CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2019
·Vol. 35
·期 4
·729-734
·
IF 1.071
Zhu Changliang,Liu Shaoying,Wang Qingyin,Zhang Hua,Wang Gongying
Poly(butylene carbonate)(PBC) has significantly promising applications as a degradable material in the field of polymers, while its poor thermal performance and low crystallization rate are its main defects. To overcome these shortcomings, a series of poly(butylene carbonate-co-spirocyclic carbonate)(PBSC) copolymers were synthesized from diphenyl carbonate, 1,4-butanediol and spiroglycol via two-step polycondensation reactions, using magnesium oxide as a catalyst. Differential scanning calorimetry(DSC) results indicated that the glass transition temperature( T g ) values of PBSC copolymers were enhanced from −19 °C to 56 °C with rising the spiroacetal moiety content. Thermogravimetric analysis(TGA) results showed that the resulting PBSCs have a higher thermal stability than that of poly(butylene carbonate). Wide angle X-ray diffraction(WXRD) patterns were characterized to investigate the crystallization behaviour of PBSCs. Tensile testing demonstrated that copolymerization of spiroacetal moieties into PBC chains imparted PBSC with favourable mechanical performance. Typically, PBSC30 had a tensile modulus of (1735±430) MPa, a tensile strength of (42±5) MPa and an elongation of 504%±36%.
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高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 6
·3747-3762
·
IF 3.917
Xing Xiao-Yan,Gu Lin,Jin Yu,Sun Rui,Xie Meng-Yun,Wu Qing-Yun
Abstract Cellulose triacetate (CTA) porous membranes were firstly prepared by the combined nonsolvent-thermally induced phase separation (N-TIPS) method. Dimethyl sulfone (DMSO2) and polyethylene glycol (PEG400) were respectively chosen as the TIPS solvent and additive of CTA, while water was used as the NIPS nonsolvent. Their Hansen solubility parameters were analyzed to understand the solution thermodynamics. Detailed investigation was applied on the effects of the polymer concentration, the coagulation bath temperature and the coagulation bath composition on the CTA porous membranes. It is found that both NIPS and TIPS effects simultaneously exist and compete with each other, and further affect the membrane morphology and performance. The NIPS effect can be promoted by lowering the CTA concentration or elevating the coagulation bath temperature, resulting in figure-like macropores and porous top surface. The obtained CTA porous membranes show a water flux as high as 2002.9 ± 55.2 L/m 2 h. On the contrary, the TIPS effect becomes the dominant factor, and leads to the symmetric sponge-like pores, which facilitate to enhance the mechanical properties. Besides, CTA porous membranes present large surface pore size as well as low fraction of figure-like macropores as increasing the DMSO2 content in the coagulation bath. These CTA porous membranes with excellent water permeability and mechanical strength are promising candidates for microfiltration or the porous substrates of thin film composite membranes. Graphical abstract
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高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 11
·2405-2414
·
IF 3.286
Wang Chengke,Tan Rong,Li Jiangyu,Zhang Zexiang
In this paper, a fluorescent method was developed for ochratoxin A (OTA) detection that uses iron-doped porous carbon (MPC) and aptamer-functionalized nitrogen-doped graphene quantum dots (NGQDs-Apt) as probes. In this method, the adsorbance of the NGQDs-Apt on the MPC due to a π–π interaction between the aptamer and the MPC results in the quenching of the fluorescence of the NGQDs-Apt. However, since OTA interacts strongly with the aptamer, the presence of OTA leads to the detachment of the NGQDs-Apt from the MPC, resulting in the resumption of fluorescence from the NGQDs-Apt. When exonuclease I (Exo I) is also added to the solution, this exonuclease specifically digests the aptamer, leading to the release of the OTA back into the solution. This free OTA then interacts with another MPC–NGQDs-Apt system, inducing the release of more NGQDs into the solution, which enhances the fluorescent intensity compared to that of the system with no Exo I. Utilizing this behavior of OTA in the presence of NGQDs-Apt, it was possible to detect concentrations of OTA ranging from 10 to 5000 nM, with a limit of detection of 2.28 nM. Our method was tested by applying it to the detection of OTA in wheat and corn samples. This method has four advantages: (1) the magnetic porous carbon is easy to prepare, its porosity enhances its loading capacity for NGQDs, it highly efficiently quenches the fluorescence of the NGQDs, and its magnetic properties facilitate the separation of the MPC from other species in solution; (2) applying double magnetic separation decreases the background signal; (3) Exo I digests the free aptamer effectively, which allows the resulting free OTA to induce the release of more NGQDs-Apt, ultimately enhancing the fluorescent signal; and (4) the proposed method presented high sensitivity and a wide linear detection range. This method may prove helpful in food safety analysis and new biosensor development (achieved by using different aptamer sequences to that used in the present work).
