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01 October 2018, Volume 34 Issue 5

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CONTENTS

2018, 34(5):  0-0. 

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Letter

Anti-TMV and Insecticidal Potential of Four Iridoid Glycosides from Gardenia Jasminoides Fruit

LI Ling, ZOU Jiyong, XIA Qing, CUI Hongmin, YOU Shengyong, LIU Yuxiu, WANG Qingmin

2018, 34(5):  697-699.  doi:10.1007/s40242-018-8197-8

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Articles

Crystal Structure and Photoluminescence Properties of Two Barium(Ⅱ) MOFs

LI Kai, HE Kunhuan, LI Quanwen, XIA Bin, WANG Qinglun, ZHANG Yinghui

2018, 34(5):  700-704.  doi:10.1007/s40242-018-8054-9

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In this article, two Ba(Ⅱ) metal-organic frameworks(MOFs), {[Ba(BPS)(H₂O)₂]·H₂O}_n(1) and[Ba(BPS)(H₂O)₂]_n(2)(H₂BPS=4,4'-bibenzoic acid-2,2'-sulfone), were synthesized and characterized. X-Ray crystal structural analyses reveal that compounds 1 and 2 have different structures, which is probably related to different coordination modes of ligand in compounds 1 and 2. It is remarkable that compounds 1 and 2 both show excellent thermal stability. The solid-state emission spectra reveal that compounds 1 and 2 both present strong luminescence emission bands at room temperature.



Au Nanoparticles Loaded on Hollow TiO₂ Microspheres with (001) Exposed Facets: a Strategy for Promoting Photocatalytic Performance

WANG Shumin, YAN Xiaoxia, ZHU Yan, DENG Dongmei, HE Haibo, LUO Liqiang

2018, 34(5):  705-710.  doi:10.1007/s40242-018-8047-8

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Au nanoparticles loaded TiO₂ hollow microspheres with exposed (001) facets(Au-HTFs) were synthesized through template-free hydrothermal process combined with a chemical reduction role. Au-HTFs displayed excellent photocatalytic activity in catalyzing oxidization reaction in organic pollutant system, which originates from the synergistic effect of the reactive (001) facets and Au nanoparticles with a wide range of absorption in visible region based on localized surface plasmon resonance effect. The unique synergistic effect could largely increase the photocatalytic performance resulting from the improvements of both the visible light aborption and the recombination of electron-hole pairs. Our findings revealed that among Au-HTFs with different Au loading percentages, Au-HTFs with 2%(mass fraction) Au loading possessed the superior photocatalytic activity.



Formation of Oxygen Vacancies on the {010} Facets of BiOCl and Visible Light Activity for Degradation of Ciprofloxacin

ZENG Xiaoxing, GONG Xiaofeng, WAN Yiqun, HE Ruyang, XU Zhaodi

2018, 34(5):  711-718.  doi:10.1007/s40242-018-8035-z

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BiOCl nanosheets with oxygen vacancies on the exposed {010} facets were assistant-synthesized by triethanolamine(TEOA) via hydrothermal method. We explored the surface properties, crystal structure, morphology and optical absorption ability of the prepared samples via various characterization technologies. The results indicate that the morphologies and microstructures of the obtained samples depend on the amount of TEOA in the synthesis. The addition of TEOA induces the production of oxygen vacancy on the surface of the samples. Therefore, the synthesized samples with TEOA-assistance hold higher photoactivity for the degradation of colorless antibiotic agent ciprofloxacin(CIP) under visible light(λ ≥ 420 nm). The obtained sample upon the addition of 20 mL of TEOA exhibits the highest photocatalytic performance, which is nearly 14 times as high as that of the sample prepared without TEOA and twice as high as that of the prepared samples with NaOH or NH₃·H₂O. The possible degradation mechanism was discussed on the basis of the experiment results.



Highly Efficient Synthesis of Au₁₃₀(SPh-Br)₅₀ Nanocluster

REN Xiuqing, FU Xuemei, LIN Xinzhang, LIU Chao, HUANG Jiahui, YAN Jinghui

2018, 34(5):  719-722.  doi:10.1007/s40242-018-8027-z

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We reported the synthesis of Au₁₃₀(SPh-Br)₅₀(Br-Ph-SH=4-bromothiophenol) nanocluster with high purity and high yield via "size focusing" and "ligand exchange" processes. The time of synthetic process was significantly reduced compared with previous synthetic routine. Au₁₃₀(SPh-Br)₅₀ was determined by UV-Vis absorption spectroscopy and matrix-assisted laser desorption ionization(MALDI) mass spectroscopy. Thermo-gravimetric analysis (TGA) and size-exclusion chromatogram(SEC) analyses confirmed the purity of Au₁₃₀(SPh-Br)₅₀. The yield of gold nanoclusters was 20% (based on HAuCl₄).



