HIGH PERFORMANCE POLYMERS
·
2022
·
IF 1.73
Xiankun Wu,Chang-an Xu,Mangeng Lu,Xiaole Zheng,Yingjie Zhan,Bifang Chen,Kunxin Wang,Huifa Meng
To explore thermal and mechanical properties of epoxy material, difunctional aromatic epoxy--divinylbenzene dioxide (DVBDO) had been synthesized by epoxidizing divinylbenzene, using the metal acetylacetone compound grafted Fe3O4 particles as the catalyst. The catalyet had high conversion and epoxy selectivity and could be recyclable. Then the polymerization of DVBDO with different diamine curing agents were reported. The structure and viscosity of DVBDO were firstly characterized. Because it had low molecular weight and viscosity, DVBDO had excellent liquidity and formability. Subsequently to clarify the properties of epoxy thermosets, experiments to determine thermal and mechanical performances were carried out, such as differential scanning calorimetry (DSC), thermal gravimetric (TGA), dynamic mechanical analysis (DMA) and tensile test. It could be observed that the thermoset polymers using DVBDO as epoxy matrix had excellent thermal (Tg was about 201°C) and mechanical properties (tensile strength was 131.99Mpa). Possibly considering that this kind of thermoset polymers had higher rigidity and crosslink density. In conclusion, a new type of one-component liquid epoxy encapsulant material with low viscosity, good filling fluidity, strong heat resistance and excellent storage performance had been developed.
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APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2021
·Vol. 105
·期 16
·6333-6343
·
IF 4.813
Wang Wei,An Chunyan,Yao Yongpeng,Meng Xiangxi,Gao Shu-Shan
The industrially important meta -cresol ( m -cresol, 3-methylphenol) is mainly produced from fossil resources by chemical methods. The microbial production of m -cresol was rarely investigated. Herein, we constructed a platform for the overproduction of m -cresol in a modified fungus Aspergillus nidulans FGSC no. A1145 ∆ST∆EM , which gave a gram-level titer using starch as carbon resource. For the biosynthesis of m -cresol, the 6-methyl salicylic acid synthase (MSAS)-encoding gene patK and 6-methyl salicylic acid decarboxylase-encoding gene patG from A. clavatus were co-expressed in the host A. nidulans . Multiple strategies, including promotor engineering, gene multiplication, and fed-batch fermentation, were applied to raise the production of m -cresol, which resulted in the titers of 1.29 g/L in shaking flasks and 2.03 g/L in fed-batch culture. The chassis cell A. nidulans A1145 ∆ST∆EM was proved to possess better tolerance to m -cresol than yeast, as it could grow in the liquid medium containing up to 2.5 g/L of m -cresol. These results showed that A. nidulans has great potential to be further engineered for industrial production of m -cresol.
Key points
• m-Cresol was de novo biosynthesized by a fungal chassis cell Aspergillus nidulans.
• Promoter engineering and gene multiplication implemented the fine-tuned genes expression.
• The titer of m-cresol reached 2.03 g/L via fed-batch culture.
Graphical abstract
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NANOTECHNOLOGY
·
2021
·Vol. 33
·期 7
·075705
·
IF 3.874
Jie Zhang,Yuying Zheng
Graphene (G) is regarded as a tremendous potential corrosion protection material owing to its perfect impermeability. However, the tendency of graphene nanosheets to agglomerate and the corrosion-promotion effect brought by its native high electrical conductivity seriously affect its anti-corrosion application. In this paper, high-energy ball milling was used to prepare graphene with excellent impermeability. Then, insulating poly(m-phenylenediamine) encapsulated graphene (G@PmPD, conductivity of 1.2 × 10−7 S cm−1) was prepared through non-covalent π–π interaction. The resulting amino-rich G@PmPD exhibits stable dispersibility and excellent compatibility in organic solvents and polymer matrix. Embedding 0.5 wt% of G@PmPD into the epoxy matrix, and the composite coating can effectively protect the steel substrate for up to 60 d. This superior corrosion resistance is attributed to the impermeability inherited by G@PmPD and the compactness improved by the cross-linking of G@PmPD and EP. Especially in the damaged state, the composite coating embedded with low conductivity G@PmPD triumphantly eliminated graphene's corrosion-promotion effect. This study provides promising inspiration for the application of graphene in anti-corrosion field.
