ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 9
·9161-9173
·
IF 2.914
Zhang Tingting,Yang Yanling,Li Xing,Wang Nan,Zhou Zhiwei
Ultrasound-assisted regeneration of powdered activated carbon (PAC) saturated with 4-chlorophenol (4-CP) was investigated in this work. The variables, i.e., acoustic frequency, density levels, regenerating solution species, spent PAC mass, and the number of repeated cycle, were optimized. The UV–Vis spectra, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), and pore structure analysis were used to characterize the regenerated PAC as compared to the virgin and spent PAC. The adsorption experiments indicated that the adsorption kinetics of 4-CP fitted well with the pseudo-second-order model, and the main chemisorption process was nonlinear and heterogeneous. The desorption results showed that the optimized regenerated conditions were identified as 40 kHz of frequency, 0.18 W/mL of sonication intensity, 0.1 M NaOH and 50% ( v / v ) ethyl alcohol mixture of regeneration solution, and 1 g/L of saturated PAC mass. Under this condition, the regeneration efficiency reached up to 86.81%. Hydroxylated oxidation products especially benzoquinone and hydroquinone were formed during ultrasound regeneration. Ultrasound mainly acted on surface functionalities, mesopores, and macropores of PAC through the hydroxyl radical oxidization resulted from the cavitation effect.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 3
·1-8
·
IF 5.479
Liu Shi Gang,Luo Dan,Han Lei,Li Nian Bing,Luo Hong Qun
A hybrid material composed of guanine-rich single stranded DNA (G-rich ssDNA) and cobalt oxyhydroxide (CoOOH) nanosheets is used as a nanoprobe for fluorometric turn-on detection of ascorbic acid (AA). The CoOOH nanosheets function as a recognition component for AA. The G-rich ssDNA is used to produce a G-quadruplex, and the G-quadruplex/thioflavin T (ThT) complex acts as a fluorescent reporter. In the absence of AA, p-phenylenediamine (PPD) is oxidized to form oxPPD which has a dark red color. It causes the fluorescence of the G-quadruplex/ThT complex to be quenched. However, in the presence of AA, the CoOOH nanosheets of the nanoprobe are preferentially reduced by AA. Hence, PPD is not oxidized, and fluorescence is not quenched. A fluorometric turn-on method was developed based on these findings. It has a detection limit of 94 nM and works in the concentration range from 1 to 10 and 20 to 80 μM. This method was applied to the determination of AA in (spiked) fruit juice samples.
Schematic presentation of a fluorescent assay of ascorbic acid (AA) is established using a nanoprobe composed of guanine-rich single stranded DNA (G-rich ssDNA) and cobalt oxyhydroxide (CoOOH) nanosheets. It is based on competitive reduction of CoOOH by p-phenylenediamine (PPD) and AA. Thioflavine T (ThT) induces the formation of fluorescent G-quadruplex/ThT complex. The oxidized form of PPD (oxPPD) can quench the fluorescence via fluorescence resonance energy transfer (FRET), but AA suppresses quenching.
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SN Applied Sciences
·
2019
·Vol. 1
·期 2
·1-7
·
IF 0
Xing An,Zhang Jun,Wang Ruzhuan,Wang Jun,Liu Xiaoyan
Recycling industrial wastes for high-value items is of strategic importance for commercial production. Fly ashes are solid waste by-products generated by coal-fired power plants. Although a large amount of annual output approach 150 million tons worldwide, fly ashes have been recycled merely into some low-value items. In order to realize the high additive value of fly ashes, we transform the solid waste fly ashes into nanostructured silicon powders and apply them as anodes active materials for lithium-ion batteries. The nanostructured silicon exhibits good electrochemical performance as lithium-ion batteries anodes with high rate capacity (1450.3 mAh g −1 at current density 4000 mA g −1 ) and reversible capacity (1017.5 mAh g −1 after 100 cycles), indicating that fly ashes can be a useful resource of anode materials to meet the need of high performance lithium-ion batteries.
