Table of Content

10 August 2016, Volume 37 Issue 8

Previous Issue    Next Issue

Content

Cover and Content of Chemical Journal of Chinese Universities Vol.37 No.8(2016)

2016, 37(8):  0-0. 

Asbtract ( )   PDF (17284KB) ( )  

Related Articles | Metrics

Articles Inorganic Chemistry

Ni-Fe LDH/Reduced Graphene Oxide as Catalyst for Oxygen Evolution Reaction

DU Shichao,REN Zhiyu,WU Jun,FU Honggang

2016, 37(8):  1415-1420.  doi:10.7503/cjcu20160173

Asbtract ( )   HTML ( )   PDF (3863KB) ( )  

Figures and Tables | References | Related Articles | Metrics

The composites of Ni-Fe layered double hydroxide(LDH) and reduced graphene oxide(rGO) were successfully prepared via a simple exfoliation and electrostatic self-assembly and were used as catalysts for electrooxidation of water(oxygen evolution reaction, OER). The exfoliated Ni-Fe LDH samples exhibited much higher water oxidation activity than the bulk ones. The onset potential was 1.470 V vs. RHE and the potential for maintaining a current density of 10 mA/cm² was 1.530 V vs. RHE. After being fabricated with rGO, the composite showed better performance for water oxidation than exfoliated Ni-Fe LDH, and the potential for maintaining a current density of 10 mA/cm² was decreased to 1.515 V vs. RHE.



Luminescence Sensing of Benzaldehyde and Cation of 3-(2-Carboxy-phenoxy)-phthalicate-based Lanthanide Complexes^†

DONG Gaoyun,LI Rui,FAN Tingting,LI Jiajia,LI Xia

2016, 37(8):  1421-1429.  doi:10.7503/cjcu20160126

Asbtract ( )   HTML ( )   PDF (3790KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Five lanthanide-organic frameworks, [Sm₂(bdbc)₂(phen)₄](1) and [Ln(bdbc)(phen)·(H₂O)][Ln=Eu(2), Gd(3), Tb(4), Dy(5), bdbc=3-(2-carboxy-phenoxy)phthalicate, phen=1,10-phenanthroline], have been synthesized and determined by X-ray single-crystal diffraction. Complex 1 is a binuclear molecule and forms a one-dimensional(1D) supramolecular architecture via hydrogen and C—H…π bonds. Complexes 2—5 are isostructural and display a one-dimensional(1D) chain structure, which form a three-dimensional(3D) supramolecular architecture via hydrogen and C—H…π bonds. Complexes 1, 2, 4 and 5 present the characteristic emission of Sm³⁺, Eu³⁺, Tb³⁺ and Dy³⁺, which are attributed to ⁴G_5/2→⁶H_J/2(J=5, 7, 9) transitions of Sm³⁺, ⁵D₀→⁷F_J(J=1—4) transitions of Eu³⁺, ⁵D₄→⁷F_J(J=6, 5, 4, 3) transitions of Tb³⁺, ⁴F_5/2→⁶H_J/2(J=15, 13) transitions of Dy³⁺, respectively. Furthermore, the luminescence properties of complex 4 were investigated. The results show that complex 4 may be used as a fluorescent probe to detect cation in aqueous solution and benzaldehyde.



Analytical Chemistry

Direct Detection of Tetracycline in Honey by Neutral Desorption-Extractive Electrospray Ionization Mass Spectrometry^†

DENG Min,FANG Xiaowei,GUO Xiali,HUANG Xueyong,LIU Xingxing,YU Tenghui,LUO Liping

2016, 37(8):  1430-1434.  doi:10.7503/cjcu20160127

Asbtract ( )   HTML ( )   PDF (964KB) ( )  

