Table of Content

10 December 2018, Volume 39 Issue 12

Previous Issue    Next Issue

Content

Cover and Content of Chemical Journal of Chinese Universities Vol.39 No.12(2018)

2018, 39(12):  0-0. 

Asbtract ( )   PDF (17674KB) ( )  

Related Articles | Metrics

Volume Contents of Chemical Journal of Chinese Universities to Vol.39(2018)

2018, 39(12):  0-0. 

Asbtract ( )   PDF (740KB) ( )  

Related Articles | Metrics

Inorganic Chemistry

Lanthanide Complexes Constructed by 2,2'-Oxybis(benzoic acid) and 1H-Imidazo[4,5-f][1,10]-phenanthroline: Fluorescence and Fluorescent Sensing for NH³†

ZHANG Dechun,XU Qiwei,LI Xia

2018, 39(12):  2611-2620.  doi:10.7503/cjcu20180009

Asbtract ( )   HTML ( )   PDF (6338KB) ( )  

Figures and Tables | References | Related Articles | Metrics

New complexes [Ln₂(2,2'-Hoba)₆(IP)₂]{Ln=Eu(1), Tb(2), 2,2'-H₂oba=2,2'-oxybis(benzoic acid), IP=1H-imidazo[4,5-f][1,10]-phenanthroline}, [Ln₂(2,2'-oba)₃(IP)](Ln=Eu(3), Tb(4)] and [Eu₂(2,2'-oba)₃(TPP)(H₂O)](5){TPP=tetrapyrido[2,3-a:3',2'-c:2″,3″-h:3″',2″'-j]phenazine} were synthesized under hydrothermal condition and characterized by X-ray single crystal diffraction(XRD), IR spectroscopy and elemental analysis. Complexes 1 and 2 have dinuclear molecular structures, complexes 3 and 4 reveal 1D line structure and complex 5 features a 3D structure. The recognition of complexes 1—5 for NH₃ was discussed with method of fluorescence spectroscopy. The results showed that they had highly sensitivity for NH₃ via a fluorescence quenching mechanism, with the quenching rates of 82.05%—97.49%. The recognition of complex 1 for NH₃ and some metal ions(Ca²⁺, K⁺, Mg²⁺, Na⁺, Zn²⁺, Cu²⁺, Cr³⁺, Ba²⁺, Al³⁺, Mn²⁺, Ni²⁺ and Pb²⁺) was studied. Luminescent investigation revealed that complex 1 could detect NH₃ with relatively high sensitivity in contrast to some metal ions, even at pH=4.0—8.0. The respective addition of some cations(Zn²⁺, Al³⁺ or Cr³⁺) into the complex 1-NH₃ system resulted in obvious fluorescent variation at 618 nm, with the fluorescent intensity at 618 nm increasing rapidly and then decreasing and a new peak occurring at 430—510 nm. Because of the synergy influence of NH₃ and Zn²⁺(Al³⁺ or Cr³⁺), if Zn²⁺(Al³⁺ or Cr³⁺) solution was added into 1-NH₃ system, the emission peak among 430—510 nm came into being. This showed that complex 1, NH₃ and Zn²⁺(Al³⁺ or Cr³⁺) had some combined action. The primary results showed that complex 1 had some sensitive recognition capability for NH₃, and this action was impacted by some metal ions.



Reversible Control of Under-oil Superhydrophobicity to Superhydrophilicity on TiO₂ Nanostructured Thin Film^†

KANG Hongjun,YU Xiaoyan,LAI Hua,CHENG Zhongjun,LIU Yuyan

2018, 39(12):  2621-2626.  doi:10.7503/cjcu20180493

Asbtract ( )   HTML ( )   PDF (2944KB) ( )  

Figures and Tables | References | Related Articles | Metrics

A TiO₂ nanostructured thin film was prepared by a simple pull-out coating method. The as-prepared TiO₂ nanostructured thin film shows under-oil superhydrophobicity with water contact angle(WCA) of 160°. Upon UV irradiation for 60 min with humidity of 20% in air, TiO₂ nanostructured thin film can switch from under-oil superhydrophobicity to superhydrophilicity. When the UV-irradiated TiO₂ nanostructured thin film was heated at 100 ℃ for 70 min, the thin film can restore initial under-oil superhydrophobic state. The results indicate the reversible control of under-oil superhydrophobicity to superhydrophilicity on TiO₂ nanostructured thin film can be realized by alternation of UV irradiation and heating process. The reversible control of under-oil water super-wetting on TiO₂ nanostructured thin film can be ascribed to the cooperative effect between the surface nanostructure and the chemical composition variation.



Preparation and Electrochemical Performance of Seaweed-based Heteroatom-containing Carbon Materials^†

WANG Yun,BEN Teng

2018, 39(12):  2627-2636.  doi:10.7503/cjcu20180297

Asbtract ( )   HTML ( )   PDF (6200KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Heteroatom-containing carbon materials SarCW-900 and LamCW-900 were prepared using two types of seaweeds as raw materials. The morphology, elemental composition, pore properties, graphitization degree and the activation mechanism of the carbon materials were discussed. The two carbon materials were used as electrode material in electrochemical capacitor and lithium-ion batteries, and the results of electrochemical measurements showed that the specific capacitance of SarCW-900 and LamCW-900 was 106 and 85 F/g, respectively. After 5000 voltammetry cycles, the specific capacitance was stabilized at 101 and 81 F/g, which decreased by only 4% or 5% respectively, indicating that SarCW-900 and LamCW-900 are ideal capacitor electrode materials. When they were used as lithium-ion battery electrode material, the specific capacity after 100 cycles was maintained at 100.3 and 33.9 mA·h/g for sarCW-900 and LamCW-900, respectively, lower than the theoretical value of pure graphite, but more stable.



