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01 August 2013, Volume 29 Issue 4

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Cover and Content of Chemical Research in Chinese Universities Vol.29 No.4(2013)

2013, 29(4):  0-0. 

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Articles

Synthesis, Structures, Fluorescence and Magnetism of Two Lanthanide Metal-organic Frameworks with CaF₂ Topology Based on Silicon-centered Tetrahedral Ligand

LI Yang-xue, XUE Ming, HUANG Lin, CHEN Si-ru, QIU Shi-lun

2013, 29(4):  611-616.  doi:10.1007/s40242-013-2473-4

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Two 3D multifunctional lanthanide metal-organic frameworks(MOFs), Pr(HTCPS)(H₂O)·2DMF·C₂H₅OH· 5H₂O(JUC-93) and Pr₃(TCPS)₂(NO₃)(H₂O)₄(DMA)₂·2DMA·C₂H₅OH·3H₂O(JUC-94)[H₄TCPS=tetrakis(4-carboxyphenyl)- silane, DMF=N,N'-dimethylformamide, DMA=N,N'-dimethylacetamide and JUC=Jilin University China] were synthesized by the self-assembly of a rigid silicon-centered tetrahedral carboxylate ligand H₄TCPS and Pr(III) ions in different solvothermal reactions. X-Ray crystallography revealed that they exhibited a rare CaF₂ topology framework, constructed from the 4-connected tetrahedral TCPS unit with the 8-connected dinuclear praseodymium cluster unit and trinuclear praseodymium cluster unit, respectively. In addition, the luminescent and magnetic properties of the two compounds were investigated.



Synthesis and Characterization of SnO₂-TiO₂ Nanocomposite withRutile-phase via Hydrothermal Method at Low Temperature

WANG Yuan-rui, LI Wen-yan, ZHOU Bing, ZHAO Xu

2013, 29(4):  617-620.  doi:10.1007/s40242-013-3067-x

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With Ti(SO₄)₂, SnCl₄·5H₂O and urea as raw materials, SnO₂-TiO₂ nanocomposites were synthesized via low temperature hydrothermal method at 80―100 ℃ in aqueous solutions. The morphologies of the products were altered systematically by varying the Ti/Sn molar ratio of the reactants, and rutile-phase particles were obtained with an average diameter of about 52.2 nm at a molar ratio of Ti/Sn=7.5. The surface composition of the composite was revealed by X-ray photoelectron spectroscopy(XPS) and X-ray diffraction(XRD) to be solely TiO₂ with a rutile structure. This new composite material exhibits a high ultraviolet absorption capacity, and its photocatalytic activity for phenol oxidation is much lower than that of the commercial titania nanoparticles(P25).



One Dimensional Iron Molybdophosphate Anionic Chains with Different Structural Arrangements Reflecting a Flexibility Character

ZHOU Yun-shan, HASSAN ul Sadaf, LI Xian-qi, ZHANG Li-juan, AHMAD Waqar, SHI Zong-hai

2013, 29(4):  621-626.  doi:10.1007/s40242-013-2446-7

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Structural comparison of a new compound[(bpp)₃H₆]Fe₂^IIIFe₂^IIMo₂₄^V(H₂PO₄)₈(HPO₄)₄(PO₄)₄O₄₈(OH)₁₂· (H₂O)₄·2H₂O(1)[bpp=1,3-di(4-pyridyl)propane] with our previously reported two compounds[(bpy)₃Fe^II]₃· Fe₂^IIIFe₂^IIMo₂₄^V(H₂PO₄)₈(HPO₄)₄(PO₄)₄O₄₈(OH)₁₂(H₂O)₄·12H₂O(2) and[(bpy)₃Fe^II]₂Fe^IIFe^IIIMo₁₂^V(H₂PO₄)₂(H_2-xPO₄)·(H_1+xPO₄)(HPO₄)₂(PO₄)₂O₂₄(OH)₆(H₂O)₂·9H₂O(x=0―1)(3)(bpy=2,2'-bipyridine), which all exhibit one-dimensional mixed-valence iron molybdophosphate anionic chains constructed by alternating connection of Fe^III ions and magic[Fe^II(Mo₆P₄O₃₁)₂] units, reveals that the non-hydrogen atomic ratios of Mo:Fe:P:O within the polymeric anionic chains are the same for all the three compounds, while the polymeric anionic chains of the different compounds bear different numbers of negative charges. And therefore there exist different numbers of counter cations per {Fe₂^III[Fe₂^II(P₁₆Mo₂₄^VO₁₂₄)]} unit found in the titled compounds. It discloses that not only are the spatial assembling of counter cations and polymeric inorganic chains of three compounds quite different, but also the O―Fe^III―O bond angles and Fe^III―O bond lengths of the three different inorganic chains exhibit small differences. What is more important is that such small changes in bond length and bond angle in the assemblage of Fe^III―O bonds lead to the considerable fluctuations of inorganic chains in their structural conformation within the three compounds, reflecting an interesting phenomenon of “flexibility" in the pure inorganic one dimensional mixed-valence iron molybdophosphate chains.



Novel Magnesium Salt Based on BTATz：Crystal Structure, Thermal Behavior and Thermal Safety

ZHANG Xian-bo, REN Ying-hui, LI Wen, ZHAO Feng-qi, WANG Bo-zhou, SONG Ji-rong

2013, 29(4):  627-631.  doi:10.1007/s40242-013-2350-1

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A new high-energy organic magnesium salt[Mg(H₂O)₆](BTATz)·2H₂O[BTATz=3,6-bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine] was synthesized and characterized by elemental analysis and Fourier transform infrared(FTIR) spectrometry. Its crystal structure was determined by X-ray single crystal diffraction. The crystal belongs to monoclinic system with space group C2/c and a=2.1329(7) nm, b=0.52275(16) nm, c=1.5909(5) nm, β=100.471(6)°, V=1.7443(9) nm³, Z=4, μ=0.361 mm^-1, F(000)=900 and D_c=1.644 g/cm³. Meanwhile, the thermal behavior of[Mg(H₂O)₆](BTATz)·2H₂O was studied under the non-isothermal conditions by differential scanning calorimetry(DSC) and thermalgravity-differential thermalgravity(TG-DTG) methods. The enthalpy, apparent activation energy and per-exponential factor of the main exothermic decomposition reaction are 898.88 J/g, 139.2 kJ/mol and 10^10.48 s^-1, respectively. The values of the self-accelerating decomposition temperature(T_SADT), the thermal ignition temperature(T_TIT) and the critical temperature of thermal explosion(T_b) for[Mg(H₂O)₆](BTATz)·2H₂O are 515.13, 532.08 and 565.99 K, respectively.



