28 April 2017, Volume 48 Issue 4

    

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Focuses & Concerns
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  Optimization of the growth interface during the growth of ZnTe crystal by the temperature gradient solution growth technique

  YIN Liying, JIE Wanqi, WANG Tao, ZHOU Boru, YANG Fan, ZHA Gangqiang

  Journal of Functional Materials. 2017, 48(4): 4001-4006. https://doi.org/10.3969/j.issn.1001-9731.2017.04.001

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  In order to optimize the growth interface during the growth of ZnTe crystal by the temperature gradient solution growth (TGSG) technique, a cylindrical ampoule pedestal is designed, which consists of a mullite sheath and a graphite core. A finite element model is established to simulate the effects of the pedestal on the transport phenomena and the growth interface during the growth. The results show that when the growth begins, there are two clockwise vortexes in the solution. The lower one is close to the growth interface and the upper one occupies the rest of the solution. The lower vortex vanishes very soon, and the upper one keeps shrinking and moving upwards. After the lower vortex disappears, the solute (ZnTe) transfers to the growth interface only by diffusion. The growth interface, which is convex first becomes flat when the first third of the ingot has grown, and turns to concave after that. The depth of the growth interface is far less than that in the growth without the pedestal. Distortion of the growth interface in the growth without the pedestal does not occur in the current growth. The optimized growth interface should be helpful to improve the grain size and the crystalline quality.
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  Properties of diatomite humidity-controlling materials and its humidity controlling mechanism

  HU Mingyu, FU Chao

  Journal of Functional Materials. 2017, 48(4): 4007-4012. https://doi.org/10.3969/j.issn.1001-9731.2017.04.002

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  The strength, water resistance, humidity-controlling performance of the diatomite humidity-controlling material has been tested experimentally. The humidity-controlling mechanism of the diatomite humidity-controlling material is investigated based on the micro-analysis of the scanning electron microscope and theory of moisture absorption/desorption of materials. The results show that due to the action of inorganic modified admixture, the compressive strength of the diatomite humidity-controlling material at 28 and 60 d are greater than 5 and 6 MPa, respectively, and the softening coefficient can reach 0.65 and 0.74, respectively. In addition, the maximum equilibrium moisture content of the material is close to 20%, and the moisture absorption/desorption rate is pretty high, which indicates that the material has an excellent humidity-controlling performance. The main role that the diatomite humidity-controlling material plays on the water molecules in the air is the capillary effect and surface chemical adsorption, and the second one is the surface physical adsorption.
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  Preparation and warming effect of a new nano photo-conversion film

  SHAO Maoni, ZHOU Ninglin, LI Wenxiu, YUAN Ping, SU Yutian, ZHANG Ming, CHI Cheng

  Journal of Functional Materials. 2017, 48(4): 4013-4017. https://doi.org/10.3969/j.issn.1001-9731.2017.04.003

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  The nano photo-conversion films were prepared by intercalation method. The films were characterized by XRD, UV-Vis, FL, TGA. The results showed that the photo-conversion film could effectively absorb ultraviolet light ranged from 206 to 360 nm which was harmful to plants and greenhouse film, convert it into blue-violet light ranged from 380 to 485 nm and show a good performance of fluoresence anti-attention. In the red-orange and blue-violet region, the transmittances of photo conversion film were 2.43% and 1.82% respectively higher than that of the control, which wasconducive to plant photosynthesis. In the UV-A, UV-B, UV-C light district, the transmittanceswere 1.35%, 4.97%, 5.54% respectively lower than that of the control, which could reduce UV damage to the plastic indoor crops and greenhouse film to some extent. Compared with the control membrane, the new nano conversion film has good heat resistance, and can raise the air and soil temperature several degrees, which is favorable to crop growth. Results of farmland experiment show that the nano photo-conversion films could effectively promote the growth of lettuce and the average fresh weigh value of lettuce increased 14.03% compared to the control. Thus, the photo-conversion films promote more crops growth.
Review & Advance
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  Development and research progress of superhydrophilic and superoleophobic polymer membrane for oil/water separation

  SHEN Shusu, ZHANG Ganwei, YANG Jingjing, ZHOU Xiaoji, BAI Renbi

  Journal of Functional Materials. 2017, 48(4): 4018-4024. https://doi.org/10.3969/j.issn.1001-9731.2017.04.004

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  The recent researches in the organic polymer membrane applied into the oil/water separation at home and abroad were reviewed. The polymer synthesis, the membrane preparation and the membrane performance were summarized in the paper.
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  Review on characteristics of interface of titanium clad steel plate

  WANG Kuan, ZHU Haiping, SONG Zhenli, TAO Boran, WANG Ying, HE Weijun, LUAN Baifeng

  Journal of Functional Materials. 2017, 48(4): 4025-4032. https://doi.org/10.3969/j.issn.1001-9731.2017.04.005

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  Titanium and its alloys have been widely used in anti-corrosion fields such as chemical reaction vessels production, heat exchanger owning to their good corrosion resistance. However, the application of titanium and its alloys have been hindered by their relatively high cost. Recently, titanium-steel clad plate has attracted much attention in research, because of the good corrosion resistance of titanium, the strength and toughness of steel, as well as the good cost performance. This paper aims to review the research status of the titanium-steel clad plate in decades, among which the typical preparation methods of the titanium-steel clad plate are summarized. Meanwhile, the characteristics of interfacial microstructures, the interfacial bonding mechanism, together with the effects of heat treatment temperature on the interfacial characteristics and bonding strength are emphatically discussed. At last, based on the relevant literature analysis and requirements in the actual industry, the research and development trends of the titanium-steel clad plate are proposed.
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  Development in characterization of graphene quantum dots

  CHENG Chaoge, LI Min, WU Qilin

  Journal of Functional Materials. 2017, 48(4): 4033-4040. https://doi.org/10.3969/j.issn.1001-9731.2017.04.006