Figures and Tables | References | Related Articles | Metrics

A novel platform of neutral desorption-extractive electrospray ionization mass spectrometry(ND-EESI-MS) for direct and rapid detection oftetracycline(TC) in honey sample without any sample pretreatment wa constructed. The results showed that the limit of detection was 1.08 ng/mL with a linear working range from 20 to 1000 ng/mL(R²>0.997) toward TC in honey; the recoveries and relative standard deviations of TC from spiked samples, at three fortification levels(50, 500, 1000 ng/mL), were 94.26%, 98.38%, 103.00% and 3.28%, 1.39%, 1.12%, respectively. Eight common commodity honey samples were detected by this method and the results reveal that 2 of them contain traces of TC, while TC is not found in the rest samples. HPLC was also applied for TC detection in the asme honey samples, and TC is not found. Therefore, this ND-EESI-MS method is sensitive, rapid and specific for quantitative analysis of TC in honey without any sample pretreatment.



Detection of Cefoperazone Sodium and Sulbactam Sodium in Biological Fluid by Quantum Dots Room Temperature Phosphorescence Probe^†

FANG Xiaoxing,ZHENG Ji,YAN Guiqin

2016, 37(8):  1435-1441.  doi:10.7503/cjcu20160082

Asbtract ( )   HTML ( )   PDF (2803KB) ( )  

Figures and Tables | References | Related Articles | Metrics

A method for the determination of trace cefoperazone sodium-sulbactam sodium(CPZ-SBT) was established using water phase synthesized 3-mercaptopropionic acid-capped Mn-doped ZnS quantum dots(MPA-Mn/ZnS QDs) as a room temperature phosphorescence(RTP) probe, which based on the phenomenon that the electron acceptor acted by CPZ-SBT can effectively quench the RTP of MPA-Mn/ZnS QDs through electron transfer. There is a good relationship between CPZ-SBT and changes on the phosphorescence intensity of MPA-Mn/ZnS QDs when the concentration of CPZ-SBT is in the scope of 0.7—84 μg/L. The correlation coefficient and detection limit of this method are 0.99 and 0.14 μg/L, respectively. Additionally, this method is able to conduct analysis simply without deoxidizer, inducer or complex sample processing, which can effectively avoid the interference of background fluorescence and scattered light in biological fluids and can be successfully applied in trace determination of CPZ-SBT in biological fluids as well.



Organic Chemistry

Synthesis and Herbicidal Activity of 2-(4-Arylxoyphenoxy)propionamide Derivatived from Benzofuranol^†

YANG Zihui,LI Beibei,YE Jiao,HU Aixi

2016, 37(8):  1442-1450.  doi:10.7503/cjcu20160335

Asbtract ( )   HTML ( )   PDF (1086KB) ( )  

Figures and Tables | References | Related Articles | Metrics

2-(4-Aryloxyphenoxy) propionamide derivatives were identified as one of the most important herbicides, which inhibited acetyl-CoA carboxylase(ACCase) to restrict fatty acid. Recent years, 2-(4-aryloxyphenoxy) propionamide derivative have developed resistance in varying degrees among weeds. Therefore, resear-ching novel 2-(4-aryloxyphenoxy) propionamide derivatives herbicide is of great importance. Seventeen of 2-(4-aryloxyphenoxy) propionamide derivatives were synthesized by multistep synthetic procedures with two key intermediates 2 and 9, starting from(R)-(+)2-(4-hydroxyphenoxy) propanoic acid and benzofuranol. The intermediate 9 was synthesized from o-phthalic anhydride and 2-aminoethanol via substitution reaction, bromination, etherification and amination. The synthetic reaction condition of intermediates 9 was discussed. The structures of target compounds 4 and 5 were confirmed by ¹H NMR, ¹³C NMR, HRMS and optical rotation. The bioassay results indicated that most of title compounds possessed a moderate herbicidal activity against crabgrass and barnyard grass at 1500 g/hm². The compounds 4a, 4b, 4i, 5e and 5h showed more than 96% activities against the crabgrass and barnyard grass at 375 g/hm².