Easily Accessible and Highly Selective “Turn-on” Fluorescent Sensor for Imaging Cadmium in Living Cells

WANG Wei, ZHANG Ying-mu, LI Yao-xian, ZHAO Qing

2013, 29(4):  632-637.  doi:10.1007/s40242-013-3126-3

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A new schiff base of phenothiazine derivative was designed for ratiometric sensing of Cd²⁺ selectively. Upon the addition of Cd²⁺ to the solution of phenothiazine derivative, the fluorescence intensity of it was enhanced in a linear fashion and the maximum fluorescence peak exhibited a blue shift from 575 nm to 525 nm. This ratiometric fluorescent sensor displays a very high sensitivity(detection limits were 0.34 and 1.0 μmol/L of Cd²⁺ using the visual fluorescence changes and UV-Vis changes, respectively), a rapid response time(<10 s) and high selectivity for Cd²⁺ over other transition metal ions. Moreover, the living cells image experiments also demonstrate the value of the sensor in fluorescent visualization of Cd²⁺ in the environmental and biological systems.



Purification and Characterization of a Novel Tetradecapeptide from Ginseng Polypeptides with Enhancing Memory Activity for Mice

LUO Hao-ming, JIANG Rui-zhi, YANG Xiao-hong, CHEN Ying-hong, HONG Tie, WANG Ying

2013, 29(4):  638-641.  doi:10.1007/s40242-013-3012-z

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Aiming at isolating and investigating the active ingredients of the aqueous extract from Panax ginseng which showed enhancing memory activity, the authors characterized one ingredient. To separate the oligosaccharides and polypeptides, a DEAE-Sephadex A-50 colum was used. The enhanced memory activity in mice was studied by Mirros water maze tesk in mice. The dose of oligosacchrides, polypeptides or Piracetam was 30 mg/kg per day with intraperitoneal administration. The oligosaccharides did not show enhancing memory effect, but polypeptides did show. This result demonstrates that the active ingredients of the aqueous extract from Panax ginseng which showed enhancing memory effect was polypeptides. The purification of the polypeptides was performed on a Sephadex G-25 column. A novel tetradecapeptide was purified from the polypeptides and its structure was determined by liquid chromatography-electrospray ionization-quadrupole-time of flight-mass spectrometry(LC-ESI-Q-TOF-MS) with the amino acid sequence of Lys-Ser-Leu-Thr-Leu-Thr-Ser-Ser-Leu-Ser-Tyr-Thr-Asp-Ser.



Novel Fluorescent Chemosensors Based on Tryptophan Unit for Cu²⁺ and Fe³⁺ in Aqueous Solution

CHENG Peng-fei, XU Kuo-xi, YAO Wen-yong, KONG Hua-jie, KOU Li, MA Xiao-dan, WANG Chao-jie

2013, 29(4):  642-646.  doi:10.1007/s40242-013-3002-1

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We reported four fluorescent chemosensors containing tryptophan units. The fluorescence spectrum titration experiments suggest that chemosensors 1, 2, 3 and 4 are highly selective for Cu²⁺ and Fe³⁺ over Li⁺, Na⁺, K⁺, Co²⁺, Zn²⁺, Ni²⁺, Hg²⁺ and Cr³⁺ via forming complexes with Cu²⁺ or Fe³⁺, which is confirmed by dramatical quench of fluoreseence in aqueous solution at pH 7.4, thus making all the chemosensors suitable for Cu²⁺ and Fe³⁺ fluorescent sensors.



Ionic Liquid-based Microwave-assisted Liquid-liquid Microextraction and High Performance Liquid Chromatography Determination of Sulfonamides from Animal Oils

FENG Xu-dong, LIANG Fang-hui, SU Rui, WU Li-jie, LI Xue-yuan, WANG Xing-hua, ZHANG Han-qi, YU Ai-min

2013, 29(4):  647-652.  doi:10.1007/s40242-013-2516-x

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The authors performed ionic liquid-based microwave-assisted liquid-liquid microextraction(IL-based MALLME) coupled with high performance liquid chromatographic separation for the determination of 6 sulfonamides (SAs) from animal oils. The target analytes were extracted from animal oil samples with sodium hydroxide solution containing 1-butyl-3-methylimidazolium tetrafluoroborateand as the extraction solvent under microwave irradiation. The experimental parameters of the IL-based MALLME, including types of ILs, volume of IL, amount of ion-pairing agent(NH₄PF₆), pH value of sample solution, and extraction temperature and time were evaluated. The limits of detection and quantification obtained were in a range of 0.4―0.5 μg/kg and a range of 1.2―1.8 μg/kg, respectively. The accuracy of the method was evaluated by analyzing five spiked animal oil samples at two fortified levels(5 and 50 μg/kg), and the recoveries of SAs varied from 81.4% to 114.5% with relative standard deviations ranging from 0.8% to 9.0%.



High Efficient Extraction of Phthalates in Aquatic Products by a Modified QuEChERS Method

WANG Wen-wen, GAO Fu-kai, LI Gui-zhi, LIU Zhen-bo, LIU Yong-ming

2013, 29(4):  653-656.  doi:10.1007/s40242-013-2417-z

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A simple, environmentally friendly and high efficient extraction method was proposed for the determination of five phthalates in aquatic products by gas chromatography combined with mass spectrometry detector (GC-MS). When this method was adopted, samples were pretreated by modified QuEChERS(quick, easy, cheap, effective, rugged and safe) method. An environmentally friendly extractant(ethanol aqueous solution) replaced toxic acetonitrile for extracting phthalates in the protein-matrix samples. Fluorescence quenching spectra of bovine serum albumin(BSA) with phthalates show that there was a high-affinity interaction between phthalate and protein, decreasing the extraction efficiency of phthalates from fish samples. However, in the 80%(volume fraction, φ) ethanol aqueous solution, a slow but full protein denaturation takes place, which would cause the unfolding of protein and the release of phthalates. Meanwhile, the fat-soluble impurities are extracted less in φ(ethanol) 80% aqueous solution than in either φ(ethanol) 100% or hydrophobic solvents in the liquid-liquid extraction procedure. Therefore the purification steps were greatly simplified. Overall recoveries were 81.77%―90.5% with limits of detection between 2.53 and 9.61 μg/L, and relative standard deviation values at 1.15%―4.85%. The proposed approach was satisfactorily applied to the determination of phthalates in real aquatic products, such as fish, shrimp and oyster.



