid chromatography tandem quadrupole linear ion trap mass spectrometry (UPLC-QTtrap-MS). METHODS: After pH adjustment with 2% formic acid, the urine samples were loaded on a WAX solid phase extraction (SPE) cartridge for extraction, purification and concentration. The eluates were collected, concentrated to dryness under nitrogen, and reconstituted with 10 mmol/L ammonium acetate aqueous solution-methanol ( V water∶ V methanol = 70∶30) before injection. UPLC was performed on a C 18 cartridge, and methanol and 10 mmol/L ammonium acetate aqueous solution was used as mobile phases with gradient elution. QTtrap-MS was operated in multiple reaction monitoring (MRM) mode, and the internal standard calibration curves were applied for quantitative analysis. RESULTS: Good linearity was obtained in the linear range, with the method detection limits and method quantification limits being 0.032 ng/L-6.5 ng/L and 0.10 ng/L-21 ng/L, respectively, for the 12 kinds of PFCs. The spiked recoveries of the 12 kinds of PFCs were 91.5%-114%, with the intra-day precision and the inter-day precision being 0.57%-16.0% and 1.88%-20.1%, respectively. The established method was applied to the determination of 12 kinds of PFCs in the urine samples of primary school students collected in one area. Nine kinds of PFCs were detected in the urine samples in this area. Among the PFCs detected, perfluorobutanesulfonic acid (PFBS) and perfluorooctanoic acid (PFOA) were the main PFCs found in the student urine samples. CONCLUSION: The method established in this study could be used to simultaneously examine 12 kinds of PFCs in urine. The method combined SPE with isotope internal standard correction and achieved good sensitivity and accuracy.

Fabrication of Ag2O/Ag decorated ZnAl-layered double hydroxide with enhanced visible light photocatalytic activity for tetracycline degradation.

The photocatalytic performance of layered double hydroxides (LDH) is usually confined to the slow interface mobility and high recombination rate of photogenerated electron-hole pairs in material. To overcome the low photocatalytic efficiency, novel Ag2O/Ag decorated LDH (LDH-Ag2O/Ag) was successfully synthesized by depositing Ag2O on the surface of LDH and then converted to Ag° nanoparticles in the right position after heat treatment. The as-synthesized LDH-Ag2O/Ag composites were characterized by Powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectra (UV-vis DRS), photoluminescence spectra (PL) and transient photocurrent (TPC) analysis. Compared with virgin LDH, the photocatalytic activities of LDH-Ag2O/Ag composites were enhanced significantly. The optimum photocatalytic efficiency of LDH-Ag10 (0.0184 min-1) was nearly 46 times higher than that of virgin LDH (0.0004 min-1). The result of active species trapping experiments indicated that •OH, h+, and •O2- have an effect on the TC degradation, where •OH played the predominant role during the photocatalytic process. The possible photocatalytic mechanisms involving the charge transfer pathway and reactive species generation during the process of TC degradation were also discussed. The improved photocatalytic activity of LDH-Ag2O/Ag could be attributed to the synergetic effect between LDH and Ag2O/Ag that extended visible light range and reduced photogenerated charge carriers recombination.

Optimization of ZnAl/Chitosan Supra-Nano Hybrid Preparation as Efficient Antibacterial Material.

The menace of antimicrobial resistance continues to increase and hence the need to discover new antibiotics, especially alternative and effective sources such as hybrid organic-inorganic, organic-organic materials, and other combinations. In this study, an antimicrobial hybrid supra-nano material was prepared by the bi-titration synthesis method of chitosan (CS) and ZnAl layered double hydroxide. Fourier-transform infrared spectrometer (FTIR), thermogravimetric and differential thermal gravimetric (TGA/DTG), ultraviolet-visible (UV-Vis), X-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses indicated that the ZnAl/CS hybrid exhibited low crystallinity with high thermal stability. The results of ZnAl/CS characterization showed the characteristic properties of the individual components ZnAl and CS, indicating a successful preparation of the ZnAl/CS hybrid. The antibacterial tests revealed that the ZnAl/CS hybrid possessed an enhanced antimicrobial effect against both Escherichia coli (E. coli, MTCC 739) and Penicilliumcyclopium (P. cyclopium, AS 3.4513). Under the central composite design (CCD) of the response surface methodology (RSM) tool, the parameters of the hybrid synthesis reaction were optimized and the result obtained was as follows: reaction pH was 11.3, reagent Zn/Al ratio was 3.27, and chitosan concentration was 1.07 g/L. After optimization, it was found that the antibacterial activity of ZnAl/CS was strengthened against E. coli as evidenced by a widening of the inhibition zone of about 41.6%. The antibacterial activity of ZnAl/CS was mainly due to the reactivation of the antibacterial activity of CS associated with the release of Zn2+ and Al3+ metal ions in addition to ZnO, Al2O3, and ZnAl2O4 compounds resulting from the method of preparation.

