RSC Advances
·
2015
·Vol. 5
·期 77
·63044-63049
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IF 3.84
Hualei Hu,Jinghui Lyu,Jie Cen,Qunfeng Zhang,Qingtao Wang,Wenwen Han,Jiayao Rui,Xiaonian Li
The effect of MgO and Pd modification on the catalytic performance of hierarchical porous ZSM-5 for benzene alkylation with methanol was investigated. The results indicated that the introduction of MgO could reduce the Brönsted acid sites which suppressed the side reaction of methanol to olefins and in turn effectively promoted the alkylation of benzene. However, the single modification of MgO could not completely suppress the formation of ethylbenzene and coke. Doping a small amount of Pd had a positive effect on inhibiting the generation of ethylbenzene and coke, which could be attributed to the hydrogenation of ethylene into ethane on Pd. The dual modified catalyst (MgO and Pd) exhibited high benzene conversion (56%) and xylene selectivity (39.1%), and the lowest ethylbenzene selectivity (0.13%) and coke content (0.4 wt%).
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RSC Advances
·
2015
·Vol. 5
·期 78
·63330-63337
·
IF 3.84
Yang Ding,Qiong Wu,Kangdi Zheng,Linkun An,Xiaoying Hu,Wenjie Mei
Two novel ruthenium(II) complexes coordinated with 6-chloro-5-hydroxylpyrido[3,2-a]phenazine (CQM), [Ru(L)2(CQM)]ClO4 [L = 1,10-phenanthroline, (1) and 2,2′-bipyridine, (2)], were investigated as potential fluorescent probes to track dynamic changes in the nuclei of living cells. Confocal laser technology was used to observe their co-location inside the cells. The results showed that both complexes were taken up by HepG2 cells, especially 1, which was localized in the cell nuclei, whereas 2 was distributed in the cell nuclei and mitochondria. Further studies by real-time fluorescence observations revealed that 1 rapidly entered the living cells, namely, HepG2, HeLa and MCF-7 cells, imaged the dynamic changes of the nuclei of living tumor cells, and exhibited low toxicity toward cells. The results demonstrated that 1 may be developed into a novel fluorescent probe for living cell nuclei. This study facilitates the development of fluorescent chemosensors with metal complexes.
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JOURNAL OF COORDINATION CHEMISTRY
·
2015
·
IF 2.012
Yan Xie,Junjie He,Tingting Wang,Heping Zeng
Reactions of Zn(II) salts, 5-(4-(1H-imidazol-1-yl)phenyl)-1H-tetrazolate (HIPT) and 2-mercaptobenzoic acid or 2-propyl-1H-imidazole-4,5-dicarboxylic acid (H3PrIDC), result in two mixed-ligand coordination polymers (CPs), [Zn2(IPT)(DSDB)(OH)]n (H2DSDB = 2,2′-disulfanediyldibenzoic acid, 1) and [Zn2(IPT)(PrIDC)(H2O)]n (H3PrIDC = 2-propyl-1H-imidazole-4,5-dicarboxylic acid, 2). Compound 1 possesses a 2-D structure built by 1-D [Zn(IPT)]n chains and DSDB2− connectors, in which the DSDB2− is generated via in situ reaction from 2-mercaptobenzoic acid. It displays a new intricate 4-nodal {3·4·6·7·8·9}{3·6·7·8·9·10}{3·8·9}{4·6·8} topology. Compound 2 displays a 3-D framework with new 3-connected topology with Schläfli symbol of (4·8·10) (8·122), in which the 1-D Zn-carboxylate chains were bridged by 3-connected IPT− ligands. The thermal stabilities and luminescence properties of 1 and 2 have also been studied. The compounds exhibit intense solid-state fluorescent emissions at room temperature.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhanyu Qian,Yinghao Wu,Wenjie Zhao
Glass fiber reinforced polymer coatings (GFRPC) are used to protect steel structures in harsh marine environments due to high mechanical strength and chemical stability. The composite coating not only suffers from impact damage by seawater and sediment but also experiences corrosion damage in the splash zone. However, the GF has weak interfacial adhesion with polymer resins due to the chemical inertia and smooth surface, which limits the service lifespan of GFPRC. Hence, ZSM-5 zeolite were in situ prepared on the surface of glass fibers by hydrothermal synthesis, and 2-mercaptobenzimidazole (MBI) was further adsorbed to obtain difunctional hybrid glass fibers (ZGFM) to enhance the interfacial adhesion strength of glass fiber/resin and also the erosion resistance and anti-corrosion ability of composite coatings. Compared to GF/EP, the interfacial shear strength of ZGFM/EP was increased by 104.39 %. After immersion under an alternating hydrostatic pressure of 20 MPa for 12 days, the impedance value of the ZGFM/EP composite coating remained at 6.40 × 10 9 Ω•cm 2 , demonstrating outstanding deep-sea anti-corrosion performance. Following the erosion test, the ZGFM/EP exhibited a reduction in mass loss and volume loss by 10.65 % and 12.55 %, respectively, in comparison to the pure EP coating. The excellent interfacial strength between ZGFM and EP ensured effective stress transfer, which prevented crack propagation, thus enhancing the mechanical properties and erosion resistance of the composite coating. Meanwhile, electrochemical experiment proves glass fiber with MBI loaded obviously inhibits the corrosion reaction.