Novel Highly Selective Fluorescent Chemosensors for Hg(II)

SU Wen-qi, YANG Bing-qin

2013, 29(4):  657-662.  doi:10.1007/s40242-013-2363-9

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Based on Rhodamine, two novel fluorescent Hg²⁺ chemosensors(R1, R2) were synthesized from inexpensive starting materials. They were designed and synthesized with o-aminophenol and o-phenylenediamine derivatives as the Hg²⁺ chelator, the comparison between the photophysical properties of two chemosensor molecules was made. The chemosensors were designed with a photoinduced electron transfer(PET) mechanism. After binding to Hg²⁺ which blocks the PET process, the fluorescence intensity of the chemosensors was enhanced by up to 15-fold. They exhibit very strong fluorescence responses to Hg²⁺ and have remarkably higher selectivity for Hg²⁺ than for other metal ions including K⁺, Na⁺, Ca²⁺, Mg²⁺, Cd²⁺, Mn²⁺, Ni²⁺, Co²⁺, Zn²⁺, Cu²⁺, Cr³⁺, Fe³⁺, Pb²⁺, Ag⁺, Al³⁺, Fe²⁺ and Sn²⁺ in Tris-HCl/sodium phosphate buffer. The fluorescence enhancement of R2 towards Hg²⁺ maintains stable in wide pH span(6.4―8.8) aqueous solutions.



Selective Solid-phase Extraction of Aloe Emodin from Aloe by Molecularly Imprinted Polymers

TIAN Ming-lei, LEE Yu-ri, PARK Dong-wha, ROW Kyung-ho

2013, 29(4):  663-666.  doi:10.1007/s40242-013-2357-7

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The extraction and separation of aloe emodin were optimized via selective molecularly imprinted solid-phase extraction. Molecularly imprinted polymer was prepared from the functional monomer, methacrylic acid and a mixture of ethanol/dodecanol(90/10, volume ratio) as porogen. It overcomes the common problems of imprin-ting biological polar compounds and shows high selectivity compared favorably with those of non-imprinted polymer and commercially available C₁₈ and silica cartridges in similar aloe emodin tests. Good linearity was obtained between 0.002 and 2.5 mg/mL(r²=0.998) with relative standard deviations below 3.3%.



Forced Degradation of Flavonol Glycosides Extraced from Ginkgo biloba

JIN Ye, ZHANG Wei-yu, MENG Qing-fan, LI Dan-hui, GARG Sajay, TENG Li-rong, WEN Jing-yuan

2013, 29(4):  667-670.  doi:10.1007/s40242-013-2352-z

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The degradation of flavonol glycosides extracted from Ginkgo biloba was performed under different conditions and the degraded products were determined by reversed-phase high performance liquid chromatography (RP-HPLC) method. Four stress conditions including acid(0.1 mol/L HCl), base(0.1 mol/L NaOH), temperature (70 ℃) and oxidation(0.03% H₂O₂, volume fraction) were used for the forced degradation studies. The pH stabilities of the flavonol glycosides were determined in phosphate buffers of varying pH values from 4.5 to 7.4. The degradation rate constants and half-life of three Ginkgo flavonol aglycones(quercetin, kaempferol and isorhamnetin) which represent Ginkgo flavonol glycosides were calculated in forced degradation and pH-stability studies of them. The results indicate that the three substances were more stable when incubated under acid condition and showed pH-dependent stability. The degradation was observed to follow first-order kinetics in all degradation studies. The stability results could provide important bases on development, preparation and storage of products of Ginkgo biloba extract and should be significantly considered during the further formulation development.



Effects of Micelle on Pyrazoles as Antioxidants in Radical-induced Oxidation of DNA

LI Yan-feng, LIU Zai-qun

2013, 29(4):  671-677.  doi:10.1007/s40242-013-3059-x

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Effects of 4-(1,3-diphenyl-1H-pyrazol-5-yl)phenol(APP), 4-(1,5-diphenyl-1H-pyrazol-3-yl)phenol(BPP) and 4-(3,5-diphenyl-1H-pyrazol-1-yl)phenol(CPP) on 2,2'-azobis-(2-amidinopropane hydrochloride)(AAPH)-induced oxidation of DNA were measured in the presence of various concentrations of Triton X-100, cetyltrimethylammonium bromide(CTAB), or sodium dodecyl sulfate(SDS) in order to clarify the influence of neutral, cationic and anionic microenvironments on antioxidant capacities of APP, BPP and CPP. Although these surfactants can protect DNA against AAPH-induced oxidation, the pyrazoles in the presence of these surfactants functioned as prooxidants when the concentrations of Triton X-100 and CTAB increased. However, CPP exhibited antioxidant property with the increase of the concentration of CTAB. On the contrary, APP, BPP and CPP were antioxidants in the presence of various concentrations of SDS. The added surfactants resulted in the complication of the microenvironments around DNA, pyrazoles and peroxyl radical(ROO^·) derived from AAPH. The anionic charge of SDS was beneficial to enhancing the antioxidant effectiveness of these pyrazoles. It can be concluded that the charge property of surfactants markedly influenced the behavior of an antioxidant in AAPH-induced oxidation of DNA.



Stereoselective Palladium-catalyzed Cross-coupling of (2-Amido-1-phenylpropyl)zinc Compounds with Aryl Bromides

TANG Shi, ZHOU Dong, LI Shu-hua, WANG Nai-xing

2013, 29(4):  678-681.  doi:10.1007/s40242-013-3057-z

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A controllable diastereoselective C(sp²)―C(sp³) Negishi coupling reaction of secondary benzylic zinc reagents with aryl bromides to form medicinally important 2-arylphenylethylamines was demonstrated. In the presence of Pd(OAc)₂ and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl(S-phos), open-chain(2-amido-1-phenylethyl)zinc reagent bearing a β-NHAc or NHCHO group undergoes coupling reaction to give syn-1-arylphenylethylamine mainly, whereas the zinc reagent bearing a sterically hindered β-amido group, for example NHCOC(CH₃)₂OTBS undergoes the coupling reaction to yield anti-1-arylphenylethylamines with a configuration inversion. In addition, a working mechanism for the stereoselective Negishi cross-coupling was also proposed.