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  Graphene quantum dots (GQDs) have attracted widespread attention in recent years. However, because of the heterogeneity of GDQs’ microstructure, research on the photoluminescence mechanism is still not clear. The microstructure of GDQs can be analyzed to the full range by modern analyzing techniques, which has important significances on the study of photoluminescence mechanism of GQDs. Herein, some general characterizing techniques were comparatively reviewed and the recent progress of advanced characterizing techniques, especially combined techniques in the research of GDQs’ microstructure and bio-imaging application was placed emphasis on. Moreover, some perspectives on characterizing techniques and research trends of GQDs were presented.
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  Research progress in L1₀ phase Fe/Co-based magnetic nanoparticles

  ZHANG Zhenrong, LIU Jinjun

  Journal of Functional Materials. 2017, 48(4): 4041-4048. https://doi.org/10.3969/j.issn.1001-9731.2017.04.007

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  The L1₀ Fe/Co-based magnetic nanoparticle with face-centered tetragonal (fct) structure possesses high magnetocrystalline anisotropy, tiny super- paramagnetic critical size and excellent chemical stability, which make it a potential material for a variety of applications, such as biomedicine, high density magnetic recording media, magnetic fluids, catalyst and permanent magnets, and have become the research hotspot of nanoscience and nanotechnology. In this paper, a review is presented for chemical preparation method of the L1₀-Fe/Co-based magnetic nanoparticles in recent years. In addition, the research progress in the ordered annealing for the Fe/Co-based nanoparticles with chemically disordered face-centered cubic (fcc) structure are briefly summarized. The problems existing in the current research are pointed out, and the future development direction is also prospected.
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  Controlled drug release systems based on biomolecule-capped mesoporous silica nanoparticles

  ZENG Peixian, ZHENG Shaoqiu, CAO Ting, ZHU Chunling

  Journal of Functional Materials. 2017, 48(4): 4049-4059. https://doi.org/10.3969/j.issn.1001-9731.2017.04.008

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  The research of MSN-based controlled drug release systems has been one of the current common interests of biomedicine and material science. Recently, biomolecules were extensively used to modify the mesoporous silica nanoparticles owning to their biocompatible, biodegradable, nontoxic and targeting properties. Herein, the research of MSN-based drug delivery systems, which were capped by various biomolecules was reviewed. It mainly was focused on the linked and responsive mechanisms between the biomolecules and the MSN. Finally, the difficulties in current research and the application prospect were discussed, which afford references and ideas for the future study in controlled drug release.
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  Nano-copper: wet-chemical synthesis and applications

  XIE Hanwen, TIAN Yu, YANG Wanliang, FU Boyan, TIAN Mengkui

  Journal of Functional Materials. 2017, 48(4): 4060-4065. https://doi.org/10.3969/j.issn.1001-9731.2017.04.009

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  Because of low-cost,stability and specific physicochemical property of raw materials, nano-copper has been widely used in the field of catalysis,electron,antibiosis and lubricant etc. The preparation method of nano-copper such as wet chemical has little restriction on experiment conditions. All variable quantities can be controlled easily in the experiment process. Preparation of nano copper by wet chemical method is summarized in this paper,the emphasis is on the option of dissolvant,precursor, active agent and reduction,the characteristics of dimension and aspect of nano-copper are described, the mechanism of development is also clarified. And its applications in different fields such as transparent conductive electrodes (TCEs),deformable conductors,sensors, biological medicine and catalysis are also discussed explicitly in this paper.
Research & Development
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  Fabrication of nanoporous PtTiCu electrocatalysts and their electrocatalytic oxidation performance

  ZHAO Yuanyuan, YIN Huiming, HE Meifeng, ZHOU Kai, PAN Deng

  Journal of Functional Materials. 2017, 48(4): 4066-4071. https://doi.org/10.3969/j.issn.1001-9731.2017.04.010

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  Melt-spun precursor PtTiCu alloy ribbons with uniform composition and structure were chemically dealloyed to attain a bicontinuous nanoporous structures as electrocatalysts for fuel cells.The electrocatalytic oxidation for methanol, formic acid, ethanol with PtTiCu catalysts as well as CO poisoning resistance of these nanoporous Pt-containing catalysts were investigated. In comparison with commericial Pt/C catalysts, np-PtTiCu electrocatalysts demonstrated better electrocatalytic performance, greater CO tolerance and preferable catalytic stability, which may be attributed to their unique 3D bicontinuous pore/ligament structures.
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  Nanoporous gold films as catalyst on the performance of hydrazine oxidation

  WANG Yan, YIN Huiming, ZHOU Kai, PAN Deng

  Journal of Functional Materials. 2017, 48(4): 4072-4074. https://doi.org/10.3969/j.issn.1001-9731.2017.04.011

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  Nanoporous gold (NPG) films are found to exhibit high electrocatalytic properties towards hydrazine (N₂H₄) oxidation. Compared with bulk gold, NPG shows not only the enhanced current but also the lower overpotential of hydrazine oxidation. The electrocatalytic activities of the as-prepared NPG films towards 10 mmol/L hydrazine oxidation in 0.5 mol/L NaOH solution were investigated by cyclic voltammetry(CV). At the NPG electrode, hydrazine oxidation in 0.5 mol/L NaOH took place at the potential of -0.6 V (vs SCE) and the peak of the potential was about -0.5 V (vs SCE). We found that after 30 min chemical dealloying, the NPG-30 min films showed a better electrocatalytic properties towards hydrazine(N₂H₄).
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  Preparation of three-dimensional V₂O₅ thin film electrode by

  TIAN Ying, LIU Zongyu, LIU Xiao, HUANG Liping

  Journal of Functional Materials. 2017, 48(4): 4075-4079. https://doi.org/10.3969/j.issn.1001-9731.2017.04.012