(3,3)-Connected Three-dimentional Supramolecular Metal Organic Polyhedral Based on Nanometresized Ligand with Magnetism Properties

ZHOU Xiaojing, LIU Lili, TAI Xishi, ZHANG Hui

2018, 34(5):  723-726.  doi:10.1007/s40242-018-8004-6

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A three-dimentinal metal organic framework[Co₂(L)Cl(DMF)₂(H₂O)](DMF)₃(H₂O)₃ based on the nanometresized ligand 4,4',4"-[1,3,5-benzenetriyltris(carbonylimino)]trisbenzoic acid was synthesized, and characterized by means of single-crystal X-ray diffraction, elemental analysis, infrared spectroscopy, thermogravimetry analysis and magnetism. This obtained structure can be considered to be constructed from 2D layer, which displays the topology of hbc based on Co₂(COO)₃ secondary building unit, and further to be linked into a 3D supramolecular architecture by N-H…O hydrogen bonds. The magnetism of the complex was carried out, which shows ferromagnetic exchange interactions.



CuCl₂/8-Hydroxyquinoline-catalyzed α-Arylation of Diethyl Malonate with Aryl Bromides

YANG Jiuquan, WU Guojie, HE Yupeng, HAN Fushe

2018, 34(5):  727-731.  doi:10.1007/s40242-018-8137-7

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A general and efficient coupling of aryl bromides with diethyl malonate is presented. The reaction provided the α-arylated diethyl malonates in moderate to good yields with a low loading of CuCl₂(5%, molar fraction) and 8-hydroxyquinoline(5%, molar fraction). This method has good compatibility for a wide range of aryl bromides.



Structure and Activity of a New Sapogenin from Chlorophytum laxum R. Br.

CHU Chenliang, CUI Ting, LI Sida, ZHAN Ruoting, GAO Youheng

2018, 34(5):  732-735.  doi:10.1007/s40242-018-8114-1

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A new steroidal sapogenin named 25-R-spirosta-3,5-dien-12β-ol(1) was isolated from the dried roots of Chlorophytum laxum R. Br. along with five known compounds, namely, diosgenin(2), stigmasterol(3), β-sitosterols(4), estigmasterol-3-O-β-D-glicopyranoside(5) and 3-O-β-authemisol(6). The structure of compound 1 was elucidated by the analysis of IR, HRESI-MS, 1D and 2D NMR spectral data. Compounds 2-5 were isolated from Chlorophytum laxum R. Br. In addition, all the compounds were evaluated for cytotoxicity on the human nasopharyngeal carcinoma cancer cell line 5-8F. Among them, the newly identified 25-R-spirosta-3,5-dien-12β-ol(1) and diosgenin(2) exhibited high cytotoxicity on 5-8F cells, with IC₅₀ values of 24.8 and 41.9 μmol/L, respectively.



Formation of β-Lactones by[2+2] Cycloaddition of Dichloroketene with Unreactive Carbonyl Compounds

DONG Xu, ZHANG Chunxia, XU Jian, ZHANG Yue, ZHAO Ying, CHEN Li

2018, 34(5):  736-743.  doi:10.1007/s40242-018-8088-z

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We report a modified process that dichloroketene generated in situ from trichloroacetyl chloride and Zn powder reacts with unreactivate carbonyl groups to afford dichloro-β-lactones in moderate to good yields. Subsequently, monochloro-β-lactones, β-lactones and β-hydroxy ester are obtained by dechlorination under different reaction conditions.



