JOURNAL OF APPLIED POLYMER SCIENCE
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2020
·Vol. 137
·期 44
·49365
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IF 2.52
Xiaoqin Zhang,Shugang Ma,Ang Shen,Jin Zhu,Zhisen Shen,Jinggang Wang,Xiaoqing Liu
Poly(butylene terephthalate-co-butylene 2,5-furandicarboxylate) copolyesters (PBTFs) were synthesized from 1,4-butanediol, dimethyl terephthalate (DMT), and 2,5-furandicarboxylic acid (FDCA) by a two-step polymerization method. Their chemical structures were confirmed by Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and carbon nuclear magnetic resonance before thermal properties were explored with differential scanning calorimeter and thermogravimetric analyzer. Results showed that PBTFs changed from semi-crystalline to completely amorphous when the content of FDCA unit was increased to 45 mol% at first, and then became crystallographic again with the further increment of FDCA unit to 75 mol%. For their mechanical properties, the tensile modulus and strength showed the similar trend, decreasing firstly and then increasing later. Their barrier to carbon dioxide and oxygen became better with the increasing of furan content due to the rigidity and higher polarity of furan ring. The performance of PBTFs copolyesters was investigated clearly, and the relative content of FDCA and DMT can be adjusted to satisfy different performance requirements.
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DYES AND PIGMENTS
·
2020
·
IF 4.613
Yujiao Tu,Suping Wang,Xiaotian Yuan,Yingying Xiang,Kunhao Qin,Yunlin Wei,Qi Zhang,Xuemei Chen,Xiuling Ji
The blue fluorescent nitrogen, phosphorus doped carbon dots ( Tg N,P-CDs) deriving from Thelephora ganbajun Zang were successfully obtained by hydrothermal method . Tg N,P-CDs possessed excellent fluorescence features and displayed strong blue fluorescence emission at 444 nm under 356 excitation with good water solubility. Tg N,P-CDs exhibited low biotoxicity and excellent biocompatibility by live/dead bacterial differentiation, cell imaging and onion epidermal staining. Furthermore, the nanoprobes showed high selectivity and sensitivity in detecting 2,4-dinitrophenol (2,4-DNP) and 4-nitrophenol (4-NP), and excellent linear range of 0–50 μM (R 2 = 0.9923) and 0–50 μM (R 2 = 0.9926) with low detection limits of 35.09 nM and 78.62 nM for 2,4-DNP and 4-NP, respectively. The Tg N,P-CDs was successfully applied to determine 4-NP and 2,4-DNP in real water and soil samples. It revealed that the inner filter effect quenching mechanism dominated in quenching of Tg N,P-CDs fluorescent by 2,4-DNP and 4-NP. It provides a new insight on the bioimaging application and environmental pollutant detection.
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JOURNAL OF CHROMATOGRAPHY A
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2020
·
IF 4.049
Rong Liu,Qing Luo,Zhongqiu Liu,Lingzhi Gong
Liquid chromatography tandem mass spectrometry has been a widely used technique for quantifying oligonucleotides in biological samples. However, lack of simple and efficient sample cleanup approach remains a challenge. Our study aimed to evaluate the major factors during the sample pretreatment process for developing optimal sample preparation workflow for oligonucleotides. In this study, we have employed a model formed with rat plasma containing a 16 mer oligonucleotide standard in order to comprehensively optimize the sample preparation procedures. These included liquid-liquid extraction (LLE), solid-phase extraction (SPE), protein precipitation (PPT) and LLE combined with SPE. LLE with phenol: dichloromethane (2:1, v:v) was found to be the most efficient sample cleanup procedure with low cost and less toxicity. Followed by the extraction, ethanol precipitation (-80 °C, 5 min) was determined to be the optimal drying conditions. Also, mass spectrometric parameters were tuned to optimal conditions. It was found that the central composite design suite was proved to be highly practical for optimizing MS parameters. Finally, the thoroughly optimized sample preparation workflow was fully validated. The developed assay provided a quantitative range of 0.25–1000 nM, with accuracy and precision were < 7.45% and < 12.20%, respectively. Matrix effect and carryover were also evaluated and no significant effect was observed.