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高影响因子
JOURNAL OF THERMAL SPRAY TECHNOLOGY
·
2021
·Vol. 30
·期 4
·873-885
·
IF 2.757
Ye Fuxing,Yang Wenqi,Yan Shuai,Yu Jianxing
CMAS corrosion is one of the significant failure mechanisms for thermal barrier coatings (TBCs). In this work, the corrosion behaviors and wettability of CMAS on M-YTaO 4 at 1350 °C are studied to evaluate the M-YTaO4 ceramics’ potential to replace YSZ. The results show that the contact angles of CMAS on M-YTaO 4 with different time (1 min, 0.5 h, 4 h, 10 h and 24 h) are around 14.3° (14.4°14.4°, 14.4°, 14.3° and 14.2°, respectively), and larger than that on YSZ (8.0°, 1 min), which means the wettability of CMAS on M-YTaO 4 is worse than that on YSZ and which is benefit to improve its corrosion resistance. The thickness of reaction layer is increasing with elapsed time, but the increasing rate is decreased, and the maximum reaction thickness is 31.42 μm at 24 h. There are four main phases after reaction, which are M-YTaO 4 , M’-YTaO 4 , Ca 2 Ta 2 O 7 and Y 2 Si 2 O 7 . For the effects of lattice distortion and thermodynamics reason, M’-YTaO 4 can retain steadily at room temperature. Besides, the chemical reaction process between CMAS and yttrium tantalite is also be discussed.
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Inorganic Chemistry Frontiers
·
2020
·Vol. 8
·期 6
·1468-1475
·
IF 5.958
Ying Hou,Bingbing Zhang,Hongping Wu,Hongwei Yu,Zhanggui Hu,Jiyang Wang,Yicheng Wu
Borophosphates are of current interest and great importance as ultraviolet (UV) and deep-UV optical functional materials. However, most of the borophosphates exclusively contain tetrahedral coordination of B and P atoms, i.e. BO4 and PO4. Few compounds contain mixed-coordinated groups, i.e. BO4, BO3 and PO4. A new strategy of large B/P ratios has been suggested to effectively synthesize three mixed-coordinated borophosphates, K3B4PO10 and K2MB4PO10 (M = Rb/Cs). Their structures all show 2D 2∞[B4PO10]3− sheets, which are separated by the alkali metal cations. The thermal behavior measurements indicate that K3B4PO10 and K2MB4PO10 (M = Rb/Cs) melt congruently and a crystal of K3B4PO10 with a size up to 4 × 2 × 1 mm3 has been grown. Property measurements show that they all possess deep-ultraviolet (UV) cut-off edges and a relatively large birefringence and are potential deep-UV birefringent crystals. In particular, the measured birefringence of K3B4PO10 is about 0.0445@532 nm, which is the largest in borophosphates with reported birefringence. This study indicates that B-rich borophosphates are promising systems to synthesize materials with large birefringence.
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APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Huiqin Wang,Jingru Guan,Jinze Li,Xin Li,Changchang Ma,Pengwei Huo,Yongsheng Yan
In this work, the ordered mesoporous CeO 2 (m-CeO 2 ) was successfully fabricated via the nanocasting pathway, through using SBA-15 as a hard template. Besides, g-C 3 N 4 /Ag/m-CeO 2 composite was successfully constructed by calcination method. Meanwhile, the obtained samples were investigated by series of test techniques. The XRD, SEM and TEM results show that the m-CeO 2 and Ag/m-CeO 2 with the ordered mesoporous trait. Besides, the EPR, Raman and XPS results suggest that the oxygen vacancies (O v ) and Ce 3+ and Ce 4+ are in g-C 3 N 4 /Ag/m-CeO 2 . In addition, the ordered mesostructure is favorable for the CO 2 molecular movement and adsorption/desorption reaction. The g-C 3 N 4 nanosheets, a promising material possessing suitable conductor band, large specific area, non-toxicity, and outstanding chemical stability, is a candidate semiconductor for CO 2 conversion. The introduction of g-C 3 N 4 nanosheets to Ag/m-CeO 2 overcomes the photocorrosion of Ag nanoparticles and Ag facilitate the transfer of photogenerated electrons. The photocatalytic activity results show that when the loading of Ag is 7 wt%, the g-C 3 N 4 /7Ag/m-CeO 2 composite exhibits the superiority activity for CO 2 photoconversion to CO (13.94 μmol/g) and CH 4 (7.39 μmol/g) under UV-irradiation in 10 h.
