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    Ion-transfer Reaction of SO42- Across the Water/1,2-dichloroethane Interface Modified by an Anion Exchange Membrane
    WANG Huanhuan, HU Daopan, JIANG Xuheng, ZHANG Yehua, CHEN Yong
    Chem. J. Chinese Universities    2016, 37 (3): 546-551.   DOI: 10.7503/cjcu20150626
    Abstract2327)   HTML76)    PDF(pc) (1546KB)(24875)       Save

    In this work, the anion-transfer reaction of highly hydrophilic sulfate across the water/1,2-dichloroethane(W/DCE) interface modified by a homogeneous anion exchange membrane(AEM) was investigated by employing cyclic voltammetry(CV), differential pulse voltammetry(DPV) and chronocoulometry. It was found that the electrochemical window could be extended by the modification of W/DCE interface with such an AEM. In addition, the well-defined CV and DPV curves corresponding to the ion-transfer of highly hydrophilic SO42- could be obtained at the modified W/DCE interface. According to the linear relationship between the peak current of CV and the square root of scan rate, as well as the equation of Randles-Sevik, the diffusion coefficient of SO42- in the membrane containing water is calculated to be about 7.6×10-8 cm2/s. In addition, the peak current of DPV increases linearly with the concentration of SO42-within the range of 5-25 mmol/L. Moreover, the standard reaction rate constant of the ion-transfer of SO42- at such an AEM-modified W/DCE interface was estimated to be about 1.49×10-3 cm/s via chronocoulometry.

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    Colloidal Lithography——Construction and Application of Nanostructured Surfaces
    ZHANG Gang*, ZHAO Zhi-Yuan, WANG Da-Yang
    Chem. J. Chinese Universities    2010, 31 (5): 839-854.  
    Abstract4073)      PDF(pc) (11337KB)(11235)       Save

    Combining “top-down” patterning with “bottom-up” self-assembly as template colloidal lithography provides a unique patterning strategy. Spontaneous formation of well-ordered colloidal arrays provides lithographic masks or scaffolds for creating useful patterns. Based on self-assembly of colloidal spheres as template, the controlled “positive” deposition of nanoparticles and “negative” etching processes could be used for the fabrication of nanostructured materials, ranging from several tens of nanometers to micrometer scales for 2D and 3D ordered architectures. The feature size can easily shrink below 100 nm by reducing the diameter of the microspheres used according to the simple correlation between the interstice size and the sphere diameter. The feature shape can be easily diversified by the crystalline structure of a colloidal crystal mask, the time of anisotropic etching of the mask, the incidence angle of the vapor beam and the mask registry. Colloidal lithography provides a complementary tool for conventional and fully “top-down” lithographic techniques, and thus holds immense promise in surface patterning. They show versatility applications such as biosensors or chemosensors using for detection tool. Colloidal lithography is also suitable for modifying surface properties which is useful for emerging applications in biotechnology and chemically and structurally designed interactive sites for the attachment.