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JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2019
·Vol. 92
·期 3
·652-661
·
IF 1.986
Li Xiaohua,Yang Zichun,Li Kunfeng,Zhao Shuang,Fei Zhifang,Zhang Zhen
In this paper, transparent flexible hydrophobic silica aerogels were prepared by replacing the traditional alcohol solvent with water, using methyltriethoxysilane (MTES) and cetyltrimethylammonium bromide (CTAB), via acid-base two steps method and CO 2 supercritical drying. The role of surfactant CTAB in the gel–sol process was revealed, and the effect of CTAB concentration on the gel structure was analyzed. With the concentration increasing, the skeleton structure of the gel gradually changed from coarse graininess to continuous fiber. The obtained aerogels showed good elastic properties. With the increasing of density, the elastic modulus of aerogels gradually increased, so that the length could be restored to 63% of the original length after 50% compression strain. Aerogels also had low thermal conductivity and good thermal stability. The thermal conductivity at room temperature was only 0.0215 W/(m·K) and the initial decomposition temperature was up to 511 °C. For the aerogel with thickness of 11.8 mm and density of 60 mg/cm 3 , it showed good sound absorption and sound insulation properties. When the sound frequency was 2000 Hz, the sound absorption coefficient was 0.91, and the sound transmission loss between 500 and 1600 Hz was 13–21 dB. This work provides a facile approach to fabricate lightweight and flexible silica aerogels for thermal and acoustic insulation applications.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 28
·28860-28870
·
IF 2.914
Sun Zhiming,Yuan Fang,Zhang Xinchao,Zhu Rui,Shen Xinyi,Sun Bingyan,Wang Bin
Nowadays, most of mineral-based adsorbents are powder form, which makes them inconvenient to collect and always easy to cause secondary pollution. In this work, an organic rectorite composite nanofiber membrane (SRt-PAN) was designed and prepared by electrospinning technique. The as-received composite nanofiber membranes were characterized by XRD and SEM analysis, proving the homodisperse and existence of SRt in PAN nanofiber membrane. A series of batch experiments for BPA adsorption were carried out to investigate the effect of different adsorption parameters, including initial concentration, pH, and temperature of pollutant solution. The influences of modifier dosage and adsorbent dosage on the adsorption performance were investigated as well. On the basis of the experiment results, the adsorption process could be well described by the pseudo-second-order model and the Langmuir isotherm. In addition, the thermodynamic parameters indicate that this adsorption process is exothermic and spontaneous. Moreover, compared with pure nanofiber membranes and organic rectorite powders, the resultant SRt-PAN adsorbents exhibited higher adsorption capacity, superior reusability, and adsorption stability. It is indicated that the hydrophobicity surface of organic rectorite should be the key factor to not only the intimate interfacial combination between the mineral and PAN, but also the enhancement of BPA adsorption capacity.
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CELLULOSE
·
2019
·Vol. 26
·期 10
·6291-6302
·
IF 3.917
Sheng Junjiao,Li Junrong,Zhao Lihong
The oleophilic nature of paper often limits its use in applications that involve direct contact with grease, but now the generation of oil-repellent surfaces has almost universally deployed environmentally detrimental approaches relying on fluorinated compounds. In this paper, non-toxic fluoro-free grease-proof papers coated with sodium alginate (SA)/sodium carboxymethyl cellulose and SA/propylene glycol alginate were prepared, the maximum of kit values reached 9. The coatings completely covered the base paper surface and penetrated into the interfiber networks to some extent, and the modified mechanical properties were obtained. It was found that the lower the air permeability was, the better the oil resistance of the biopolymer coatings on fiber substrate was. For coatings with high surface energy, as the surface energy is dominated by the polar part, the stronger the polarity, the greater the repulsion to oil. The reduction of surface energy can effectively improve the anti-wettability for oil and water.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 6
·1-8
·
IF 5.479
Li Yufei,Zhang Huanhuan,Cai Xuan,Zhao Hongli,Magdassi Shlomo,Lan Minbo
Two kinds of carbon-based nanozymes were constructed from the same precursor of zeolitic imidazolate framework-8 (ZIF-8) for O 2 •− determination. Hollow carbon cubic nanomaterial (labelled as HCC) was obtained by chemically etching ZIF-8 with tannic acid and a subsequent calcination. A porous carbon cubic nanomaterial (labelled as PCC) was prepared by directly pyrolysis. Then HCC and PCC were immobilized on the surface of screen printed carbon electrodes (SPCE), fabricating HCC and PCC modified electrodes (denoted as HCC/SPCE and PCC/SPCE). HCC/SPCE, best operated at −0.5 V (vs. Ag/AgCl), has a sensitivity of 6.55 × 10 2 nA μM −1 cm −2 with a detection limit of 207 nM (at S/ N = 3) for O 2 •− sensing. And PCC/SPCE, best operated at −0.4 V (vs. Ag/AgCl), exhibited a superior performance for O 2 •− detection with a sensitivity of 1.14 × 10 3 nA μM −1 cm −2 and a low detection limit of 140 nM (at S/ N = 3). The two sensors possess excellent reproducibility and stability. They were used to sense O 2 •− released from HeLa cells.