Facile Preparation of Modifying Layered Double Hydroxide Nanoparticles for Drug Delivery.

Mg-Al-NO3 hydrotalcite (p-LDH) was employed as a carrier for the controlled release of 5-Fluorouracil (5-FU). The p-LDH was pretreated by acid-pretreatment to gain a more stable material (a-LDH) in acid medium for oral administration. It demonstrated that the a-LDH had smaller crystal size, particle sizes and higher permanent charge density (σp) compared with that of the p-LDH by means of XRD, SEM, FT-IR, UV-vis DRS, TG-DSC, BET/BJH and other techniques. The FU/a-LDH and FU/p-LDH delivery systems were obtained using anion-exchange method. The in vitro 5-FU drug release studies showed that no burst release phenomenon was observed at the beginning of release tests. The in vitro 5-FU release behaviors of the delivery systems at initial pH 4.6 and 7.5 were studied which could be described by first-order and Bhaskas models. Combined with the XRD and FT-IR analyses of the solid residues of the FU/a-LDH and FU/p-LDH after the release, it was found that the dissolution mechanism was mainly responsible for the release behavior of the FU/p-LDH at initial 4.6, while the anion-exchange between intercalated 5-FU and phosphate anions mechanism was responsible for the FU/a-LDH at pH 4.6 and 7.5 as well as FU/p-LDH at pH 7.5. It is concluded that the hydrotalcites could be used as the basis of a tunable drug delivery carrier for 5-FU.

[Technology and MethodsSimultaneous Determination of 9 Natural Ingredientsin Functional Food for Anti-hangover and Hepatoprotection by High Performance Liquid Chromatography].

OBJECTIVES: To develop a rapid method of high performance liquid chromatography coupled with variable wave length UV detection for simultaneous determination of 9 natural functional ingredients including puerarin, silymarin, quercetin hydrate, schisandrol A, curcumin, tanshinoneI, tanshinoneIIA, cryptotanshinone, and dihydrotanshinoneIin functional food for anti-hangover and hepatoprotection. METHODS: The samples were ultrasonically extracted with 90 % ethanol (V/V) and centrifuged at 10 000 r/min for 10 min prior to HPLC analysis. The nine target analytes were separated on a C18 column with gradient elution using methanol and water (The pH value was adjusted to 2.5 using H3PO4) as the mobile phase. Qualitative analysis was carried out using retention times of the chromatographic peaks, while the external standard curves were established for quantification. RESULTS: Under the optimal analytical conditions, the peak area of each analyte and its concentration had a good correlation within the linear range ( r≥0.998). The limits of detection and quantification of the method were 0.38-0.73 mg/kg (S/N=3) and 1.27-2.43 mg/kg (S/N=10), respectively. The spiked recoveries of the analytes were 88.9%-103.2%, and the relative standard deviations were 1.3%-3.7%. CONCLUSIONS: The method for the determination of 9 functional ingredients in functional food for anti-hangover and hepatoprotection was proposed for the first time in this study. The results showed that it could meet the requirement of routine analysis and quality control and evaluation.

[Phase transition behavior and thermodynamic analysis of hydrotalcite flame-retardant].