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RSC Advances
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2020
·Vol. 10
·期 42
·25402-25407
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IF 3.119
Xiaodong Lv,Peng Gao
Based on the electron-transfer mechanism between the template and quantum dots (QDs), an optical sensor was structured. It is a phenol sensor, which has the room-temperature phosphorescence (RTP) property of Mn-doped ZnS QDs and high selectivity of molecular imprinted polymers (MIPs). On the surface of the silane modified Mn-doped ZnS QDs, the phenol sensor was prepared by double cross-linker precipitation polymerization in the absence of any stabilizer and additive. Double cross-linkers, divinylbenzene (DVB) and ethyleneglycol dimethacrylate (EGDMA), make a great contribution to the imprinted polymerization with hydrogen-bonding interaction. Then, as a result of the functional monomer, methacrylic acid (MAA), a carboxylic acid was grafted onto the surface of ZnS QDs:Mn@MIPs. Under optimal conditions, the phenol determination experiment had a linear range of 5.0 to 55 μmol L−1 with a correlation coefficient of 0.9984, and a high imprinting factor (IF) of 3.43. In addition, the prepared ZnS QDs:Mn@MIPs were successfully used to detect phenol in real water samples. Therefore, this work provided a highly selective and sensitive RTP probe for phenol determination.
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EUROPEAN POLYMER JOURNAL
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2020
·
IF 3.862
Rui Xu,Bolong Li,Jiale Ding,Wei Li,Yunhe Zhang
Photoinduced electron transfer/energy transfer (PET/ET) plays a very important role in improving the nonlinear optical (NLO) response. AlPc-Aqn and HAlPc-Aqn with donor-acceptor (D-A) structure were prepared by grafting aluminum phthalocyanine (AlPc) and hyperbranched aluminum phthalocyanine (HAlPc) through anthraquinone axial covalent bonding. After the axial covalent connection, the formed D-A phthalocyanine materials enhance the PET/ET process between the phthalocyanine ring and the anthraquinone structure, which results in significant fluorescence quenching and effectively improves the material's NLO properties. The discrepancy of LUMO levels (ΔE) further confirms that both AlPc-Aqn and HAlPc-Aqn formed a D-A system. This effectively promotes the electron transfer between the anthraquinone and the phthalocyanine ring, performing enhanced NLO response. Furthermore, compared to AlPc-Aqn, the special three-dimensional structure of HAlPc-Aqn brings a more efficient PET/ET process and exhibits a larger nonlinear absorption coefficient.
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Journal of Material Cycles and Waste Management
·
2020
·Vol. 22
·期 5
·1639-1647
·
IF 1.974
Xu Yanmei,Xie Guangna,Bei Ke,Wang Liang,Wang Junliang,Chou I-Ming,Pan Zhiyan
Recycling of chemicals from waste plastics is important for the reutilization of resources and the reduction of environmental pollution. The phase behaviors of poly (1,4-cyclohexylene dimethylene terephthalate) (PCT) in water at different temperature and time were observed in a fused silica capillary reactor (FSCR) with a microscope. The effects of the reaction temperature (260−340 °C), the reaction time (30−90 min), and the mass ratio of water/PCT (6:1−14:1) on the degradation of PCT were studied in an autoclave reactor on the basis of the results obtained from the FSCR. Under our research conditions, depolymerization of both 1,4-cyclohexanedimethanol and terephthalic acid (TPA) generated mainly phenol, and the maximum yield of phenol was obtained at 340 °C after its reaction with a water/PCT mass ratio of 10:1 for 90 min. Moreover, a reaction mechanism of PCT degradation in subcritical water was proposed. Our results suggest that PCT can be depolymerized rapidly and completely in subcritical water to produce phenol, and this method is conducive to the recycling of waste PCT.