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  V₂O₅ film was directly grown on Ni foam substrate by a facile chemical bath deposition method. The morphology and structure of as-prepared V₂O₅ film was conducted by SEM and XRD, and the specific surface and pore distribution were measured by nitrogen adsorption and desorption measurements. The orthorhombic V₂O₅ presents three-dimensional flower-like porous microstructure with BET area of 68.7 m²/g and average pore diameter of 7.2 nm. The electrochemical performance of V₂O₅ film electrode in 3 mol/L KNO₃ solution was investigated by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge measurements. The results demonstrates that the 3D flower-like microstructure and large pores shows excellent pseudocapacitance behavior and good stability, delivering capacitances of 392, 338 and 276 F/g in 3 mol/L KNO₃ at current densities of 1, 2 and 3 A/g, respectively.
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  Strength degradation law of asphalt mixture under the action of static water

  GAO Junqi, XU Yuan, LU Hongqiang, SHENG Yuxiang

  Journal of Functional Materials. 2017, 48(4): 4080-4084. https://doi.org/10.3969/j.issn.1001-9731.2017.04.013

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  The field cores drilled from the asphalt pavement are soaked for long time after vacuum saturation. Water absorption is tested every three months. The split strength and TSR of asphalt mixtures were measured by the split test. Moreover, the cohesion and internal friction angle of soaked mixtures were studied by the split and unconfined compression strength tests at 60 ℃. Two fitting methods are used to fit the trend of the change of cohesion and internal friction angle. The test results show that the water absorption of the soaked mixtures increased rapidly at early stage. But at later stage, moisture began to infiltrate into the micropores, resulting in the slow decrease of the water absorption. Under the long-term soaked duration, the split strength and TSR of asphalt mixtures all decreased. The decline rate of the first 6 months was larger, the latter gradually slowed down. The decline rate of the early stage was 3-4 times of the latter. With one year of immersion time, the cohesion in the binder decreased 0.08 MPa, which approximately showed a linear change, and the internal friction angle decreased by 10.3 degrees, which generally presented parabolic variation.
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  Biomimetic synthesis of calcium carbonate by imidazole-1-acetic acid-grafted-chitosan

  CHEN Zhangxu, ZHENG Bingyun, HUANG Xiaodan, LIAN Xiaohua, WU Baorong

  Journal of Functional Materials. 2017, 48(4): 4085-4089. https://doi.org/10.3969/j.issn.1001-9731.2017.04.014

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  Imidazole-1-acetic acid grafted chitosan (IACS) was used as the organic matrix for biomimetic synthesis of calcium carbonate. The effects of pH value and aging time on morphology and polymorph of calcium carbonate were investigated. The products were characterized by FT-IR, XRD and FESEM. The result showed the sole rhombohedral calcite was formed in pure water. Whereas the coexistence of spherical vaterite and rhombohedral calcite were gained with adding one of histidine, imidazole-1-acetic acid or imidazole-1-acetic acid grafted chitosan. In presence of IACS, the content of vaterite varied from 0.759 to 0.546 when the pH value increased from 6.00 to 9.00. At the other hand, decreasing the aging time was favourable to the growth of vaterite. The result indicated that IACS was an effective biological template to control the morphology and polymorphs of calcium carbonate. This study could be helpful to offer new method for the biomimetic synthesis of novel biomaterials and understand the mechanism of biomimetic synthesis.
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  Study on synthesis of SnO₂-CuO nanocatalysts and effect of CO₂ on the performance of electrochemical reduction

  MA Chengyu, SUN Wei, CHA Xianghao, FAN Mengyang, ZHANG Yanjing

  Journal of Functional Materials. 2017, 48(4): 4090-4095. https://doi.org/10.3969/j.issn.1001-9731.2017.04.015

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  Composite SnO₂-CuO nanocatalysts were prepared by co-precipitation methods, and applied to the technique about greenhouse gases CO₂ electroreduction. The result indicates that catalytic activity of composite SnO₂-CuO depended on the molar ratio of SnO₂ and CuO. When the ratio of SnO₂ was 50%, the SnO₂(50%)-CuO(50%) showed the best catalytic performance. The onset potential of SnO₂(50%)-CuO(50%) could reach to -0.75 V and the current density at -1.25 V could be as high as about -24 mA/cm². Test results show that the electric capacity of SnO₂(50%)-CuO(50%)/GDL was as high as 200 μF/cm² and had more 30 μF/cm² than the area of gas diffusion electrode (GDL). SnO₂(50%)-CuO(50%) was made up of nanoparticles with an average diameter of about 50 nm. The length between particles was about 100 nm, which was good for the contact between CO₂ and electroreduction. Ion chromatography measurement demonstrates that when electrolysis at -1.0 V for 1 h, the maximum Faraday efficiency of formic acid could be high up to 74.1%. The stability of SnO₂(50%)-CuO(50%) was outstanding after even 30 hours electrolysis. So the SnO₂-CuO nanocatalysts have great catalytic activity.
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  Photoelectric properties of single phase Cu₂O thin films prepared by direct current reactive magnetron sputtering

  WANG Jinxia, HONG Ruijin, ZHANG Tao, TAO Chunxian, ZHANG Dawei

  Journal of Functional Materials. 2017, 48(4): 4096-4099. https://doi.org/10.3969/j.issn.1001-9731.2017.04.016

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  Cuprous oxide (Cu₂O) thin films were fabricated by DC reactive magnetron sputtering at room temperature. Effects of deposition time on crystal structure, phase composition, surface morphology, resistivity and surface-enhanced Raman scattering properties of the Cu₂O films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), four-probe tester and Raman spectroscopy, respectively. The results show that the single-phase transparent conductive Cu₂O film is obtained at the deposition time of 3 and 6 min. The phases of Cu₂O films vary from amorphous to polycrystalline with the preferred orientation in (111) plane with the deposition time increasing. The surfaces of thin films consist of densely spherical grains and the Root mean square (RMS) roughness increases as the deposition time increasing. The resistivity decreased. With the Rhodamine B (RhB) as the probe molecule, Raman scattered spectrum was detected on the samples. By comparison of different samples, the results demonstrate the Raman signal was enhanced by surface roughness increased.
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  Research of tribological characteristics of resin matrix composites reinforced by woven fabric of carbon fiber