Flavonoids from Litchi(Litchi chinensis Sonn.) Seeds and Their Inhibitory Activities on α-Glucosidase

REN Shen, XU Duo-duo, GAO Yang, MA Yu-ting, GAO Qi-pin

2013, 29(4):  682-685.  doi:10.1007/s40242-013-3030-x

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With the bioactivity-guided method, a new flavanone glycoside, together with nine known flavonoids were isolated from 50% aqueous ethanol of litchi(Litchi chinensis Sonn.) seeds. The chemical structure of the new compound was elucidated via 1D and 2D nuclear magnetic resonance(NMR) techniques and mass spectrometry to be (2S)-pinocembrin-7-O-(6"-O-α-L-arabinosyl-β-D-glucopyranoside)(1), and the nine known compounds were determined to be quercetin(2), phlorhizin(3), pinocembrin-7-O-glucoside(4), kaempferol-7-O-β-D-glucopyranoside(5), onychin(6), nairutin(7), narcissin(8), pinocembrin-7-O-[(6"-O-β-D-glucopyranoside)-β-D-glucopyranoside](9) and pinocembrin-7-O-[(2",6"-di-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside](10). Some of the isolated flavonoids were tested for their inhibitory effects on α-glucosidase. And compounds 2 and 3 showed stronger inhibitory activity than positive control.



Synthesis and Luminescent Properties of Iridium Complexes with Reduced Concentration Quenching Effect

ZHANG Li-ying, LI Bin, WANG Jian-xing

2013, 29(4):  686-689.  doi:10.1007/s40242-013-3005-y

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Three novel cyclometalated ligands 1-benzyl-2-phenyl-1H-benzoimidazole(BPBM), 1-(4-methoxy-benzyl)-2-(4-methoxy-phenyl)-1H-benzoimidazole(MBMPB) and 4-[2-(4-dimethylamino-phenyl)-benzoinidazol-1-ylmethyl]-phenyl-dimethyl-amine(DBPA) were designed and synthesized, and the corresponding highly efficiency green-emitting phosphorescent iridium complexes Ir(BPBM)₂(acac)(1), Ir(MBMPB)₂(acac)(2) and Ir(DPBA)₂(acac) (3) with acetylacetone(acac) as auxiliary ligand were also synthesized. The ligands are functionalized by bulky non-planarity substituents, thus the phosphorescent concentration quenching is substantially suppressed, and all the complexes exhibit bright photoluminescence(PL) in solid state. The photo-physical properties of the three iridium complexes were researched in detail. The results indicate that they have potential application in fabricating non-doped electrophosphorescence device.



Synthesis and Herbicidal Activities of Potassium Methyl 1-(Substituted Phenoxyacetoxy)alkylphosphonate

WANG Tao, WANG Wei, PENG Hao, HE Hong-wu

2013, 29(4):  690-694.  doi:10.1007/s40242-013-2525-9

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A series of potassium methyl 1-(substituted phenoxyacetoxy)alkylphosphonates(9a―9o) was designed and synthesized. The results of preliminary bioassays indicate that most of the title compounds possess excellent pre-emergence and post-emergence herbicidal activities against Brassica napus, Amaranthus mangostanus, Medicago sativa, Echinochloa crusgalli, and Digitaria sanguinalis at a dosage of 1500 g/ha(1 ha=10000 m²). Especially, potassium methyl 1-(2,4-dichlorophenoxyacetoxy)-1-(4-methylphenyl)methylphosphonate(9g) and potassium methyl 1-(2,4-dichlorophenoxyacetoxy)-1-(furan-2-yl)methylphosphonate(9j) show the best herbicidal activity against five tested weeds with more than 85% inhibitory rate in pre-emergence.



Synthesis of Novel Flavanone Derivatives and Their Anti Staphylococcus aureus Evaluation

XU Qing-hui, LI Ji-zhen, HE Jiang-hua, ZHAO Xin, HUO Qi-sheng

2013, 29(4):  695-698.  doi:10.1007/s40242-013-2519-7

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The authors synthesized two novel flavanones bearing iso-pentenyl side chain and evaluated their anti Staphylococcus aureus(S. aureus) activity. The target compounds 7a[2-5'-(1",2"-dimethylallyl)-2'-methoxy-4',5,7-tetrahydroxyflavanone] and 7b[2-5'-(1",2"-dimethylallyl)-3'-methoxy-4',5,7-tetrahydroxyflavanone] were synthesized respectively through total four steps starting from 2,4,6-trihydroxy acetophenone(3) and the corresponding iso-pentenyl substituted benzaldehyde(1), in which the 1,2-dimethyl-2-propenyl group had been introduced previously via abnormal Claisen rearrangement. The bioactivities of the two flavanones against S. aureus strains ATCC 25923, 29213, and MRSA 252 were evaluated, showing the same minimum inhibitory concentration(MIC) value of 16 μg/mL.



Synthesis of 2-Oxazolines from Ethyl α-Cyanocinnamate Derivatives with Acetamide and N-Bromosuccinimide

CHEN Zhan-guo, XIA Wei, WEN Hua, WANG Dan, LI Ya-nan, HU Jun-li

2013, 29(4):  699-705.  doi:10.1007/s40242-013-2420-4

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An efficient method for the one-pot synthesis of 2-oxazolines from ethyl α-cyanocinnamate derivatives with acetamide and N-bromosuccinimide(NBS) in the presence of K₃PO₄ was developed. The reaction was performed smoothly and cleanly to give 2-oxazolines in good to excellent yields(up to 95%) in acetone at room temperature. Thirteen examples were investigated and the results indicated that a large range of α-cyanocinnamate derivatives could be suitable for this method. Based on the outcomes of experiment, a possible consecutive nucleophilic addition-cyclization pathway was proposed.



Synthesis and Antiviral Activity of N-Adamantyl-2- amino(or 2-phenoxy)-acylamides

LIU Dan, FAN Zi-chen, JIANG Jia-mei, WEI Jing, XIN Jian-chuang

2013, 29(4):  706-709.  doi:10.1007/s40242-013-2380-8

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New N-adamantyl-2-amino-acylamides(3a―3f) and N-adamantyl-2-phenoxy-acetamides(6a―6d) were designed and synthesized by the modification of the amino group of amantadine 1 and the structures were confirmed by mass spectra(MS) and ¹H NMR spectra. The antiviral potencies of the synthesized compounds were evaluated against the replication of influenza virus A/H₃N₂ subtype in Madin-Darby canine kidney(MDCK) cells. Among the amantadine derivatives, compound 3a had the strongest antiviral potency and showed activity similar to that of amantadine. Interestingly, the bulky and extended lipophilic moieties on the α-position of the carbonyl group resulted in decreases in potency.



One-pot Three-component Mannich Reaction Catalyzed by 2-Hydroxylpyridine

JIN Li-li, LEI Yun-tao

2013, 29(4):  710-713.  doi:10.1007/s40242-013-2362-x

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An effcient synthetic protocol for the β-amino carbonyl compounds was developed via one-pot three-component Mannich reaction of aromatic aldehydes, aromatic amines and cyclohexanone catalyzed by 2-hydroxylpy-ridine under mild reaction conditions. β-Amino carbonyl compounds were obtained in moderate to good yields and reasonable diastereoselectivities. The effects of different solvents, catalyst amounts and the scope of different substrates on the Mannich reactions were investigated. The plausible reaction mechanism was also discussed.



