CHINESE JOURNAL OF POLYMER SCIENCE
·
2012
·Vol. 31
·期 3
·377-387
·
IF 0.919
Shi Xue-bo,Wu Chun-lei,Rong Min-zhi,Czigany Tibor,Ruan Wen-hong,Zhang Ming-qiu
To improve creep resistance of directional polytetrafluoroethylene (PTFE) films, epoxy grafted nano-SiO 2 is mixed with PTFE powder before sintering and calender rolling. The aligned macromolecular chains (especially those in amorphous region) of the composite films can be bundled up by the nanoparticles to share the applied stress together. In addition, incorporation of silica nanoparticles increases crystallinity of PTFE and favors microfibrillation of PTFE in the course of large deformation. As result, PTFE films exhibit lower creep strain and creep rate, and higher tensile strength and hardness. The work is believed to open an avenue for manufacturing high performance fluoropolymers by nano-inclusions.
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DOI
高影响因子
CELLULOSE
·
2018
·Vol. 25
·期 8
·4591-4602
·
IF 3.809
Gao Kezheng,Guo Yaqing,Niu Qingyuan,Fang Hua,Zhang Linsen,Zhang Yong,Wang Lizhen,Zhou Liming
Cellulose nanofiber/chitin nanofiber (CCN) suspensions can be converted into uniform composite hydrogels under acidic condition, because the chitin nanofiber and cellulose nanofiber have C6 carboxylate groups on their surfaces, which form hydrogen bonds. However, the electrostatic repulsion caused by the amino cations on the chitin nanofiber surface can prevent the formation of hydrogen bonds to a certain extent under acidic condition. When the charged state of C2 amino groups change at neutral pH, 3D hydrogen-bonded network of cellulose nanofiber/chitin nanofibes composite hydrogels can be retained. Therefore, the mechanical strength of CCN composite hydrogels decreases dramatically with the increase of the chitin nanofiber content. The locally unidirectional crystallization process of hexagonal prism ice crystal in the hydrogel can be affected by variations in the mechanical strength of CCN composite hydrogels. Thus, the microstructures of CCN composite aerogels can be effectively adjusted by changing the chitin nanofiber content. The composite aerogel containing 30% chitin nanofibers has a honeycomb microstructure and optimum mechanical property at intermediate strains. There are numerous stacked mesopores in the nanosheet structural units of all CCN composite aerogels, and the stacked pore size distribution is relatively unaffected by the ratio of cellulose nanofibers to chitin nanofibers. CCN-70 composite aerogel (containing 70% chitin nanofiber) has the highest Barrett-Emmett-Teller (BET) surface area (approximately 94 m 2 g −1 ). Graphical Structure and properties of CCN aerogels can be effectively controlled by chitin nanofibers due to C6 carboxylate and C2 amino groups on the surface of chitin nanofibers.
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DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2008
·Vol. 19
·期 3
·487-493
·
IF 2.101
Ma Shuhui,Mu Wei,Gao Jigang,Zhou Jie
A novel spectrofluorometric method, using 2-(2-pyridyliminomethyl)phenol as a fluorescent probe, was developed for the determination of superoxide anion radical (O 2
•− ) and superoxide dismutase activity (SOD). The new fluorescent probe was synthesized and characterized with elemental analysis and IR spectra. It was oxidized by O 2
•− to form a less fluorescence product. Based on this reaction, a spectrofluorometric method was proposed and successfully used to determine superoxide anion radicals and SOD activity. The effects of interferences were studied. The reaction was simple, precise and sensitive. It was applied to determine SOD activity in garlic, papaya and spinach successfully.
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE
·
2019
·Vol. 30
·期 4
·41
·
IF 2.467
Wang Lina,Cao Weiwei,Wang Xi,Li Peili,Zhou Jie,Zhang Gaoke,Li Xin,Xing Xiaodong
For cartilage tissue repairing, it remains a key challenge to design implant materials with antibacterial activity, proper degradation rate and mechanical property. In this research, antibacterial nanodiamonds (QND, QND-Ag) modified acrylate-terminated polyurethanes (APU) were prepared. By the addition of nanocomposites, the crystallinity of modified APU obviously increased, which indicates a strong interaction between NDs and APU. Tensile and compression tests were carried out to evaluate the improved mechanical properties. Compared with APU, APU(10%PEG)/QND-Ag possessed the increased modulus and strength, a nevertheless slight decrease in elongation at break. Due to the dual actions of contact-killing of cationic polymers and release-killing of the Ag NPs, QND-Ag-containing polyurethane showed excellent antibacterial activity against Staphylococcus aureus . Moreover, APU containing polyethylene glycol showed a significant increase in degradability rates. Consequently, owing to the dual effect of crystallinity and hydrophilicity, our modified APU exhibited the proper degradation rate adaptable to the healing rate of cartilage tissue. Furthermore, the CCK-8 results demonstrated that synthesized samples were low toxic. Therefore, APU(10%PEG)/QND-Ag holds great promise for the application of cartilage tissue repairing.
