CHEMICAL ENGINEERING JOURNAL
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2017
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IF 6.216
Yunyun Xie,Wenxiu Yang,Mozhen Wang,Xuewu Ge
The creation of high surface area and effective active sites is the key problem for the synthesis of high-performance porous carbon materials. In this work, polyacrylonitrile-coated fibrous silica (F-SiO 2 @PAN) microspheres were prepared by in situ polymerization of acrylonitrile on fibrous mesoporous silica microspheres induced by γ-ray radiation. After F-SiO 2 @PAN microspheres were carbonized and etched with hydrofluoric acid, uniform fibrous N-doped porous carbon (FNC) microspheres with an average size of 286 nm and a molar ratio of C/N of 5.2 were successfully prepared. As revealed by TEM, SEM, and N 2 adsorption-desorption isotherms analysis, FNC microspheres have a hierarchal micro-macroporous structure with a particular high surface area of 554.5 m 2 /g. The FNC microspheres also exhibit a good water dispersibility and an excellent adsorption ability to rhodamine B in water. The equilibrium adsorption capacity of FNC microspheres could reach 95.4 mg/g, which is 1.6 times as that of the primary silica template microspheres. The adsorption kinetics and thermodynamics of FNC microspheres are in accord with the pseudo-second-order kinetic equation and Freundlich isotherm model, respectively. This work provides a facile synthesis method for novel N-doped hierarchical micro-macroporous carbon microsphere as a potential high-performance adsorbent material.
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Journal of Materials Chemistry B
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2017
·Vol. 5
·期 39
·7974-7984
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IF 4.543
Yuzheng Wu,Haifeng Li,Zhouquan Rao,Huaqiang Li,Yan Wu,Jianhao Zhao,Jianhua Rong
The controlled protein adsorption and delivery of thermosensitive poly(N-isopropylacrylamide) (PNIPAM) nanogels were investigated under different temperatures, pH values and ionic strengths by using bovine serum albumin (BSA) as a model protein. The BSA adsorption in deionized water was due to one or several of four contributions, i.e. the electrostatic attraction between BSA and nanogels, the seizing action of nanogels to BSA, the hydrophobic interaction between BSA and nanogels, and the physical diffusion of BSA, depending on the temperature and pH value. At 37 °C and pH 4.0, the largest BSA adsorption of 23.5 μg mg−1 was achieved by the above four contributions following electrostatic attraction (48%) > seizing action (21%) > hydrophobic interaction (16%) > physical diffusion (15%). The BSA adsorption in different sodium chloride solutions exhibited a maximum of 17.2 μg mg−1 at 0.03 M, which was influenced by the charge shielding of Na+ ions, salting out of BSA and nanogel aggregation. Most adsorbed BSA molecules were distributed on the nanogel surface except a few standing in the nanogel interior. The adsorbed BSA could be controllably delivered by tailoring the temperature and pH value, and with the aid of sodium dodecyl sulfate. The conformation of BSA adsorbed in hydrochloric acid solution (pH 4.0) significantly changed due to the acid environment and the electrostatic attraction between BSA and nanogels, but it could be completely recovered when BSA was delivered in deionized water or physiological saline. This work is instructive to design the controllable adsorption and delivery of proteins by using PNIPAM-based hydrogels as carriers.
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JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2014
·Vol. 161
·期 12
·F1202
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IF 2.859
Hui Wang,Qin Ma
A new nitrogen-doped carbon support for Pt-based electrocatalysts was prepared by carbonizing polypyrrole formed on the surface of WO3 nanoparticles (WO3-CNx). Morphologies of WO3-CNx and PtSn/WO3-CNx were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. PtSn nanoparticles were well-dispersed on the surface of WO3-CNx. Electrocatalytic results showed that PtSn/WO3-CNx is more active than PtSn/C in the ethanol oxidation reaction (EOR), since smaller PtSn nanoparticles were grown on the surface of WO3-CNx and highly electrically conductive WO3-CNx facilitated the electron transport occurred during the EOR. PtSn/WO3-CNx also exhibited better durability and higher stability in ethanol oxidation reaction than PtSn/C. These results indicated that WO3-CNx has potential to be used as a catalytic support with high-performance for Pt-based electrocatalysts used in fuel cells.
