JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 10
·6110-6123
·
IF 4.22
Fu Tianyi,Ding He,Zhang Jingshuang,Bai Peng,Lyu Jiafei,Guo Xianghai
Abstract Hierarchical aluminosilicate zeolites with uniform mesoporosity were successfully synthesized by one-stage crystallization under constant temperature with a novel single-head quaternary ammonium salt ([C 18 H 37 –N + (CH 3 ) 2 –C 6 H 12 –N(CH 3 ) 2 ]Br − ) as mesoporogen and structure-directing agent (SDA). Through precisely controlling the molar ratio of Si/Al and synthetic time, the mesoporous 3D wormhole framework (MCM-48) and crystalline microporous MFI structure were simultaneously constructed, revealed by a series of in-depth characteristic studies. Combining the advantages of the significantly improved diffusion from the mesoporous MCM-48 and the strong framework acidity of the crystalline microporous MFI zeolite, the hierarchical aluminosilicate zeolites exhibited outstanding catalytic activity with good reusability towards bulky aldol condensation compared with the conventional meso- or microporous zeolites. Graphical abstract
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Reaction Kinetics Mechanisms and Catalysis
·
2020
·Vol. 130
·期 2
·1027-1042
·
IF 1.52
Shi Qiqi,Guo Heqin,Chen Congbiao,Hou Bo,Jia Litao,Li Debao
In the present work, a series of sulfonic polymer-based acid catalyst PDS-x’s was obtained by hydrothermal method. The physical and chemical properties of the catalysts were characterized by X-ray diffraction, N 2 adsorption–desorption isotherms, thermogravimetric analysis, Fourier transform infrared spectrometer, pyridine-adsorbing IR, acid–base titration, X-ray photoelectron spectroscopy, and CHNS elemental analysis. The carbonylation of formaldehyde was chosen as a probe reaction to test the catalytic performance. The results show that the content of acid sites and specific surface area can be adjusted by changing the molar ratio of sodium 4-vinylbenzenesulfonate (SVBS) to divinylbenzene (DVB). The catalyst performance results show that the PDS-x’s can efficiently catalyze glycolic acid synthesis. And a high glycolic acid yield up to 96% was obtained on PDS-2.1 due to its large specific surface area, plentiful mesoporosity as well as suitable acid concentration. This data are even higher than those on super-strong CF 3 SO 3 H and commercial resin Amberlyst-15. Moreover, the carbonylation of formaldehyde is a structure-sensitive reaction, the isolated and monolayer dispersed -SO 3 H is much more active than aggregated −SO 3 H. Furthermore, the catalyst has high stability.
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Frontiers of Chemical Science and Engineering
·
2020
·Vol. 15
·期 2
·269-278
·
IF 3.552
Hou Yuexin,Li Xiaoyun,Sun Minghui,Li Chaofan,Bakhtiar Syed ul Hasnain,Lei Kunhao,Yu Shen,Wang Zhao,Hu Zhiyi,Chen Lihua,Su Bao-Lian
Hierarchical single-crystal ZSM-5 zeolites with different Si/Al ratios (Hier-ZSM-5- x , where x = 50, 100, 150 and 200) were synthesized using an ordered mesoporous carbon-silica composite as hard template. Hier-ZSM-5- x exhibits improved mass transport properties, excellent mechanical and hydrothermal stability, and higher catalytic activity than commercial bulk zeolites in the benzyl alcohol self-etherification reaction. Results show that a decrease in the Si/Al ratio in hierarchical single-crystal ZSM-5 zeolites leads to a significant increase in the acidity and the density of micropores, which increases the final catalytic conversion. The effect of porous hierarchy on the diffusion of active sites and the final catalytic activity was also studied by comparing the catalytic conversion after selectively designed poisoned acid sites. These poisoned Hier-ZSM-5- x shows much higher catalytic conversion than the poisoned commercial ZSM-5 zeolite, which indicates that the numerous intracrystalline mesopores significantly reduce the diffusion path of the reactant, leading to the faster diffusion inside the zeolite to contact with the acid sites in the micropores predominating in ZSM-5 zeolites. This study can be extended to develop a series of hierarchical single-crystal zeolites with expected catalytic performance.