Synthesis and Bioactivity Evaluation of Novel N-Pyridylpyrazolemethanamine Derivatives

HUA Xuewen, WEI Wei, ZHU Liangliang, ZHOU Yunyun

2018, 34(5):  744-750.  doi:10.1007/s40242-018-8083-4

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To further explore the structure-activity relationship(SAR) of amide bridge moeity of anthranilic diamides derivatives, a series of N-pyridylpyrazole derivatives was designed, synthesized and their biological activities were evaluated. The chemical structures of novel target compounds were confirmed by ¹H nuclear magnetic resonance (NMR), ¹³C NMR and elemental analyses(EA). Bioassay results of insecticidal activity demonstrated that the target compound 6h displayed 70% lethality rate against oriental armyworms at 200 mg/L. Moreover, most compounds displayed moderate to excellent antifungicidal activities against Fusarium oxysporum f. sp. cucumerinum, Cercospora arachidicola Hori, Botryosphaeria dothidea, Alternaria solani, Gibberella zeae and Phytophthora capsici at 50 mg/L. In particular, compound 6e showed 61.5% and 92.3% inhibition rate against Cercospora arachidicola Hori and Botryosphaeria dothidea, which was superior to the commercial positive control Chlorothalonil. These results will provide a potential clue for exploring novel high-effective agrochemicals.



Base-catalyzed Formation of Enamines from β,β-Dicyanostyrene Derivatives with N-Bromosaccharin

KANG Nan, CHEN Zhanguo

2018, 34(5):  751-757.  doi:10.1007/s40242-018-8055-8

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A new method for the synthesis of functional enamines from β,β-dicyanostyrene derivatives and N-bromosaccharin(NBSA) was developed. In the presence of Na₂CO₃, the the reaction of β,β-dicyanostyrene derivatives with NBSA can generate the corresponding enamines smoothly in a mixed solvent of dichloromethane and N,N-dimethylformamide (DMF)(volume ratio 1:1) at 50℃. The reaction of 14 kinds of β,β-dicyanostyrene derivatives with NBSA was investigated. Screened olefins afforded the corresponding enamines in good to excellent yields(up to 94%), indicating that the method has a wide adaptability for the substrate. The catalyst used is inexpensive and stable for storage. The amino groups of all products in their structures are on the α-position of products, revealing the reaction has an excellent regioselectivity. The possible pathway involving aminobromination of β,β-dicyanostyrene derivative with NBSA first and then elimination of HBr process in one pot has been proposed. The structures of all products were confirmed by ¹H NMR, ¹³C NMR and HRMS analysis.



QM/MM Investigations on the Bioluminescent Decomposition of Coelenterazine Dioxetanone in Obelin

YUE Ling

2018, 34(5):  758-766.  doi:10.1007/s40242-018-8237-4

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The bioluminescent mechanism of colenterazine dioxetanone(CZD) in the photoprotein of Obelia(obelin) was investigated by the combined quantum and molecular mechanics(QM/MM) method at TD-DFT level, which involved the real protein environment in decomposition of 1,2-dioxetanones. The anionic decomposition of CZD in (CZD+H₂O)^- model can go through a charge transfer(CT) catalyzed asynchronous-concerted process, which can be elucidated by the gradual reversible CT initiated luminescence(GRCTIL) mechanism. The neutral CZD in (CZDH+H₂O) decomposes through an uncatalyzed non-CT biradical process. The anionic decomposition catalyzed by CT, in which the S₀/S₁ surface "double crossing" hence has ability to provide high quantum yield of singlet chemiexcitation is thus more possible in bioluminescence of photoprotein.



Exploration on Charge Transfer and Absorption Spectra of Spiro[fluorene-9,90-xanthene]-based Polyoxometalate Hybrids Toward High Performance Dye-sensitized Solar Cell

WANG Shuo, GAO Yu, SU Xiaofang, YAN Likai

2018, 34(5):  767-771.  doi:10.1007/s40242-018-8168-0

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Based on spiro[fluorene-9,90-xanthene](SFX, dye 1), the Lindqvist-type polyoxometalate(POM) functionalized with SFX and its derivatives(dyes 2-4) used in dye-sensitized solar cells(DSSCs) were designed and investigated with the density functional theory(DFT) and time-dependent DFT(TD-DFT) calculations. The results indicate that Lindqvist-type POM is the main contribution to the lowest unoccupied molecular orbital(LUMO) and affects the LUMO energies of dyes 2-4. The maximum absorptions of the designed dyes containing POM(dyes 2-4) are red shifted comparing with that of dye 1. The introduction of electron-donating group onto SFX segment is helpful to red shift the absorption spectra. The major factors affecting the performance of DSSCs, including light harvesting and electron injection were evaluated. Considering the absorption spectra and photovoltaic parameters, dyes 3 and 4 are promising high performance dye sensitizers in n-type DSSCs.



