30 June 2015, Volume 46 Issue 12-生态
    

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    研究 开发
  • Oil-water self-assembly synthesis of Ag@AgCl/K4Nb6O17 and enhanced photocatalytic degradation of organic pollutants
    . 2015, 46(12-生态): 1-0.
    Abstract ( ) Knowledge map Save
    The composite photocatalyst of Ag@AgCl/K4Nb6O17 was composed of by the oil-water self-assembly method, on the basis that K4Nb6O17 was prepared in the high-temperature solid-state method. The microstructure, morphology and properties of Ag@AgCl/K4Nb6O17 composite photocatalyst were characterized by means of XRD, SEM, TEM, EDX, UV-vis, PL, BET; and the photocatalytic performance was valued by the degradation of methylene blue (MB), phenol, and Rhodamine B (Rh B) under visible light irradiation. The results shows that Ag@AgCl particles with the size of about 20nm were dispersed in two-dimensional layer structure on the surface of K4Nb6O17 and the absorption of visible light of the composite photocatalyst ranged from 400 nm to 800 nm due to the surface plasmon resonance of Ag. The degradation rate of MB solution over Ag@AgCl (25 wt. %)/K4Nb6O17 under the visible light irradiation reaches 88.2% in an hour, which is more than two times compared with the sum of the Ag@AgCl and K4Nb6O17 degradation rate. The composite photocatalyst still exhibited high catalytic activity after recycled five times, and photocatalytic activities for the degradation of phenol and Rh B were also observed. The degradation mechanism of Ag@AgCl/K4Nb6O17 composite photocatalyst was proposed.
  • The influence and mechanism of nano-TiO2 on the toughness of cement-based materials
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    . 2015, 46(12-生态): 2-0.
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    The influences of nano-TiO2 (NT) on microstructures and mechanical properties of cement mortars were studied by strength test, scanning electron microscope (SEM), X-ray diffraction (XRD) and mercury intrusion porosimetry (MIP). Results show that, 3% NT can significantly improve the tensile and flexural strengths, which increase by 68.2% and 63.2% at 28 days respectively compared those without NT. And it also promotes the precipitation of AFt crystals, which increase by 62.6%. The tensile and flexural strengths have significant positive correlation to the formation amount of AFt. The internal porosity, and harmful pore of hardened mortars at 28 days decrease by 37.0% and 37.9% respectively, while the harmless pores increase by 41.0%, namely pores of mortars are significantly refined and shift to harmless pores. The result of research indicates that 3% NT can effectively improve the toughness and compactness of mortars, and the template nucleation effect and crystal growth regulation effects of NT on the formation of hydration products are presented.
  • Preparation and adsorption properties studies of potassium contained hydroxyapatite powders
    Hairong YIN;
    . 2015, 46(12-生态): 3-0.
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    Ca3(PO4)2 powder was synthesized by chemical precipitation .Then put powder into the crucible of Al2O3，after high temperature treatment obtain α-Ca3(PO4)2 powder .Soaking into the KOH solution at 120℃，after different times，obtained potassium contained hydroxyapatite powders.Characterized by X-ray diffraction，transmission electron microscopy. Then put the powder into the NaF solution for adsorpting F-.Experimental results was described by pseudo-first-order kinetic model and second-order kinetic model. It was found that pseudo- second-order kinetic model was effective,show faster adsorption rate and adsorption mechanism mainly through ion exchange. Process of fluoride ion adsorption was described by Langmuir/Freundlich model, used Langmuir model fit better, static adsorption maximum capacity is 31.55 mg.g-1.
  • Adsorption behavior of bovine serum albumin by histidine-grafted-chitosan/ poly(L-lactide) scaffolds
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    . 2015, 46(12-生态): 4-0.
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    Histidine-grafted-chitosan/ poly(L-lactide) (NHCS/PLLA) scaffolds were prepared by the dual phase separation technique. Adsorption behavior of bovine serum albumin (BSA) by NHCS/PLLA scaffolds in simulated body fluid (SBF) was investigated, while the adsorption isotherm, adsorption kinetics and thermodynamics of behavior were studied too. The results indicated that these scaffolds were effectively to adsorb BSA, NPs3 were the better for adsorbing BSA of all NHCS/PLLA scaffolds. The adsorption capacity of them were 928.53 mg?g-1, which could be reused for separation and purification of BSA, and could provide a carrier for other protein and tissue engineering.