Synthesis and Biological Activities of Novel Anthranilic Diamides Analogues Containing Benzo[b]thiophene

ZHANG Ji-feng, LIU Chen, LIU Peng-fei, YAN Tao, WANG Bao-lei, XIONG Li-xia, LI Zheng-ming

2013, 29(4):  714-720.  doi:10.1007/s40242-013-2319-0

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A series of novel anthranilic diamides analogues containing benzo[b]thiophenyl ring was designed and synthesized. Their structures were characterized by melting points, ¹H nuclear magnetic resonance(¹H NMR) and high-resolution mass spectrometry(HRMS). The bioassay tests indicate that their insecticidal activities were weak to moderate. Antibacterial tests indicate that some of the compounds showed favourable activity in vitro against Physalospora piricola, Alternaria solani, Cercospora arachidicola, Gibberella sanbinetti and Phytophthora infestans at a dosage of 50 mg/L.



Activities of a Novel Phenanthrene Imine to Kill Tumor Cells

WANG Xu-dong, JIN Li-min, SUN Zhi, LI Dong-ni, LIU Tie-mei

2013, 29(4):  721-723.  doi:10.1007/s40242-013-3250-0

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A novel phenanthrene imine was synthesized from 9,10-phenanthrenequinone, 1,4-diazabicyclo octane (Dabco), 2,6-dimethylaniline, 2,6-diisopropylaniline and TiCl₄ via standard Schlenk and vacuum-line or glovebox techniques. 3-(4,5-Dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide(MTT) assay and flow cytometry(FCM) were used to detect the activities of the compound to kill tumor cells and the mechanisms of action were investigated in the study. The results show that the compound is active in killing tumor cells. Mechanistic investigations found that the compound could induce apoptosis of tumor cells.



Extraction of Geniposide and Its Application in Anesthesiology

XU Dan, DONG Yu-xiang, FENG Wei, GE Hong-yan, LI You-tian, JIANG Yang, WANG Li-jie, SONG Da-qian

2013, 29(4):  724-729.  doi:10.1007/s40242-013-3078-7

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We tried to develop an efficient strategy to isolate geniposide from Gardenia fruit and use it to treat chronic pain. Eight extraction solvents and three extraction methods were respectively compared with each other for the efficiency of geniposide extraction from Gardenia fruit. Extraction with 80% ethanol under reflux was found to give the highest yield of geniposide. Orthogonal experiment was conducted to optimize the reflux conditions and the optimal conditions are a mass(of Gardenia jasminoides Ellis powder) to volume(of solvent, 80% ethanol) ratio of 1:7 and reflux twice for 60 min each. The geniposide obtained by the reflux method was tested on the rats with chronic constriction injury(CCI) for pain relief. The results show that geniposide can enhance pain threshold and relieve pain via repressing tumor necrosis factor-α(TNF-α) expression in either ipsilateral or contralateral dorsal root ganglion(DRG) cells. These results suggest that geniposide treatement may be an effective clinical method to relieve pain based on the mechanism of molecular biology at DRG due to nerve injury.



Effect of Candesartan Cilexetil as a Sensitive and Effective Inhibitor of SHP-1 on Insulin Signaling Pathway

ZHANG Lei, ZHANG Shi-tao, ZHANG Xiao-ping, SUN Jing, WANG Yong-sen, LIU Yue-long, XUE Miao-miao, WANG Zhi, XING Shu, MA Jun-feng, LI Wan-nan, FU Xue-qi

2013, 29(4):  730-734.  doi:10.1007/s40242-013-2505-0

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The protein tyrosine phosphatases(PTPs) comprise a family of enzymes that specifically dephosphorylate tyrosyl residues. Among them, SHP-1 has been regarded as one of the best validated intracellular tyrosine phosphatases. Downregulation of SHP-1 has shown remarkable efficacy in improving insulin sensitivity in vivo in insulin signaling pathway. In this study, we found the role of Candesartan cilexetil targeting at SHP-1. The results indicate that Candesartan cilexetil was a competitive inhibitor to SHP-1(IC₅₀=85.6 μmol/L and K_i=24 μmol/L). We also found that Candesartan cilexetil was more sensitive towards SHP-1 compared with other PTPs. Through the consequence of Western blotting, it showed that Candesartan cilexetil can strengthen the level of tyrosine phosphorylation of several key cellular proteins[such as insulin receptor(IR), insulin receptor substrate(IRS) and ERK] in insulin signaling pathway in HepG₂ cells and improve the insulin sensitivity through inhibiting the protein phosphorylation of SHP-1. These findings showed that Candesartan cilexetil might be an important inhibitor of SHP-1 and had a great application potential in the treatment of diabetes through inhibiting the level of SHP-1 in insulin signaling pathway.



Supercapacitor Performance of Hollow Carbon Spheres by Direct Pyrolysis of Melamine-formaldehyde Resin Spheres

MA Fang-wei, SUN Li-ping, ZHAO Hui, LI Qiang, HUO Li-hua, XIA Tian, GAO Shan

2013, 29(4):  735-742.  doi:10.1007/s40242-013-3181-9

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The nitrogen and oxygen co-doped hollow carbon spheres(HCSs) were prepared via a simple pyrolysis of solid melamine-formaldhyde resin spheres. The carbonization temperature has an important influence on the specific surface area, pore-size distribution and heteroatom contents of HCSs. The synergistic effects of those physical and chemical properties on supercapacitor performance were systematically investigated. Among the HCSs obtained at different temperatures, HCSs-800(co-doped HCSs at 800 ℃) exhibits the best reversible specific capacitance in 2 mol/L H₂SO₄ electrolyte and meanwhile maintains a high-class capacitance retention capability. The nitrogen heteroatoms were confirmed to play a crucial role in improving capacitance in an acid medium. This kind of nitrogen doped HCSs is a potential candidate for an efficient electrode material for supercapacitors.



Catalysts for Hydration of Cyclohexene to Cyclohexanol

FANG De-ren, LU Jin-yan, ZHANG Hui-min, LI Jie, WANG Yan-yan

2013, 29(4):  743-746.  doi:10.1007/s40242-013-3091-x

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The hydration of cyclohexene was determined in a stirred tank of 100 mL in a batch mode in the presence of modified or unmodified resin as catalyst. The ion-exchange sulfonate resin was modified with alkyl secondary amine. At an optimum amination rate of 15%, the conversion of cyclohexene reached to 22% and the selectivity of cyclohexanol was 95.6%. In a temperature range of 90―150 ℃, the activity and selectivity of the modified resin ca-talyst were much higher than those of the unmodified resin catalyst, which was attributed to the inclusion formed between cyclohexene and alkyl chain and also the quasi-lipophilic phase formed around the outer surface of resin beads. The formed quasi-lipophilic phase formed enhanced the conversion of cyclohexene and depressed the formation of by-products.