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    Cover and Content of Chemical Journal of Chinese Universities Vol.34 No.9(2013)
    Chem. J. Chinese Universities    2013, 34 (9): 0-0.  
    Abstract1502)      PDF(pc) (16292KB)(8270)       Save
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    Cover and Content of Chemical Journal of Chinese Universities Vol.34 No.2(2013)
    Chem. J. Chinese Universities    2013, 34 (2): 0-0.  
    Abstract1622)      PDF(pc) (14662KB)(6743)       Save
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    Recent Advance of Hydrothermal Growth of ZnO and TiO2 Nano-tree Arrays
    ZHAO Feng-Hua YANG Xian-Feng GAO Qiong, WU Ming-Mei*
    Chem. J. Chinese Universities    2011, 32 (3): 451-461.  
    Abstract3862)      PDF(pc) (11044KB)(4721)       Save
    Branched tree-like nanoarrays are emerging as an exciting addition to the family of oriented semiconducting nanomaterials. Besides high temperature solid state and vapor-liquid-solid (VLS), a site-specific sequential nucleation and growth route to the systematic building of hierarchical, complex, and oriented ZnO micro/nanostructures in solution synthesis has been developed. Herein, we present a one-step, low cost, and environment-benign route to growing large-scale arrays of zinc oxide and titanium dioxide by solution chemistry. The growth mechanism and their possible applications have been suggested.
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    Cited: Baidu(5)
    Preparation, Characterization and Drug Release of Biodegradable Solid Lipid Nanoparticles
    GUAN Qing-Xiang, ZHU Kun, LIN Tian-Mu, GUAN Qing-Tao, GUO Jie*, YIN Jian-Yuan*
    Chem. J. Chinese Universities    2010, 31 (11): 2298-2302.  
    Abstract3270)      PDF(pc) (581KB)(4716)       Save
    Biodegradable solid lipid nanoparticles loaded with pueraria flavones(PF-SLN) were prepared by emulsification evaporation-solidification at low temperature with a biodegradable material, stearic acid as the carrier. The morphology and particle size of PF-SLN were measured by TEM and laser light scattering technique, respectively. The physical status of the drug in PF-SLN was analyzed by X-ray powder diffractometry. Its entrapment efficacy in SLN and release were also investigated. PF-SLN is near spherical in shape and the average diameter is (263.82±3.6) nm. Its entrapment effciency (EE) is (67.53±0.12)%. X-ray powder diffraction analysis results show that the pueraria flavones are dispersed with the state of molecular or tiny particles in the matrix of SLN. The results show that the release of PF-SLN occurs rapidly in the early stage and then slowly which accumulate up to 50% in 12 h . The drug release slowly from SLN following matrix erosion. The release profile fits well to the Higuchi equation.
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    Cited: Baidu(4)
    Cover and Content of Chemical Journal of Chinese Universities Vol.34 No.1(2013)
    Chem. J. Chinese Universities    2013, 34 (1): 0-0.  
    Abstract1556)      PDF(pc) (16401KB)(4594)       Save
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    Adsorption and Conformational Changes of Melittin on the Surface of Functionalized Gold Nanoparticles
    WANG Lei, DANG Yong-Qiang, ZHANG Min, SUN Jian, WU Yu-Qing*
    Chem. J. Chinese Universities   
    Abstract2226)      PDF(pc) (479KB)(4169)       Save
    As the wide applications of gold nanoparticles(GNPs) in various fields as the biochemistry and biomedicine, the present investigation is geared to the practical demand. Recently, the capability of sulphydryl carboxylate functionalized GNPs to promote the folding of a positive charged peptide into an α-helix was established. This design allowed favorable electrostatic interactions between the nanoparticles and the peptide when the positive charged residues were positioned in a cofacial manner along the helix and was responsible for the assisted folding observed. GNPs coated with different chain lengths of sulphydryl carboxylate are prepared by adding sulphydryl carboxylate into GNPs solution which is synthesized via reducing tetrachloroauric acid(HAuCl4) by sodium borohydride. The structure of the functionalized GNPs can make it interact with electriferous proteins. Multiple spectral means have been used to study the interaction between the functionalized GNPs and melittin. The results show that the functionalized GNPs induced melittin to form α-helix by electrostatic interactions, and it is directly related with the chain length of sulphydryl carboxylate.
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    Cited: Baidu(10)
    Controllable Reduction and Structural Characterizations of Graphene Oxides
    YANG Xu-Yu, WANG Xian-Bao, LI Jing, YANG Jia, WAN Li, WANG Jing-Chao
    Chem. J. Chinese Universities    2012, 33 (09): 1902-1907.   DOI: 10.3969/j.issn.0251-0790.2012.09.005
    Abstract7213)      PDF(pc) (2733KB)(4103)       Save

    Graphene with different reduction degree was prepared by controling the reduction time. The structures and properties of graphene were characterized systematically by Fourier transform infrared spectroscopy(FTIR), UV-Vis spectroscopy, Raman spectroscopy, X-ray diffrations(XRD), thermo-gravimetric analysis(TGA) and electrical conductivity measurements. Moreover, transmission electron microscopy(TEM), scanning electron microscopy(SEM) and atomic force microscopy(AFM) were employed to compare the morphologies of graphene oxide with those of graphene. The results showed that with the increase of reduction time, the oxygen-containing groups were removed gradually and the absorption peak of ultraviolet displayed a gradual red-shift, besides, the ratio of the Raman intensities(ID/IG) of graphene increased markedly, and the thermal stability was improved significantly. The characterization of microstructures reveals that graphene consists of thicker layer structures and more crumples than those of graphene oxide.