Synthesis and Anti-HBV Activities of the Indirect Galactopyranosyl Derivatives of Matijin-Su^†

XU Guangcan,YUAN Jie,LIU Qingchuan,HUANG Zhengming,LIANG Guangyi,XU Bixue

2016, 37(8):  1451-1459.  doi:10.7503/cjcu20160222

Asbtract ( )   HTML ( )   PDF (1514KB) ( )  

Figures and Tables | References | Related Articles | Metrics

To explore the effect of the length of the linker on the activities of the derivatives of Matijin-Su(MTS) with potential for hepatic targeting, six galactosyl derivatives of MTS with potential for hepatic targeting were synthesized by binding galactosyl to derivatives of MTS using triethylene glycol or tetraethylene glycol as a linking arm, and their structures were confirmed by means of ¹H NMR, ¹³C NMR, ¹H-¹H COSY, HMQC and ESI-MS. The anti-HBV activities of those compounds were evaluated using HepG2 2.2.15 cells. The screening results showed that all the target compounds had inhibitory effect on HBV DNA replication in HepG2 2.2.15 cells in a dose-response manner. The inhibition rates of compounds 15b(72.24%), 15c(56.49%), 15f(65.24%) on the replication of HBV DNA were better than other tested compounds, when the in concentration of the drug was 50 μg/mL. The results can provide reference for further research of hepatic targeting MTS derivatives. For the evaluation of the hepatic target distribution of galactopyranosyl derivatives of MTS, compound 15b with best anti HBV activity will be selected to do tissue distribution experiments in vivo and comparative study with derivative of MTS(13b) and Y101.



Physical Chemistry

Ionic Hydrogen Bonding Between Arginine Side Chain and Nucleic Acid Bases^†

LI Lei,HUANG Cuiying,JIANG Xiaonan,GAO Xichan,WANG Changsheng

2016, 37(8):  1460-1467.  doi:10.7503/cjcu20160346

Asbtract ( )   HTML ( )   PDF (2436KB) ( )  

Figures and Tables | References | Related Articles | Metrics

The optimal structures of twenty-two hydrogen-bonded complexes composed of one charged arginine side chain molecule and one nucleic acid base in gas phase were obtained at the MP2/6-31+G(d,p) level. The binding energies in gas phase were evaluated at the MP2/aug-cc-pVTZ level including basis set superposition error(BSSE) correction. The optimal structures for these hydrogen-bonded complexes in water solvent were further obtained by using PCM model combined with the MP2/6-31+G(d,p) method. The binding energies in water solvent were evaluated by using PCM model combined with the MP2/aug-cc-pVTZ method. It is found that the ionic hydrogen bonding strength between the arginine side chain and one of the five nucleic acid bases highly correlates to the charge transfer between the two monomers, the electron density at the hydrogen bond critical point, and the second-order stabilization energy. Compared to the neutral hydrogen bond, the ionic hydrogen bond exhibits more significant covalent character. It is also found that the stability of the hydrogen-bonded complexes can be predicted according to the enthalpy change of the protonation reaction of the nucleic acid bases. The more negative the enthalpy change of the protonation reaction, the more stable the hydrogen-bonded complexes.



Studies of (CH₃OH)_n(n=3—12) and [Na(CH₃OH)_n]⁺(n=3—6)via ab initio and ABEEMσπ/MM^†

YU Yongbo,LIU Cui,GONG Lidong

2016, 37(8):  1468-1475.  doi:10.7503/cjcu20160307

Asbtract ( )   HTML ( )   PDF (1259KB) ( )  

Figures and Tables | References | Related Articles | Metrics

The stable structures, charge distributions and binding energies of cyclic methanol cluster(CH₃OH)_n(n=3—12) and [Na(CH₃OH)_n]⁺(n=3—6) were studied via ab initio and the atom bond electronegativity equalization fluctuating charge force field(ABEEMσπ/MM). Based on the ab initio results, the ABEEMσπ/MM fluctuating charge potential function were constructed and the related parameters were determined for the above systems. The results show that the structures, binding energies and other properties from ABEEMσπ/MM are in consistent with the ab initio calculation, and better than the OPLS/AA force field. The average absolute deviation(AAD) of bond length is less than 0.004 nm, and the relative root mean square deviations(RRMSDs) of bond length, bond angle and binding energy are less than 3.8%, 1.7% and 6.8%, respectively. The linear correlation coefficients of the charge distributions of ABEEMσπ/MM and ab initio calculation are all above 0.99.