Exonuclease I (Exo I)-assisted fluorescent method for ochratoxin A (OTA) detection using magnetic porous carbon (MPC), nitrogen-doped graphene quantum dots (NGQDs), and double magnetic separation
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高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 3
·1-9
·
IF 5.479
Ma Yujun,Yu Ying,Lin Bixia,Zhang Li,Cao Yujuan,Guo Manli
Copper nanoclusters (CuNCs) were synthesized starting from glutathione and copper(II) nitrate. They show blue fluorescence peaking at 432 nm when excited at 334 nm. In the presence of o -phenylenediamine (OPD), the blue fluorescence is decreased, but a yellow fluorescence appears with a peak at 557 nm. UV-visible absorptiometry, fluorometry and fluorescence lifetime measurements were used to show that OPD is oxidized by the small fraction of copper(II) ions present in the CuNCs to form the oxidized form of o -phenylenediamine (oxOPD) which displays weak yellow fluorescence, while the blue fluorescence decreases. The ratio of fluorescences at 557 and 432 nm increases linearly in the 0.15 to 110 μg·L −1 OPD concentration range, and the detection limit is 93 ng·L −1 . Compared to the method based on the use of dissolved Cu(II), the employment of CuNCs reduces the detection limit by a factor of 40. The method was applied to the determination of OPD in spiked environmental water and industrial wastewater samples. Recoveries ranged from 96.8 to 100.3%.
Schematic presentation of a ratiometric fluorometric method for detection of o-phenylenediamine (OPD) based on copper nanoclusters (CuNCs). OPD is oxidized by Cu 2+ present in CuNCs to form the oxidized form of o -phenylenediamine (oxOPD). FRET occurred between oxOPD and CuNCs, and the F 557 /F 432 value is amplified.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 26
·27063-27072
·
IF 2.914
Wang Mengyun,Wang Daiyao,Qiu Shiyi,Xiao Junyang,Cai Huahua,Zou Jing
In this study, a sensitive and low-cost multi-wavelength spectrophotometric method for the determination of hydrogen peroxide (H 2 O 2 ) in water was established. The method was based on the oxidative coloration of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) via Fenton reaction, which resulted in the formation of green radical (ABTS •+ ) with absorbance at four different wavelengths (i.e., 415 nm, 650 nm, 732 nm, and 820 nm). Under the optimized conditions ( C ABTS = 2.0 mM, C Fe 2+ = 1.0 mM, pH = 2.60 ± 0.02, and reaction time ( t ) = 1 min), the absorbance of the generated ABTS •+ at 415 nm, 650 nm, 732 nm, and 820 nm were well linear with H 2 O 2 concentrations in the range of 0–40 μM ( R 2 > 0.999) and the sensitivities of the proposed Fenton-ABTS method were calculated as 4.19 × 10 4 M –1 cm –1 ,1.73 × 10 4 M –1 cm –1 , 2.18 × 10 4 M –1 cm –1 , and 1.96 × 10 4 M –1 cm –1 , respectively. Meanwhile, the detection limits of the Fenton-ABTS method at 415 nm, 650 nm, 732 nm, and 820 nm were respectively calculated to be 0.18 μM, 0.12 μM, 0.10 μM, and 0.11 μM. The absorbance of the generated ABTS •+ in ultrapure water, underground water, and reservoir water was quite stable within 30 min. Moreover, the proposed Fenton-ABTS method could be used for monitoring the variations of H 2 O 2 concentration during the oxidative decolorization of RhB in alkali-activated H 2 O 2 system.