Multispectral Plasmon of Anisotropic Core-shell Gold Nanorods@SiO₂: Dual-band Absorption Enhancement with Coupling Dye Molecules

CHE Yuping, WANG Yang, YOU Tingting, CHANG Huaiqiu, YIN Penggang, ZHAI Jin

2018, 34(5):  772-780.  doi:10.1007/s40242-018-8120-3

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Direct evidence of effects of surface plasmon resonance(SPR) of gold nanorods(GNRs) on dual-band light absorption enhancement with coupling dye molecules was reported by introducing gold nanorod@SiO₂(GNR@SiO₂) core-shell nanoparticles into a photoelectric conversion system. GNR with asymmetric shape had unusual anisotropic SPR[transversal surface plasmon resonance(TSPR) and longitudinal surface plasmon resonance(LSPR)]. The excellent SPR of GNR made it a promising candidate as enhancing light absorption material to increase power conversion efficiency(PCE). The PCE was improved nearly 17.2% upon incorporating GNRs, mostly due to the increase in J_sc, while V_oc and FF were unchanged. The improvement was mostly contributed by the SPR of the GNRs with coupling of N719. And there was also a complementary to N719 in visible light range. Therefore, SPR is an effective tool in improving the photocurrent and consequently enhancement of PCE. The TSPR and LSPR effects of GNRs on light harvesting were reflected in the increased monochromatic incident photon-to-electron conversion efficiency(IPCE). We also utilized finite-difference time-domain(FDTD) to investigate the light coupling of GNRs with TiO₂. Compare to the base anode, the IPCE of optimized electrode showed significant improvement and peaks broadening at 500-600 nm and 610-710 nm. We got an increase in overall conversion efficiency from 6.4% to 7.5%.



Accurate Control of Deuterated Locations and Amount of Deep Blue Ir(dfpypy)₂pic for Phosphorescent Efficiency Enhancement: Evaluations from Theoretical Aspect

Xiaoyu, WANG Yu, FAN Yong, BAI Fuquan, XU Jianing

2018, 34(5):  781-785.  doi:10.1007/s40242-018-8086-1

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A well-known deep-blue emitting iridium(Ⅲ) complex was selected for deuterium isotope effect evaluation, both on deuterated locations and numbers, through theoretical investigation. It was revealed that the containment of the d site deuteriation of ancillary ligand picolinate enabled the non-radiative deactivation process to be repessed, and thereby improving the quantum efficiency through such a simple and controllable approach.



Theoretical Study on the Kinetics for the Reactions of Heptyl Radicals with Methanol

ZHAO Zhongrui, SONG Jinou, SU Boyang, WANG Xiaowen

2018, 34(5):  786-791.  doi:10.1007/s40242-018-8026-0

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Ab initio study of the reactions of n-heptyl radicals(1-C₇H₁₅, 2-C₇H₁₅, 3-C₇H₁₅, and 4-C₇H₁₅) with methanol was conducted over the temperature range of 300-1500 K. Transition states for the reaction channels producing C₇H₁₅OH, CH₃, C₇H₁₅OCH₃, H, C₇H₁₆, CH₂OH and CH₃O were identified and the geometries of all stationary points were calculated at BB1K/MG3S level of theory. The potential barrier heights of the corresponding transition states were predicted by the CBS-QB3//BB1K and G4//BB1K methods, indicating that the eight H-abstraction channels are more kinetically favorable than the channels where OH transfers from CH₃OH to C₇H₁₅ and where the C₇H₁₅OCH₃+H products are given. The rate constants of H-abstraction channels were calculated with TST and TST/Eck. Both the forward and reverse rate constants have positive temperature dependence and the tunneling effect is only important at the temperature lower than 700 K. For the reactions of H-atom abstraction from methyl in CH₃OH by n-heptyl, a reverse and the corresponding forward rate constant are roughly equal. For the reactions of H-atom abstraction from OH in CH₃OH by n-heptyl, a reverse rate constant is larger by several orders of magnitude than the corresponding forward one.