  LI Hui, DU Jianhua, WANG Haoxu, LYU Yingying, YANG Hongwei

  Journal of Functional Materials. 2017, 48(4): 4100-4104. https://doi.org/10.3969/j.issn.1001-9731.2017.04.017

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  The phenolic resin composites reinforced by 2.5D woven fabric of carbon fiber were prepared by hot pressing process. Dry tribological properties and wet tribological properties of the material were evaluated by MS-T3001 friction and wear tester. Superficial microstructure of friction material was observed by scanning electron microscope (SEM) and three-dimensional laser microscope. Results show that under the condition of dry friction, friction coefficient decreased firstly and then increased with the increasing of the relative sliding speed but had no significant changes with the increasing of work load. The fluctuation interval of friction coefficient is 0.12-0.26. Under the condition of wet friction, friction coefficient continuously decreased with the increasing of the relative sliding speed and work load. The fluctuation interval of friction coefficient is 0.08-0.13. Friction coefficient and friction temperature had considerable fluctuation under the condition of dry friction and keep stable under the condition of wet friction in continuous friction experiment. Abrasive wear is the main form of wear for dry friction, but in wet friction, whose main wear form is abrasive wear and fatigue wear.
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  Electrochemical deposition of nanocrystalline NiO thin films and their optical properties

  WU Zhaohui, GAN Xiaoyan, DU Xiangjun, LIU Keyong

  Journal of Functional Materials. 2017, 48(4): 4105-4109. https://doi.org/10.3969/j.issn.1001-9731.2017.04.018

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  Nanocrystalline NiO thin films were deposited on FTO-coated glass substrates by a cathodic electrochemical deposition method by using Ni(NO₃)₂ aqueous solution as electrolyte. Crystallinity, surface morphology and optical properties of NiO thin films obtained were characterized by XRD, ultraviolet and visible light transmittance spectrum and so on. Results show that deposition of NiO is greatly affected by the deposition potential and deposition time. At optimal conditions (-0.9 V for 2-5 min), NiO thin film obtained is dense, uniform and pin-hole free in surface morphology and the transmittance of which in the visible range is as high as 85%.
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  Controlling the growth conditions to prepare millimeter size single crystal graphene by chemical vapor deposition

  ZHOU Guoqing, HU Lin, WEI Lingzhi, ZHANG Fapei

  Journal of Functional Materials. 2017, 48(4): 4110-4115. https://doi.org/10.3969/j.issn.1001-9731.2017.04.019

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  The effective controlling of the graphene nucleation and growth kinetics is critical to grow single crystal graphene. In this paper, single crystalline graphene with a large size of 4 mm was achieved via the optimization of the processing parameters of low pressure chemical vapor deposition (CVD). The graphene samples are proved to be high quality single-layer graphene, inspected by a series of structural and morphological characterizations. Furthermore, the sub-millimeter size multi-layer single crystal graphene with A-B stacking, as well as the overlapped layer structure formed by two converged graphene domains was observed. It is also found that the properties of the Cu substrates such as its bulk oxygen content play a significant role on nucleation density and morphology of single crystal graphene, by utilizing three types of copper foil substrates for the CVD process. Surface texture of three types of the Cu foils also exhibit different transition behavior after the CVD process. Finally, the field effect transistors based on the as-deposited large-size single crystal graphene have been fabricated, displaying high carrier mobility.
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  Preparation of TiO₂/Cu₂O film based on wood substrate and behavior of negative oxygen ions production

  GAO Likun, LI Jian

  Journal of Functional Materials. 2017, 48(4): 4116-4121. https://doi.org/10.3969/j.issn.1001-9731.2017.04.020

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  Anatase TiO₂ particles with Cu₂O particles were doped on wooden substrates through a two-step method and further modification is employed to create remarkable superamphiphobic surface. The morphological feature, crystal form, chemical state, optical properties and wettability of the as-prepared TiO₂/Cu₂O-coated wood were analyzed using field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (UV-Vis) and contact angle measurement. Meanwhile, it has proved that the TiO₂/Cu₂O-coated wood has the property of negative oxygen ions production under UV light. The results showed that comparing with the TiO₂-coated wood, the property of negative oxygen ions production of TiO₂/Cu₂O-coated wood was drastically improved by doping with Cu₂O particles under UV irradiation. Furthermore, the TiO₂/Cu₂O-coated wood after hydrophobization is imparted with superhydrophobic and superoleophobic properties, antibacterial actions against escherichia coli, and negative oxygen ions production under UV irradiation. In the paper, a new material for formaldehyde degradation is offered, and the functional wood-based materials have great potentials in the applications of new-style functional materials.
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  Research on preparing and gas-sensitivity characterization of Pd-doping SnO₂

  QI Tianjiao, WANG Hui, HAO Xiaofei, LIU Xiaofeng

  Journal of Functional Materials. 2017, 48(4): 4122-4126. https://doi.org/10.3969/j.issn.1001-9731.2017.04.021

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  Pd doped on SnO₂ were prepared by deposition. The morphology, surface chemistry and crystal structure of these nanoparticles were characterized by SEM, XPS and XRD. Planar indirectly heated sensor components were prepared by Pd-doping SnO₂ suspension. The hydrogen-sensing properties of the as-prepared samples were investigated by potentiostatic method. The results show that Pd-doping SnO₂ have excellent hydrogen sensing properties and choice under the room temperature. At the same time, it has good sensitivity with different H₂ concentrations, presenting a certain linear relationship with the change of H₂ concentration.
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  Mechanical properties and corrosion behavior of stored uranium

  QIU Zhicong, ZOU Dongli, HE Lifeng, ZHAO Yawen, XIAO Dawu, GUO Yakun

  Journal of Functional Materials. 2017, 48(4): 4127-4130. https://doi.org/10.3969/j.issn.1001-9731.2017.04.022