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JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 28
·13815-13823
·
IF 3.553
Wang Zhen,Zhu Yanjiao,Ji Dong,Li Zhifeng,Yu Haibin
Hexagonal boron nitride nanosheets (h-BNNSs) are known to exhibit numerous prominent performances. However, scalable synthesis of h-BNNSs with a green, simple method has been difficult to achieve. In this study, xylitol-assisted discontinuous ball milling exfoliation (XADBME) of hexagonal boron nitride (h-BN) was proposed as a novel strategy for scalable synthesis of h-BNNSs. First, the high yield (above 80 wt%) could be achieved smoothly with this green chemistry method. Moreover, the as-synthesized h-BNNSs exhibited large lateral size, ultra-thin, defect-free. Lastly, the as-synthesized BNNSs and cellulose nanofibers (CNFs) were compounded to form a series of membrane materials. The mentioned membranes exhibited high in-plane thermal conductivity and prominent UV absorption characteristics. 70 wt% BNNS membrane [3.4 W(mK) −1 ] exhibited nearly 400% higher in-plane thermal conductivity than that of membrane without BNNS [0.7 W(mK) −1 ]. Thus, it shows promising applications in thermal management of electronic display screens, eye protection equipment, as well as portable mobile devices.
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JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 24
·10689-10698
·
IF 3.553
Zhang Rong,Xiang Bo,Feng Min,Xu Yujiao,Xu Lei,Xia Liru
Smart windows can slow down the heating rate in buildings to a certain extent and realize energy savings and emission reduction. Various approaches have attempted to make windows ‘smart’ by tailoring their thermal insulation behavior in response to environmental changes. However, there is still room for further improvement in their efficiency and automation performance. Here, based on photothermal functional fillers and shape memory substrates, a new type of photoactuator for smart windows—passively controlled shuttering—was designed. The photoactuator was composed of VO 2 @SiO 2 and methyl methacrylate butyl acrylate polymer (MBP). These two functional components had similar transition temperature (30 °C), and the photothermal conversion of VO 2 @SiO 2 stimulated the shape memory behavior of the composite. It was demonstrated that the intelligent performance was closely related to the shape memory properties of MBP and the phase transition characteristics of VO 2 NPs, which synergistically modified the solar regulation ability. The results suggest that this new type of optical driving window has potential applications in the field of wearable sensors, energy conservation and medical devices.
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JOURNAL OF NANOPARTICLE RESEARCH
·
2020
·Vol. 22
·期 5
·1-13
·
IF 2.132
Maimaiti Halidan,Wang Shixin,Awati Abuduheiremu,Xu Bo
Graphene oxide/silica (GO/SiO 2 ) containing various inorganic particles is obtained by using the Xinjiang Wucaiwan coal as carbon source and silicon source. The ruthenium/graphene oxide/silica (Ru/GO/SiO 2 ) composite was prepared by loading Ru nanoparticles on the surface of GO/SiO 2 . Then, the photocatalytic ammonia synthesis performance was investigated while characterizing the structure of Ru/GO/SiO 2 . On the one hand, the Ru can be sufficiently dispersed to make the surface plasmon resonance (SPR) effect enhance significantly. On the other hand, the quantum confinement effect of the defect structure on the Ru/GO/SiO 2 can effectively separate electron and hole, and it can participate in the reducing/oxidizing reaction of photocatalytic ammonia synthesis.
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JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 22
·9425-9435
·
IF 3.553
Guo Yufei,Wang Li,Xu Lijuan,Peng Canwei,Song Yonghai
A flexible ascorbic acid (AA)-imprinted poly(o-phenylenediamine) (ploy(o-PD))/zeolite imidazole frameworks-67 (ZIF-67)/carbon cloth (CC) electrode was prepared for electrochemical sensing AA. The flexible AA-imprinted poly(o-PD)/ZIF-67/CC electrode was prepared by growing ZIF-67 on flexible CC, electropolymerization of o-PD with AA on ZIF-67/CC and eluting template molecules AA. The results showed that the spherical ZIF-67 crystals were arranged evenly and firmly on the fibers of CC surface. The diameter of spherical ZIF-67 crystals was approximately 500–600 nm, and the spherical ZIF-67 crystals catalyzed the oxidation of AA well. A layer of poly(o-PD) with AA-imprinted pores was covered on the ZIF-67/CC electrode, so the AA-imprinted poly(o-PD)/ZIF-67/CC electrode exhibited better selectivity toward AA detection and good stability. The molecularly imprinted sensor exhibits high sensitivity, and the sensitivity could reach 959.9 μA/mM −1 cm −2 , the detection limit was 0.019 μM, and the concentration range of AA was 0.057 μM–11.4 0 mM. The AA-imprinted poly(o-PD)/ZIF-67/CC electrode also showed higher stability and repeatability. The results proved that the spherical ZIF-67 crystals were good electrode materials for electrochemical AA biosensors.