The hydrotalcite with the properties of flame-retardant, eliminating smoke, filling and thermostability is a new kind of inorganic flame retardant. In the work, the MgAl hydrotalcite as flame retardant with Mg/Al molar ratio of 4 (MgAl-LDH) was prepared by using urea as the precipitating agent. The thermolysis behavior of the MgAl-LDH flame retardant was investigated by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and thermogravimetry-differential scanning calorimetry (TG-DSC) as well as self deconvolution and curve-fitting analyses. Thermal phase transition of the MgAl-LDH was clarified, especially the characteristics of the hydroxyl groups (-OH) in the brucite-like layers and the changes in coordinate of the carbonate (CO3(2-)) from the interlayers. Based on thermodynamic data, thermal decomposition process was discussed. By.XRD analysis; it was found that the phase change took place when the decomposition temperature increased. The MgAl-LDH was decarbonated basically to MgAl mixed metal oxides (Mg-Al-O) at 500 °C, and impurity MgAl204 phase formed at 600 °C. According to the analyses of FT-IR, TG-DSC and curve-fitting technique, the hydroxyl groups (-OH) in the brucite-like layers possessed three the ligands such as [Al-OH-Al], [Al-OH-Mg] and [Mg-OH-Mg] modes. Dehydroxylation of the brucite-like layers based on the binding forces, where the [Mg-OH-Mg] among the three modes was the most difficult to be re- moved during the pyrolysis process. In the same way, the CO3(2-) ligands also possessed three modes such as H2O-bridged CO3(2-), monodentate and bidentate coordination modes. Based on the thermodynamic analysis, the thermodynamic properties of the hydrotalcite as flame retardant were evaluated, and the expressions of the Gibbs free energy, (ΔrGθT), as a function of temperature, were derived for the Mg8Al2 (OH)20CO3 crystal. Thermodynamic analysis showed that the removal of -OH from the brucite-like layers was spontaneous process, when the Gibbs free energy (ΔrGθT) was under zero at the temperature (T) above 228. 65 °C. The result and datum were close to the experimental result from the TG-DSC analyses, indicating that the relationship between the Gibbs free energy (ΔrGθT) and temperature (T) from thermodynamic analysis was reliable.

Amino acid profiles and quality from lotus seed proteins.

BACKGROUND: Protein composition, amino acid profile and nutritional value of the lotus seed and its Osborne fractions were investigated. The seed was rich in protein with 19.85%, and showed well balanced amino acid composition compared with FAO/WHO pattern, Its nutritive properties were similar to those observed in the reference soybean protein. Phenylalanine, tyrosine, leucine and lysine were the limiting amino acids in the seed proteins. The albumin and globulin were the main protein fraction, the amino acid profile and nutritional value were close to the seed protein. RESULTS: Changes in transition temperature and thermal stability were observed through different solvent extractions. Albumin possessed the predominant thermal stability (81.4 °C) followed by globulin (74.49 °C), prolamin (69 °C) and glutelin (65.6 °C). So, solvent compositions influence the profile of AAs and their nutritive value, and aqueous solvent with 0.1 mol L⁻¹ NaCl was an efficient protein solubiliser. CONCLUSION: The results indicated that the extraction processes influenced the lotus seed protein quality and thermal stability. Overall, the study revealed that the lotus seed protein was nutritionally well-balanced protein and might be of significant importance in the formulation of diets for humans.

Ni-Co-Mn hydrotalcite-derived hierarchically porous sulfide for hybrid supercapacitors.

Ternary transition metal sulfides have attracted much attention due to their superior electrochemical properties. Nevertheless, it is difficult to commercialize sulfides due to their intrinsic properties such as dull reaction kinetics and an insufficient number of active sites. Herein, a self-supporting porous NiCoMnS sulfide (NiCoMnS/NF) arrayed on nickel foam (NF) with 3D honeycomb-like structure was designed and prepared via a hydrothermal and post-sulfidation process. It was found that the 3D hierarchically network architecture, constructed by nanosheets with abundant cavities, endowed NiCoMnS/NF with a high specific area and rich ion/electron-transport channels, which facilitated ion/electron transfer and Faradaic reaction kinetic. The optimal NiCoMnS/NF exhibited a markedly improved electrochemical performance due to the merits of complementary multi-composition and unique 3D network structure with multi-level "superhighways". Furthermore, the NiCoMnS//AC device fabricated with NiCoMnS/NF cathode and activated carbon (AC) anode delivered an excellent specific charge and exceptional energy density. This work offers a reference for designing the structure of electrode materials.

Tuning oxygen vacancy in Bi2WO6 by heteroatom doping for enhanced photooxidation-reduction properties.