TNT Vapor Concentration Based on the Continuous and Compact LTA Zeolite Membranes^†

GUO Yanan,GONG Miaomiao,DOU Xincun

2018, 39(12):  2637-2643.  doi:10.7503/cjcu20180211

Asbtract ( )   HTML ( )   PDF (5635KB) ( )  

Figures and Tables | References | Related Articles | Metrics

The continuous and compact LTA zeolite membranes were prepared on α-Al₂O₃ support via a rubbing-shaving seeding method and then further fabricated into a concentrator to concentrate 2,4,6-trinitrotoluene(TNT) vapor utilizing the kinetic radius difference between the gas and the pore size of molecular sieves. The diffusion limit enable the TNT vapor to be trapped in the confined space of concentrator, with a concentration factor of 31.8 evaluated under static and dynamic conditions. Such concentration method based on compact molecular sieve membranes is of great significance for the real-time and ultrasensitive detection of TNT vapor.



Preparation of Gold Nanoflower-double Layer Silica Core-shell Nanoparticles and Their Photothermal Properties and Metabolism in vivo^†

SONG Wenzhi,LI Hui,ZHANG Yan,HE Dan,LI Yingzi,HUANG Zhenzhen,LIU Xin,YIN Wanzhong

2018, 39(12):  2644-2650.  doi:10.7503/cjcu20180299

Asbtract ( )   HTML ( )   PDF (2321KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Gold nanoflower-double layer silica core-shell nanoparticles were prepared by a seed-mediated growth strategy and a modified Stöber method. The photothermal properties and the biotoxicity in vivo of the as-prepared core-shell nanoparticles were studied. The nude mice bearing oral cancer cell CAL27 were taken as the animal model to investigate the distribution, metabolism and passive targeting enrichment of the core-shell nanoparticles in vivo by the photoacoustic imaging technique. The results showed that the as-prepared core-shell nanoparticles exhibited excellent photothermal conversion properties in near infrared(NIR) region. The core-shell nanoparticles could be well metabolized in the liver, and could be excreted outside of the body through the intestinal tract. More importantly, the core-shell nanoparticles exhibited passive targeting enrichment in the tumor tissue through EPR effect. Our study show that the gold nanoflower-double layer silica core-shell nanoparticles would be an ideal photoacoustic imaging agent and a NIR photothermal therapy agent for diagnose and therapy of malignant tumors such as oral cancer.



Analytical Chemistry

Application of Kilowatt MPT-AES in Oil Analysis^†

YAN Yuwei,JIN Wei,ZHU Dan,ZHANG Tao,YING Yangwei,SHAN Jin,ZHANG Xuchen,YU Bingwen,CHEN Ting,LIU Chao,JIN Qinhan

2018, 39(12):  2651-2657.  doi:10.7503/cjcu20180377

Asbtract ( )   HTML ( )   PDF (2122KB) ( )  

Figures and Tables | References | Related Articles | Metrics

The direct atomization injection analysis of oil samples by the kilowatt microwave plasma torchatomic emission spectrometry(MPT-AES) device was realized for the first time. To demonstrate the performance of this device, eight metal elements in the directly diluted lubricating oil were tested and the changes of plasma morphology during injection were recorded. The results show the high accuracy of our device with the R² values of the linear regression equations of all tested elements are greater than 0.995. Furthermore, the detection limit of this device achieves a comparable level to the traditional ICP-AES method. These results further suggest that our MPT-AES device have a great potential in the analysis and online rapid monitoring of oil-based maintenance. At the same time, an online oil mixing device was developed, which makes the operation of elements detection more convenient and the injection volume more accurate, and is especially suitable for the collection, direct dilution and injection of trace samples.



Molecular Probe for the Determination of Hydroxyl Radicals in Heterogeneous Systems: Coumarin^†

HAN Ruixia,LÜ Jitao,ZHANG Shuzhen

2018, 39(12):  2658-2664.  doi:10.7503/cjcu20180364

Asbtract ( )   HTML ( )   PDF (2894KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Three common molecular probes—disodium terephthalate(TPA), sodium benzoate(BA) and coumarin(COU), with the corresponding transformation products of which are 2-hydroxyterephthalic acid(hTPA), salicylic acid(SA) and 7-hydroxycoumarin(7-hCOU) were assessed, respectively. The results showed that transformation products of TPA and BA were adsorbed seriously on ferrihydrite(the maximum adsorption capacity were 2.49 and 2.09 mg/g, respectively), which made them unsuitable to be used in heterogeneous systems. Moreover, COU was much better than TPA and BA in terms of sensitivity, linearity and concentration range responded to ·OH. And 7-hCOU had lower limit of detection than hTPA and SA(0.005, 0.046 and 0.072 μmol/L, respectively). COU was further demonstrated to be capable of quantifying ·OH produced in microbe-mineral systems and soil and sediment systems during redox cycle, where it showed great stability and reproducibility. It proved to be a reasonable molecular probe to apply to other ·OH production processes in heterogeneous systems and natural environment. Notably, it should be in the same pH buffer when comparing ·OH concentration between different systems since the pH has a great influence on the ·OH production.