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  The mechanical properties and surface corrosion behaviors of uranium stored at ambient temperature and air environment for 10 years were investigated. The experimental results show that when comparing with unstored specimens, the yield strength of stored uranium increased about 13%, and the tensile strength, impact toughness, elongation and area reduction decreased about 0.8%, 10.4%, 14.0% and 33.3%, respectively. The surface flakiness morphology of uranium corrosion at air environment was observed, and the formation factors for this should be mainly attributed to the water vapor at air environment. Meanwhile, Si impurity in air environment accelerated the occurrence of uranium surface corrosion spots.
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  Thermal stable orange luminescence of Na(Y_1.5Na_0.5)F₆∶Eu³⁺ and its fluorescence enhancement

  PANG Tao, ZHOU Yuan

  Journal of Functional Materials. 2017, 48(4): 4131-4135. https://doi.org/10.3969/j.issn.1001-9731.2017.04.023

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  Hexagonal Na(Y_1.5Na_0.5)F₆∶Eu³⁺ phosphors are synthesized by a simple hydrothermal method. At 300 K,the phosphors produce twelve emission peaks at the range of 460-720 nm when excited by 394 nm near ultraviolet radiation,corresponding to the ⁵D_n(n=0,1,2)→⁷F_J (J=1,2,3,4) transitions of Eu³⁺ ions,respectively. The main wavelength of emission spectra is 590 nm with color saturation of 0.97. When the temperature of sample raises to 420 K,only little color shifting can be observed. Through fitting the relational curves Ln(I₀/I-1) and 10 000/T,the thermal activation energy is calculated to be 0.324 eV. Na(Y_1.5Na_0.5)F₆∶Eu³⁺ phosphors are suitable for the bonding of power devices due to the good thermal stability. After coating SiO₂ on surface of the particles,an enhanced luminescence is obtained. But the fluorescence enhancement strongly depends on the thickness of SiO₂ shell. A model on competition between enhancement and quenching is used to explain the phenomenon.
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  Fabrication and study of AlN fine powder and ceramics

  WANG Yu, XIE Jianjun, WANG Tun, DING Maomao, ZHANG Lei, LEI Fang, SHI Ying

  Journal of Functional Materials. 2017, 48(4): 4136-4140. https://doi.org/10.3969/j.issn.1001-9731.2017.04.024

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  The wet-chemical method is proposed for the preparation of a binary carbonaceous aluminium xerogel by using aluminium isopropoxide and sucrose as the raw materials at a given temperature and pH value. AlN ultrafine powders with diameters less than 1.0 micron were prepared by chemical decomposition of aluminum and carbon sources in xerogel at high temperature and carbon-thermal reduction. The as-prepared powders were pure and had low oxygen content. Finally, by adding a CaF₂-Y₂O₃ binary sintering additives and using pressureless sintering technology, the compact AlN ceramics with high-thermal conductivity were prepared successfully. The relative density and thermal conductivity of AlN ceramics sintered at 1 800 ℃ are above 99% and 180 W/(m·℃) respectively.
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  Preparation and characterization of phenol-melamine-formaldehyde aerogels

  YI Dong, LIU Mi, ZHOU Guifang, XU Zhenyang, PENG Yu, SHI Xianpan, ZHU Jiayi, BI Yutie

  Journal of Functional Materials. 2017, 48(4): 4141-4144. https://doi.org/10.3969/j.issn.1001-9731.2017.04.025

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  Phenol-melamine-formaldehyde (PMF) aerogels were prepared using phenol, melamine and formaldehyde via sol–gel method, followed by supercritical drying. The effect of different reactant ratio on gelation time and aerogel density was studied. The structural properties of PMF aerogels were characterized by the field emission scanning electron microscopy (FESEM), N₂ adsorption and desorption, Fourier transform Infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and the brunauer-emmett-teller (BET) methods. The results indicated that the gelation time of PMF aerogels was about 2-6 h at 85 ℃ and its density could be as low as 38 mg/cm³. Comparing to the traditional MF aerogel, the density and gelation time of PMF aerogel had a significant decrease. The PMF aerogel had a typical three dimensional structure made up of nano-particles with an open porous network. The N₂ adsorption/desorption result showed that the PMF aerogel had a high specific surface area of about 383.03 m²/g and pore diameter of about 19 nm, which was typical mesoporous materials. According to thermal analysis, the PMF aerogel maintained good stability under 380 ℃.
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  Influence of magnetic field annealing on saturation magnetostriction and μ_i-T curves for Fe_74.5Cu₁Nb₂Si_17.5B₅ nanocrystalline alloy

  SHI Ruimin, WANG Zhi, ZHENG Yan, LU Jianmin

  Journal of Functional Materials. 2017, 48(4): 4145-4148. https://doi.org/10.3969/j.issn.1001-9731.2017.04.026

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  The influence of magnetic field annealing on the saturation magnetostriction (λ_S) and coercive force (H_C) together with μ_i-T curves for Fe_74.5Cu₁Nb₂Si_17.5B₅ nanocrystalline alloy was investigated. It was found that H_C decreased and μ_i enhanced at relativelylower temperature (below 350 ℃) for field annealed samples, which is due to the reduced λ_S.
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  Study on compatibilizing mechanism of liquid natural rubber for natural rubber/silica composites prepared by wet mixing

  HE Fan, WU Yuyang, YUAN Tianyuan, LIAO Shuangquan

  Journal of Functional Materials. 2017, 48(4): 4149-4153. https://doi.org/10.3969/j.issn.1001-9731.2017.04.027