  • Preparation and photocatalytic performance of the nano- CdS/chitosan composite particles
    ;Zhi-Biao HU ;;ma-tai DING
    . 2015, 46(12-生态): 5-0.
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    The nano-CdS/chitosan composite particles were prepared successfully by using in-situ synthesis method，the photocatalytic degradation of methyl orange wastewater using the catalyst was investigated under visible light, the influences of correlative factors on methyl orange degradation rate were investigated . The experimental results indicated that oxidation reaction of photocatalytic degradation was first order reaction, the methyl orange wastewater could be more efficiently degradated in an acid media, when the proper dosage of composite particles were used for the sixth times, the degradation rate of methyl orange was still 81.51% after 60 minute, indicating the composite particles had a good ability to inhibit light corrosion and long reusage life.
  • Study on The North American Rock Asphalt Modified Mechanism Based on Microstructure
    Wen-Tong HUANGGuo-yuan XU;Yu LIU;Duan-yi WANG
    . 2015, 46(12-生态): 6-0.
    Abstract ( ) Knowledge map Save
    The softening point test and dynamic shear temperature sweep test have been used to analyze high temperature performance of North American rock modified asphalt. Fluorescence microscopy, differential scanning calorimetry and nuclear magnetic resonance spectrum have been used to study modified asphalt microstructure with various mixing amounts of the North American rock asphalt. The results suggest that the North American rock asphalt can：1) increase the rheological performance and thermal stability of asphalt effectively, thereby improving the anti-rutting properties and the anti-aging properties of modified asphalt. 2) reinforce asphalt intermolecular forces, improving viscosity and temperature sensitivity of modified asphalt. 3) the North American rock asphalt has a double modifying function on base asphalt, physically and chemically.
  • Effect of Calcium Phenylphosphonate on Crystallization and Melting Behavior of Poly(L-lactic acid)
    CAI YAN HUA
    . 2015, 46(12-生态): 7-0.
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    In order to prepare more nucleating agents for poly(L-lactic acid) (PLLA), calcium phenylphosphonate (CP) with 1.544nm interiamellar spacing was synthesized from phenylphosphonic acid and calcium chloride, and the crystallization and melting behavior of PLLA/CP materials were investigated. Non-isothermal crystallization behavior showed that CP as a heterogeneous nucleating agent can improve the crystallization rate of neat PLLA. Upon the addition of 0.7% CP, the onset crystallization temperature of PLLA/CP increased from 105.88℃to 115.47℃, and the crystallization enthalpy increased from 1.379 J?g-1 to 33.90 J?g-1. Melting behavior indicated that double melting peaks of PLLA/CP materials resulted from melting-recrystallization.
  • Synthesis Mechanism and Water Tolerance of Bone Glue Adhesive Material Modified by Al (Ⅲ)
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    . 2015, 46(12-生态): 8-0.
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    Abstract: A type of bone glue adhesive material modified by Al(III) was prepared by the application of Al(III) ions. The modification mechanism of bone glue with Al (Ⅲ) was speculated. The speculation was verified by the test results of FT-IR, XRD, PL and XPS. Water tolerance of the modified bone glue material prepared in this paper was characterized by means of SEM and the wetting angle detector. After effect of Al(III) and glue, the characteristic peak intensity decreased and the redshift was found by the test result of FT-IR. It showed that conjugation of CA structure is stronger than glue. XRD spectra showed that Al (Ⅲ) and bone glue coordination reaction happened, not just simple adhesion on the surface of the bone glue. PL spectra proved the Al (Ⅲ) and glue reaction produced a rigid planar structure, lead to weak fluorescence of bone glue hair strong fluorescence. XPS spectra found C, N, O binding energy is reduced after the reaction, proved that delocalized Π key was formed in CA molecule. The above test result showed that: the coordination reaction between Al (Ⅲ) and and of the bone glue peptide chains, makes the peptide chains cross-link together by Al(Ⅲ), forming stable network with five-member ring structure. The test results of SEM show that the CA membrane is more neat, smooth, dense than collagen membrane surface; surface wetting angle testing found that the contact angle of CA is 92.45 °, and the contact angle of collagen membrane is only 42.58 °.It showed the water resistance of CA is better and the use of Al (Ⅲ) on collagen changed significantly improved water resistance performance of bone glue
  • Preparation and properties of maleic anhydride/butyl acrylate grafted poly(lactic acid) copolymer
    Wei-hua LUO ;;;;
    . 2015, 46(12-生态): 9-0.