Synthesis of Hollow PtNi/Graphene Cellular Monolith Catalysts and Their Electrochemical Performance^†

XU Kai,LI Yi,ZHAO Nan,DU Wenxiu,ZENG Weiwei,GAO Shuai,CHENG Xiaonong,YANG Juan

2016, 37(8):  1476-1484.  doi:10.7503/cjcu20160264

Asbtract ( )   HTML ( )   PDF (8223KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Hollow platinum nickel/graphene cellular monolith(PtNi/GCM) electrocatalysts were synthesized via a two-step method of sonochemical-assisted reduction and gelatinization reaction. X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), scanning electronic microscopy(SEM) and transmission electron microscopy(TEM) were employed to characterize the structures, compositions and morphologies of as-prepared catalysts. The activity and stability of the catalysts for oxygen reduction reaction(ORR) were studied with electrochemical workstation and rotating disk electrode(RDE). The results show that different molar ratios of Pt to Ni in the precursor have great influence on the porous structure, particle morphology and dispersion of the catalyst. In particular, the PtNi/GCM electrocatalyst that was prepared with Pt/Ni molar ratio of 1∶1 in the precursor has the desirable structure and was uniformly distributed. The PtNi/GCM showed the excellent electrocatalytic activities and durability toward ORR. The mass and specific activities at half-wave potential of 0.494 V were 1.09 A/mg_Pt and 1.02 mA/cm², respectively, which were 5.4 and 3.5 times those of commercial Pt/C(0.20 A/mg_Pt and 0.29 mA/cm²).



Preparation and Supercapacitance of Ni₃(HCOO)₆/Reduced Graphene Oxide Electrode Materials^†

FU Rongrong,LUO Min,MA Yonghua,YANG Shun

2016, 37(8):  1485-1490.  doi:10.7503/cjcu20160234

Asbtract ( )   HTML ( )   PDF (2984KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Ni₃(HCOO)₆/rGO electrode materials with sandwich structure were obtained via a facile synergistic self-assembly solvothermal route. As a electrode material for supercapacitor, the composites exhibited large specific capacitance and good cycling stability. The rGO loading is important factors in determining the phase, morphology and electrochemical property of as-prepared Ni₃(HCOO)₆/rGO composites. The optimum conditions were achieved as follows: the synthesis temperature of 100 ℃, reaction time of 24 h and 8 mg/mL of graphene oxide addition. Ni₃(HCOO)₆/rGO composite delivered a large specific capacitance of 940 F/g at a scan rate of 5 mV/s in 1 mol/L KOH electrolyte. Also, it displayed good electrochemical stability with 96.28% of the initial capacitance over consecutive 500 cycles at 4 A/g.



Hydrothermal Synthesis of Ni_xCo_1-xS₂ and Its Discharge Performance in Thermal Batteries

YANG Kunkun,ZHAO Ping,YANG Shaohua,ZHAO Yanlong

2016, 37(8):  1491-1498.  doi:10.7503/cjcu20160168

Asbtract ( )   HTML ( )   PDF (3062KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Ni_xCo_1-xS₂(x=0, 0.1, 0.3, 0.5, 0.7, 0.9, 1.0) powders were prepared by hydrothermal method using NiCl₂, CoSO₄ and Na₂S₂O₃ and characterized with X-ray diffractometer(XRD), scanning electron microscope, laser particle size distribution analyzer and differential thermal analyser(DTA). A single cell was prepared with a Ni_xCo_1-xS₂ cathode, a LiSi anode and a LiCl-KCl(MgO) molten salt electrolyte by pressed-power process. The effects of Ni and Co contents in Ni_xCo_1-xS₂ cathode materials on the discharge performance of thermal battery were investigated. The results suggest that the single cell cathode material with Ni_0.3Co_0.7S₂ cathod has the best performance and the resistance is relatively low. The cell voltage can reach 1.899 V, and the specific capacity can reach 276.5 mA·h/g with a cut-off voltage of 1.5 V at a constant current density of 100 mA/cm² and a temperature of 450 ℃.