Influence of NaCl on Cathode Performance of Solid Oxide Fuel Cells

LIU Run-ru, WANG De-jun, LENG Jing

2013, 29(4):  747-750.  doi:10.1007/s40242-013-3052-4

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Degradation induced by sodium chloride in air was investigated for (La_0.8Sr_0.2)_0.98MnO₃(LSM) and La_0.6Sr_0.4Co_0.2Fe_0.8O₃(LSCF) cathodes in solid oxide fuel cells(SOFC). Cell performance was measured by volatilizing NaCl to be supplied to the cathode at a constant current density of 200 mA/cm² for up to 100 h. At 800 ℃, an exposure of the cathode to 30 mg/L NaCl caused negligible degradation of LSM at least for 100 h. Slight change in the composition of the cathode materials was observed which may imply the gradual degradation of cell performance for the long-term. In addition, cell performance degradation was compared between 700 ℃ and 900 ℃, being poisoned by 30 mg/L NaCl. Degradation was negligible for LSM cathode, while LSCF cathode showed slightly poor tolerance at 700 ℃ due to the decomposition of the cathode material. Further studies should be done to clarify the long-term influence of NaCl on cathode performance.



SERS Study of Co-doped TiO₂ Nanoparticles

XUE Xiang-xin, JI Wei, MAO Zhu, LI Zhi-shi, GUO Zhi-nan, ZHAO Bing, ZHAO Chun

2013, 29(4):  751-754.  doi:10.1007/s40242-013-3051-5

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Single-phase Co-doped TiO₂(Co_xTi_1-xO₂) nanoparticles(NPs) synthesized via a simple sol-hydrothermal method were used as surface-enhanced Raman scattering(SERS) substrates. Interestingly, it was found that SERS signals were enhanced greatly compared to those of pure TiO₂ nanoparticles when an amount of Co²⁺ ions were doped into the TiO₂ lattice. Detailed results clearly show that Co element as Co²⁺ was incorporated into the TiO₂ lattice and the defects were created due to the substitution of Co²⁺ ions for the Ti⁴⁺ ions. The Co²⁺ doping increases the defect concentration of Co_xTi_1-xO₂ NPs. An amount of defects is beneficial to the charge-transfer so as to increase the SERS activities. A possible mechanism of charge-transfer from Co_xTi_1-xO₂ NPs to molecules was then briefly discussed.



From Amorphous Carbon to Carbon Nanobelts and Vertically Oriented Graphene Nanosheets Synthesized by Plasma-enhanced Chemical Vapor Deposition

WANG Xin, ZHAO Cui-mei, DENG Ting, LIU Ji-yue, LI Bo, ZHENG Wei-tao

2013, 29(4):  755-758.  doi:10.1007/s40242-013-3044-4

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Carbon materials with various structures were produced via plasma-enhanced chemical vapor deposition by controlling substrate temperature and mixed gases in the atmosphere. Scanning electron microscopy(SEM), transmission electron microscopy(TEM), high resolution transmission electron microscopy(HRTEM) and Raman spectroscopy were employed to investigate the morphology and structure of the materials. The results show that at a low substrate temperature(100 ℃) in CH₄:Ar(flow rate ratio was 100 cm³/min:10 cm³/min), amorphous carbon formed on Si(100) that could act as a support for the growth of carbon nanobelt and layer graphene at 800 ℃. Vertically oriented multi-layer graphene nanosheets(GNs) were catalyst-free synthesized on Si and Ni foam at 800 ℃ in a mixture of CH₄:Ar(20 cm³/min:60, 80 and 100 cm³/min). The capacitor character investigated by cyclic voltammetry and galvanostatic charge/discharge indicates that for the as-synthesized GNs, the electrochemical capacitance is very small(16 F/g at current density of 16 A/g). However, having been treated in acidic solution, the GNs exhibited good capacitive behavior, with a capacitance of 166 F/g, and after 800 charge/discharge cycles at 32 A/g, the capacitance could retain about 88.4%. The enhancement of specific capacitance is attributed to the increase of specific surface area after etching treatment of them.



Multivariate Curve Resolution Combined with On-line Infrared Spectroscopy for Researching the Synthesis Mechanism of 3,4-Bis(4’-aminofurazano-3’)furoxan

WU Nan, SUN Kun-lun, LIU Yu, YANG Xiao-feng, LI Hua

2013, 29(4):  759-764.  doi:10.1007/s40242-013-3043-5

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3,4-Bis(4'-aminofurazano-3')furoxan(DATF), one of a new generation of high energy density materials, shows lots of interesting properties such as lower sensitivity, excellent thermal stability and superior detonation performance in chemistry and physics. In this paper, on-line infrared(IR) spectroscopy was used to monitor the synthesis process of DATF. The concentration profiles and IR spectra of the components were determined by analyzing the IR data via principal component analysis(PCA), evolving factor analysis(EFA) and multivariate curve resolution-alternating least squares(MCR-ALS). The geometric configurations of reactant, intermediates and product were optimized with the density functional theory(DFT) at B3LYP/6-31+G(d, p) level. Their vibrational frequencies and IR spectra were obtained on the basis of vibrational analysis. The result obtained by the chemometric resolution methods agreed well with that obtained by quantum chemical calculation method, which demonstrated the reliability of the proposed chemometric resolution methods. The unstable intermediate 3-amino-4-oxycyanofurazan(AOF) was confirmed via comparing the IR spectra resloved by chemometric resolution methods with those calculated by B3LYP/6-31+G(d,p) and analyzed by MCR-ALS. Finally, the possible synthesis mechanism of DATF was deduced by analyzing the above IR spectra.



Characteristics and Kinetics of Nitrobenzene Reduction by Sucrose-modified Nanoiron

LI Hui, ZHAO Yong-sheng, ZHAO Ran, MA Bai-wen, CHEN Zi-fang, SU Yan, ZHOU Rui

2013, 29(4):  765-770.  doi:10.1007/s40242-013-3041-7

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Sucrose-modified nanoscale zero-valent iron(SM-NZVI) was prepared with liquid phase reducing method, and characterized by transmission electron microscopy(TEM) and X-ray diffraction(XRD) for the shape and structure. The size of SM-NZVI particles was about 100―150 nm and they displayed better dispersity. The degradation of nitrobenzene(NB) in water by SM-NZVI was carried out in batch experiments. The results indicate that the efficiency of NB reduction via SM-NZVI increased by 44.24% compared with that via NZVI, and coexistent Ca²⁺, Mg²⁺, HCO₃^- and other ions showed little effect on NB reduction but negative influence on aniline(AN) production. Furthermore, the kinetic researches indicate that NB reduction with SM-NZVI could be described by pseudo first-order kinetic model at different initial pH values and iron dosage. The oxidation products of iron were mainly Fe₃O₄ and Fe₂O₃ with irregular shape.