Heteroatom doping was recently regarded as an effective method to tune the band gap and improve the separation and transfer of photogenerated electron-hole pairs in semiconductor photocatalysts. Herein, a novel S,F-codoped Bi2WO6 (S,F-Bi2WO6) with suitable oxygen vacancies was synthesized via the hydrothermal-calcination and post-sulfurization, for efficient Cr(VI) reduction and methyl orange (MO) degradation under visible light. The amount of surface oxygen vacancies could be controlled by adjusting the S/F ratio during the doping process, which modulated the band structure and photogenerated charge behavior of Bi2WO6. The optimal S0.10F-Bi2WO6 exhibited an excellent photooxidation-reduction performance, which Cr(VI) reduction and MO degradation efficiencies were 1.6 and 2.6 times than those of the pristine Bi2WO6 without oxygen vacancy under visible-light, respectively. The enhanced photooxidation-reduction performance was because the right amount of oxygen vacancies could effectively narrow the bandgap and improve the separation efficiency of electron-hole pairs. Thus, this work offered a mild and simply approach for preparing heteroatom doped Bi2WO6 and a potential to be extended to the synthesis of other doped materials for environmental remediation.

Novel hierarchical carbon microspheres@layered double hydroxides@copper lignosulfonate architecture for polypropylene with enhanced flame retardant and mechanical performances.

Due to the inherent defect of flammability of polypropylene (PP), a novel and highly efficient carbon microspheres@layered double hydroxides@copper lignosulfonate (CMSs@LDHs@CLS) flame retardant was designed and prepared, which was attributed to the strong electrostatic interaction between carbon microspheres (CMSs), layered double hydroxides (LDHs) and lignosulfonate as well as the chelation effect of lignosulfonate on copper ions, and then it was incorporated into the PP matrix. Significantly, CMSs@LDHs@CLS not only observably improved its dispersibility in PP matrix, but also simultaneously achieved excellent flame retardant properties for composites. With the addition of 20.0 % CMSs@LDHs@CLS, the limit oxygen index of CMSs@LDHs@CLS and PP composites (PP/CMSs@LDHs@CLS) reached 29.3 % and achieved the UL-94 V-0 rating. Cone calorimeter tests indicated that the peak heat release rate, total heat release and total smoke production of PP/CMSs@LDHs@CLS composites exhibited declines of 28.8 %, 29.2 % and 11.5 %, respectively, compared with those of PP/CMSs@LDHs composites. These advancements were attributed to the better dispersibility of CMSs@LDHs@CLS in PP matrix and illustrated that CMSs@LDHs@CLS observably reduced fire hazards of PP. The flame retardant property of CMSs@LDHs@CLS might relate to condensed phase flame retardant effect of char layer and catalytic charring of copper oxides.

[Determination of canthaxanthin and astaxanthin in egg yolks by reversed phase high performance liquid chromatography with diode array detection].

OBJECTIVE: A method using reversed phase high performance liquid chromatography (RP-HPLC) coupled with diode array detector (DAD) was developed for the simultaneous determination of canthaxanthin and astaxanthin in egg yolks. METHODS: Samples were extracted with acetonitrile in ultrasonic bath for 20 minutes and then purified by freezing-lipid filtration and solid phase extraction (SPE). After being vaporized to dryness by nitrogen blowing and made up to volume with methanol, the extract solution was chromatographically separated in C18 column with a unitary mobile phase consisting of acetonitrile. The proposed method was validated in terms of linearity, precision, accuracy, and limit of detection (LOD). RESULT: Regression analysis revealed a good linearity between peak area of each analyte and its concentration (r > or = 0.998). The intra- and inter-day relative standard deviations (RSDs) were less than 3.6% and 5.2%, respectively. LODs of canthaxanthin and astaxanthin were 0.035 and 0.027 microg/mL (S/N = 3). The average recoveries of canthaxanthin and astaxanthin were 91.5% and 88.7%. CONCLUSION: The proposed method is simple, fast and easy to apply.

[Second structure of the protein factions from lotus seeds].

Following the sequential Osborne extraction procedure, the proteins of lotus seeds were classified. The secondary structures of albumin, globulin, prolamine and glutelin fractions were determined by Fourier transform infrared spectroscopy (FTIR). The FTIR images of amide I and III bands from the four protein fractions were analyzed using Fourier deconvolution and curve-fitting technique. The results showed that there were minor differences in every corresponding peak position and peak area percent of secondary structure between albumin and globulin as well as between prolamin and glutelin. But there were differences in every corresponding peak position between albumin (or globulin) and prolamin (or glutelin). Especially the area percents of the corresponding nonrandom structures (alpha-helix and beta-sheet) of albumin and globulin were significantly larger than those of prolamin and glutelin. The contents of nonrandom structures of albumin and globulin extracted with 0.1 mol x L(-1) NaCl solution were about 55% and those of prolamine and glutelin fractions were only at round 40%, indicating that the secondary structures of the salt-extraction protein were ordered and stable.