Degradation of Perfluorooctanoic Acid by UV/Chloride Process^†

GUO Rui,ZHANG Chaojie,ZHANG Geng,ZHOU Qi

2016, 37(8):  1499-1508.  doi:10.7503/cjcu20160156

Asbtract ( )   HTML ( )   PDF (2373KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Based on the characteristic of perfluorooctanoic acid(PFOA) that it is vulnerable to be nucleophile attacked, we developed a new method for the degradation of PFOA in aqueous phase with chloride as a mediator. In this study, 185 nm ultraviolet photolysis of chloride leads to the generation of hydrated electrons, which contribute to the defluorination of PFOA. Chloride, ultraviolet, and anaerobic environment are all the necessary factors to ensure the effective degradation of PFOA. In this system, when the concentration of PFOA is 0.03 mmol/L, the optimal reaction conditions are \begin{array}{c}{c}_{C{l}^{{}^{-}}}\end{array}/c_PFOA=10.0, pH=10.0, with temperature being 25 ℃. Under these conditions, the degradation and defluorination rates of PFOA after 23 h’s reaction are 99.6% and 65.0%, respectively. Kinetic analysis indicated that the decomposition of PFOA fits the first order model with a rate constant of 6.3×10^-3 min^-1. The degradation products are fluorinion, perfluorinated carboxylic acid with short-carbon-chains, formic acid, and acetic acid. According to the degradation products, we proposed two major degradation pathways of PFOA: direct cleavage of C—F bonds and C—C bonds due to the attack by hydrated electrons; and decarboxylating by ultraviolet irradiation and defluorinate by hydrolysis. This method is of great significance to eliminate the PFOA in wastewater.



Synthesis of the Supported Au Polystyrene/poly(acrylic acid) Composite Microspheres and Their pH Regulated Performance^†

TENG Xiaobo,ZHANG Chunxia,ZHANG Ying

2016, 37(8):  1509-1520.  doi:10.7503/cjcu20160084

Asbtract ( )   HTML ( )   PDF (6111KB) ( )  

Figures and Tables | References | Related Articles | Metrics

The core-shell polystyrene(PS)/poly(acrylic acid)(PAA) composite microgels with pH sensitivity were synthesized via two-step polymerization method. Au nanoparticles were supported onto pH sensitivity composite microgels via in situ reduction of chloroauric acid(HAuCl₄) using NaBH₄ as reduction agent and sodium citrate as stabilizer. The results demonstrated that the plasmonic coupling of gold nanoparticles could be regulated, and the diffusion of reactive substrates availably controlled, due to the shrinkage and swelling performance of the shell chains under the different acid and alkali conditions. The optical property and catalytic activity of Au NPs could be regulated by changing the micro-environment of composite microgels. Therefore, the performance of composite materials could be realized the pH-controllable.



Activity of Catalysts Reduced by Plasma in CO₂ Methanation^†

ZHANG Yanping,YANG Chunhui,CHEN Pan,RAN Tangchun,LI Jiao,YIN Yongxiang

2016, 37(8):  1521-1527.  doi:10.7503/cjcu20150948

Asbtract ( )   HTML ( )   PDF (3113KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Ni-Ce/γ-Al₂O₃ and Ni-Ce-LDHs/γ-Al₂O₃ catalyst precursors were synthesized by impregnation and in situ chemical-growing methods, respectively. These precursors were reduced by Ar-H₂ cold plasma jet and conventional H₂ thermal reduction. The evaluation of these catalysts were carried out in a CO₂ methanation reaction system. The results showed that the catalysts reduced by plasma had better catalytic activity, the reaction start-temperature with catalysts reduced by plasma was 20—30 ℃ lower than that with catalysts by conventional method. The catalysts were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), CO₂-temperature programmed desorption(CO₂-TPD), as well as X-ray photoelectron spectrum(XPS). The results showed that plasma reduction could remarkably improve the dispersion of active components, the alkalinity of support and the size of crystal metal particles. It was these improvements that enhanced the activity of catalysts in methanation reaction.