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DALTON TRANSACTIONS
·
2016
·Vol. 45
·期 16
·7124-7130
·
IF 4.177
Li-Jun Zhang,Yan-Yan Li,Peng-Fei Liu,Ling Chen
New borophosphates Li3Cs2M2B3P6O24 (M = Pb, Sr) have been synthesized by high-temperature solid-state reactions. The single-crystal X-ray diffraction data reveal their non-centrosymmetric cubic space group P213 and lattice parameters of a = 12.7246(3) Å and 12.687(2) Å and V = 2060.31(8) Å3 and 2042.3(4) Å3 for Li3Cs2Pb2B3P6O24 and Li3Cs2Sr2B3P6O24, respectively. They are three-dimensional (3D) [BP2O8]3−∞ anionic frameworks formed by a new double six-membered ring building unit consisting of BO4 and PO4 units joined alternately. Interestingly, such a double six-membered ring is regarded as the structural variation of the 12-membered ring in the known KSrBP2O8, fusing at the BO4 tetrahedron induced by the coexistence of the Li+ and Cs+ cations with their large size difference. The title compounds show weak SHG intensity and exhibit photoluminescence emissions at 410 nm for Li3Cs2Pb2B3P6O24 and 440 nm for Li3Cs2Sr2B3P6O24.
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JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2015
·
IF 3.615
Yansheng Liu,Bo Qiao,Xinlin Li,Xuanduong Le,Wei Zhang,Jiantai Ma
Palladium metal nanoparticles have been applied to hydrodechlorination of chlorophenols in contaminated water using H 2 as a clean and sustainable reductant. However, there are two major challenges to widespread technology adoption which are the activity loss caused by nanoparticle aggregation and the difficulty of nanoparticle recovery. In this study, a synthesis of a core-shell structured catalyst with encapsulated Pd nanoparticles has been given and whose catalytic activity has been tested in hydrodechlorination of chlorophenols under 1 atm H 2 at room temperature. The catalyst material consists of a nonporous silica core decorated with Pd nanoparticles that are further encapsulated within an ordered mesoporous silica shell. Well-defined mesopores (2.4 nm) provide a physical barrier to prevent Pd nanoparticle (∼10 nm) movement, aggregation and detachment from the support into water. Compared with some supported Pd catalysts such as Pd/AC and Pd/Al 2 O 3, SiO 2 /Pd@m-SiO 2 exhibits higher catalytic performance. After 5 times of recycling, catalytic activity of SiO 2 /Pd@m-SiO 2 reduces slightly and this result confirms the good recyclability of SiO 2 /Pd@m-SiO 2 . The function of the mesoporous shell, preventing aggregation of active nanoparticles, suggests a promising general strategy of using metal nanoparticle catalysts for water purification and related aqueous-phase applications.
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Analytical Methods
·
2014
·Vol. 7
·期 3
·1133-1139
·
IF 1.938
Zhengyu Yan,Yan Yu,Jianqiu Chen
A novel sensing system has been designed for the detection of m-phenylenediamine based on carbon quantum dots (CQDs)-improved chemiluminescence (CL) in a luminol–potassium permanganate (KMnO4) system. The CQDs were synthesized by pyrolyzing a mixture of citric acid (CA) and glycine (Gly). Under the action of CQDs and KMnO4, the luminol can be oxidized by synergy, which significantly increases the chemiluminescence intensity. In this work, it has been demonstrated that this facile methodology can offer a rapid, sensitive and reliable detection of m-phenylenediamine with a detection limit as low as 1.02 × 10−3 g L−1 and a dynamic range from 2.0 × 10−3 to 3.0 × 10−1 g L−1, which shows a promising application prospect.