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CHINESE CHEMICAL LETTERS
·
2017
·
IF 1.932
Muhammad Ammar,Yan Cao,Peng He,Li-Guo Wang,Jia-Qiang Chen,Hui-Quan Li
A set of mono- and bimetallic (Zn-Co) supported ZSM-5 catalysts was first prepared by PEG-additive method. The physicochemical properties of the catalysts were investigated by FTIR, XPS, XRD, N 2 adsorption-desorption measurements, SEM, EDS and NH 3 -TPD techniques. The physicochemical properties showed that the ZnCo 2 O 4 spinel oxide was formed on the ZSM-5 support and provided effectual synergetic effect between Zn and Co species for the bimetallic catalyst. Furthermore, bimetallic supported ZSM-5 catalyst exhibited weak, moderate and strong acidic sites, while the monometallic supported ZSM-5 catalyst showed only weak and moderate or strong acidic sites. Their catalytic performances for thermal decomposition of hexamethylene–1,6–dicarbamate (HDC) to hexamethylene–1,6–diisocyanate (HDI) were then studied. It was found that the bimetallic supported ZSM-5 catalysts, especially Zn-2Co/ZSM-5 catalyst showed excellent catalytic performance due to the good synergetic effect between Co and Zn species, which provided a suitable contribution of acidic sites. HDC conversion of 100% with HDI selectivity of 91.2% and by-products selectivity of 1.3% could be achieved within short reaction time of 2.5 h over Zn-2Co/ZSM-5 catalyst.
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RSC Advances
·
2016
·Vol. 6
·期 97
·94976-94988
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IF 3.289
Longfei Liao,Ying Liu,Zengyong Li,Junping Zhuang,Yanbin Zhou,Size Chen
Amino modified Fe3O4@SiO2 (Fe3O4@SiO2–NH2) was used to immobilize Cu2+ and VO2+ for preparing Fe3O4@SiO2–NH2–Cu2+ and Fe3O4@SiO2–NH2–VO2+ catalysts. Various technologies had been used for the characteristics of catalysts, such as XRD, XPS, FT-IR, SEM, TEM and VSM. The catalytic performance of Fe3O4@SiO2–NH2–VO2+ in HMF oxidation could be significantly enhanced by the use of Fe3O4@SiO2–NH2–Cu2+ as the co-catalysts. The type of reaction solvents showed a great influence on the oxidation of HMF. The highest HMF conversion reached up to 98.7% at 110 °C in toluene with an optimal 2,5-diformylfuran yield of 85.5%. Moreover, the Fe3O4@SiO2–NH2–Cu2+ and Fe3O4@SiO2–NH2–VO2+ catalyst exhibited great stability and could be readily applied in the next recycle after magnetic separation.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2017
·
IF 2.843
Changsheng Zhang,Qinming Wu,Chi Lei,Shuxiang Pan,Chaoqun Bian,Liang Wang,Xiangju Meng,Feng-Shou Xiao
Large crystalline particles of ZSM-5 zeolites (S-ZSM-5) have been successfully synthesized by adjusting crystallization time and Si/Al ratios in the starting solid mixtures in the absence of water solvent. Catalytic tests in the methanol-to-olefins (MTO) reaction show that these S-ZSM-5 zeolites obtained from the solvent-free route exhibit superior catalytic properties including excellent propylene selectivity and extraordinarily long life in the MTO reaction. Particularly, when the crystallization time is 30 h and the Si/Al ratio in the starting solid mixture is adjusted at 150 under the solvent-free conditions, the S-ZSM-5-30h-150 catalyst with the large particle sizes (10–20 μm) gives propylene selectivity as high as 50.0% and catalyst life as long as 9 h, which are much better than those (propylene selectivity at 38.9% and catalyst life of 3 h) of the conventional ZSM-5 zeolite with smaller crystals (ca. 5 μm) synthesized from the hydrothermal route. High-resolution TEM images of these S-ZSM-5 zeolites demonstrate that there is mesoporosity in the samples. More interestingly, these mesopore size distributions could be adjusted by the crystallization time during the solvent-free synthesis. Obviously, the presence of mesoporosity is very favorable for the mass transfer, and an appropriate Si/Al ratio in the zeolite framework could offer suitable acidic density for the catalytic conversion, which should be responsible for the superior catalytic properties in the MTO over the S-ZSM-5-30h-150 catalyst. The features of mesoporosity in the S-ZSM-5 crystals and sustainability for the solvent-free synthesis could be potentially important for wide applications of these S-ZSM-5 zeolites in the future.