Illustration of the synthesis of the hollow carbon cubic nanomaterial (HCC) and of the porous carbon cubic nanomaterial (PCC), and the scheme for detection of superoxide anions in HeLa cell.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 4
·1-8
·
IF 5.479
Wen Zhuoqi,Song Shanliang,Hu Tantan,Wang Chuanxi,Qu Fengdong,Wang Pei,Yang Minghui
A series of dual-emission fluorescent probes was prepared from copper nanoclusters (Cu NCs) and carbon dots (CDs). They show two emission peaks (blue at 469 nm and red at 622 nm) when photoexcited at 365 nm. Upon exposure to sulfide, the Cu NCs will be deteriorated because they react with sulfide to form CuS. This results in the quenching of the red fluorescence of the Cu NCs, while the blue fluorescence of the CDs remains constant. Thus, the color of the nanocomposite changes from red to blue. The ratio of the fluorescences at the two wavelengths decreases linearly in the 2–10 ppb (26–128 nM) sulfide concentration range, and the limit of detection is 0.33 ppb (4.3 nM). The nanocomposite also was placed in an agar gel and then incorporated into a paper strip for fluorometric monitoring of gaseous hydrogen sulfide.
Schematic presentation of the synthesis of Cu NCs (copper nanoclusters)-CDs (carbon dots) dual-emission nano-assembly, Cu NCs-CDs-agar fluorescent film and their application for the detection of sulfide and H 2 S.
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高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 7
·4405-4415
·
IF 3.917
Pourmortazavi Seied Mahdi,Kohsari Iraj,Zandavar Hamed,Foroutan Koudehi Masoumeh,Mirsadeghi Somayeh
Abstract Electrospinning was used to fabricate composite nanofibers based on nitrocellulose (NC), and some additives comprising aluminum nanoparticles, Fe 2 O 3 nanoparticles and diaminofurazan (DAF). The appropriate mechanical properties (such as elasticity, stiffness and tensile strength) accompanied by the suitable combustion rate of these fibers make them attractive for the utilization in the propellant formulations. The results of this work show that the average diameter of electrospun composite nanofibers (NC fibers containing Al/Fe 2 O 3 /DAF) is 80 nm. Thermal behavior of the fabricated nanofibers was characterized by DSC technique. The results showed that thermal decomposition of the nanofibers happens at the temperature 190 °C. In this study, two non-isothermal kinetics analysis methods (i.e., Kissinger and Starink) were used to predict kinetic parameters of thermal decomposition, such as activation energy and frequency factor; as well as, thermodynamic parameters (ΔG # , ΔH # , and ΔS # ). The results yield activation energies about 219 kJ mol −1 for thermal decomposition of the nanofibers. Moreover, it was found that the thermal stability of Al/Fe 2 O 3 /NC nanofibers in the presence of DAF improves and hence it has a positive effect on the safety of this nanocomposite. Graphical abstract
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Nature Communications
·
2019
·Vol. 10
·期 1
·1-8
·
IF 11.878
Deng Mucong,Feng Yongan,Zhang Wenquan,Qi Xiujuan,Zhang Qinghua
Over the past century, the search for lead-free, environmentally friendly initiating substances has been a highly challenging task in the field of energetic materials. Here, an organic primary explosive featuring a fused-ring structure, 6-nitro-7-azido-pyrazol[3,4-d][1,2,3]triazine-2-oxide, was designed and synthesized through a facile two-step reaction from commercially available reagents. This organic initiating substance meets nearly all of the stringent criteria of environmentally friendly primary explosives for commercial applications: it is free of toxic metals and perchlorate, has a high density, high priming ability, unusual sensitivities towards non-explosive stimuli, excellent environmental resistance, decent thermal stability, high detonation performance, satisfactory flowability and pressure durability, and is low-cost and easy to scale-up. These combined properties and performance measures surpass the current and widely used organic primary explosive, DDNP. The fused-ring organic primary explosive reported herein may find real-world application as an initiating explosive device in the near future.