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ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2020
·
IF 7.864
Wenxiao Zheng,Liuyi Zhu,Sheng Liang,Jinshao Ye,Xin Yang,Zhenchao Lei,Zhang Yan,Yongdong Li,Chaohai Wei,Chunhua Feng
Inorganic constituents in real wastewater, such as halides and carbonates/bicarbonates, may have negative effects on the performance of electrochemical systems because of their capability of quenching HO•. However, we discovered that the presence of Cl– and HCO3– in an electrochemical system is conducive to the formation of ClO•, which plays an important role in promoting the simultaneous elimination of biorefractory organics and nitrogen in secondary coking wastewater effluent. The 6-h operation of the coupled electrochemical system (an undivided electrolytic cell with a PbO2/Ti anode and a Cu/Zn cathode) at a current density of 37.5 mA cm–2 allowed the removal of 87.8% of chemical oxygen demand (COD) and 86.5% of total nitrogen. The electron paramagnetic resonance results suggested the formation of ClO• in the system, and the probe experiments confirmed the predominance of ClO•, whose steady-state concentrations (8.08 × 10–13 M) were 16.4, 26.5, and 1609.5 times those of Cl2•– (4.92 × 10–14 M), HO• (3.05 × 10–14 M), and Cl• (5.02 × 10–16 M), respectively. The rate constant of COD removal and the Faradaic efficiency of anodic oxidation obtained with Cl– and HCO3– was linearly proportional to the natural logarithm of the ClO• concentration, and the specific energy consumption was inversely correlated to it, demonstrating the crucial role of ClO• in pollutant removal.
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JOURNAL OF HAZARDOUS MATERIALS
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2020
·
IF 9.038
Kejian Li,Xiaozhong Fang,Zhaoyang Fu,Yang Yang,Iqra Nabi,Yiqing Feng,Aziz-Ur-Rahim Bacha,Liwu Zhang
Sulfite is recently found to be promising in enhancing photocatalytic pollutants degradation, which is a byproduct from flue gas desulfuration process. Herein, 4-chlorophenol (4-CP) photodegradation was systematically investigated in a sulfite mediated system with g-C 3 N 4 as photocatalyst. The degradation efficacy was improved by about 3 times with addition of 25 mM Na 2 SO 3 . The dominant responsible reactive oxygen species for chlorophenols remediation in the presence of sulfite included O 2 ·− , SO 3 ·− , and SO 4 ·− as confirmed by radical quenching experiments and electron spin resonances technology. In-situ DRIFTs results indicated the improved cleavage of C Cl and C H bonds with the simultaneous formation of C O and C C bonds when bisulfite was added. Degradation intermediates such as 4-chlorocatechol, hydroquinone, and muconic acid were detected by HPLC-MS. Furthermore, the photodegradation mechanisms of 4-CP were tentatively discussed . Other chlorophenols (phenol, 2-CP, 2,4-DCP, and their mixture) were also efficiently removed in the system, suggesting that sulfite could be universally applied in photocatalytic wastewater purification.
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Processes
·
2020
·Vol. 8
·期 9
·1021
·
IF 2.753
Daiyin Yin,Shuang Song,Qi Xu,Kai Liu
The matrix/fracture conductivity of a fractured low-permeability reservoir is variable, and its heterogeneity is serious. When carrying out deep profile control measures, it is difficult to inject under the premise of ensuring the plugging effect. According to the characteristics of the fractured low-permeability reservoir in Chaoyanggou Oilfield, the polymer/chromium ion deep profile control system was optimized via a viscosity evaluation experiment, liquidity experiment and oil displacement experiment. The experimental results show that the high molecular weight main agent/low concentration system and low molecular weight main agent/high concentration system can meet the gel strength requirement. The evaluation results of the injection ability and plugging performance of the fractured low-permeability core show that a high molecular weight profile control system is difficult to inject, while a low molecular weight profile control system has a poor plugging performance and high cost after simulated shear. Therefore, the formulation of the profile control system was determined to be a polymer with a molecular weight of 16 million g·mol−1as the main agent with a concentration of 1000–1500 mg·L−1. As assisting agents, the concentrations of thiourea, NaCl and NaHCO3were 900 mg·L−1, 800 mg·L−1and 700 mg·L−1, respectively. The plugging rate of the system was 87.6%, and the resistance coefficient was 19.2. Finally, a fractured low-permeability core model with parallel long cores was designed, and the optimal profile control system was used for the core oil-displacement experiment. Compared with the water-flooding experiment, the plugging rate can be increased by 6.9–8.0%.Keywords:fractured low-permeability reservoirs;polymer/chromium-ion;deep profile control system