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DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2019
·Vol. 37
·期 8
·797-805
·
IF 2.804
Chai Sheng-Chao,Xu Tian-Yang,Cao Xiao,Wang Gang,Chen Quan,Li Hao-Long
Nanoparticle-polymer composites exhibit unusual mechanical properties and chain dynamics when the nanoparticle size is smaller than the entanglement mesh size of the matrix polymer chains, corresponding to the ultrasmall regime defined by de Gennes. However, the mechanism is still ambiguous due to the lack of suitable model systems. Here, we develop an ultrasmall nanoparticle system by using a bimodal grafting strategy to graft both short alkyl chains and long polystyrene chains onto the polyoxometalate molecular nanoparticles with a tunable repulsive potential between the nanoparticles, thus facilitating their uniform dispersion in polystyrene matrices. Linear viscoelasticity of the resultant nanocomposites changes with increasing the filler content, which shows a decrease in both plateau modulus and terminal relaxation time, indicative of a dilution effect of the nanoparticles. Namely, the entanglement network becomes sparser with increasing the filler content.
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高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2018
·Vol. 36
·期 8
·943-952
·
IF 2.016
Liu Heng,Zhuang Rui,Dong Bo,Wang Feng,Hu Yan-Ming,Zhang Xue-Quan
A series of mono- and binuclear Co(II) complexes ( Co1 – Co7 ) supported by quinoline-2-imidate ligands were synthesized and thoroughly characterized. Measured by single crystal X-ray crystallography, complexes Co1 and Co3 adopted distorted tetrahedral structures around the cobalt center. Upon activation by ethylaluminium sesquichloride (EASC), these cobalt complexes exhibited high catalytic activity and cis -1,4-selectivity towards 1,3-butadiene polymerization. The effects of ligand environment, polymerization temperature, and cocatalyst types on the polymerization were investigated in detail. Interestingly, the binuclear Co(II) complexes exhibited high thermal stability, and the polymer yields were up to 97.2% even at a high temperature of 70 °C.
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高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2014
·Vol. 32
·期 11
·1564-1574
·
IF 1.42
Li Ming,Zhang Li-fen,Tao Mei-xia,Cheng Zhen-ping,Zhu Xiu-lin
In this work, a fluorescent monomer 2-(9-carbazolyl) ethyl vinyl ether (CEVE) was synthesized in our lab, and its photo-induced living cationic copolymerization behavior with isobutyl vinyl ether (IBVE) was investigated in detail using diphenyliodonium chloride (DPICl)/2,2-dimethoxy-2-phenylacetophenone (DMPA) and zinc bromide (ZnBr 2 ) initiating system in dichloromethane solution at 5 °C, −5 °C, and −15 °C, respectively. The living nature of this copolymerization system was confirmed by adding fresh comonomer method after the copolymerization almost finished. In addition, the obtained fluorescent copolymer poly(IBVE- co -CEVE) has a low glass transition temperature ( T
g ), below −10 °C.
研究领域:
高分子化学
·
功能高分子
·
光响应材料
·
聚合反应机理
·
荧光材料
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DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2016
·Vol. 127
·期 3
·1889-1895
·
IF 1.781
Yuan Kangkang,Gan Xinzhu,Wang Xinqiang,Zhu Luyi,Zhang Guanghui,Xu Dong
The present study fully reports the decomposition of polyacetylacetonatozirconium (PAZ) in air with thermogravimetry–differential scanning calorimetry and Fourier transform infrared spectroscopy. The influence of water vapor on the decomposition of PAZ was characterized with the Fourier transform infrared spectroscopy. Crystallization and phase transformation of PAZ were studied by X-ray diffraction and Raman spectroscopy. The experimental results show that water vapor promotes the decomposition of PAZ and crystallization of zirconia compared with air. Furthermore, the effect of different amount of stabilizer Y(NO 3 ) 3 ·6H 2 O on the pyrolysis and phase stabilization of PAZ shows that NO 3
− was beneficial to the oxidation of organic components and the formation of Y 2 O 3 could stabilize tetragonal zirconia and hinder grain growth.
研究领域:
材料化学
·
无机化学
·
纳米材料
·
热分析
·
光谱学
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DOI
高影响因子
MICROCHIMICA ACTA
·
2010
·Vol. 171
·期 3
·385-392
·
IF 2.648
Yin Huanshun,Zhou Yunlei,Liu Tao,Cui Lin,Ai Shiyun,Qiu Yanyan,Zhu Lusheng
An amperometric biosensor for nitrite was prepared by immobilizing cytochrome c (Cyt c) on a gold electrode that was modified with Nafion and a Cu-Mg-Al layered double hydroxide (Cu-LDH). The Cu-LDH was characterized by Fourier transform infrared spectroscopy and powder X-ray diffraction. The UV-visible spectrum suggests that Cyt c retains its native conformation in the modified film. The direct electrochemical investigation indicated that the composite film represents a good platform for the immobilization of Cyt c as well as an excellent promoter for the electron transfer between Cyt c and the gold electrode. Moreover, the biosensor showed a remarkable bioelectrocatalytic activity for the oxidation of nitrite with a linear range from 0.75 to 123 μM. The detection limit is 2 × 10 −7 M (S/ N = 3). The biosensor was successfully applied to the determination of nitrite in food samples.