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Science China-Technological Sciences
·
2019
·Vol. 62
·期 7
·1217-1223
·
IF 2.18
Miao Xiao,Han Lu,Wang Lei,Wang Min,Sun XiaoHui,Zhu XiaoTao,Ge Bo
The traditional superhydrophobic materials are not ideal for treating residual pollutants after oil-water separation. In this paper, a simple and economical method was developed for the fabrication of multi-functional superhydrophobic materials PDVB x /TiO 2 composites, through in situ polymerization. The performance of the superhydrophobic composite was studied. The results showed that the low surface energy of PDVB 2.5 /TiO 2 composite with the micro-nano scale roughness would result in excellent superhydrophobicity. In addition, the PDVB 2.5 /TiO 2 composite exhibits optimum effect on the degradation of methyl orange (MO) with the degradation efficiency of 97.8%. What is more, the applications of the composite materials could be expanded to other fields, such as the degradation of drug ciprofloxacin hydrochloride (CIP). Finally, we expanded the application of the PDVB x /TiO 2 composites to tribology, and found its excellent performance in reducing wear and antiwear.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 10
·2189-2200
·
IF 3.286
Liu Lu,Du Jie,Liu Wen-e,Guo Yongliang,Wu Guofan,Qi Weinan,Lu Xiaoquan
Enzyme-mimicking (nanozyme)-based biosensors are attractive owing to their unique catalytic efficiency, multifunctionality, and tunable activity, but examples of oxidase-like nanozymes are quite rare. Herein, we demonstrated that histidine-capped gold nanoclusters (His@AuNCs) possessed intrinsic oxidase-like activity, which could directly oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) to blue colored ox-TMB without H 2 O 2 . The assembly of reduced graphene oxide (RGO) with His@AuNCs could further improve its oxidase-like activity and the His@AuNCs/RGO nanocomposites had a lower Michaelis constant ( K m ) and higher catalytic constant ( K cat ) for TMB oxidation. Furthermore, compared to other nanomaterials, the as-prepared His@AuNCs/RGO also exhibited enhanced electrocatalytic activity toward TMB. Interestingly, nitrite inhibited the catalytic (chromogenic) and electrocatalytic processes of His@AuNCs/RGO in the oxidation of TMB. The oxidase-like and electrocatalytic activity of His@AuNCs/RGO was evaluated with nitrite and TMB as substrates, and the results indicated that TMB and nitrite might share the same catalytic active sites. On the basis of these findings, a colorimetric and electrochemical sensor was developed with the His@AuNCs/RGO composite as an oxidase mimic for determination of nitrite with linear ranges of 10–500 μM and 2.5–5700 μM, respectively. The developed method was successfully applied to the detection of nitrites in real samples. The present work suggests that the oxidase-like nanozyme is not only suitable for colorimetric assay but also for development of electrochemical sensors in bioanalysis.
The colorimetric and electrochemical detection of nitrite using His@AuNCs/RGO.
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