Effect of Yttrium and Citric Acid on the Hydrodesulfurization Performance of Unsupported Nickel Phosphide^†

SONG Hua,YU Qi,XU Xiaowei,SONG Hualin,JIANG Nan,LI Feng,CHEN Yanguang

2016, 37(8):  1528-1534.  doi:10.7503/cjcu20150923

Asbtract ( )   HTML ( )   PDF (3232KB) ( )  

Figures and Tables | References | Related Articles | Metrics

The Yttrium(Y), citric acid(CA) and combined Y and CA modified bulk nickel phosphide(Ni-P) catalysts were prepared by temperature programmed reduction(TPR) method. The catalysts were characterized by means of X-ray diffraction(XRD), N₂-adsorption specific surface area measurements(BET), CO chemisorption uptake measurements, X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM). The effects of Y and CA on catalyst activity for dibenzothiophene(DBT) hydrodesulfurization(HDS) were studied. The results indicated that both Y and CA can promote the transformation from Ni_xP_yO_z amorphous phase to nickel phosphide active phase, suppress the formation of Ni₅P₄ phase and therefore promote the formation of Ni₂P active phase. Addition of Y or CA can increase the surface area and suppress the enrichment of phosphorus on surface, leading to a smaller and highly dispersed active phase particles. The Y, CA and combined Y and CA modified nickel phosphide catalysts were proved to possess higher HDS activity than Ni-P sample. The DBT conversions of catalysts followed the order: Y-Ni-P-CA>Ni-P-CA>Y-Ni-P>Ni-P. At the conditions of 340 ℃, 3.0 MPa, WHSV of 1.5 h^-1 and H₂/oil volume ratio of 700, the DBT conversion of the Y-Ni-P-CA catalyst reached 97%, which is an increase of 35% when compared with that found for bulk Ni-P sample.



Synthesis, Characterization and Aggregation Behavior of Polyethylene Glycol-conjugated Hydroxycamptothecin^†

QIU Chuanlong,LI Chunfang,LI Dongxiang,HOU Wanguo

2016, 37(8):  1535-1541.  doi:10.7503/cjcu20150895

Asbtract ( )   HTML ( )   PDF (1748KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Methoxypolyethylene glycol(MPEG)-conjugated hydroxycamptothecin(HCPT), denoted as MPEG-HCPT, was synthesized via etherification reaction between terminal hydroxyl of MPEG and 10-hydroxy of HCPT, and they were characterized via ¹H NMR and FTIR. The effect of MPEG conjugation on the solubility and lactone-ring stability of HCPT was investigated, as well as its aggregation behavior. The mass fraction of HCPT in the derivative was approximately 33% and the solubility of the MPEG-HCPT in buffer solutions of pH 4.8 and 7.2 at 37 ℃ were respectively 5.23 and 7.90 mmol/L, significantly higher than those of pristine HCPT(0.0026 and 0.035 mmol/L). The pK_ah(K_ah, the apparent hydrolysis equilibrium constant) of MPEG-HCPT at 37 ℃ was determined to be approximately 7.12, higher than that of pristine HCPT(ca. 6.67), indicating that the MPEG conjugation could enhance the lactone-ring stability of HCPT. The MPEG-HCPT exhibited obvious surface activity, and could form aggregates in water with a aggregation micelle concentration of 0.46 mmol/L.



Polymer Chemistry

Dual Light-emitting Properties of Hydroxyl-terminated Poly(lactic acid) Based on Benzophenone Derivatives^†