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高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 149
·期 11
·3184-3193
·
IF 2.372
Pei Yongli,Zhao Jinxian,Shi Ruina,Wang Xuhui,Li Zhong,Ren Jun
Abstract A series of three-dimensional (3D)-interconnected hierarchical porous carbons (HPCs) were prepared through a “leavening” strategy. α-Cellulose and NaHCO 3 were used as a raw material and foaming agent, respectively, to support copper catalysts (Cu/HPC) for dimethyl carbonate (DMC) synthesis by the oxidative carbonylation of methanol. The calcination temperature had a significant influence on the textural properties of the HPC and the catalytic performance of the Cu/HPC. The catalyst calcined at 900 °C exhibited the highest catalytic activity with a DMC space–time yield of 2018 mg/(g h). The characterization results indicated that the outstanding catalytic activity was related to the highest dispersion of copper species and to a high content of surface Cu 0 species, which can be attributed mainly to the enhanced anchoring effect of abundant micro- and mesopores of a 3D-interconnected network. In addition, the well-developed 3D-interconnected hierarchical porous structure provided a rapid and efficient channel for reactant and product transport and migration, which enhanced the catalytic performance. This work expands the potential application range of HPC materials and presents a novel procedure to prepare catalysts for DMC synthesis. Graphic Abstract
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 7
·1-9
·
IF 5.479
Qin Xiaofei,Geng Liping,Wang Qianqian,Wang Yan
A photoelectrochemical (PEC) method is described for aptamer-based detection of ofloxacin (OFL). It is making use of a TiO 2 nanotube array (NTA) that is sensitized with a structure composed of polydopamine and silver sulfide nanoparticles. The NTA were prepared by a two-step synthetic method. First, the TiO 2 nanotube electrode was covered with Ag 2 S nanoparticles via successive ionic layer adsorption and reaction strategy. Next, they were coated with a thin film of polydopamine (PDA) by in-situ polymerization. The inorganic/organic nanocomposites exhibit distinctly enhanced visible-light PEC activity. This was exploited to fabricate a PEC aptasensor. The PDA film serves as both the sensitizer for charge separation and as a support to bind the aptamer against OFL. The aptasensor undergoes a decrease in photocurrent due to the formation of the aptamer-OFL complex. Under the optimized conditions and at a typical working potential of 0 V (vs. Hg/Hg 2 Cl 2 ), the NTA has a linear response in the 5.0 pM to 100 nM OFL concentration range and a 0.75 pM detection limit (at S/ N = 3). The aptasensor was successfully applied to the determination of OFL in spiked milk samples.
Schematic illustration for the preparation and mechanism of the photoelectrochemical aptasensor for ofloxacin. TiO 2 NTs: TiO 2 nanotube arrays; PDA: polydopamine; MCH: 6-mercapto-1-hexanol; OFL: ofloxacin; PEC: photoelectrochemistry; CB: conduction band; VB: valence band; LUMO: the lowest unoccupied molecular orbital; HOMO: the highest occupied molecular orbital; AA: ascorbic acid.
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高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 9
·5807-5819
·
IF 3.917
Fang Kuanjun,Xie Ruyi,Liu Xiuming,Zhao Gaojie,Han Dongmei,Chen Weichao,Shi Zhen,Hao Longyun,Cai Yuqing
Abstract The low utilization of dyestuff in textile coloration leads to serious environmental pollution and wasting of resources. Dye/polymer nanospheres have high absorbing, reflecting and scattering light properties due to the large specific surface area, the regular shape, and the uniform size. In the present study, we report the reactive dye/poly(styrene-butyl acrylate-trimethyl ammonium chloride) composite nanosphere as a highly efficient colorant for cationic cotton fabrics. The dye contents of the four colored nanospheres can reach to 217–404 mg/g. The hydration diameters of the composite nanospheres are 83–101 nm for four different reactive dyes. They have the negative zeta potentials, approximately − 25.3 to − 37.6 mV. The reactive dye/copolymer nanospheres exhibit much more powerful coloration ability for cotton fabrics and higher dye utilization than the ordinary reactive dyes. The color depths of cotton fabrics dyed with colored nanospheres are 2.8, 4.9, 10.6 and 4.2 times of the values of the corresponding dye colored samples. The dye/copolymer nanospheres have much larger color gamut than the ordinary dyes. The color durability and levelness of the dye/copolymer nanospheres on cotton fibers are good enough for practical applications. What’s more important is that the residual dye/copolymer nanospheres in the dye bath can be reused in the next dyeing process. This novel nanosphere dyeing method does not only save the colorants but also avoid the discharging of colored sewage. Graphical abstract The reactive dye/poly(St-BA-VBT) nanospheres were successfully fabricated by adding the cationic poly(St-BA-VBT) nanospheres dispersions into reactive dye solutions. This article offered a novel dyeing method for cotton fabrics using dye/poly(St-BA-VBT) nanospheres. These colored nanospheres can endow the cotton fabrics with good color performance and avoid the discharging of colored waste water, which provide a green way for textile coloration.