Water-soluble Supramolecular Fluorescent Probe for Sensing Carbendazim and Its Application in Living Cell Imaging^†

YANG Mei,LIU Qing,TANG Qing,WANG Chenghui,YANG Meixiang,SUN Tao,HUANG Ying,TAO Zhu

2018, 39(12):  2665-2672.  doi:10.7503/cjcu20180319

Asbtract ( )   HTML ( )   PDF (3728KB) ( )  

Figures and Tables | References | Related Articles | Metrics

A host-guest complex between cucurbit[8]uril(Q[8]) and acridine orange(AO) was used as a fluorescent probe for detecting the carbendazim(CBZ). 2AO@Q[8] fluorescent probe was designed and used to detect carbendazim with high sensitivity and selectivity with a detection limit of ca. 10^-8 mol/L. A good linear relationship of emission intensity at ca. 529 nm for CBZ at concentrations of 0.4—5.0 μmol/L was observed. The proposed sensing mechanism was investigated via ¹H NMR spectroscopy combined with density functional theory calculations at the B3LYP/6-31G(d) level. The cell imaging study showed that the 2AO@Q[8] complex could be used to detect carbendazim in prostate cancer(PC3) cells, which may help to sense carbendazim in biological system.



Effect of Pore Structure on Protein Capacity in Macroporous Polymer Chromatographic Supports

LI Heng,WANG Shaoyun,FANG Jiaxuan,ZHAO Lan,JIN Haibo,HE Guangxiang,GUO Xiaoyan,GU Qingyang,HAO Siwen,RE Ziya,ZHI Weijie,YU Hongbin,ZHANG Rongyue

2018, 39(12):  2673-2678.  doi:10.7503/cjcu20180304

Asbtract ( )   HTML ( )   PDF (3023KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Macroporous microspheres were prepared through suspension polymerization, based on a copolymer of glycidyl methacrylate and ethylene glycol dimethacrylate, which were used for functional monomer and crosslinking agent, respectively. The effect of porogen on microspheres structure was evaluated in terms of pore size and surface area. The anion exchanged supports were prepared through derivation of microspheres with poly(ethylene imine). The relation of the microspheres structure and the protein capacity was examined on these anion exchanged media. The results indicated that the pore size of microspheres increased with the poor solvent in the porogen(good solvent/poor solvent=1:1—1:3.5), however, the surface area showed a contrary trend. The ion exchanged capacity(0.11—0.27 mmol/mL) increased with the surface area of the microspheres(4—38 m²/g), and the responding static binding capacity of proteins also show a positive correlation with the surface area. The dynamic binding capacity of proteins firstly increased and then retained a changeless value in the pore range of 301—1524 nm. This value was retained at 13 mg/mL when the pore size was more than 410 nm. It indicated that the surface area could not influence the dynamic binding capacity while the pore size of media was beyond some value. Furthermore, the large biomolecular transport in the microspheres was observed through laser scanning confocal microscopy. The results indicated that hepatitis B virus surface antigen(HBsAg) could enter freely the microsphere with all of above pore size. The above results provide a reference for fabrication of the chromatographic supports.



Organic Chemistry

Synthesis of Liraglutide Through Threonine Ligation^†

FAN Jiahui,BIAN Yanan,SU Xianbin

2018, 39(12):  2679-2685.  doi:10.7503/cjcu20180350

Asbtract ( )   HTML ( )   PDF (2026KB) ( )  

Figures and Tables | References | Related Articles | Metrics

A new method for the synthesis of liraglutide was reported, using threonine ligation to couple the segment histidine¹-glycine⁴ and the segment threonine⁵-glycine³¹. This method addressed the problem of low coupling efficiency at N-terminal residuals of liraglutide. The lysine²⁰ side-chain modification group was directly introduced onto the unprotected linear peptide by controlling pH of the solution. The ligation reaction was achieved with 76.4% overall yield. This new method is featured with the advantages of high chemoselectivity and mild reaction conditions, and has a potential of industrial application.



Different Pathways for the Cyclocondensation Reactions of 1,2-Diamine and 1,2-Diketone^†

ZHU Lei,HAN Junyan,CHANG Haizhen,QIU Yuyuan,ZHANG Yanan,PENG Danni,HU Wei,MIAO Shaobin

2018, 39(12):  2686-2692.  doi:10.7503/cjcu20180302

Asbtract ( )   HTML ( )   PDF (2164KB) ( )  

Figures and Tables | References | Related Articles | Metrics

It is generally acknowledged that in protic organic solvents, 1,2-diamine reacts with 1,2-diketone to form an aromatic compound containing the pyrazine ring. As expected, the condensation reactions of 1,4-bis-[(triisopropylsilyl)ethynyl]naphthalene-2,3-diamine or 1,4-bis[(triisopropylsilyl)ethynyl]anthracene-2,3-diamine with 3,5-di-tert-butyl-1,2-benzoquinone yielded diazatetracene and diazapentacene derivatives. Meanwhile, naphthoazepin and anthroazepin derivatives which contained the imidazole ring were also obtained. Naphthoazepin and anthroazepin derivatives contained a seven-membered ring. All new compounds were characterized by proton and carbon-13 nuclear magnetic resonance spectroscopy, UV-vis spectrophotometry, high resolution mass spectrometry and single crystal X-ray diffraction. The possible reaction mechanisms were proposed as well.