Electroreduction of Tungsten Oxide(VI) in Molten Salts with Added Metaphosphate

MALYSHEV Victor, GAB Angelina, POPESCU Ana-Maria, CONSTANTIN Virgil

2013, 29(4):  771-775.  doi:10.1007/s40242-013-3003-0

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Tungstate ions WO₄^2- are not electrochemically active in chloride melts. Upon introduction of PO₃^- ions into the melt, two waves appear in the voltammograms at potentials-0.1—-0.2 V and-0.3—-0.5 V vs. Pb/Pb²⁺ reference electrode. With a PO₃^- concentration ratio of 0.01<[PO₃^-]/[WO₄^2-]<0.18, the potentiostatic electrolysis product of WO₄^2-at the above mentioned potentials is metallic tungsten; a NaPO₃ concentration increase for ratios[PO₃^-]/[WO₄^2-]>> 0.18 results in tungsten phosphide in electrolysis product. Cyclic voltammograms and dependence of half-peak potentials on electrode polarization rate indicate the irreversible character of the electrode process. Electrode process modeling allows us to state that the first wave in the voltammogram of KCl-NaCl-Na₂WO₄-NaPO₃ system corresponds to tungsten oxychlorides discharge while the second wave appears due to the discharge of ditungstate ions. In the voltammograms of Na₂WO₄-NaPO₃ melts, reduction wave was observed at-1.1—-1.2 V potentials. Proportionality of limiting current to NaPO₃ concentration, constancy of I_d/v^1/2 ratio, and I_d/nFc constant kinetic value equal to (8.3—9.5)×10^-5 cm/s for steady-state wave indicate that electrode process rate is limited by electrochemically active particle diffusion to the electrode. Nascent ditungstate ions become electrochemically active in the overall electrode process. Charge transfer stage is reversible.



Absorption and Fluorescence Emission Spectra of Molecules Containing Azo and/or Oxadiazole Units

WANG Chang-sheng, YU Nan, LIU Peng

2013, 29(4):  776-781.  doi:10.1007/s40242-013-2462-7

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The ground state structures of a series of organic molecules containing azo and/or oxadiazole units were obtained by means of density functional theory B3LYP/6-31G(d) method. The first singlet excited state structures were optimized by virtue of singlet-excitation configuration interaction CIS/6-31G(d) method. The absorption and fluorescence emission spectra were then evaluated via the time-dependent density functional theory B3LYP and PBE1PBE methods with 6-311++G(3df,2p) basis set. The calculation results show that compared with those of their parent molecules A-H, B-H, C-H, D-H, the absorption and emission wavelength values of all the derivatives show red shifts. The derivatives containing both the oxadiazole and methoxyl units are good candidates for longer absorption wavelength materials. The effects of azo, oxadiazole, and methoxyl units on the absorption and emission wavelength were discussed.



Mechanism of Xylan Pyrolysis by Py-GC/MS

WANG Shu-rong, LIANG Tao, RU Bin, GUO Xiu-juan

2013, 29(4):  782-787.  doi:10.1007/s40242-013-2447-6

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In order to investigate the decomposition behavior of hemicellulose, xylan was chosen as the representative of hemicellulose to study the fast pyrolysis on the combination system of analytical pyrolyzer and gas chromatograph coupled with mass spectrometer(Py-GC/MS). The main condensable products of xylan pyrolysis consisted of acids, aldehydes, and ketones; while gas products contained CO₂, CO, CH₄ and H₂. Acetic acid and furfural were the most abundant products with the highest contents of 20.11% and 20.24% respectively. While furfural and acetic acid were formed competitively with residence time and temperature increases, the distribution of xylan pyrolysis products did not vary with the residence time and temperature, while the total content of several kinds of products changed a lot. According to the analysis of experimental data, a reaction pathway of xylan decomposition was deduced so as to illustrate the formation mechanism of main products.



Predicting Glass Transition Temperature of Polyethylene/Graphene Nanocomposites by Molecular Dynamic Simulation

SHENG Yan-zhen, YANG Hua, LI Jun-yin, SUN Miao

2013, 29(4):  788-792.  doi:10.1007/s40242-013-2443-x

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The glass transition temperature of polyethylene/graphene nanocomposites was investigated by molecular dynamic simulation. The specific volumes of three systems(polyethylene, polyethylene with a small graphene sheet and two small graphene sheets) were examined as a function of temperature. We found that the glass transition temperature decreases with increasing graphene. Then the van der Waals energy changes obviously with increasing graphene and the torsion energy also plays an important role in the glass transition of polymer. The radial distribution functions of the inter-molecular carbon atoms suggest the interaction between PE and graphene weakens with increasing graphene. These indicate that graphene can prompt the motion of chain segments of polymer and decrease the glass transition temperature (T_g) of polymer.



Recycle Adsorption of Cu²⁺ on Amine-functionalized Mesoporous Silica Monolithic

ZHAO Da-zhou, JING Shu-bo, XU Jia-ning, YANG Hong, ZHENG Wei, SONG Tian-you, ZHANG Ping

2013, 29(4):  793-797.  doi:10.1007/s40242-013-2442-y

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3-Aminopropyltriethoxysilane functionalized worm-like mesoporous silica monolithic(WMSM-NH₂) was prepared and used as a new regenerable adsorbent for the removal of Cu²⁺ ions. The analysis results show that the WMSM-NH₂ monolithic had a high efficiency value of 99.3% for Cu²⁺ remediation when the Cu²⁺ solution was at an initial concentration of 10.32 mg/L. The regeneration study of the WMSM-NH₂ monolithic presented that the adsorption efficiency of 89.0% was remained and a mass of 92.0% was left after seven adsorption-desorption cycles were executed. The monolithic material with high resistance to the acid and good mechanical stability can facilitate the operations of adsorption and regeneration of the adsorbent.