RONG Jiameng,ZHOU Cao,XU Dong,SUN Wei,HUANG Xiaowen,ZHANG Xingyuan

2016, 37(8):  1542-1550.  doi:10.7503/cjcu20160326

Asbtract ( )   HTML ( )   PDF (4388KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Two kinds of benzophenone derivatives:(4-[(2-hydroxyethyl)(methyl)amino] phenyl) benzophenone(NBP), (4-chlorophenyl)(4-[(2-hydroxyethyl)(methyl)amino] benzophenone(NBP-Cl), and a series of hydroxyl-terminated polylactic acid(PLA) with different molecular weight were prepared based on D,L-lactide polymerization. The structures and properties of NBP, NBP-Cl and PLA were characterized. Optical test results showed that the NBP and NBP-Cl only had fluorescence emission property at room temperature, however, PLA demonstrated fluorescence and phosphorescence dual light-emitting properties; the heavy atom effect enhanced the room temperature phosphorescence of PLA, but which decreased the phosphorescence lifetime; with the decrease of the molecular weight of PLA, the phosphorescence lifetime increased and then reduced. PLA thermal gravimetric analysis(TGA) data showed that this material had excellent thermal performance, which greatly broaden the applications of the dual light-emitting materials.



Preparation and Properties of Surface Imprinted Magnetic Cellulose Microsphere with Highly Selective Adsorption^†

GE Hao,HUANG Hailong,XU Min

2016, 37(8):  1551-1558.  doi:10.7503/cjcu20160248

Asbtract ( )   HTML ( )   PDF (3243KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Molecularly imprinted magnetic composite microspheres(MIP-MCM) were prepared by a surface functional monomer-directing system. Cellulose and Fe₃O₄ composite microsphere was the core and then was coated a layer of MIP on the surface. Fourier transform Infrared spectra(FTIR), X-ray powder diffraction(XRD), vibrating sample magnetometry(VSM) methods were used to characterize the structure of MIP-MCM. In this article, Rhodamine B(RhB) was chosen as the template molecule. The adsorption abilities of MIP-MCM toward RhB were studied through adsorption kinetics and adsorption thermodynamics. The adsorption kinetics curves met pseudo-second-order model more. The adsorption isotherms could be described by both Langmuir and Freundlich isotherm models. The maximum adsorption amount was calculated to be 0.542 mg/mg, much higher than the common adsorbents. MIP-MCM was also adsorption-selective to RhB with highly regenerate and kept stable in a wild pH and temperature range. In brief, MIP-MCM is very potential in the application of removal of dye and sewage treatment.



Reversible Controlling Underwater Oil Adhesion on Shape Memory Polymer Surface^†

LÜ Tong,CHENG Zhongjun,LAI Hua,ZHANG Enshuang,LIU Yuyan

2016, 37(8):  1559-1564.  doi:10.7503/cjcu20160231

Asbtract ( )   HTML ( )   PDF (3973KB) ( )  

Figures and Tables | References | Related Articles | Metrics

A surface with shape memory microstructures was prepared by the template method, after O₂ plasma. The surface shows low adhesive underwater superoleophobicity. It is found that under the external pressure, the surface would lose the underwater superoleophobicity for the destroyed microstructure, and meanwhile, the surface becomes high adhesive to the oil droplet. After heating the surface at 120 ℃ and plasma action, both surface microstructure and the low adhesive superhydrophobicity can be recovered. The results indicate that the adhesive property can be controlled reversibly by controlling the surface microstructures. Different microstructures results in different wetting states, as a result, the surface shows different adhesions. On the surface with hierarchical structures, oil droplet resides in the low adhesive Cassie state, while on the crushed surface, the oil droplet resides in the high adhesive Wenzel state.



Synthesis of Oil/Water Separation Membranes via Grafting Acrylic Acid onto Poly(vinylidene fluoride) Modified by Tetraethyl Ammonium Hydroxide^†