Physical Chemistry

Spatial Density Correlation in Polymer Melts^†

PAN Deng,SUN Zhaoyan

2018, 39(12):  2693-2699.  doi:10.7503/cjcu20180626

Asbtract ( )   HTML ( )   PDF (2160KB) ( )  

Figures and Tables | References | Related Articles | Metrics

The spatial density correlation in glass-forming polymer melt with different chain architectures was investigated using molecular dynamics simulation. The local environment of each bead was identified. Using the Voronoi construction, the results indicate that the chain ends have more local volume in the average level and the mobility of chain ends is higher. Moreover, the distributions of local volume become narrow when decreasing temperature and the rescaled distributions follow a master curve, implying that the melts have qualitatively similar amorphous structure for different chain architectures. The loosely and densely packed particles were identified according to their local volume. Both loosely and densely packed particles tend to form clusters, and the loosely packed particles was larger than that by densely packed particles. The simulation results demonstrate the spatial correlation of loosely packed particles is stronger, which might help to understand the glass forming behavior of polymer melts.



Synthesis of Urea Ammonium Halide Cocrystal and Theoretical Study of Its Influencing Factors in Water System^†

YAN Xuan,XUE Bingchun,LIU Erbao

2018, 39(12):  2700-2706.  doi:10.7503/cjcu20180481

Asbtract ( )   HTML ( )   PDF (2035KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Three urea ammonium halide cocrystals were synthesized by slow evaporation technique. It was found that the urea ammonium chloride was still easy to synthesize than the other two urea ammonium halide. The first-principles method was used to construct isomorphous urea ammonium fluoride and urea ammonium bromide cocrystal unit cell based on the original unit structure of urea ammonium chloride. The stability, packing coefficient, formation energy of the three urea ammonium halide cocrystal structures, halogen ion radius and electronegativity, and ionic hydration energy were compared. The results showed that for the urea ammonium bromide cocrystal, the larger Br^- radius leads to the deformation of the internal cavity of the urea cell, and the hydrated cluster of bromide ions is stable, which will hinder the entry of Br^- into the urea channel; for urea ammonium fluoride cocrystal, the electronegativity of F^-makes the fluoride ion hydrate cluster F^-(H₂O)₅ very stable, preventing the bare F^- entering the urea cavity; for the urea ammonium chloride cocrystal, the electronegativity and radius size of Cl^- are both moderate, the stability of hydrated ion clusters is appropriate, all these factors make it easy to enter the urea cavity.



Molecular Design of Lower Photodegradation Fluoroquinolone Antibiotics and Their Photolysis Paths Inference^†

ZHAO Xiaohui,CHU Zhenhua,LI Yu

2018, 39(12):  2707-2718.  doi:10.7503/cjcu20180475

Asbtract ( )   HTML ( )   PDF (3361KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Dividing the obtained data of photodegradation half-life(t_1/2) for 12 fluoroquinolones(FQs) into the training set and test set in a radio of 4:1(random combination), comparative molecular field analysis(CoMFA) and comparative molecular similarity indices analysis(CoMSIA) were used to establish 3D-QSAR models to predict the lgt_1/2 values of the remaining 14 FQs, with the structural parameters as independent variables and the lgt_1/2 values as the dependent variables through the Sybyl-x software. The results showed that the cross-validation correlation coefficients(q²) for CoMFA and CoMSIA models constructed by random combination were 0.564—0.655(>0.5) and the non-cross-validated correlation coefficients(r²) were 0.996—1.000(>0.9), indicating that the models were robust and predictive. The prediction of the photolysis t_1/2 found that the fourth type of FQs generally had a higher t_1/2 value than the third type of FQs. Taking ciprofloxacin(CIP) as the target molecule, introducing the smaller groups at the selected C13 position of CIP helped to design 9 modified CIP molecules with t_1/2 values significantly decreased, and the t_1/2 value of the modified molecule with the introduction of OH groups reduced most(27.2%). The photodegradation paths inference of CIP molecules and modified molecules indicated that the minimum energy barrier was required for the path of aromatic ring hydroxylation during CIP photodegradation, and the oxidative decarboxylation reaction had the largest energy barrier and the most paths of piperazine ring fracture. For the modified CIP molecules, the energy barriers of three reactions, aromatic ring hydroxylation, oxidative decarboxylation, and hydroxylation defluorination remained basically unchanged but the energy barrier required for the piperazine ring fracture significantly reduced. Evaluation of the biodegradability of modified CIP molecules and their photolysis products revealed that not only the photolytic activity of modified CIP molecules increased, but also the biodegradability increased by 0.26% to 59.71%, and the biodegradability of the photolysis products also increased significantly(12.03%—34.38%). It indicated that CIP and modified CIP molecules can eventually generate products with significantly improved biodegradability through photodegradation in favor to further control the environmental behaviors of FQs.