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Nanoscale
·
2016
·Vol. 8
·期 46
·19270-19279
·
IF 7.76
Zheng Zhang,Yunsheng Chen,Heng Xu,Yan Wo,Zhen Zhang,Ying Liu,Weijie Su,Daxiang Cui,Yixin Zhang
Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) is an alternative therapy for hypertrophic scars (HS), which destroys human hypertrophic scar fibroblasts (HSF). However, the poor permeability of ALA both in HS tissue and HSF significantly restricts the PDT of HS. To overcome these barriers, ALA-loaded ethosomal vesicles (ALA-ES) were developed by a pH gradient active loading method and characterized by morphology, entrapment efficiency (EE) and stability. Results show that prepared ALA-ES are homogenous spherical lamellar vesicles, 53 ± 7 nm in size, 50.6 ± 2.3% in EE and have excellent stability. In vitro transdermal delivery studies through HS tissue were carried out by using Franz diffusion cells. Compared to the traditional ALA hydroalcoholic solution (ALA-HA), ALA-ES achieve higher drug retention in less administration time, and fluorescence microscopy showed that ALA-ES penetrate into the deeper dermis of HS in a shorter time, indicating that ALA-ES can enhance the penetration of ALA into HS. Additionally, ALA-ES was visualized in HS tissue for the first time by transmission electron microscopy (TEM). The irregular and collapsed ALA-ES suggest that they can squeeze through narrow spaces to the target area and release ALA into HS. Taking HSF as the target, the transcellular delivery of ALA-ES into HSF cells was investigated by intracellular protoporphyrin IX (PpIX) accumulation. The efficiency of PDT for HSF cells, including the formation of reactive oxygen species (ROS) and cell apoptosis, were also well investigated. Furthermore, the detailed changes of HSF were observed by TEM. The results strongly indicate that ALA-ES can facilitate ALA penetration into HSF cells, and can cause a higher level of cell apoptosis or necrosis than ALA-HA. ALA-ES with high EE is therefore a promising transdermal delivery system for topical ALA administration and has great potential in ALA-PDT of HS.