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APPLIED ORGANOMETALLIC CHEMISTRY
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2012
·Vol. 26
·期 11
·600-603
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IF 2.061
Dongsheng Bai,Huanwang Jing,Guangjian Wang
The synthesis of cyclic carbonates from epoxides and carbon dioxide catalyzed by cyanocobalamin and n -Bu 4 NI system was achieved under 0.8 MPa CO 2 pressure at 140°C without organic solvents. Propylene carbonate was obtained in 99% yield within 6 h under the optimized reaction conditions. The cyanocobalamin catalyst could be recycled with water and retained moderate catalytic activity. Copyright © 2012 John Wiley & Sons, Ltd.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2014
·Vol. 131
·期 23
·
IF 1.64
Nenmei Jian,Tao Xu
In this article, we report that thermoresponsive poly( N -isopropyl acrylamide) (PNIPAAm) was successfully grafted onto a cotton fabric (CF) surface by free-radical solution grafting polymerization; we obtained a thermoresponsive CF-grafted PNIPAAm. This reaction system only contained four constituents: the monomer, solvent, initiator, and CFs. Ammonium peroxydisulfate was chosen as the initiator, and water was chosen as the solvent. A series of initiator concentrations and grafting polymerization temperatures were used in the experiments, and their effects on the grafting ratio ( G ) were also studied. Also, the effects of the G of CF- g -PNIPAAm on their corresponding thermoresponses was studied further. The structure of CF- g -PNIPAAm was characterized by Fourier transform infrared spectroscopy–attenuated total reflectance analysis and scanning electron microscopy analysis. The G of CF- g -PNIPAAm was measured by a gravimetric method. The thermoresponse of CF- g -PNIPAAm was characterized by modulated differential scanning calorimetry, water contact angle measurements, and wetting time measurements. The experiments manifested the following results: (1) the initiator concentration and grafting polymerization temperature both influenced G, (2) the grafted PNIPAAm covered the CF surface, (3) the CF- g -PNIPAAm showed thermoresponsive hydrophilicity/hydrophobicity, and (4) a relationship existed between the thermoresponse of CF- g -PNIPAAm and the corresponding G . © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 41193.
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JOURNAL OF MOLECULAR STRUCTURE
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2013
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IF 1.404
Zhihua Cui,Xin Li,Xidong Wang,Kemei Pei,Weiguo Chen
Two N -heterocycle-containing benzotriazole compounds ( CBHDCP , CBMPP ) were synthesized and their structures were confirmed by FT-IR, 1 H NMR, mass spectroscopy and elemental analysis. Their spectral properties compared with that of a common commercial benzotriazole UV absorber Tinuvin 326 in solvents were measured and analyzed using molecular orbital calculations. It was found that the experimentally obtained optical properties were in close agreement with the theoretically obtained results. Besides, CBMPP is much superior to CBHDCP acting as an effective UV absorber on polyethylene terephthalate fabric due to its combinative higher exhaustion and higher molar extinction coefficient. The exhaustion difference on polyethylene terephthalate fabric among N -heterocycle-containing benzotriazoles ( CBHDCP , CBMPP ) and Tinuvin 326 were then measured and explained by the solubility parameter theory. The results agreed with the rule that compounds with higher exhaustion on fiber have solubility parameter much closer to that of fiber polymer.
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SUPRAMOLECULAR CHEMISTRY
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2015
·
IF 2.394
Bo Xiao,Ying Fan,Ning-Ning Ji,Xiao-Jie Cheng,Chuan-Zeng Wang,Jia-Jia Zhou,Sai-Feng Xue,Zhu Tao,Qian-Jiang Zhu
Using the one-pot, direct strategy reported by Su and co-workers, we have synthesised a series of cucurbit[n]urils (Q[n], n = 5–8) and alkyl-substituted cucurbit[6]urils (SQ[6]s) anchored on polymers. Acrylamide, as a typical monomer, was used to synthesise a series of Q[n]s (n = 5–8) and SQ[6]-anchored polyacrylamides (PAMs) using a persulfate salt as initiator and oxidant. The Q[n]s (n = 5–8) and SQ[6]-anchored PAM samples have been characterised by 1H NMR, 1H NMR titrations of probe guests, Fourier-transform infrared and thermogravimetric analyser. The results confirmed that PAM chains had been successfully grafted on the back of the Q[n]s (n = 5–8) and SQ[6]s through an in situ radical polymerisation approach. It was further confirmed that the hydrophobic cavities of the Q[n]s on the polymers were still freely accessible. This synthetic approach may be extended to a variety of Q[n]s that are difficult to functionalise.
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Nanoscale Research Letters
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2014
·Vol. 9
·期 1
·1-7
·
IF 2.481
Ji Jianwei,Wang Guan,You Xiaozeng,Xu Xiangxing
Silicon quantum dots (Si QDs) attract increasing interest nowadays due to their excellent optical and electronic properties. However, only a few optoelectronic organic molecules were reported as ligands of colloidal Si QDs. In this report, N -vinylcarbazole - a material widely used in the optoelectronics industry - was used for the modification of Si QDs as ligands. This hybrid nanomaterial exhibits different spectroscopic properties from either free ligands or Si QDs alone. Possible mechanisms were discussed. This type of new functional Si QDs may find application potentials in bioimaging, photovoltaic, or optoelectronic devices.