Facile Preparation of Protonated g-C₃N₄ Nanobelts in Concentrated Sulfuric Acid with Enhanced UV Light Photocatalytic Activity for Photodegradation of Organic Dyes^†

LI Jiaojiao,ZHAO Weifeng,ZHANG Gai,MA Aijie,CHEN Weixing,ZHOU Hongwei

2018, 39(12):  2719-2724.  doi:10.7503/cjcu20180460

Asbtract ( )   HTML ( )   PDF (2738KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Graphitic carbon nitride(g-C₃N₄) nanobelts were prepared by a simple method which involves exfoliating bulk g-C₃N₄ in concentrated H₂SO₄ due to the strong protonation ability and rapid hydration heat effect of 98% H₂SO₄ when mixed with water. The obtained samples were characterized by means of X-ray diffraction(XRD), scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FTIR), UV-Vis diffuse reflectance spectroscopy(UV-Vis DRS) and photoluminescence(PL) spectroscopy. The characterization results revealed that a significant protonation occurs between the g-C₃N₄ and H₂SO₄ moleculars, making the band gap of the as-prepared g-C₃N₄-H₂SO₄ nanobelts much larger than that of the bulk g-C₃N₄. Therefore, the UV light adsorption was greatly improved compared to that of bulk g-C₃N₄, and the electron-hole recombination was also reduced after the modification process. Methylene blue(MB) dye was used as the target pollutant to further investigate the UV photoactivity of the g-C₃N₄-H₂SO₄ nanobelt samples. It was found that the protonated nanobelts can decompose almost 100% of MB within 2 h, much superior to the bulk g-C₃N₄ under UV light.



Synthesis and Electrochemical Performance of Silica/Porous Lignin Carbon Composites as Anode Materials for Lithium-ion Batteries^†

LI Changqing,YANG Dongjie,XI Yuebin,QIN Yanlin,QIU Xueqing

2018, 39(12):  2725-2733.  doi:10.7503/cjcu20180436

Asbtract ( )   HTML ( )   PDF (6215KB) ( )  

Figures and Tables | References | Related Articles | Metrics

The alkali lignin(AL) derived from pulping liquor was used as raw materials to prepare the silica/quaternized alkali lignin composite(SiO₂/QAL) by hydrothermal reaction, and then the silica/porous lignin carbon composite(SiO₂/PLC) was obtained after carbonization and etching. SiO₂/PLC exhibited a specific surface area of 1069 m²/g and mesoporous pore size of 20 nm on average. As anode materials for lithium-ion batteries, silica nanoparticles were dispersed uniformly in the porous lignin carbon with a three dimensional network, leading to better cycle performance and rate capability. The electrochemical measurement showed that SiO₂/PLC displayed a high capacity of 820 mA·h/g after 100 cycles at a current density of 100 mA/g and 235 mA·h/g at a large current density of 5 A/g.



Colour Change of Red Iron Oxide by One-step Method Using Oxidant^†

JIANG Xue,FU Yao,HUANG Dan,GUO Yupeng

2018, 39(12):  2734-2738.  doi:10.7503/cjcu20180417

Asbtract ( )   HTML ( )   PDF (3603KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Taking iron oxide red as raw material, iron oxide red with better quality was prepared by a one-step calcination method with sulfuric acid as oxidant. The results show that when iron oxide red and 60%(mass fraction) sulfuric acid were mixed and calcined at 750 ℃, the color of the product was the best. The results of XRD, SEM, HRTEM, UV-Vis and elemental analysis EDX show that the crystal form of iron oxide red was unchanged before and after calcination, but the morphology was more regular, the particle size was more uniform, and the color was more vivid after calcination.



Preparation and Electro-catalytic Property of Self-supported Nickel Nanowire Array Electrode^†

DU Mengmeng,SUN Haijun,GAO Shan,YE Xiaoli,QIAO Lei,GUO Fen

2018, 39(12):  2739-2745.  doi:10.7503/cjcu20180405

Asbtract ( )   HTML ( )   PDF (5289KB) ( )  

Figures and Tables | References | Related Articles | Metrics

A self-supporting nickel nanowire array(NNA) electrode was prepared by using the low-melting point alloy and porous polycarbonate template, and its catalytic performance toward hydrazine electro-oxidation was studied. SEM, XRD and TEM results show that the NNA electrode consists of a nickel plate and nickel nanowire arrays supported on it. The cotton-like surface of nickel nanowires provides the NNA electrode with the additional specific surface area. Cyclic voltammograms and chronopotential measurements show that when the concentration of hydrazine is 24.6 mmol/L, the onset oxidation potential of the electrode is as low as -0.25 V, and the oxidation current density is as high as 163 mA/cm². When the concentration of hydrazine is relatively low, the hydrazine electro-oxidation reaction and the Ni(OH)₂/NiOOH conversion reaction of the electrode coexist. When the concentration of hydrazine reaches a relatively high level, only hydrazine electro-oxidation occurs. The reaction order of hydrazine species approximately equals to 1, and the reaction activation energy is 16.13—21.24 kJ/mol. The integrated, open structure makes the NNA electrode show significantly better electrocatalytic performance than commercial nickel piece and nickel foam, and exhibit excellent stability.