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Nanomaterials
·
2020
·Vol. 10
·期 9
·1703
·
IF 4.324
Xiaomeng Yang,Xiaorui Zeng,Guihong Han,Dong Sui,Xiangyu Song,Yongsheng Zhang
The growing demand for high performance from supercapacitors has inspired the development of porous nanocomposites using renewable and naturally available materials. In this work, a formaldehyde-free phenolic resin using monosaccharide-based furfural was synthesized to act as the carbon precursor. One dimensional halloysite nanotube (HNT) with high porosity and excellent cation/anion exchange capacity was mixed with the phenol-furfural resin to fabricate carbonaceous nanocomposite HNT/C. Their structure and porosity were characterized. The effects of the halloysite nanotube amount and carbonization temperature on the electrochemical properties of HNT/C were explored. HNT/C exhibited rich porosity, involving a large specific surface area 253 m2·g−1with a total pore volume of 0.27 cm3·g−1. The electrochemical performance of HNT/C was characterized in the three-electrode system and showed enhanced specific capacitance of 146 F·g−1at 0.2 A g−1(68 F·g−1for pristine carbon) in electrolyte (6 mol·L−1KOH) and a good rate capability of 62% at 3 A g−1. It also displayed excellent cycle performance with capacitance retention of 98.5% after 500 cycles. The symmetric supercapacitors with HNT/C-1:1.5-800 electrodes were fabricated, exhibiting a high energy density of 20.28 Wh·Kg−1at a power density of 100 W·Kg−1in 1 M Na2SO4electrolyte. The present work provides a feasible method for preparing composite electrode materials with a porous structure from renewable phenol-furfural resin and HNT. The excellent supercapacitance highlights the potential applications of HNT/C in energy storage.Keywords:halloysite nanotube;phenol-furfural resin;composite porous carbon;supercapacitors
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ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Yumei Qin,Zhaoyang Ding,Wenwei Guo,Xiaolu Guo,Cheng Hou,Bang-Ping Jiang,Chun-Guang Liu,Xing-Can Shen
The utilization of diffusive solar energy through photocatalytic processes has received tremendous attention. Herein, a full-solar-spectrum photocatalyst with strong near-infrared (NIR) photoactivity, which is based on the synergy of oxygen vacancies (OVs) and doped boron that is cointegrated into zirconia (B@ZrO2–OV), is designed in this work. The doped photocatalyst is prepared via a controlled one-step NaBH4 reduction from white ZrO2. Density functional theory (DFT) calculations reveal that simultaneously introduced OVs and boron dopants on ZrO2 induced a narrow band gap (4.78 eV) and achieved charge separation (work function of 4.12 eV), thus confirming its excellent photocatalytic activity in the degradation of rhodamine B under NIR irradiation. In contrast, oxygen-deficient ZrO2 and white ZrO2 were inactive under NIR light. Therefore, this synergistic strategy provides an efficient way to use the narrow band gap of a classic semiconductor zirconia as a highly efficient catalyst for full-solar-spectrum-driven photocatalysis.
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WATER RESEARCH
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2020
·
IF 9.13
Jun Wang,Xiaoguang Duan,Jian Gao,Yi Shen,Xiaohui Feng,Zijun Yu,Xiaoyao Tan,Shaomin Liu,Shaobin Wang
A rational design of structure-tailored and functionalized nanocarbons for peroxymonosulfate (PMS) activation is important in metal-free catalysis for degradation of water contaminants. In this work, we employed ionic liquids (ILs) for synthesis of porous carbon materials (PCMs) as a PMS activator for oxidative removal of naproxen and systematically investigated the functions of structure defects, oxygen functional groups and heteroatom doping toward the catalytic oxidation. A positive linear correlation between reaction rate constants and carbon defect ratios of PCMs revealed that the structural defects played an important role in PMS activation. Electron paramagnetic resonance (EPR) spectra, radical quenching experiments and electrochemical analysis tests verified nonradical-dominated oxidations via electron transfer and 1 O 2 . Structural vacancies, ketonic C=O groups and graphitic-N atoms on carbons have been revealed to be the active sites for the nonradical pathways via direct electron transfer or generation of O 2 •− / 1 O 2 . This work provides new insight into the reaction mechanism and structure-performance relationships of the catalytic centers in nonradical oxidation.
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危险品化学品经营许可证（带存储）