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高影响因子
ENERGY & FUELS
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2017
·
IF 3.091
Zhongqi Ren,Mengyao Wang,Yong Li,Zhiyong Zhou,Fan Zhang,Wei Liu
The designer nature of ionic liquids (ILs) has driven their exploration and application in countless fields because of their unique phiscochemical properties. In this work, two ester-functionalized ionic liquids (ILs), N-ethyl acetate-N-methylimidazole bis(trifluoromethylsulfonyl)imide ([Eamim][NTf2]) and N-ethyl acetate-N-methylimidazole sulfocyanide([Eamim][SCN]), were prepared. Two ternary systems, benzene-hexane-[Eamim][NTf2] and benzene-hexane-[Eamim][SCN], were investigated in terms of both quantum chemical calculation and liquid–liquid extraction experiments. Quantum chemical calculation results showed that the interaction between ILs and benzene was larger than that between ILs with n-hexane. The liquid–liquid extraction results showed that the selectivity reached 29.55 with [Eamim][NTf2], while the selectivity reached 61.44 with [Eamim][SCN] at 25 °C. The vapor permeation process was conducted through a supported membrane with ILs. The influences of operating temperature and the feed concentration of benzene were investigated. With the increase of temperature, the selectivity of benzene increased at first and then decreased. When the concentration of benzene was 0.5 and the temperature was 35 °C, the selectivity of benzene reached 16.05, while the flux was 22.14 g·h–1·m–2. The stability of the membrane in the vapor permeation was also tested and could remain steady for 60 h.
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ORGANIC & BIOMOLECULAR CHEMISTRY
·
2024
·Vol. 22
·期 36
·7485-7491
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IF 2.9
Zi-Xuan Hu,Shu-Rui Li,Qing-Jun Xia,Ting Wang,Josef Voglmeir,Göran Widmalm,Li Liu
Here we report an enzymatic approach to synthesize N-formylneuraminic acid (Neu5Fo) containing sialosides, through a five-enzyme cascade. This method stands as an alternative to traditional chemical syntheses, aiming for precision and efficiency in generating sialosides with a tailored N-formyl group generated directly from formic acid. The newly synthesized Neu5Fo was characterized using various NMR techniques revealing a conformational equilibrium at the amide bond of the formyl group in slow exchange on the NMR time scale with a trans : cis ratio of ∼2 : 1. This work not only suggests potential for exploring the biological roles of sialosides but also points to the possibility of developing novel therapeutic agents.
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Journal of the Taiwan Institute of Chemical Engineers
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2024
·
IF 5.5
Song Zou,Yimu Wang,Yu Wan,Zhenxing Wang,Shuang Gao,Qingsong Luo,Yanting Wang,Changhao Feng
Background It is imperative to monitor the levels of n-butanol in the environment for the preservation of ecosystems and safeguarding human health. As a potential substitute for n-butanol sensors, the LaFeO 3 nanofibers show encouraging promise. Methods We have used the electrospinning method to successfully construct a series of Fe doping LaFe 1+x O 3 ( x = 0, 0.03, 0.05, 0.07) nanotubes. Through the use of XRD, FESEM, TEM, and EDS, the sample's morphological structure and composition were examined. Significant findings With a quick response/recovery time of 9/15 s, the gas sensor based on LF 1.05 O 3 nanotubes showed a staggering response of 33.6 at 150 °C toward 100 ppm n-butanol. Compared to the other test gases, this sensor demonstrated remarkable n-butanol selectivity. Furthermore, a methodical examination of the sensing mechanism was carried out.
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INDUSTRIAL CROPS AND PRODUCTS
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2024
·
IF 5.6
Wenwei Zhang,Tianjin Li,Xinping Ouyang,Xueqing Qiu
To cope with the challenge of insufficient interaction between lignin macromolecules and catalytic active sites in heterocatalysis systems which hindered the efficient hydrogenolysis of lignin, a lignin-derived N-doped macroporous carbon supported Ru catalyst (Ru/LNPC) was prepared via the pyrolysis of alkali lignin with potassium hydroxide as the activator and ammonium oxalate as the pore forming agent. The LNPC carrier featured a hierarchical porous structure with the diameter of macropores ranging from 50 nm to 10 μm, enhancing the adequately contact between the lignin macromolecules and Ru NPs. The doping nitrogen in the carbon carrier led to well dispersed Ru nanoparticles with average size of 1.08 nm, providing abundant active metallic centers. Therefore, Ru/LNPC exhibited excellent catalytic activity and stability to hydrogenolysis of lignin. Under the condition of 1.0 MPa H 2 at 280 ºC for 2 h, Ru/LNPC contributed to the yield of 45.6 % aromatic monomers from the depolymerization of lignin. After five recycling, Ru/LNPC still showed significant activity. This work provided a new strategy for designing catalysts for efficient hydrogenolysis of lignin and further facilitating its high-value utilization.
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