YAN Kaibo,GUO Guibao,LIU Jinyan

2016, 37(8):  1565-1572.  doi:10.7503/cjcu20160224

Asbtract ( )   HTML ( )   PDF (2758KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Poly(vinylidene fluoride)-graft-poly(acrylic acid)(PVDF-g-PAA) membranes were prepared via phase bulk modification in tetraethyl ammonium hydroxide(TEAH) liquid, grafting acrylic acid(AA) onto PVDF by benzoyl peroxide(BPO) as a initiator. After that, the copolymer was casted into a flat membrane via immersion phase inversion. The chemical composition, morphology and the separation performance of the PVDF-g-PAA membrane were charaterized. Moreover, the effect of variable grafting conditions on grafting degree was investigated as well as the optimal surface contact angle for the grafting ration was obtained. It was proved that the PVDF was taken off HF to produce carbon double bonds and acrylic acid was grafted onto the modified PVDF backbones, forming a homogeneous pore distribution in interior and exterior of the membrane. The water contact angle of PVDF-g-PAA membranes decreased with increasing the grafting degree. The optimized hydrophilicity of the modified PVDF membrane was modified with 45%(mass fraction) of AA at 85 ℃ for 4 h, when this condition the grafting degree of membrane was 20.1%; the porosity and mean pore size was 65.3% and 78.0 nm, respectively; the contact angle decreased from 57.5° to 14.3° within 60 s. Water flux increased to 571.33 L/(m²·h), rejection ratio and flux recovery ratio up to 94.3% and 88.7%, respectively. The flux decline ratio was only 9.8%. The separation performance of the PVDF-g-PAA membrane was significant improvement compared to that of the pure PVDF membrane.



Experimental Study and Theoretical Phase Diagram Calculation for Polystyrene Membranes Prepared by Supercritical CO₂-induced Phase Inversion^†

LIU Xuewu,CHEN Shuhua,ZHAN Shiping

2016, 37(8):  1573-1579.  doi:10.7503/cjcu20160208

Asbtract ( )   HTML ( )   PDF (3686KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Microporous asymmetric polystyrene(PSt) membranes were prepared by supercritical CO₂-induced phase inversion. The experiments were designed and conducted to investigate the effects of different process parameters, such as temperature, CO₂ pressure and PSt concentration in casting solution, on the membrane morphologies, pore size distribution and especially on the porosity of the membranes. The ternary phase diagrams of polystyrene/supercritical CO₂/toluene system were determined based on the extended Flory-Huggins theory of polymer solutions of Tompa. The prepared PSt membrane had a cellular structure. The porosity of the products was in the range of 53.54%—84.67%; and it showed a tendency of increasing to a peak and then decreasing with the increase of each parameter(temperature, pressure or PSt concentration). The theoretical phase diagrams indicated that pressure has more influence in changing the binodal curve location than that of temperature.



Preparation and Properties of Flame Retardant Waterborne Polyurethane Nanocomposites via Click Reaction^†

LI Xingjian,JU Yunpeng,CHANG Degong,ZHANG Yiheng

2016, 37(8):  1580-1588.  doi:10.7503/cjcu20160177

Asbtract ( )   HTML ( )   PDF (5376KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Polyurethane bearing the alkyne functions as pendant groups was synthesized via functional monomer 2,2-di(prop-2-ynyl) propane-1,3-dio as chain extender. Flame retardant waterborne polyurethane(WPU) nanocomposites were prepared by the Click reaction between alkyne-functionalized PU and azido-modified nano-montmorillonite(MMT), nano-aluminum hydroxide(ATH) and magnesium hydroxide(MH). The structures of the flame retardant WPU nanocomposites were characterized by Fourier transform Infrared spectrometer(FTIR), proton nuclear magnetic resonance spectroscopy(¹H NMR) and scanning electron microscopy(SEM). The influence of the ratio of nano flame retardants and preparation methods on limit oxygen index, dynamic combustion performance and thermal degradation behavior of the WPU nanocomposites were studied by the comparative study. The findings on flame resistance study indicated that when the mass fractions of MMT-N₃, MH-N₃ and ATH-N₃ were 7%, 2% and 1%, respectively, the oxygen index of the composites prepared by Click reaction was 7% higher than that of pure WPU, time to ignition was lengthened from 10 s to 29 s, and the peak heat release rate and smoke release rate were reduced by 41% and 42%, respectively. TGA results showed that when the mass fraction of MMT-N₃ of 10%, the temperature at 50% mass loss of MMT/WPU composites prepared by Click reaction increased 21 ℃ compared with the WPU. SEM analysis of the composite section and combustion residue showed that Click reaction is an effective method to disperse nanomaterials in polymer matrices.