Adsorption Mechanism of Composite Whisker on Copper Ions and Lead Ions

LIU Juan, XUE Wenjing, BAO Yongchao, CHENG Wanyi

2018, 34(5):  792-797.  doi:10.1007/s40242-018-8015-3

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A new kind of inorganic composite adsorbent based on chitin whiskers(CHW) and potassium tetratitanate whiskers(PTW) was synthesized via the thermal deposition to remove Cu²⁺ and Pb²⁺ from wastewater. CHW could be successfully coated on the surface of PTW when thermal treated 8 times. The adsorption process was better fitted with the Langmuir and Freundlich models. The adsorption process was more conformed to the Pseudo-second-order model. The results from XPS(X-ray photoelectron spectrum) further show that the adsorption mechanism between CHW-PTW and Cu²⁺, Pb²⁺ are both ion exchange and chemical adsorption. Thermodynamic parameters suggest that the adsorption processes are nonspontaneous. The adsorption of Cu²⁺ and Pb²⁺ is endothermic and exothermic, respectively.



Metastable Phase Equilibrium in the Reciprocal Quaternary System LiCl+MgCl₂+Li₂SO₄+MgSO₄+H₂O at 348.15 K and 0.1 MPa

YU Xiaoping, WANG Qin, GUO Yafei, DENG Tianlong

2018, 34(5):  798-802.  doi:10.1007/s40242-018-7407-8

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The metastable solubilities and the physicochemical properties including density and pH of the reciprocal quaternary system(LiCl+MgCl₂+Li₂SO₄+MgSO₄+H₂O) at 348.15 K and 0.1 MPa were determined using the isothermal evaporation method. The dry-salt diagram and water-phase diagram were plotted based on the experimental data. There are five invariant points, eleven univariant curves, and seven crystallization zones corresponding to hexahydrite, tetrahydrite, kieserite, bischofite, lithium sulfate monohydrate, lithium chloride monohydrate and lithium carnallite. Comparison between the stable and metastable diagrams at 348.15 K indicates that the metastable phenomenon of magnesium sulfate is obvious, and the crystallization regions of hexahydrite and tetrahydrite disappear in the stable phase diagram. A comparison of the metastable dry-salt phase diagrams at 308.15, 323.15 and 348.15 K shows that with the increasing of temperature the epsomite crystallization zone disappears from the dry-salt phase diagram of 303.15 K, and a new kieserite crystallization zone is presented at 348.15 K. The density and pH in the metastable equilibrium solution present regular change with the increasing of Jänecke index J(2Li⁺), and the calculated densities using the empirical equation agree well with the experimental values.



Solid-liquid Equilibria in the Ternary System (NaCl+SrCl₂+H₂O) and (KCl+SrCl₂+H₂O) at 288.15 K and 0.1 Mpa

LI Dongchan, FAN Rong, YANG Sennan, ZHANG Ziyi

2018, 34(5):  803-807.  doi:10.1007/s40242-018-7395-8

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Solid-liquid phase equilibria of the two ternary systems (NaCl+SrCl₂+H₂O) and (KCl+SrCl₂+H₂O) at T=288.15 K and p=0.1 MPa were studied using the isothermal dissolution equilibrium method. Solubilities of the equilibrium liquid phase were determined, and the solids were also investigated by the Schreinemaker method of wet residues. In the ternary system (NaCl+SrCl₂+H₂O) at 288.15 K, there is one invariant point corresponding to (NaCl+SrCl₂·6H₂O) and two crystallization regions corresponding to NaCl and SrCl₂·6H₂O. The crystallized area of SrCl₂·6H₂O decreased with the increasing temperature, while that of NaCl increased slightly. In the ternary system (KCl+SrCl₂+H₂O) at 288.15 K, there is one invariant point(KCl+SrCl₂·6H₂O) and two crystallization regions corresponding to KCl and SrCl₂·6H₂O. Both systems belong to a simple eutectic type, and neither double salts nor solid solutions were formed. On the basis of Pitzer-Harvie-Weare model, the solubilities of the two systems at 288.15 K were demonstrated. A comparison showed that the calculated solubilities agreed well with the experimental data.