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    Cited: Baidu(21)
    Synthesis of Nitrogen-doped Graphene and Its Electrocatalytic Performance Toward Oxygen Reduction Reaction
    LI Jing, WANG Xian-Bao, YANG Jia, YANG Xu-Yu, WAN Li
    Chem. J. Chinese Universities    2013, 34 (4): 800-805.   DOI: 10.7503/cjcu20120658
    Abstract5533)      PDF(pc) (2932KB)(3997)       Save

    A series nGs with different electrocatalytic abilities toward oxygen reduction reaction(ORR) was prepared via a two-steps pyrolysis method by controlling the reaction temperature on the physical mixture of graphene oxideand urea. Transmission electron microscopy and scanning electron microscopy display nG with highly wrinkled and overlapping structures. X-ray photoelectron spectroscopy shows that nitrogen is successfu-lly doped in graphene with the formation of pyridinic N, pyrrolic N and graphitic N, and the maximum nitrogen content is 6.6%(molar fraction). Cyclic voltammogram and rotating disk electrode measurement show that nGs exhibit high electrocatalytic activity with an onset potential of 0.1 V in an acid electrolyte. Moreover, the nGs catalyzed oxygen reduction revealed a favorable formation of water via a four-electron pathway and excellent stability over Pt/C catalyst. Furthermore, the nG obtained at 200 ℃ in the first pyrolysis step displays the best catalytic perfor-mance.

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    Cited: Baidu(18)
    Configuration Interaction in Valence Bond Theory
    SONG Ling-Chun, WU Wei, CAO Ze-Xing, ZHANG Qian-Er
    Chem. J. Chinese Universities    2001, 22 (11): 1896-1897.  
    Abstract1871)      PDF(pc) (123KB)(3941)       Save
    Configuration interaction tenichque is applied to the valence bond theory. Virtual VBorbitals are built, which are localized and orthogonal to their corresponding occupied orbitals and the excited VBstructures are defined, which come from their corresponding fundamental VBstructures. The testing calculations of H2, LiH, HFshow that the VBresults using CImethod match those of the molecular orbital based on the coupled cluster CCSDmethod, and the CItechnique may become a useful tool in VBmethod.
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    Perovskite Solar Cells: Work Mechanism and Major Factors Affecting Their Performances
    QIAN Liu, DING Liming
    Chem. J. Chinese Universities    2015, 36 (4): 595-607.   DOI: 10.7503/cjcu20140927
    Abstract5821)   HTML40)    PDF(pc) (5173KB)(3901)       Save

    Hybrid organic-inorganic perovskites were first introduced to photovoltaic community in 2009. In subsequent years, the power conversion efficiency has increased from 3.8% to ~20%, leaving dye-sensitized solar cells and bulk-heterojunction solar cells far behind. “Perovskite” is a crystal possessing the same crystal structure as calcium titanate, namely, ABX3. Perovskites have unique properties, like broad absorption spectra, high absorption coefficient, ambipolar charge transport, long exciton lifetime and very low binding energy of exciton. Currently, the architecture of perovskite solar cells has been simplified from meso-structured solar cells to planar-heterojunction solar cells, getting closer to the low-cost, high-efficiency target for practical application. Many innovative researches are pushing the application of this new photovoltaic material to the climax. This review summarizes the working mechanism of perovskite solar cells and expounds several key factors affecting device performance, i.e. components, crystallization and morphology, transport layers, electrode materials and planted bulk-heterojunction. However, we should note that perovskites have some drawbacks impeding its commercialization. Perovskites are sensitive to oxygen and water vapor, making the solar cells unstable in the ambient; it is challenging to prepare large films because the morphology of perovskite film is difficult to control; the use of the toxic metal, lead, will also undermine the credit earned by their outstanding photovoltaic performance. It is very important for us to understand those mechanism and factors affecting device performance, and to find approaches to deal with instability, toxicity, and bad morphology.