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Scientific Reports
·
2020
·Vol. 10
·期 1
·1-7
·
IF 3.998
Dong Xiuli,Tang Jiayuan,Chen Xiangming
An excellent pre-column fluorescent derivatization reagent N-acetylhydrazine acridone for the quantitative determination of malondialdehyde was synthesized. Malondialdehyde was derivatized at 80 °C for 30 min in the presence of trichloroacetic acid. The separation of the derivative was performed on an Agilent ZORBAX SB-C18 column in conjunction with gradient elution. The excitation and emission wavelengths were 370 nm and 420 nm, respectively. The developed method demonstrated good linear relationship in the range of 0.02 pmol to 2.5 pmol (r = 0.9998). The calculated limit of detection and limit of quantification were 2.5 fmol and 8.3 fmol, respectively. The analytical precisions of the method were in the range of 1.36–2.27% (intra-day) and 2.36–3.92% (inter-day) respectively. The method was sensitive, specific and simple. It was successfully implemented to analysis the malondialdehyde in rat prostate.
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高影响因子
Nature Communications
·
2020
·Vol. 11
·期 1
·1-11
·
IF 12.121
Wang Ying,Shang Xiaotong,Shen Jinni,Zhang Zizhong,Wang Debao,Lin Jinjin,Wu Jeffrey C. S.,Fu Xianzhi,Wang Xuxu,Li Can
The stoichiometric photocatalytic reaction of CO 2 with H 2 O is one of the great challenges in photocatalysis. Here, we construct a Cu 2 O-Pt/SiC/IrO x composite by a controlled photodeposition and then an artificial photosynthetic system with Nafion membrane as diaphragm separating reduction and oxidation half-reactions. The artificial system exhibits excellent photocatalytic performance for CO 2 reduction to HCOOH and H 2 O oxidation to O 2 under visible light irradiation. The yields of HCOOH and O 2 meet almost stoichiometric ratio and are as high as 896.7 and 440.7 μmol g −1 h −1 , respectively. The high efficiencies of CO 2 reduction and H 2 O oxidation in the artificial system are attributed to both the direct Z-scheme electronic structure of Cu 2 O-Pt/SiC/IrO x and the indirect Z-scheme spatially separated reduction and oxidation units, which greatly prolong lifetime of photogenerated electrons and holes and prevent the backward reaction of products. This work provides an effective and feasible strategy to increase the efficiency of artificial photosynthesis.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 14
·11411-11424
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IF 2.22
Liu Chunping,Liu Ling,Yang Dan,Zhang Liqun
This paper offers a simple, low-cost, and effective method to prepare high-performance dielectric elastomer. 4-chorophenethyl alcohol as dipole functionalizes crosslinker and then the functional crosslinker is utilized to prepare a novel dipolar silicone elastomer (SRCl). The introduction of dipole reduces regular arrangements of molecular chains and the dispersive crosslinking is formed in SRCl. The dipolar crosslinkers are evenly distributed in the crosslinking network, so the mechanical, dielectric, and electromechanical properties are improved. The dielectric elastomer actuator made of the SRCl with 15% dipoles exhibits a maximum actuated strain of 9.97% and the SRCl with 12% dipoles shows the highest breakdown field strength of 73.33 V/μm, which is increased by 156% and 52%, respectively, compared with pure silicone elastomer (SR, 3.89% at 48.23 V/μm). In addition, barium titanate (BT) nanoparticles as filler is mixed with SRCl to prepare the SRCl/BT composites. It is found that the dielectric property of composites is dominated by the matrix polarity. The electrostatic interaction between hydroxyl groups on BT nanoparticles and chlorine groups on the SRCl matrix improves the dispersion of BT nanoparticles in SRCl matrix. The maximum actuated strain of SRCl/20% BT (11.97%) is 3 times as high as SR (3.89%).