Preparation of Ag-MnFe₂O₄-bentonite Magnetic Composite for Pb(Ⅱ)/Cd(Ⅱ) Adsorption Removal and Bacterial Inactivation in Wastewater

LI Qin, ZHAO Yongsheng, QU Dan, WANG Haoying, CHEN Jin, ZHOU Rui

2018, 34(5):  808-816.  doi:10.1007/s40242-018-7372-2

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An Ag-MnFe₂O₄-bentonite composite was synthesized by a chemical co-precipitation method and used for adsorption removal of Pb(Ⅱ), Cd(Ⅱ) and disinfection. The result of X-ray diffraction indicate that the diffraction peaks of MnFe₂O₄ and Ag can be perfectly indexed to the cubic spinel MnFe₂O₄(JCPDS No.88-1965) and metallic Ag(JCPDS No.41-1402), respectively. The results of scanning electron microscopy and energy dispersive X-ray spectroscopy manifest the deposition of MnFe₂O₄ and Ag on the bentonite surface and the presence of Mn, Fe and Ag. The result of X-ray photoelectron spectroscopy displayed that the composition of Ag-MnFe₂O₄-bentonite was Mn(Ⅱ), Fe(ⅡI) and metallic Ag. The analysis of Brunauer-Emmett-Teller showed that the specific surface area of Ag-MnFe₂O₄-bentonite was the largest compared with that of bentonite, MnFe₂O₄ and MnFe₂O₄-bentonite. Thermodynamic studies revealed that the adsorption of Pb(Ⅱ) and Cd(Ⅱ) ions was spontaneous and endothermic. Langmuir model showed an adsorption capacity of 129.87 mg/g for Pb(Ⅱ) and 48.31 mg/g for Cd(Ⅱ) ions. The adsorption kinetics of Pb(Ⅱ) and Cd(Ⅱ) ions onto Ag-MnFe₂O₄-bentonite can be best described by a pseudo-second-order model. The adsorption rate constant of the pseudo-second-order model was 0.0019 g·mg^-1·min^-1 for Pb(Ⅱ) and 0.0065 g·mg^-1·min^-1 for Cd(Ⅱ) ions. In addition to the adsorption experiment, the antibacterial properties of Ag-MnFe₂O₄-bentonite were studied through plate count method. Gram-negative(G-) bacteria Escherichia coli and Gram-positive(G+) bacteria Lactobacillus plantarum were used to test the antibacterial properties. The results showed that the composite demonstrated excellent antibacterial activity. Thus, Ag-MnFe₂O₄-bentonite can be employed as an adsorbent as well as an antimicrobial agent.



Adsorption Activity and Molecular Dynamics Study on Anti-corrosion Mechanism of Q235 Steel

ZHANG Weiwei, LI Huijing, WU Yanchao, LUO Qi, LIU Huanhuan, NIU Lin

2018, 34(5):  817-822.  doi:10.1007/s40242-018-7349-1

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The correlation between inhibition efficiency and molecular structures of the inhibitor during hydrochloric acid corrosion of Q235 steel was studied by quantum chemical calculations and molecular dynamics(MD) simulation. The proton affinity(PA) calculations demonstrated that 2-(quinolin-2-yl)quinazolin-4(3H)-one inhibitor has the tendency to be protonated in hydrochloric acid, which was in good agreement with experimental observations. Besides, quantum chemical parameters revealed that the protonated corrosion inhibitor molecules were more easily adsorbed on Q235 steel surface and improved the corrosion resistance of steel. MD simulations were implemented to search for the adsorption behavior of this molecule on Fe (110) surface, which might be used as a convenient tool for estimating the interaction mechanism between inhibitor and iron surface.



Metastable Phase Equilibrium of the Quaternary System Na⁺, Rb⁺, Mg²⁺//Cl^--H₂O at 298.2 K

WU Liting, ZENG Ying, YAN Dongming, FENG Shan, YU Xudong

2018, 34(5):  823-827.  doi:10.1007/s40242-018-7304-1

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The component solubilities, densities and refractive indices of the quaternary system Na⁺, Rb⁺, Mg²⁺//Cl^--H₂O at 298.2 K were measured using an isothermal evaporation method. Based on the gathered data, a metastable phase diagram, a water content diagram, and a density/refractive index vs. composition diagram were constructed. The results show that this system is of a complex type with a double salt rubidium carnallite (RbCl·MgCl₂·6H₂O) formed at 298.2 K. Double salt rubidium carnallite, whose component point locates in its own crystallization zone in the dry salt phase diagram, belongs to congruent double salt at 298.2 K. Accompanied by the double salt that was formed, there are two invariant points in the phase diagram that cosaturated with three salts and an equilibrated solution. The cosaturated salts for the two invariant points are MgCl₂·6H₂O+RbCl·MgCl₂·6H₂O+ NaCl and NaCl+RbCl+RbCl·MgCl₂·6H₂O, respectively. Both invariant points are commensurate invariant points in the evaporation process, and the two invariant points are evaporative dry points. The sizes of the crystalline regions of the salts are in the order of NaCl > RbCl > RbCl·MgCl₂·6H₂O > MgCl₂·6H₂O.