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    Fundamental Flaw of Marcus Theory
    ZHU Xiao-Qing, YANG Jin-Dong
    Chem. J. Chinese Universities    2013, 34 (10): 2247-2253.   DOI: 10.7503/cjcu20130183
    Abstract6043)      PDF(pc) (1419KB)(3793)       Save

    Marcus theory is a theory originally developed by Rudolph A. Marcus in 1956 based on Libby's idea about electron transfer mechanism according to the two-sphere model with the help of the continuous medium theory and the electrostatic mechanics to describe the kinetics of the outer-sphere electron transfer reactions in solution, which states that the activation free energies of the outer-sphere electron transfer reactions have the quadratic relationship with the corresponding reaction free energy changes. Having been developed by Marcus and many other chemists for more than 50 years, Marcus theory has received extensive application in various fields. Meanwhile, the research object of Marcus theory has been extended from the outer-sphere electron transfer reactions to the inner-sphere electron transfer reactions, even more to the nucleus transfer reactions. Because the reaction coordinates of the transition state of the electron transfer reactions in Marcus inverted region go beyond the region between the initial state and the final state of the reactions in the same reaction coordinate system, which evidently does not obey the natural change logic, we have never accepted Marcus theory as a scientific theory, even though some experimental observations were reported by Miller and Closs as well as many other chemists to support Marcus inverted region. In order to dig out the origin of Marcus theory error, in this study we examined the following questions about the classical Marcus theory:(1) What are the prerequisites(or assumptions) of Marcus theory? (2) How do Marcus free energy parabolas for the reactant system and for the product system form? (3) What factors determine the feature of Marcus free energy parabolas? (4) How does the classical Marcus equation form? (5) What is the criterion of Marcus inverted region? After the examinations, the following conclusions can be made:(1) Marcus theory directly conflicts with the law of conservation of energy and has the error in principle; (2) Marcus inverted region is impossible; (3) the experimental observations for Marcus inverted region reported in the literatures are all spurious.

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    Cited: Baidu(1)
    Chem. J. Chinese Universities   
    Abstract1853)      PDF(pc) (2251KB)(3219)       Save
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    Self-assembly of 3D Nanocrystal-superlattices
    MENG Ling-Rong, PENG Qing*, ZHOU He-Ping, LI Ya-Dong*
    Chem. J. Chinese Universities    2011, 32 (3): 429-436.  
    Abstract3894)      PDF(pc) (10535KB)(3173)       Save
    The assembly of nanocrystals into various ordered structures is key to their future applications. In this article, we describe the recent progresses in the assembly routes and mechanisms of the three-dimensional superlattices of nanocrystals. This review focuses on the techniques of nanocrystal assembly based on solvent evaporation of colloidal solutions, non-solvent diffusion, micelle-induced aggregation, hydrogen bonding linkage, electrostatic interactions, DNA base-pairing, external field-assistance, and oil-water interface templating. The existing challenges and future development of nanocrystals assembly are also discussed.
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    Cited: Baidu(1)
    Synthesis of Silicalite-1 with Hierarchical Porosity
    CHEN Li, WANG Yi-Meng*, HE Ming-Yuan
    Chem. J. Chinese Universities    2010, 31 (11): 2131-2135.  
    Abstract3170)      PDF(pc) (1864KB)(3141)       Save
    Hierarchical Silicalite-1 aggregates were synthesized by the assembly of Silicalite-1 zeolite seeds under different concentrations of P123. The samples were characterized by X-ray diffraction, IR spectroscopy, TEM and N2 adsorption to evaluate the physico-chemical properties of the mesoporous zeolite aggregates. The sample preserved a single well-defined peak in low-angle XRD patterns, at the same time, the diffraction peaks of Silicalite-1 appeared at wide-angle XRD patterns indicate the formation of MFI structure in the composite. The uniform worm-like pore distributed among the ZSM-5 zeolite aggregates was confirmed by TEM image.
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    Cited: Baidu(6)
    Preparation and Conductive Behavior of Graphene by Electrochemical Method
    ZHU Long-Xiu, LI Ying-Zhi, ZHAO Xin, ZHANG Qing-Hua
    Chem. J. Chinese Universities    2012, 33 (08): 1804-1808.   DOI: 10.3969/j.issn.0251-0790.2012.08.031
    Abstract4129)      PDF(pc) (1881KB)(2792)       Save
    A one-step electrochemical approach was employed to produce graphene dispersion with the perfect structure and excellent conductive property by exfoliation of graphite in electrolyte. Transmission electron microscopy and Raman spectroscopy were used to characterize morphology and structure of the as-prepared graphene. Four-probe method was employed to measure the conductivity of the graphene, and the temperature dependent conductivity was investigated by model fitting. At low temperature range of 100 K<T<120 K, carrier transport behavior is explained by two-dimensional variable range hopping based on the σ-exp temperature dependence. At high temperature range of 200 K<T<500 K, the dependence of conductivity on the temperature is consistent with the express of σ-exp(-ΔE/k0T), and thus carrier transport behavior is well described by thermal activation model. In addition, the outstanding electrical properties suggest that high quality of graphene with less defect can be obtained. This simple method offers a great promise in production of large-scale graphene platelets to meet extensive applications.
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    Cited: Baidu(9)
    Quantitative and Qualitative Analyses of Oxygen-containing Surface Functional Groups on Activated Carbon
    LI Na, ZHU Jian, ZHA Qing-Fang
    Chem. J. Chinese Universities    2012, 33 (03): 548-554.   DOI: 10.3969/j.issn.0251-0790.2012.03.022
    Abstract4106)      PDF(pc) (469KB)(2637)       Save