Upgrading of Bio-oil by Catalytic Esterification^†

CHENG Yanyan,SUI Guanghui,CHEN Zhimin,WEI Qingling,DUAN Yajun,WANG Xiaofeng,YANG Xiaomin,WANG Zichen

2018, 39(12):  2746-2751.  doi:10.7503/cjcu20180404

Asbtract ( )   HTML ( )   PDF (1492KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Bio-oil pyrolyzed from rice husk was separated into light-oil and heavy-oil by vacuum distillation. The heavy-oil was upgraded by catalytic esterification with sulfuric acid to prepare ethanol-bio-oil. Then the sulfuric acid catalyst was separated from ethanol-bio-oil using neutralizer. Effects of the catalytic esterification and neutralization on the pH value of ethanol-bio-oil were investigated. The component and molecular weight of raw bio-oil and the ethanol-bio-oil were analyzed by GC/MS and GPC. The results show that the pH value of ethanol-bio-oil can reach 5.86 under the following optimized reaction conditions, 120 ℃, 3 h, sulfuric acid as catalyst, ethanol as solvent. The influence sequence of neutralizers on the pH value of ethanol-bio-oil is as following, BaO≈BaCO₃<CaCO₃<nano-CaCO₃<CaO. In addition, after the progress of catalytic esterification, not only did esters increase by 26.1%, acids and phenols in ethanol bio-oil decrease by 15.9% and 12.8%, respectively, but also did the molecular weight of ethanol-bio-oil decrease by 90%.



Fresh Hierarchical Periodic Silver SERS-active Substrate with the Band-aid Protecting Layer^†

XU Weiqing,GUAN Shulin,WANG Yi,WANG Xinnan,TAO Yanchun,XU Shuping

2018, 39(12):  2752-2757.  doi:10.7503/cjcu20180366

Asbtract ( )   HTML ( )   PDF (4318KB) ( )  

Figures and Tables | References | Related Articles | Metrics

A novel band-aid like, hierarchical periodic structured, multilayered surface-enhanced Raman scattering(SERS) substrate was developed, which allows a fresh silver surface when peeling off the protector. It was prepared by the vacuum deposition of a thick Ag layer(600 nm) on a hierarchical periodic structured anodic alumina(AAO) that was achieved by anodizing a pre-patterned Al base by means of the nanoimprint lithography with a hard Ni mask, while the AAO layer plays a role of surface protector. Then, the Ag side was glued to a glass slide. When it is used for SERS, the AAO layer can be peeled off to allow for a naked, fresh Ag surface for SERS measurements. This method solves the problem of oxidation and pollution of traditional Ag SERS substrates, ensuring the freshness of the SERS substrate. The AAO preparation steps are largely simplified compared with other AAO preparation procedures. Owing to the use of the nanoimprint lithography, the periodic structure of the Ni stamp can be well copied, which insures the reducibility of the final SERS substrate in SERS measurements. Apparently, the substrate preparation is time-saving and easier, which makes this band-aid like SERS substrate promising for being a commercial SERS substrate.



Preparation and Application of Superhydrophobic and Robust Graphene Composites Oil/Water Separation Material^†

QIU Lijuan,ZHANG Ying,LIU Shuaizhuo,ZHANG Qian,ZHOU Ying

2018, 39(12):  2758-2766.  doi:10.7503/cjcu20180332

Asbtract ( )   HTML ( )   PDF (6403KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Superhydrophobic reduced graphene oxide-wrapped melamine sponge(RGO-MS) was prepared via a facile surface modification method with graphene oxide(GO) modification amphipathic melamine sponge(MS). X-ray diffraction(XRD), Raman spectra, Fourier transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM) were used to investigate the structure, morphology and component of RGO-MS. The mechanical property, hydrophobicity, oil adsorption capacity, reusability and oil/water separation efficiency of RGO-MS were also explored. The results revealed that reduced graphene oxide(RGO) coating was closely linked to MS skeleton. In addition, RGO-MS possesses outstanding adsorption capacity for floating oil and heavy oil underwater, and could maintain ultra-high adsorption capacity even after 50 adsorption-squeezing cycles which is as high as 90 % of its initial adsorption capacity. Moreover, RGO-MS exhibits extremely high separation efficiency up to 4.5×10⁶ L/(m³·h) under non-turbulent and 3×10⁶ L/(m³·h) under turbulent condition water/oil system. Therefore, RGO-MS has a huge application prospect in dealing with the large-scale removal of oil and organic spillage cleanup.



Preparation and Application of High Performance Lithium Titanate/reduced Graphene Oxide Nanocomposites for Lithium Batteries^†

SUN Bing,JIANG Shang,WANG Runwei,NI Ling,QIU Shilun,ZHANG Zongtao

2018, 39(12):  2767-2773.  doi:10.7503/cjcu20180250

Asbtract ( )   HTML ( )   PDF (5681KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Mesoporous lithium titanate/reduced graphene oxide anode material was synthesized by a simple hydrothermal method. The morphology and structure of the obtained materials were characterized. The electrochemical properties of the obtained materials were tested. The results show that the lithium titanate/reduced graphene oxide anode material posseses high specific surface area and the lithium titanate nanosheets are not easy to agglomerate; the initial discharge specific capacity is increased to 182.2 mA·h/g at 0.1C rate; and the cycling performance is greatly improved, with a cupacity of 160.6 mA·h/g after 500 cycles at 5C rate.