研究领域:
生物分析化学
·
电化学传感
·
食品分析
·
生物传感器
·
分子诊断
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DOI
高影响因子
IONICS
·
2019
·Vol. 26
·期 1
·263-272
·
IF 2.289
Luo X. Y.,Meng B.,Xia Z. D.,Chen Q. B.,Dong D. Z.,Zhao M. Y.
In order to investigate the effects of Na 2 CO 3 /ZnO co-addition on the sinterability and electrical conductivity of BaZr 0.1 Ce 0.7 Y 0.1 Sc 0.1 O 3-δ (BZCYSc) ceramic, Na 2 CO 3 and ZnO were added and BZCYSc/ZnO/Na 2 CO 3 ceramic was prepared by mechanical ball milling and high-temperature sintering in air. The crystalline structure, micro-morphology, chemical composition, density, and electrical conductivity of the sintered ceramics were characterized by XRD, SEM, EDS, Archimedes method, and electrochemical impedance spectrum, respectively. The grains size of BZCYSc-2%ZnO-5%Na 2 CO 3 is about 2.5~5 μm. Na 2 CO 3 /ZnO co-addition is beneficial to improve the sinterability and electrical conductivity of BZCYSc. The sintering temperature of BZCYSc can be lowered from 1550 to 1350 °C when 2 mol%ZnO is added. At 550 °C, the electrical conductivities of BZCYSc-2%ZnO-10%Na 2 CO 3 and BZCYSc are 1.90 × 10 −3 S/cm and 1.81 × 10 −3 S/cm. The activation energies of BZCYSc and BZCYSc-2%ZnO-10%Na 2 CO 3 are 0.7529 eV and 0.5641 eV, respectively.
研究领域:
材料科学
·
无机非金属材料
·
固态离子学
·
能源材料
·
陶瓷工程
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DOI
高影响因子
IONICS
·
2019
·Vol. 26
·期 2
·627-637
·
IF 2.289
Zhai Huanhuan,Shuai Yi,Wang Yu,Chen Kanghua
As a negative electrode material, the main drawbacks of Li 4 Ti 5 O 12 (LTO) are its low electric conductivity and poor Li-ion diffusion coefficient. Fortunately, elements modification to address these problems is an effective method. Herein, we firstly report Ni and F co-modified LTO material which is synthesized via a solid-state reaction. Powder X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy were conducted to investigate the structure and morphology. Afterwards, we surprisingly find that Ni and F co-modification can reduce the overall charge transfer resistance of LTO for part of Ti 4+ converts into Ti 3+ and Ni 2+ ions supply the charge carriers. When test in battery, a superior discharge capacity of 236.1 mAh g −1 at 0.036 A g −1 is obtained, much higher than that of pristine LTO (196.9 mAh g −1 ). Furthermore, it still retains a discharge capacity of 174.6 mAh g −1 after 200 cycles at 0.18 A g −1 and exhibits an excellent rate performance.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固体化学
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高影响因子
Journal of Coatings Technology and Research
·
2017
·Vol. 15
·期 3
·505-514
·
IF 1.557
Zhao Yuan,Huang Chongxing,Bei Ronghua,Su Hongxia,Wang Shuangfei
Silicon oxide (SiO
x
) films are widely used as barrier layers in different types of commodity packaging and have caught the interest of manufacturers and researchers alike owing to their high barrier functionality, good acid and alkali resistance, ability to withstand high-temperature and microwave treatments, and good transparency. In this study, we first synthesized polylactic acid (PLA) films by extrusion calendaring and then deposited a SiO
x
layer on the PLA films by plasma-enhanced chemical vapor deposition to prepare SiO
x
/PLA composite films. We then evaluated the barrier functionality of the SiO
x
layer and elucidated its underlying mechanism. We also analyzed its effect on the mechanical properties of the composite films by comparing the oxygen and water vapor transmission rates, soil degradation performances, and surface morphologies of the two types of synthesized films (uncoated and coated with SiO
x
). The results showed that, because of the SiO
x
layer, the barrier properties and mechanical properties of the SiO
x
/PLA composite films were better than those of the uncoated films. In particular, the oxygen and water vapor transmission rates of the composite films were approximately 8–10 and 6–8 times lower, respectively, than those of the uncoated PLA films. In addition, the SiO
x
layer lowered the rate of soil degradation of the composite films, owing to which the weight-loss rates of the composite films were also lower than those of the uncoated films. Further, the tensile strengths and elongations at break of the composite films were higher because of the SiO
x
layer. Graphical
研究领域:
材料科学
·
高分子材料
·
包装工程
·
表面改性
·
生物降解材料
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DOI
高影响因子
危险品化学品经营许可证（带存储）