Ceiling Degree of Polymerization for Brush Polymers Prepared via ROMP of Poly(tert-Butyl Acrylate) Macromonomers

QIAO Yaping, YUAN Xiaoyan, ZHAO Yunhui, REN Lixia

2018, 34(5):  828-832.  doi:10.1007/s40242-018-8126-x

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Controlled preparation of brush polymers is important in the design of functional materials. In this study, poly(tert-butyl acrylate) macromonomers functionalized with norbornenyl end group(NB-PtBA) were synthesized via atom transfer radical polymerization in three different molecular weights, 2000(NB-PtBA-2k), 3000(NB-PtBA-3k), and 8000(NB-PtBA-8k). Additionally, brush polymers with PtBA as side chains were synthesized via ring-opening metathesis polymerization(ROMP). Kinetic studies on ROMP of NB-PtBA showed that there was a ceiling degree of polymerization(CDP) for the brush polymers, beyond which the polymerization of NB-PtBA was out of control. For brush polymers of P[NB-PtBA-2k] and P[NB-PtBA-3k], CDPs were estimated to be ca. 400, but the value of P[NB-PtBA-8k] was ca. 100. Therefore, the controlled ROMP of brush polymers was critical at the CDP limit with increased macromonomer molecular weight.



Preparation and Evaluation of iPP/GO Microfiltration Membrane with Enhanced Antifouling Property

WANG Fang, ZHAO Yajing, WANG Xin, LI Yingdong, CHENG Lan, LI Pingli

2018, 34(5):  833-838.  doi:10.1007/s40242-018-8038-9

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Isotactic polypropylene(iPP) and graphene oxide(GO), dispersed in dibutyl phthalate(DBP) and dioctyl phthalate(DOP), were blended to prepare organic-inorganic-blended microfiltration membranes using thermally induced phase separation(TIPS). These membranes were characterized by scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FTIR), contact angle measurements, mechanical properties, permeation tests, and porosity measurements. The morphology studied by SEM shows larger pores of the GO-blended membranes when compared to those of unmodified iPP membranes. Composite iPP/GO membranes achieve better performance in terms of water fluxes and pure water fluxes recovery ratio due to the hydrophilic nature of GO when compared with the pure iPP membranes. The addition of GO increases the permeability and the tensile strength by 352.98% and 123%, respectively, and also decreases the contact angle from 125° to 52.33°. We concluded that the composite membrane with 0.3% GO has the best antifouling ability of the membranes tested because it has the highest values of mean pore radius, porosity, and water flux observed in this study.



Four Coordination Polymers Assembled with a New Biscarboxyl-functionalized Schiff Base Ligand

KANG Dawei, XIE Jingjing, LIU Yingying, MA Jianfang

2018, 34(5):  839-843.  doi:10.1007/s40242-018-8030-4

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Based on a new biscarboxyl-functionalized Schiff base ligand 1,2-cyclohexanediamino-N,N'-bis[3-methoxyl-5-(p-carboxyl-phenylazo)] salicylidene(H₄L), four polymers,[(CH₃)₂NH₂]₂·[Mn₃(L)₂(H₂O)₄]·2DMF(CP1),[Fe₂(L)(H₂O)(DMF)](CP2),[(CH₃)₂NH₂]·[Cu(HL)]·H₂O(CP3) and[Ni₂(L)(teta)]·2DMF·H₂O(CP4), have been synthesized(teta=5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). In CP1, both of the internal[N₂O₂] pocket and the external carboxylate groups of L^4- anion are ligated by Mn²⁺ ions, and the structure displays a layer. In CP2, the Fe²⁺ cations are linked by L^4- anions to form a binuclear double chain. CP3 displays a[Cu₂(HL)₂] dimer. In CP4, the Ni²⁺ ions are connected by L^4- anions to form a chain. The structures are further linked by hydrogen bonds to form 2D or 3D supramolecular architectures, respectively. CP1 exhibits adsorption ability to three organic dyes.