Renewable lignin-based surfactant modified layered double hydroxide and its application in polypropylene as flame retardant and smoke suppression.

A novel and environmentally friendly lignin-based surfactant sodium lignosulfonate (SLS) modified layered double hydroxide (LDH) flame retardant (LDH-LS) was fabricated via co-precipitation method, and subsequently incorporated into polypropylene (PP) matrix to obtain the PP and LDH-LS composites (PP/LDH-LS) by melt blending method. The XRD, FT-IR and XPS results indicated that SLS had successfully modified LDH by adsorbing on the surface of the LDH nanosheet. The WCA and SEM results revealed that the hydrophobic property of LDH-LS had been evidently improved, and it displayed a more homogeneous dispersion than virgin LDH in the PP matrix. Furthermore, cone calorimetry tests (CCT) illustrated that the peak heat release rate (PHRR), total heat release (THR), and total smoke release (TSR) of PP/LDH-LS composites exhibited declines of 62.9%, 25.1%, and 43.3% compared with those of Neat PP, respectively. Besides, the PP/LDH-LS achieved a LOI value of 29.4% and a UL-94 V-0 rating, whereas the PP/LDH showed only a LOI value of 25.2% and a UL-94 V-2 rating at 20 wt% loading. These improvements of flame retardant properties can be attributed to that the well-dispersed LDH-LS and synergistic flame retardancy between LDH and SLS.

Controllable architecture of the NiCoZnS@NiCoFe layered double hydroxide coral-like structure for high-performance supercapacitors.

The rational design of the morphological structure of electrode materials is considered as an important strategy to obtain high-performance supercapacitors. So, NiCoZnS materials with different Ni/Co/Zn molar ratios on Ni foam (NF) were synthesized, in which the Ni/Co/Zn molar ratio plays a key role in the morphological structure and electrochemical performances. Furthermore, the pre-prepared NiCoZnS materials act as substrates to guide the self-assembling of NiCoFe layered double hydroxide (LDH) nanosheets on the substrate surface to form core-shell electrode materials (NiCoZnS@NiCoFe-LDH) with a 3D mesoporous hierarchical network structure for further improving electrochemical performances. The unique interconnected coral-like NiCoZnS1@NiCoFe-LDH with a large specific surface area (93.1 m2 g-1) and high specific capacitance is achieved at the Ni/Co/Zn molar ratio of 1 : 1 : 1. Benefiting from the unique structural feature and respective merits of the NiCoZnS and NiCoFe-LDH, the NiCoZnS1@NiCoFe-LDH demonstrates an ultrahigh specific capacitance of 1524.0 C g-1 (3386.7 F g-1) at 1.0 A g-1 and excellent 95.0% capacitance retention at 10 A g-1 after 5000 cycles. As for practical application, the assembled NiCoZnS1@NiCoFe-LDH//AC delivers a favorable energy density of 66.25 W h kg-1 at 1500 W kg-1 and a long-term cycling lifetime (86.04% retention at 5.0 A g-1 after 10 000 cycles), which suggests promising potential in energy storage and conversion.

[Determination of dimethyl sulphate in environmental samples with GC-ECD].

OBJECTIVE: To develop an gas chromatography-electrophoretic capture detection (GC-ECD)method for determining dimethyl sulphate (DMS) in environmental samples. METHODS: The environmental samples were dissolved with acetone and the DMS was reacted with KI. The reaction product of methyl iodide was extracted with Hexane and determined by GC-ECD, with HP-5 (30.0 m x 0.32 mm x 0.25 microm) as column, high purity nitrogen as carries, 60 degrees C for column temperature and 240 degrees C for ECD and injector temperature, and 5:1 for split ratio. RESULTS: The linear range appeared from 0.05 microg/mL to 2.0 microg/mL. The detection limit was 0.0011 microg/mL. The precision [measured by relative standard deviation (RSD)] of peak area and reserved time for the standard solution was 4.95% and 0.15% respectively for intra-day detections, and 5.99% and 0.83% respectively for inter-day detections. Satisfactory results were obtained for the analysis of environmental samples. The RSD for the water and soil samples were 9.6% and 7.5% respectively and the recoveries were 76.0%-85.0% and 82.0%-110.0% respectively. CONCLUSION: The method was simple, accurate, sensitive and applicable for DMS analysis in environmental samples.