    The petroleum coke based activated carbon was oxidized by ammonium persulfate. The type and distribution of oxygen-containing surface functional groups(OCFGs) on activated carbon before and after oxidation was monitored using elementary analysis, FTIR spectrometry, temperature-programmed desorption coupled with mass spectrometry(TPD-MS), X-ray photoelectron spectroscopy(XPS), and X-ray absorption near edge structure(XANES) spectroscopy. The results obtained from these methods were compared with each other. It was found that using the TPD-MS method currently reported in the literature to quantify various OCFGs on the carbon surface on the basis of TPD-CO2 and TPD-CO profiles is significantly superior to the others due to its good accuracy and reproduction along with simple experimental conditions. Both of the concentration of OCFGs obtained by XPS and XANES methods are under the estimated ones.

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    Cited: Baidu(14)
    Luminescent Properties of Ce3+-Doped Sr2MgSiO5 Blue-emitting Phosphor
    YANG Zhi-Ping, LIU Yu-Feng, XIONG Zhi-Jun
    Chem. J. Chinese Universities   
    Abstract2451)      PDF(pc) (309KB)(2534)       Save
    The intense blue emitting phosphors Sr2MgSiO5∶Ce3+ were synthesized by high temperature solid state reaction method, and their luminescence properties were studied. The intense blue-emission band present a peak fixed at 420 nm, which consists of two peaks located at 408 and 445 nm, respectively. The two peaks are originated from the transition 5d2F5/2(4f) and 5d2F7/2(4f) of Ce3+ ions. The energy level difference value of the two emission bands is 2 038 cm-1, which is consistent with the theoretic value(2 000 cm-1) between the ground state: 2F5/2 and 2F7/2 of Ce3+ ions. The excitation spectra extend from 250 to 400 nm and the peak positions around 365 nm. In addition, the effect of the concentration of Ce3+ ions and the role of charge compensation of different ions to the emission intense were investigated, the experiment results suggest that when the proportion of Ce3+ ions to Sr2MgSiO5 were 0.03(molar ratio), the strongest emission was obtained. Li+, Na+, K+ and Cl- ions can all enhance the intensity of the emissions; especially Cl- ions gave the best improvement.
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    Fabrication of Polymeric Hollow Structure by Electrospinning
    BAI Fan, WU Jun-Tao, GONG Guang-Ming, SUN Na, ZHAO Yong, JIANG Lei
    Chem. J. Chinese Universities    2013, 34 (4): 751-759.   DOI: 10.7503/cjcu20120734
    Abstract4568)      PDF(pc) (4193KB)(2533)       Save

    Polymeric hollow micro/nano-material has a potential application prospects in a lot of fields, by virtue of its unique physical and chemical properties. Electrospinning is a kind of methods to prepare nanoscale continuous filament. In recent years, using electorspinning to construct the hollow micro/nano-material efficiently and simply has received much attention. This article reviews the progress in preparation of polymeric hollow fibers and spheres by electrospinning, and prospects its development in different functional material fields.

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    Cited: Baidu(9)