Polymer Chemistry

Coordinate Interaction Between Monosulfide and Au Surfaces^†

LI Xun,XUE Yurui,SONG Yu,ZHANG Wenke

2018, 39(12):  2774-2780.  doi:10.7503/cjcu20180496

Asbtract ( )   HTML ( )   PDF (2628KB) ( )  

Figures and Tables | References | Related Articles | Metrics

We have employed atomic force microscopy(AFM)-based single molecule force spectroscopy(SMFS) to quantify the stability of the individual thioether-gold contact in isolated as well as in a self-assembled monolayer. The external factors that affect the sulfide-gold binding strength were investigated at the single-molecule level. The results show that the alkyl sulfide molecule formed coordinate bond on gold surface. Compared with reduced gold, the oxidized gold can enhance the sulfide-gold interactions in both isolated individual monosulfide-gold contacts and in self-assembled membranes(SAMs). Also, the solution condition can affect the stability of Au—S coordinate bonds.



Preparation and Properties of Grafted Polyethylene/GMS Grafted Modified SiO₂ Blends^†

CHU Ming,ZHANG Jianfu,QU Lihang,LI Meiyuan,ZHU Dantong,LI Wenfei,YAO Zhanhai

2018, 39(12):  2781-2788.  doi:10.7503/cjcu20180345

Asbtract ( )   HTML ( )   PDF (5374KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Dripping agricultural films can be obtained by adding dripping agents into the polymeric matrix, but the delaying and controlling migration of dripping agents is still challenging. Therefore, the graft of monostearic acid acrylic acid diglyceride(AGMS) and modified nano SiO₂(SiO₂-g-PAGMS) was prepared, and then the blend of AGMS, SiO₂-g-PAGMS, polyethylene, grafted polyethylene, modified SiO₂ were extruded in proportion and blown film. Acceleration dripping test at 60 ℃ showed that the maximum dripping duration of the film with SiO₂-g-PAGMS, polyethylene and grafted polyethylene compound could reach 36 d. Under the same conditions, it was 1.50 times and 2.25 times higher than the film of AGMS, polyethylene, grafted polyethylene compound, and SiO₂-g-PAGMS/polyethylene, respectively. Other results showed that haze and crystallization temperature of the grafted polyethylene compound/SiO₂-g-PAGMS blend decreased, while melting temperature increased, and the change of tensile strength of film was less than 11%.



Preparation of Green Star-topology Phosphazene Flame Retardant and Properties of Flame-retardant Epoxy Resin^†

LU Lingang,CHENG Zhe,QIU Xinming,WANG Huiya,YANG Shousheng,QIAN Xiaodong,WANG Xuebao

2018, 39(12):  2789-2796.  doi:10.7503/cjcu20180339

Asbtract ( )   HTML ( )   PDF (3629KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Based on the molecular structure design, a new type of flame retardant named six[4-(5,5-methyl-1,3,2-dioxanone endophosphoryl) phenoxy] cyclotriphosphazene(HDDCPPCP) was prepared by hexachloro-cyclotriphosphazene, p-hydroxybenzaldehyde, phosphorus oxychloride and neopentyl glycol. This new flame retardant, ammonium polyphosphate(APP) and multi walled carbon nanotubes(MWCNT) were added to epoxy resin(EP). After that, the HDDCPPCP/APP/MWCNT/EP flame-retardant composites were prepared. Limiting oxygen index(LOI), horizontal burning(UL-94), cone calorimetry(CONE), tensile, bending and impact methods were used to study the combustion, thermal and mechanical properties of the flame-retardant composites. The experimental results show that the combustion parameters of EP2(HDDCPPCP/APP/MWCNT/EP) composites perform better when the total mass of fraction of flame retardant system is 30% and the mass fraction of MWCNT is 2%. The LOI of EP2 is 42.8%, it shows good flame retardancy, smoke suppression and anti-poisoning properties. The peak heat release rate(pk-HRR), average heat release rate(av-HRR), average effective heat combustion(av-EHC), and average CO release rate(av-CO) of EP2 are respectively reduced by 92.5%, 93.0%, 65.2%, and 66.6% compared with EP0. EP2 have good tensile strength, break elongation, bending strength and bending modulus, which are respectively 110.46 MPa, 6.24%, 1259.99 MPa and 377.72 MPa.



Toughing Polylactide with Topological Slide-ring Structure and Its Shape Memory Effect and Mechanism^†

WU Ruiqing,LAI Jingjuan,PAN Yi,DENG Jinni,ZHENG Zhaohui,DING Xiaobin

2018, 39(12):  2797-2804.  doi:10.7503/cjcu20180293

Asbtract ( )   HTML ( )   PDF (1825KB) ( )  

Figures and Tables | References | Related Articles | Metrics

To toughen brittle poly(L-lactic acid), the topological slide-ring architecture was introduced by ring opening polymerization of L-lactic acid initiated by hydroxypropyl modified α-CD-based polyrotaxane(HPPR). The thermal properties, mechanical properties, dynamic mechanical properties and shape memory performance of slide-ring polylactic acid based polyurethane(SR-PLAU) and other all samples were investigated. The results show that, the embedding of the slide-ring structure not noly greatly improves the strain at break of polylactic acid, and significantly improves the mechanical properties, but also enables the material good shape memory performance, compared to CC-PLAU and PLA/HPPR. The shape memory mechanism of SR-PLAU was proposed and demonstrated by the stress relaxation characteristics of the materials.