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  Natural rubber/silica composites(NR/SiO₂) was prepared by wet mixing technology with liquid natural rubber (LNR) as compatibilizer. Micro-Structure, tensile fracture surface, mechanical properties and filler-rubber interaction were studied by scanning electron microscopy, FT-IR spectroscopy and universal tensile machine. The rubber-filler interaction was evaluated by Mooney-Rivilin equation and interfacial interaction equation quantitatively. The compatibilizing mechanism of LNR for W(NR/SiO₂) composites was also investigated. The results showed that the SiO₂ particles are tightly encompassed by NR in the presence of LNR and fracture surfaces appeared toughness fracture; good mechanical properties was observed, the tensile strength increase by 25.73% when silica was 60 phr; the equations showed that filler-rubber interaction have great enhancements under certain amount of silica. It is reveal that LNR has better compatibility, which is attributed to LNR reaction with both NR and SiO₂ to form compatibilizing interface.
Process & Technology
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  Phase field simulation of dendrite growth with boundary heat flux by finite element method

  FANG Pengjun, LIU Xinyu, ZHANG Lei, XU Yi

  Journal of Functional Materials. 2017, 48(4): 4154-4158. https://doi.org/10.3969/j.issn.1001-9731.2017.04.028

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  Based on the phase model reported by Beckermann and Karma, a phase-field approach which incorporates both solute and heat equations was built. Finite element method is used to solve such equations numerically. The various dendritic growth patterns with the boundary heat flux of Al-3.0wt% Cu alloy were studied. It is found that the boundary heat flux significantly alters the local heat and solute transfer at the solidification front, thus the dendrite morphology was influenced. Under heat flux extraction from the boundary, owing to the greater actual undercooling, there is a stronger tendency for the dendrite to grow faster and a thin diffusion layer in front of the growth dendrite, leading to serious microsegregation of dendrite. However, under heat flux input from the boundary, owing to the less actual supercooling, there is inhibition of dendrite growth and forming a thick diffusion layer, leading to weakening of dendrite microsegregation.
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  Complex modification of amphoteric modified bentonite with Tween20 and its structure characteristics

  REN Shuang, MENG Zhaofu, MA Linli, LI Wenbin, LIU Wei, BAI Dan

  Journal of Functional Materials. 2017, 48(4): 4159-4163. https://doi.org/10.3969/j.issn.1001-9731.2017.04.029

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  Batch processing method was employed to study the adsorption law of Tween20(TW20, T) of dodecyl dimethyl betaine(BS-12) amphoteric modified bentonite. Meanwhile, the influence of pH, temperature, different modification proportions of BS-12 and ionic strength on adsorption of TW20 was investigated. The structural feature of amphoteric/non-ion compound modified bentonite was characterized by N₂ adsorption-desorption isotherms, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. The adsorption capacity of BS-12 modified bentonite by 50% CEC (50BS) of TW20 is notably higher than BS-12 modified bentonite by 100% CEC(100BS). BS-12 bentonite’s absorption quantity to TW20 varied in U-shape curve along with the increase of pH, while decreasing along with the reduction of temperature and the increase of ionic strength. Research on surface properties shows that when there are increments for TW20 modification proportion, total organic carbon content, interlayer spacing, and the specific surface area has a decrease. TW20’s absorption onto 50BS got into bentonite interlayer structure through the method of inserting into the layers. External surface absorption is dominant on 100BS. TW20’s absorption on BS-12 modified soil sample surface is a coexisting absorption mode of electrostatic adsorption and partitioning absorption. In the adsorption of Cd²⁺ and phenol experiment, when the modification ratio is 100BS-0.25T, the adsorption capacity of phenol is the largest, and the maximum Cd²⁺ adsorption capacity is at 100BS-0.25T.
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  Analysis of precipitation phase in typical deformation zone of C194 copper alloy based on continuous extrusion

  LI Mingliang, LIU Ping, LIU Xinkuan, SU Honglin, CHEN Xiaohong

  Journal of Functional Materials. 2017, 48(4): 4164-4167. https://doi.org/10.3969/j.issn.1001-9731.2017.04.030

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  The microstructures in typical deformation zones such as adhesion,before and after 90°bending,extended forming region during continuous extrusion of C194 copper alloy were studied by sampling and analysis with TEM. The results indicate that in the adhesion area,second phase precipitation do not occur,but deformation induces grain tension and a small amount of dislocation. In before 90°bending zone,a small size of about 30nm second phase precipitates in the round or oval shape appear at grain boundaries,which are Fe₃P compounds. In some areas of dislocation,tangles develop into dislocation cell. In after 90°bending zone,a large number of second phase particles uniformly disperse in the grain with the sizes about 3-5 nm. At the same time,the number of second phase particles with larger sizes in the grain boundary of former deformation has also increased,and their sizes become larger,with an average of 45-50 nm. In the expansion forming zone,the number of small precipitates,which diffuse in the grains increases significantly. At the same time,compared with the former deformation zone,the size has increased,reaching about 10-15nm.
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  Study on the phase transformation behaviors with rising temeprature and heat treatment process of the GH925 high-temperature and corrosion-resistant alloy

  ZHANG Yubi, YANG Xiaoliang, GAO Xiaoli, TANG An

  Journal of Functional Materials. 2017, 48(4): 4168-4173. https://doi.org/10.3969/j.issn.1001-9731.2017.04.031

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  The phase transformation behaviors, solid-solution aging heat treatment processes, mechanic properties and microstructure of the forged GH925 alloy were investigated by means of differential scanning calorimetry (DSC), scanning electron microscopy (SEM), electron probe microanalysis (EPMA) characterization methods, etc. The research results show that the phase transformation sequence of the forged alloy during elevated temperature from 25 to 1 100 ℃ is MC phase (initial transformation temperature is 540 ℃, terminated transformation temperature is 1 043 ℃, the same below), γ′ phase (578-978 ℃), M₂₃C₆-M₇C₃ (679-758 ℃), σ phase (723.5-879 ℃) and η phase (807-978 ℃). The optimum comprehensive mechanical properties of the forged alloy can be obtained by 990-1 010 ℃×2 h solid-solution and 740-760 ℃×8 h aging heat-treatment. An amount of hard and brittle needle flake σ phase precipitates along the grain boundaries after the heat-treatment of 1 000 ℃×2 h solid-solution and 780 ℃×8 h aging, resulting in a sharp decline of the aolly’s impact toughness at this aging temperature.
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  Effect of temperature on the synthesis and electromagnetic properties of BaTiO₃