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JOURNAL OF MOLECULAR LIQUIDS
·
2016
·
IF 2.74
Jiang Xiao,Yongzhong Jia,Chenglong Shi,Xingquan Wang,Ying Yao,Yan Jing
A novel liquid–liquid extraction system was investigated for the selective separation of lithium isotopes using ionic liquids (ILs = [C 6,8,10,12 mim] + [PF 6 ] - ) as extraction solvent and benzo-15-crown-5 (B15C5) as extractant. The effects of the concentration of lithium salt , counter anion of lithium salt, initial pH of aqueous phase, and extraction temperature on the lithium isotopes separation were studied. The maximum single-stage separation factor α of 6 Li/ 7 Li obtained in the present study was 1.038 ± 0.002, indicating the lighter isotope 6 Li was enriched in organic phase while the heavier isotope 7 Li was concentrated in the aqueous phase. The formation of 2:1 complex Li(B15C5) 2 + in the IL phase was determined on the basis of slope analysis method. The large value of the free energy change (− G 0 = 77.87 J mol −1 ) indicated the high separation capability of the lithium isotopes by B15C5/30%CH 3 Cl-70% C 6 mimPF 6 mixture extraction system. Lithium in Li(B15C5) 2 + complex was stripped by 0.5 mol·L −1 HCl solution. The extraction system offers high efficiency, simplicity application prospect to separation lithium isotope separation from LiCl solution.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2016
·Vol. 408
·期 27
·7595-7605
·
IF 3.125
Bo Chunmiao,Wang Chaozhan,Wei Yinmao
Immobilized metal affinity chromatography (IMAC) has been widely used for the specific separation of biopolymers. However, leakage of metal ions from IMAC adsorbents is of concern in IMAC. In this study, we designed a novel tridenate bis(5-methyltetrazolium)amine (BMTA) to reduce the leakage of metal ions by improving the affinity to immobilized metal ions. The ligand was bonded onto silica via three-step reaction to prepare a high-performance IMAC stationary phase. The chromatographic behaviors of ribonuclease A, cytochrome c , and lysozyme on the Cu(II)-, Ni(II)-, and Zn(II)-chelated stationary phase were investigated with respect to pH effect and elution with an imidazole gradient. The retention times of these three proteins increased by increasing the pH of the mobile phase but decreased by increasing the concentration of the competitive displacer. The retaining strength of the three proteins on the chelated stationary phase were in the order Cu(II) > Ni(II) > Zn(II). The behavior of these three proteins was consistent with the properties of a typical IMAC. The BMTA ligand exhibited a much stronger affinity for Cu(II) and Ni(II) than iminodiacetic acid (IDA), which is often regarded as a standard tridentate IMAC ligand. Quantum mechanical calculations at the B3LYP/6-31G level were used to image the coordination mode of the protein-metal ions-BMTA complex. In addition, a fused histidine-tagged cecropin b-human epidermal growth factor (CB-EGF) from Escherichia coli crude extract was purified by the Ni(II)-chelated stationary phase, and the purity of the CB-EGF was determined to be at least 90 %. These results suggest that the BMTA ligand may have potential applications in the preparation of therapeutics.
A novel ligand of tridenate bis(5-methyltetrazolium)amine (BMTA) was designed to reduce the leakage of metal ions from the column in immobolized metal affinity chromatography (IMAC).
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ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Wei Zhang,Jingyan Xie,Wei Hou,Yangqing Liu,Yu Zhou,Jun Wang
Supported catalysts are widely studied, and exploring new promising supports is significant to access more applications. In this work, novel copper-containing MOR-type zeolites Cu–MOR were synthesized in a one-pot template-free route and served as efficient supports for vanadium oxide. In the heterogeneous oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) with molecular oxygen (O2) under ambient pressure, the obtained catalyst demonstrated high yield (91.5%) and good reusability. Even under the ambient air pressure, it gave a DFF yield of 72.1%. Structure–activity relationship analysis indicated that the strong interaction between the framework Cu species and the guest V sites accounted for the remarkable performance. This work reveals that the Cu–MOR zeolite uniquely acts as the robust support toward well-performed non-noble metal heterogeneous catalyst for biomass conversion.
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RSC Advances
·
2016
·Vol. 6
·期 84
·80368-80382
·
IF 3.289
Yating Shen,Yunlei Zhang,Enwei Zhu,Yao Chen,Pei Jin,Meng Liu,Yongsheng Yan,Chunxiang Li
Herein, hierarchical pore foam catalysts (HPFCs) containing Brønsted–Lewis acidic sites and with hierarchical porous properties were synthesized, and their catalytic performance was applied to convert cellulose into HMF through a one-pot reaction. Sulfated ZrO2 nanostructures (SZs) were synthesized through grafting ZrO2 onto the surface of mesoporous silica nanoparticles, and superacid was further introduced onto the surface of the ZrO2 shells through sulfuric acid treatment and calcination. The representative SZs firstly acted as stabilizers in the synthesis of oil-in-water (O/W) Pickering high internal phase emulsions (Pickering HIPEs). After a subsequent ion-exchange process, Brønsted acidic sites were located on the surface of HPFCs. The resulting HPFCs exhibit advantageous properties for catalysis, such as favorable meso–macro porosity, strongly acidic surfaces, and structural stability. Compared with other catalysts (e.g., one without superacid and mesopores (HPFCs-1) and another (HPFCs-2) without mesopores), HPFCs-3 manifested more efficiently (42%) the production of 5-hydroxymethylfurfural (HMF) from cellulose. This study develops a promising method for the fabrication of specific functional solid catalysts, which can be applied to the value-added conversion of abundant cellulose.
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