Simulation of Perforated Lamelar Structures of Diblock Copolymer Induced by Surface Patterns^†

RONG Jingjing,MA Lan,ZHU Youliang,HUANG Yineng,SUN Zhaoyan

2018, 39(12):  2805-2810.  doi:10.7503/cjcu20180263

Asbtract ( )   HTML ( )   PDF (3850KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Dissipative particle dynamics simulations were employed to study the phase behavior of diblock copolymer on the surface of substrate with the induction of circular patterns. Four types of perforated lamelar structures(PLS) were found by adjusting the radius of circular pattern and the thickness of film, which are named as PLS-Ⅰ, PLS-Ⅱ, PLS-Ⅲ and PLS-Ⅳ according to phase connectivity. The phase diagram was obtained by systematically changing circular radius and the thickness of film. Moreover, the mechanism of forming these structures was proposed. The result could provide theoretical supports for the design and development of diblock copolymer functional film materials.



Synthesis of Binuclear Complexes Containing Phenoxyimine Ligands and Application for Ethylene Polymerization and Copolymerization^†

ZHANG Cui,WANG Lijuan,LÜ Zhongwen,XU Sheng,MI Puke

2018, 39(12):  2811-2819.  doi:10.7503/cjcu20180256

Asbtract ( )   HTML ( )   PDF (2289KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Binuclear complexes with phenoxyimine ligand were designed and synthesized, in which the ligands were synthesized by a condensation reaction of p-phenylenediamine and substituted salicylaldehyde. Binuclear complexes C1—C6 were synthesized by the TiCl₄·2THF or CpZrCl₃·DME reacted with the ligands treated with triethylamine, trimethylchlorosilane or sodium hydride. Both the ligands and the compounds were well characterized by ¹H NMR, ¹³C NMR, IR, element analysis and MS. When combined with methylaluminoxane(MAO), the binuclear complexes show higher activity for ethylene polymerization. The effects of polymerization factors such as temperature, pressure of ethylene, ratio of aluminum to titanium or zirconium on the catalytic activity and polymer molecular weight were also investigated. The experimental results show that the activity of the catalysts reached 10⁵—10⁶ g/(mol M·h); and the catalyst C5 has the highest catalytic activity of 1.23×10⁶ g/(mol Zr·h). However, the C4 could keep higher catalytic activity when the molar ratio of Al/Ti was lower to 50:1, and the molecular weight of the polymer was higher to 1.11×10⁶. It is also found that the catalyst could effectively catalyze the copolymerization of ethylene with 1-octene and the insertion rate of 1-octene could reach to 10.65%(molar fraction).



Construction of Nanocavity in Membranes Based on Hollow Polymer Microspheres and Effects on Gas Permeation Performance^†

KANG Changyong,DING Xiaoli,ZHAO Hongyong,WANG Xinlan,ZHANG Yuzhong,WANG Lina

2018, 39(12):  2820-2824.  doi:10.7503/cjcu20180197

Asbtract ( )   HTML ( )   PDF (3144KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Hollow polymer microspheres were prepared by polymerization of tetraethylane and dipentaerythritol hexaacrylate at the oil-water interface of surfactant-free microemulsion using the interfacial initiator. The membranes with nanocavities were formed by casting the hollow microspheres microemulsion and the effects of the nanocavities on the gas permeability and selectivity of the separation membrane were investigated. The results show that the resulting hollow microspheres have an average size of 116.7 nm, and a hollow structure with a shell thickness of 10—20 nm. The permeability of membranes with nanocavities increased significantly compared with the intrinsic permeability of shell material. At 35 ℃, 0.2 MPa, the permeability coefficient of CO₂ of hollow microspheres membranes increased by 1.4—5.7 times and the separation coefficient also improved.



Water Absorption Characteristics of Different Polyamide Resins and Their Effects on the Diffusion and Polymerization of St Monomer

TAN Yinle, HUANG Chenghuan, GUO Zhaoxia, YU Jian

2018, 39(12):  2825-2832.  doi:10.7503/cjcu20180189

Asbtract ( )   HTML ( )   PDF (2847KB) ( )  

References | Related Articles | Metrics

The water absorption characteristics of different polyamide resins and their effects on the diffusion and polymerization of styrene(St) monomers were studied. The results show that PS content of PA/PS nanoalloy increases with the increase of water content of PA pellets. The maximum PS contents of PA6, PA66 and MXD6 are 6.7%, 2.5% and 1.6%, respectively, under the conditions of difussion and polymerization at 90 ℃. Diffusion and subsequent polymerization of St occur in the amorphous regions of PA pellets, the PS nanoparticles ranging in size from 10 to 100 nm and distribute uniformly. Owing to the reinforcement effect of rigid PS particles to PA, the tensile strength and Young’s modulus of the PA/PS nanoalloy improved significantly.