  GAO Qiao, SUN Shibing, HUANG Shiming, TIAN Yingliang, REN Longfang

  Journal of Functional Materials. 2017, 48(4): 4174-4178. https://doi.org/10.3969/j.issn.1001-9731.2017.04.032

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  Tetragonal BaTiO₃ nano powders have been synthesized via sol-gel process in this paper. The phase structure, morphology and electromagnetic parameters of the BaTiO₃ nanometer powders were investigated by X-ray diffraction (XRD),scanning electron microscope (SEM) and vector network analyzer at different heat treatment temperatures. Moreover, the MATLAB programming was applied to calculate the electromagnetic parameters and obtain the changing curve of reflectivity with the variation of frequency in the range of 2-18 GHz. It was found that the content of tetragonal BaTiO₃ would be first increased and then decreased with the increment of the heat treatment temperature and the size of grains increased gradually. When the heat treatment temperature reached 1 000 ℃, the sample exhibited the best dielectric loss properties. Then, MATLAB programming was used to calculate the reflectivity, whose bandwidth over -10 dB could be up to 3.8 GHz. In the meanwhile, the minimum reflectivity appeared at 14 GHz and could reach -25.13 dB.
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  Study on preparation and tribological performance of surface metallization of rice husk ceramic particles

  YU Dongrui, HU Enzhu, HU Xianguo, HU Kunhong, TANG Yuchao, HU Enbao

  Journal of Functional Materials. 2017, 48(4): 4179-4183. https://doi.org/10.3969/j.issn.1001-9731.2017.04.033

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  Rice husk ceramic (RHC) particles can be prepared by carbonization process of rice husk power, which is an important method to comprehensive utilization of rice husk. Surface metallization method is a very important technology to expand the scope of application of rice husk ceramic particles. In this paper, electroless plating method was conducted to complete surface metallization of rice husk ceramic particles. Single factor and orthogonal experiments methods were utilized to optimize technological parameters. Effect of Ni-RHC on the tribological performance of aluminum based composite was investigated using a micro-tribometer. The surface morphology and composition of Ni-RHC particles were analyzed by X-ray diffraction spectroscopy (XRD) and high resolution transmission electron microscopy (HRTEM). Results showed that the optimized technological parameters of temperature, plating time, pH and concentration of sodium hypophosphite were 60 ℃, 180 min, 11 and 180 g/L, respectively. The diameter of Ni particles was approximate 40~50 nm, which dispersed on the surface of RHC particles. The Ni-based RHC particles can obviously promote the wear resistance and friction reduction properties of aluminum based composites.
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  Synthesis and properties of a fluorescent probe for Mg²⁺ based on a chromone-derived hydrazone Schiff-base

  PAN Boya, LIANG Weidong, SU Ce, LI Guanbin

  Journal of Functional Materials. 2017, 48(4): 4184-4188. https://doi.org/10.3969/j.issn.1001-9731.2017.04.034

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  In this article,a chromone-derived Schiff-base ligand L called 6-hydroxy-3-formylchromone nicotinic hydrazone has been designed,synthesized and evaluated as a Mg²⁺ratiometric fluorescent probe. The structure of this ligand L was confirmed by IR,NMR and its optical properties were investigated in DMSO. The results show that there is a weak fluorescence emission peak at 431 nm. The presence of Mg²⁺could reduce the fluorescence emission intensity and generate a new strong fluorescence emission peak at 529 nm. Moreover,the detection of Mg²⁺ by L was not interfered with other common competing metal ions. The detection limit of ligand L for sensing Mg²⁺ was 9.16×10^-7mol/L and the binding constant concentration of L with Mg²⁺ was5.65×10^-8 mol/L. This ligand L was coordinated with Mg²⁺(mole ratio of 1∶1) to form a complex (L-Mg),which was attributed to the inhibition of the photo-induced electron-transfer (PET) phenomenon.
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  Effect of low-temperature plasma treatment on wettability of fiber felt

  SONG Yang, LI Fangjun

  Journal of Functional Materials. 2017, 48(4): 4189-4193. https://doi.org/10.3969/j.issn.1001-9731.2017.04.035

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  The low-temperature plasma treatment was used to improve the surface performance and wettability of the fiber felt. The low-temperature plasma treatment was applied on the untreated polyethylene melt-blown fiber felt and the properties of the contact angle, functional groups and morphology of the surface of the fiber felt treated by air plasma and acrylic acid gas plasma are characterized by contact angle meter, infrared spectrometer and scanning electron microscopy. The results show that with the increase of the discharge time and discharge power, the surface hydrophilicity of the fiber felt has promoted. The surface had grafted hydroxyl (—OH), aldehyde (—CHO), carbonyl (CO) and other hydrophilic functional groups. Besides, some changes have taken place in surface morphology and surface micro roughness is increased. Such a series of changes eventually make the fiber felt surface wettability improve effectively.
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  Synthesis of brush-like grafted copolymer HPS-g-PCL and its drug-releasing behavior

  TAN Zhongyuan, ZHOU Jianping, LIU Zhilei, LIU Wenjie, MA Yuming

  Journal of Functional Materials. 2017, 48(4): 4194-4198. https://doi.org/10.3969/j.issn.1001-9731.2017.04.036