Electrochemical Study and Application on Shikonin at Poly(diallyldimethylammonium chloride) Functionalized Graphene Sheets Modified Glass Carbon Electrode

AN Jing, LI Ji-ping, CHEN Wen-xia, YANG Chun-xia, HU Fang-di, WANG Chun-ming

2013, 29(4):  798-805.  doi:10.1007/s40242-013-2436-9

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The electrochemical behaviors of shikonin at a poly(diallyldimethylammonium chloride) functionalized graphene sheets modified glass carbon electrode(PDDA-GS/GCE) have been investigated. Shikonin could exhibit a pair of well-defined redox peaks at the PDDA-GS/GCE located at 0.681 V(E_pa) and 0.662 V(E_pc)[vs. saturated calomel electrode(SCE)] in 0.1 mol/L phosphate buffer solution(pH=2.0) with a peak-to-peak separation of about 20 mV, revealing a fast electron-transfer process. Moreover, the current response was remarkably increased at PDDA-GS/GCE compared with that at the bare GCE. The electrochemical behaviors of shikonin at the modified electrode were investigated. And the results indicate that the reaction involves the transfer of two electrons, accompanied by two protons and the electrochemical process is a diffusional-controlled electrode process. The electrochemical parameters of shikonin at the modified electrode, the electron-transfer coefficient(α), the electron-transfer number(n) and the electrode reaction rate constant(k_s) were calculated to be as 0.53, 2.18 and 3.6 s^-1, respectively. Under the optimal conditions, the peak current of differential pulse voltammetry(DPV) increased linearly with the shikonin concentration in a range from 9.472×10^-8 mol/L to 3.789×10^-6 mol/L with a detection limit of 3.157×10^-8 mol/L. The linear regression equation was I_p=0.7366c+0.7855(R=0.9978; I_p: 10^-7 A, c: 10^-8 mol/L). In addition, the modified glass carbon electrode also exhibited good stability, selectivity and acceptable reproducibility that could be used for the sensitive, simple and rapid determination of shikonin in real samples. Therefore, the present work offers a new way to broaden the analytical application of graphene in pharmaceutical analysis.



Degradation of Hydrogenated Nitrile-butadiene Rubber in Aqueous Solutions of H₂S or HCl

CONG Chuan-bo, CUI Can-can, MENG Xiao-yu, LU Shao-jie, ZHOU Qiong

2013, 29(4):  806-810.  doi:10.1007/s40242-013-2401-7

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The degradation of hydrogenated nitrile-butadiene rubber(HNBR) soaped in aqueous solutions of H₂S and HCl was investigated. The samples unexposed and exposed to different solutions were characterized by ¹³C nuclear magnetic resonance(¹³C NMR), X-ray photoelectron and infrared spectroscopies. In contrast to those of unexposed samples and samples soaped in HCl solution, the mechanical properties of samples exposed to H₂S solution significantly deteriorated, in which the new groups of C(=O)―NH₂, C―S―C and C=S emerged. The mechanism of C=S and C―S―C formation was speculated, except for that of the formation of group C(=O)―NH₂, which was widely discussed in acidic condition such as HCl solution. The formation of C―S―C was due to radical reaction initiated by mercapto radical and that of C=S was due to nucleophilic reaction initiated by mercapto cations. This finding is helpful to understanding the seal failure of HNBR in working environment containing H₂S.



Preparation of Anion Exchange Membrane Based on Imidazolium Functionalized Poly(arylene ether ketone)

ZHOU Hao, ZHANG Na, MA Wen-jia, ZHAO Cheng-ji, NA Hui

2013, 29(4):  811-815.  doi:10.1007/s40242-013-2467-2

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The authors presented a novel synthetic route for the imidazolium functionalized poly(arylene ether ketone)s, derived from an engineering plastics polymer, a poly(arylene ether ketone) with 3,3',5,5'-tetramethyl-4,4'-dihydroxybiphenyl moiety(PAEK-TM). The preparation of anion exchange membranes comprised converting benzylic methyl groups to bromomethyl groups by a radical reaction, followed by the functionalization of bromomethylated PAEK with alkyl imidazoles, i.e., methyl, butyl or vinyl imidazole. The structure of imidazolium functionalized PAEK was proved by ¹H NMR spectra. A class of flexible and tough membranes was then achieved by subsequent film-forming and anion exchange processes. The water uptake and hydroxide conductivities of membranes are comparable or superior to those of quaternary ammonium(QA) anion exchange membranes. This work demonstrated a new route for non-QA anion exchange membrane design, avoiding the chloromethylation reagent and precisely controlling the degree and location of imidazolium groups.



Improving Performance of Inoculating Alloy Wires by Coating a Boron Nitride Layer

CHENG Shao-heng, FAN Feng-yang, XU Yang, LI Shuo, ZHU Pin-wen, LI Hong-dong, LIU Jun-song

2013, 29(4):  816-819.  doi:10.1007/s40242-013-2379-1

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The paper reports the deposition(by magnetron sputtering) and properties of polycrystalline boron nitride (BN) layers on commercial inoculating alloy wires. As is characterized by means of Fourier transform infrared(FTIR) spectroscopy, electron energy dispersive X-ray(EDX) spectroscopy and scanning electron microscopy(SEM), the thin BN layers consist of hexagonal and orthorhombic BN phases and are smooth without cracks. Organism transferring-circles experiments reveal that the adhesion between the BN layer and alloy wire is very good after tens of cycles. It is demonstrated that the BN layers covered wires are biomaterial lubricious and self-cleaning. As a result, BN layer would effectively enhance the function and efficiency of inoculating alloy wires, which could be widely applied to bio-experimentation and biomedicine apparatuses.



Adsorption-desorption of Silica Nanoparticles on Poly(ethylene glycol) Brushes Grafted onto Au Substrate Studied by Quartz Crystal Microbalance

WANG Da-peng, YANG Mu-quan, DONG Zhi-xin, BO Shu-qin, JI Xiang-ling

2013, 29(4):  820-824.  doi:10.1007/s40242-013-2343-0

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The adsorption-desorption of silica nanoparticles(NPs) on poly(ethylene glycol)(PEG) grafted onto gold(Au) substrate was studied by quartz crystal microbalance with dissipation monitoring(QCM-D) technique. The results of frequency and dissipation show that SiO₂ NPs can be adsorbed strongly on PEG-SH brushes at pH of 9.6, and a new dense and rigid construction is formed. Adjusting the pH from 9.6 to 12.3 resulted in the desorption of silica NPs from the PEG brushes because of a significant weakening of the hydrogen bond between the silica NPs and PEG chains. In addition, the viscoelastic properties of the system during the adsorption-desorption process were also analyzed via the relationship between the normalized frequency(Δf/n) and mass. And the corresponding atomic force microscopy(AFM) images also exhibit morphological changes during the above process, consistent with the changes in viscoelasticity.