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JOURNAL OF NANOBIOTECHNOLOGY
·
2020
·Vol. 18
·期 1
·1-14
·
IF 6.518
Mo Canlong,Lu Lulu,Liu Danyang,Wei Kun
Background Psoriasis is a malignant skin disease characterized as keratinocyte hyperproliferation and aberrant differentiation. Our previous work reported that a bibenzyl compound, erianin, has a potent inhibitory effect on keratinocyte proliferation. To improve its poor water-solubility, increase anti- proliferation activity, and enhance the skin delivery, erianin loaded dendritic mesoporous silica nanospheres (E/DMSNs) were employed.Results In this work, DMSNs with pore size of 3.5 nm (DMSN1) and 4.6 nm (DMSN2) were fabricated and E/DMSNs showed pore-size-dependent, significantly stronger anti-proliferative and pro-apoptotic effect than free erianin on human immortalized keratinocyte (HaCaT) cells, resulting from higher cellular uptake efficiency. In addition, compared to free erianin, treatment with E/DMSNs was more effective in reducing mitochondrial membrane potential and increasing cytoplasmic calcium levels, which were accompanied by regulation of mitochondria and endoplasmic reticulum stress (ERS) pathway. Porcine skin was utilized in the ex vivo accumulation and permeation studies, and the results indicated higher drug retention and less drug penetration in the skin when administered as the E/DMSNs-loaded hydrogel compared to the erianin-loaded hydrogel.ConlusionsThis work not only illustrated the further mechanisms of erianin in anti-proliferation of HaCaT cells but also offer a strategy to enhance the efficiency of erianin and the capacity of skin delivery through the DMSNs drug delivery systems.
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MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 6
·1-9
·
IF 6.232
Qin Peige,Zhu Wenli,Han Lizhen,Zhang Xiaowan,Zhao Bing,Zhang Xuebin,Lu Minghua
The monodispersed mesoporous SiO 2 @metal-organic framework (MSN@MIL-101(Fe)) composites were prepared by grafting MSN-NH 2 onto MIL-101(Fe) particles with a solvothermal method. The adsorption ability of the composites was greatly improved compared to that of pristine MSNs or MIL-101(Fe) for phytohormones (Phys). The MSN@MIL-101(Fe) composites were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive spectrometer, and mapping analysis. Using MSN@MIL-101(Fe) composites as sorbent, a dispersive solid-phase extraction procedure (dSPE) was developed to extract three endogenous Phys (abscisic acid (ABA), indole-3-aceticacid (IAA), and indole-3-butyric acid (IBA)) and two exogenous Phys (1-naphthylacetic acid (1-NAA) and 2-naphthylacetic acid (2-NAA)) prior to HPLC-DAD analysis. The experimental parameters including sample volume, sorbent amount, adsorption time, adsorption pH, desorption time, and desorption solvent on extraction efficiency were optimized and evaluated. Under optimized conditions, the working range of 0.08 to 0.45 ng mL −1 with enrichment factors from 144 to 207 were achieved. The linear range is 0.75–200 ng mL −1 for IAA, 0.20–200 ng mL −1 for ABA, and 1.0–200 ng mL −1 for IBA, 1-NAA, and 2-NAA. With MSN@MIL-101(Fe) as sorbent for extraction of Phys and determination by HPLC-DAD, two endogenous Phys (IAA and ABA) were detected from mung bean sprouts which were made in a laboratory, and the results were further confirmed by high-resolution mass spectrometry. The composites can be applied to extract other small molecules, which have similar chemical structures with Phys in biological, environmental, and food samples.
Schematic presentation of a dispersive solid-phase extraction using monodispersed mesoporous SiO 2 @metal-organic framework composites (MSNs@MIL-101(Fe)) as the sorbent for extraction, clean-up, and preconcentration of phytohormones in mung bean sprouts prior to HPLC-DAD analysis.
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