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  With amylose as the starting material, hydroxypropyl starch (HPS) was first prepared via hydroxypropylation reaction. Then, by using tin(Ⅱ) trifluoromethanesulfonate (Sn(OTf)₂) as the catalyst, graft copolymer HPS-g-PCL with brush-like structure between HPS and caprolactone was successfully synthesized via ring-opening polymerization. The effect of reaction temperature and reaction time on the graft yield was investigated, and the structure of HPS-g-PCL was characterized by infrared spectroscopy(FT-IR) and nuclear magnetic resonance (¹H NMR). The results indicate that Sn(OTf)₂ is a more efficient catalyst than stannous octoate. The graft yield increased as the reaction time or temperature increased. The results of surface contact angle show that the hydrophilicity of the graft copolymer decreased gradually as the grafting yield increased. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) observations demonstrate that the graft copolymer can self-assemble into spherical micelles in the selective solvents. By using ibuprofen as the model drug, the drug-release behavior of the micelles was investigated, indicating that the drug ibuprofen can be well loaded into the micelles, and a controlled-release behaviour was found with the loaded micelles. The sustained release rate of the drug in the micelles, which was over 80%, decreased with the increasing of graft yield.
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  Molecularly imprinted polymers based on multiwalled carbon nanotubes surface for the fabrication and application of oxacillin

  ZHANG Yingying, WANG Bing, LU Peipei

  Journal of Functional Materials. 2017, 48(4): 4199-4204. https://doi.org/10.3969/j.issn.1001-9731.2017.04.037

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  In this work, a novel strategy for the imprinting of oxacillin molecule on the surface of multiwalled carbon nanotubes (MWNT) was proposed. In brief, MWNTs were firstly coated with a layer of vinyl group modified silica, followed by a precipitation polymerization with oxacillin as the template, ethylene glycol dimethacrylate (EGDMA) as the crosslinker, ethyl alcohol as solvent and 2,2-azobisisobutyronitrile (AIBN) as the initiator, respectively . The performances of MWNTs@SiO₂@MIPs were characterized by UV, FT-IR, TG and SEM. The properties involving adsorption dynamics and selective recognition capacity were demonstrated. As a result, MWNTs@SiO₂@MIPs show a higher adsorption capacity than MIPs and MWNTs@SiO₂@NIPs. The maximum adsorption amount is up to 92μmol/g and the distribution coefficient is 20.36. Furthermore, MWNTs@SiO₂@MIPs show a better recognition ability to oxacillin and a higher imprinting efficiency. The products with regeneration can be recycled in a short term.
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  Preparation of manganese barium ferrite materials with primary mineral by direct method

  ZHAO Yang, LIU Zuohua, SHU Jiancheng, ZHANG Xinran, TAO Changyuan, LIU Renlong

  Journal of Functional Materials. 2017, 48(4): 4205-4210. https://doi.org/10.3969/j.issn.1001-9731.2017.04.038

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  Using mineral of manganese carbonate and barium carbonate as materials from Chengkou, Chongqing, manganese barium ferrite materials were prepared by chemical co-precipitation method. Effects of the precipitation pH, calcination temperature and calcination time on the formation of manganese barium ferrite materials were studied. The manganese barium ferrite was characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The experimental results show that the calcination temperature has a decisive influence on the formation of a manganese barium ferrite. The high crystallinity and well microstructure manganese barium ferrite with M_S=40.5 A·m²/kg and H_C=3.58×10⁵ A/m can be synthesized in precipitation pH=9 by calcining at 1 000 ℃ for 2 h.
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  Contrastive study on properties of inorganic particleboard with a mixture of wheat straw and wood

  PAN Yage, ZHU Lingbo, TANG Qian, HUANG Qinghua, LU Li, ZHENG Xia

  Journal of Functional Materials. 2017, 48(4): 4211-4215. https://doi.org/10.3969/j.issn.1001-9731.2017.04.039

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  With wheat straw, wood and environment friendly Mg-based inorganic adhesive as main materials, inorganic particleboards with a mixture of wheat straw and wood were manufactured by hot-pressing technology. Homogenous particleboard was made by the way of mixing wheat straw and wood uniformly. Three-layered particleboard-1 was made with wood as surface layer and wheat straw as center ply. Three-layered particleboard-2 was made with wheat straw as surface layer and wood as center ply. Physical and mechanical properties and flame retardancy of three kinds of particleboards were contrastively analyzed. Results show that modulus of rupture (MOR) and modulus of elasticity (MOE) of three-layered particleboard-2 are higher than the other two kinds of particleboards, internal bond strength (IB) of that is lower, and thickness swelling (TS) of that is higher than homogenous particleboard. In addition, increasing ratio of wheat straw and wood can improve the IB of three-layered particleboard-2. Compared with the other two kinds of particleboards,heat release rate(HRR) and total heat release(THR) of three-layered particleboard-2 are lower and time to ignition of that is longer, indicating that three-layered particleboard-2 has better flame retardant performance, which can be improved by increasing ratio of wheat straw and wood. The better mat structure is three-layered particleboard with wheat straw as surface layer and wood as center ply and increasing ratio of wheat straw and wood properly could improve its comprehensive performance.
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  Design and preparation of the novel PDC-SiCN wired passive high temperature sensor

  YU Yuxi, LI Yan, XIA Fansen, HAN Qingkai

  Journal of Functional Materials. 2017, 48(4): 4216-4220. https://doi.org/10.3969/j.issn.1001-9731.2017.04.040

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  High temperature sensor is intensive needed in the aspect of monitoring the harsh temperature environment of aero-engine.In this paper,the wired passive microwave temperature sensor is prepared based on the novel high temperature resistant polymer derived ceramic-silicon carbonitride (PDC-SiCN).This PDC-SiCN acts as temperature sensitive medium and can realize the wired passive transmission of temperature information.The resonator of the temperature sensor is formed by the filling medium PDC-SiCN and surface layer metal silver.The transmission line is the combination of coplanar waveguide line and coplanar antenna to realize the transmission of the microwave information.In addition,slotting in the side of the resonator can realize the transmission of broadband excitation signal and resonance signal between the transmission line and resonator.The numerical simulation of the transmission characteristic of this sensor is conducted by using HFSS software.Finally,the PDC-SiCN wired passive high temperature sensor which satisfies the maximum transmission efficiency is designed and prepared according to the simulated and optimized structure sizes.Results indicate that the operating frequency of the designed sensor is 10.16 GHz,and it can realize the measurement in the variable range of 500 MHz according to the dielectric temperature characteristic of the PDC-SiCN materials.