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Xiaotong Wang,Qingling Zhao,Qinghong Song,He Bu,Jie Gao,Lanlan Li,Xiaofei Yu,Xiaojing Yang,Zunming Lu,Xinghua Zhang
Carbon dots (CDs) possess the merits such as energy efficiency, green sustainability and environmental friendliness, comparing with top-down synthesis methods at higher pressure or temperature condition. Here, a variety of emission states CDs were prepared by using the method of room temperature chemistry by selecting green raw materials such as glucose, p-phthalaldehyde and m-diethylaminophenol. The luminescence mechanism was studied in detail. The luminescent center of blue emitting carbon dots (B-CDs) and green emitting carbon dots (G-CDs) is C O bond, and the increased contents of C O bond lead to the creation of new energy levels between the energy gaps of HOMO and LUMO levels, which results in the red shift of luminescence wavelength. The emission state of red emitting carbon dots (R-CDs) is due to the formation of amino N. In addition, R-CDs have an exclusive respond to dopamine (DA) and are regarded as good fluorescent probes for detecting DA. Furthermore, the addition of ascorbic acid (AA) restores the luminescence of R-CDs quenched by DA. Therefore, R-CDs has great application potential as a selective fluorescent “turn on-off” probe.
研究领域:
化学
·
生物分析
·
材料科学
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Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Yanjie Niu,Hongguan Wang,Sixi Guo,Jie Xu,Yingkun Zhu,Fanhui Guo,Yixin Zhang,Jianjun Wu
Coal gasification fine slag is typical coal-based solid waste, and the crux to its resource utilization is the co-utilization of carbon and ash. A novel iron-doped mineral and carbon composite electrocatalyst (Fe-FSAPH) was synthesized by depolymerizing and reconstituting the ash phase for the collaborative electrocatalytic degradation of m -cresol wastewater. Exogenous iron participated in and promoted mineral reconstitution, increasing Si(-O)1/Si(-O)3 ratio (0.37→1.18) and promoting the formation of active Si-OH groups. The iron-doped minerals dispersedly developed with a sheet-like on carbon matrix, which improved intimate physical proximity and synergistic behavior of carbon/minerals. The obtained Fe-FSAPH, with a specific surface area of 246.52 m 2 /g, has a large diffusion rate constant K D2 (2.98 mg·min −0.5 /g) in the rate-limiting step of m -cresol adsorption. Its electrochemical performances exhibit excellent, including cyclic voltammetry charge of 8.52 mC/cm 3 , charge-transfer resistance of 0.59 Ω, and Tafel slope of 159 mV/dec. The m -cresol with a concentration of 194.67 mg/L could be electrooxidized within 18 min due to the abundance of •OH and O 2 •- in the Fe-FSAPH system, which accelerated the radical attack reaction. Moreover, Si-OH groups catalyzed conversion of •OH to O 2 •- by generating oxygen vacancies and undergoing dehydroxylation, shortening the rapid reaction time of m -cresol removal to 14 min. The introduction of iron enhanced the synergy of carbon and minerals, with •OH generated via the Fenton-like reaction, offering a convenient environment for mineral catalysis. Hence, the study provided new ideas for the comprehensive utilization of carbon and ash and treatment of waste by waste.
研究领域:
环境科学
·
材料科学
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POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Tinghao Wu,Yingqi Gu,Dong Zhao,Guodong Jiang,Tingwei Wang,Yucai Shen
Paper-based materials have become increasingly prevalent in the packaging and daily life. However, paper is flammable and hydrophilic, hindering its widespread application. Here, a novel reactive flame retardant of m-xylylenediamine phytate ammonium (MPAP) was prepared. Cellulose paper with superior flame-retardant and hydrophobic properties was successfully prepared by surface spraying technology and impregnation process, through the reaction of flame retardant and poly(methylhydrosiloxane) (PMHS) with cellulose fibers. The water contact angle (WCA) of the modified paper was 122.6°, while the limit oxygen index (LOI) value reached 41 %, which had significant self-extinguishing performance. The total heat release rate of the modified paper was reduced from 12.8 kJ/g to 0.6 kJ/g. The modified paper also exhibited excellent performance for oil/water separation. Furthermore, this effective and simple strategy can also be applied to other cellulose-contained substrates for the application in construction, textiles, furniture and other fields.
研究领域:
材料科学
·
化学工程
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危险品化学品经营许可证（带存储）