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高影响因子
Tungsten
·
2019
·Vol. 1
·期 1
·101-109
·
IF 0
Zhang Xiangyong,Fei Hao,Wu Zhuangzhi,Wang Dezhi
Tungsten disulfide (WS 2 ) has been considered as a promising hydrogen evolution reaction (HER) candidate due to its high activity, robust chemical stability, and earth-abundant resources. However, the inert basal planes and low electrical conductivity greatly hinder its development in HER. Increasingly, the density of active sites through the structural designing is one of the most effective strategies to enhance the HER performance. Herein, we report a facile one-step hydrothermal method for synthesizing flower-like WS 2 nanosheets for highly efficient HER. Besides, the effect of preparation temperature is also been discussed. The optimized WS 2 nanosheets exhibit the enhanced HER activity in strong acidic solutions with a low Tafel slope and a good stability. The improvement of the HER performance can be attributed to sheet-like nanostructures, which greatly increase the edge sites and defects, resulting in a high density of exposed active sites. Besides, these sheet-like nanostructures also can make the acidic electrolyte easily accessible to the surface of WS 2 and accelerate the electron transfer rate.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 5
·1-9
·
IF 5.479
Ren Hailong,Zhang Yang,Liu Longlong,Li Yangguang,Wang Dongyang,Zhang Ruyue,Zhang Wenjing,Li Yingchun,Ye Bang-Ce
Hollow molybdenum-dopamine spheres were synthesized and thermally annealed to form hollow Mo 2 C/C spheres. The morphology, composition and electrochemical behavior of spheres were characterized. A glassy carbon electrode (GCE) was modified with the spheres and then used for simultaneous detection of hydroquinone (HQ), catechol (CC), and resorcinol (RS). Distinct oxidation peaks can be observed for HQ, CC and RS at potentials of −0.004 V, 0.10 V and 0.44 V (vs. SCE). The responses to HQ, CC and RS are linear in the concentration ranges of 0.3~1000 μM, 2~2000 μM and 3~600 μM, respectively. The corresponding detection limits are 0.12, 0.19 and 1.1 μM (at S/ N = 3). The sensor was then applied to quantify HQ, CC, and RS in tap water, river water and vegetable juice. Recoveries ranged from 93.5% to 106.5%. The modified GCE is repeatable, reproducible, stable and selective for HQ, CC and RS.
Schematic presentation of a novel electrochemical sensor based on a glassy carbon electrode modified with hollow Mo 2 C/ carbon spheres for determination of hydroquinone, catechol, and resorcinol.
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高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2019
·Vol. 91
·期 2
·353-363
·
IF 1.986
Sun Xiaoxiao,Hu Dalin,Yang Li–Ye,Wang Nan,Wang Yang-Guang,Ouyang Xiao–kun
Abstract As a typical metal–organic framework material, UiO-66 has good potential for removing pharmaceuticals and personal care products from water. However, the application of this powdery adsorbent has been limited by the difficult recovery from the liquid. To overcome this weakness, we prepared composite beads constituted by sodium alginate and UiO-66 by solidification in CaCl 2 solution. The material was characterized by SEM, FTIR, XRD, BET, and TGA methods. These composite beads were applied to remove a common antibiotic Levofloxacin (LOFX) from water, and the experimental parameters (i.e., initial LOFX concentration, adsorption time, pH, and adsorbent dose) were optimized. The adsorption data could be satisfactorily fitted to the Langmuir isotherm model ( R 2 = 0.9871) and the pseudo-second-order kinetic model ( R 2 = 0.9990). The regeneration experiment of the composite beads revealed that the adsorption efficiency of levofloxacin was higher than 70% even after 5 cycles.
Scheme 1 Synthesis route of UiO-66/CA
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高影响因子
Silicon
·
2019
·Vol. 12
·期 3
·585-594
·
IF 1.21
Wang Qikun,Wang Yongqing,Chang Qibing,Liu Han,Yang Yulong,Zhang Xiaozhen
To obtain the ultrafine pigment for ink-jet printing, ultrafine spherical Pr-ZrSiO 4 pigment was prepared by sol-gel-microemulsion method (S-G-M). In the emulsion, ZrO 2 and SiO 2 sols are used as water phase, cyclohexane serves as oil phase, Triton X-100 and 1-hexanol are chosen as surfactant and co-surfactant, respectively. The results show that without the introduction of demulsifier, the sol/oil microemulsion system is demulsified automatically due to the transformation of liquid/liquid to solid/liquid interface following the transformation from sol to gel. The obtained Pr-ZrSiO 4 pigment owns uniform spherical particles with the average particle size of about 0.785 μm, which is suitable for the ink-jet printing. The CIE coordination of the pigment is L* = 87.63, a* = −3.82, b* = 65.68, which shows bright lemon yellow. Hence, the ultrafine pigment in this work has the good application prospects.
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高影响因子
危险品化学品经营许可证（带存储）