Hydrophilization of Polyurethane Foam Carriers in MBBR with Hyperbranched Polymeric Diazonium Salts

LI Shang, WANG Jilei, TUO Xinlin, HE Yaning

2018, 34(5):  844-848.  doi:10.1007/s40242-018-8025-1

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In recent years, there has been a considerable research interest in moving-bed biofilm reactor(MBBR) for its efficiency and stability. This work proposes a new way to modify the hydrophilicity of polyurethane foam(PU) carriers via the layer-by-layer self-assembly of hyperbranched polymeric diazonium salt(M-HB-DAS) and poly(sodium-p-styrenesulfonate)(PSS). Modified carriers showed very good adsorption for microbes according to the results of scanning electron microscope(SEM). Biochemical experiments on wastewater treatment confirm that the modified PU carriers can improve the removal rate of chemical oxygen demand(COD).



Modulation of Supramolecular Interactions of Urea-based Supramolecular Polymers via Molecular Structures

LU Zhiyi, TANG Liming

2018, 34(5):  849-856.  doi:10.1007/s40242-018-8006-4

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Linear bis-urea D230 series and branched tris-urea T403 series of supramolecular monomers were synthesized using low molecular weight polyetheramine D230, T403 and isocyanates with diverse functional groups. Rheological tests reveal that the materials possess special thermal and mechanical properties due to the strong hydrogen bonding interactions between terminal urea groups and the high flexibility of the polyetheramine middle segments. By enhancing the hydrogen bonding interactions through electronic effects of the substituted urea groups, the mechanical properties of the bulk material can be increased. Moreover, the branched T403 series with higher hydrogen bonding density also shows better performance against D230 series with the same substituted urea groups. The presence of π-π stacking between the phenyl groups in samples with phenylurea residues, which complements the hydrogen bonding, was also confirmed by fluorescence spectroscopy, therefore resulting in a stronger supramolecular polymer network.



Effect of Temperature on Thermal Treatment of Silica Coated Magnetic Nanoparticles

LI Yu, ZHANG Penghong, ZHAO Huipeng, DU Xiaoqiang, LI Junping, LIU Laishuan

2018, 34(5):  857-861.  doi:10.1007/s40242-018-7431-8

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In the quest for developing a catalyst with as many desired characteristics, a facile synthetic route was designed for the preparation of mesoporous silica coated magnetic nanoparticles(MSMNP) employing a colloid mill reactor. The composite particles were characterized by the techniques, such as nitrogen adsorption-desorption isotherms, scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction patterns (XRD), thermo-gravimetric analysis(TGA), Fourier transform infrared spectroscopy(FTIR) and vibrating sample magnetometer(VSM), etc. The analysis showed that the resulted MSMNP composites were composed of silica shell layers with open pores connecting channels and NiFe₂O₄ with spinel structure, so the thermal treatment temperature did not show significant effect on pore textural properties, and its specific surface areas were in the range of 443-474 m²/g, while pore volume of about 0.8 cm³/g with an average pore size of around 9.5 nm. The composites with super paramagnetic nature were encapsulated entirely with amorphous silica layers contributing to optimum porosity and abundant surface hydroxyl groups.



Hollow-glass-microsphere-based Biphenyl Epoxy Resin Composite with Low Dielectric Contant

XU Weiwei, NA Hui, ZHAO Chengji

2018, 34(5):  862-866.  doi:10.1007/s40242-018-7419-4

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In this study, rigid 4,4'-diglycidyl(3,3',5,5'-tetramethylbiphenyl) epoxy(TMBP)-based composites were developed by the incorporation of varying percentages of commercial hollow glass microspheres(HGMs, QH-450) into the TMBP resin used for electronic packaging. The thermal and mechanical properties as well as the morphology of all the composites were characterized, and dielectric properties were characterized by advanced analytical techniques. The results reveal that a series of TMBP/QH-450 composites exhibits higher initial degradation temperatures(T_d,5%>300℃), and the residual char and glass transition temperature were clearly improved with QH-450 loading. In addition, all epoxy composites exhibited a lower dielectric constant ranging from 3.74 to 3.06 at 1.2 MHz because the lower dielectric properties of the inert gas used as the core of the QH-450 decreased molecule polarity. Hence, this developed TMBP/QH450 system demonstrates potential applications in electronic packaging.