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    Abstract: Maleic anhydride (MAH)/butyl acrylate (BA) grafted poly(lactic acid) (PLA) copolymers (mPLAs) were prepared through solution grafting copolymerization using benzoyl peroxide as initiator, MAH and BA as monomers. The structure and properties of the graft copolymers were characterized by fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and thermogravimetry (TG). The monomer graft degree on PLA first increases and then decreases with increasing mass ratio of BA to MAH. It reaches the highest value of 1.96% when the mass ratios of BA to MAH and MAH to PLA are 1/1 and 3/100 respectively. Compared with the pure PLA, mPLAs exhibit lower crystallinity and decreased thermal stability. A higher monomer graft degree is associated with a lower crystallinity of the samples. With the increase of mass ratio of BA to MAH, both the melting temperature and glass transition temperature of mPLAs have a trend of declining.
  • The impact on sizing agent performance prepared by hydrolyzed collagen with Ultrasound Optimized its size
    qun WANG;
    . 2015, 46(12-生态): 10-0.
    Abstract ( ) Knowledge map Save
    The ultrasonic cell crusher was used to pretreated of hydrolyzed collagen, collagen structure changes before and after ultrasound were measured by FRIT, XRD, TG, the results shows that ultrasound does not change the structure of collagen. The influence of particle size and particle size distribution of collagen, before and after ultrasonic with different ultrasonic time and ultrasonic power, were measured by using nano-particle size, experimental results show that ultrasonic time and power in a certain range can indeed change the particle size of collagen, and less affected when the scope was exceed. In ultrasonic process, the collagen molecules into small molecules, while small molecules bonding with macromolecules by hydrogen. The hydrolyzed collagen after ultrasonic treatment were modified to get a sizing agent, and then be used for paper surface sizing, by investigating the performance of paper after sizing, to find out the relationship between the particle size of synthetic sizing agent and sizing performance of the sheets after sizing.
  • Study on the repair performance of phosphoaluminate cement
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    . 2015, 46(12-生态): 11-0.
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    This paper studied the properties of repair materials and influence factors of adherence of new and old concrete bond strength. The repair material was phosphaoaluminate cement. Properties of the repair between phosphoaluminate cement mortar and Portland cement mortar were investigated. Through the half repair and middle repair methods, the flexure strength of bonding interface was determined,and the bonding interface was analysed.By means of SEM-EDS, a preliminary bonding mechanism of bonding interface zone was proposed. The test results show that: the interface bond strength of the phosphoaluminate cement as repair materials was significantly higher than that with traditional Portland cement as repair material, especially in the early ages,it was found that: the changes in the regional elements in the interface PALC- POC" is a continuous. The elements may enter each other side on the interface region of Portland and Phosphoaluminate cement.There may be a chemical combination in the "P - Si" bonding interface.
  • Experimental study on shock resistance of magnesium phosphate cement
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    . 2015, 46(12-生态): 12-0.
    Abstract ( ) Knowledge map Save
    Abstract: Magnesium phosphate cement is made by mixing magnesium oxide, phosphates and retarder, forming a new type of fast hardening and high strength cementitious materials through chemical reactions at room temperature. Magnesium cement performance under impact force of phosphoric acid were studied, combined with SEM analysis of the reasons of magnesium phosphate cement impact properties changing. Research shows that the impact resistance of magnesium phosphate cement is poor and different admixtures have some impact on its performance. we can see that there are fewer minor cracks and more closely structure inside magnesium phosphate cement of the better impact resistance by SEM analysis.
  • Synthesis and properties of polyurethane alcohol dispersion modified by epoxy resin and its membranes
    . 2015, 46(12-生态): 13-0.
    Abstract ( ) Knowledge map Save
    Hydroxyl-terminated polyurethane modified by epoxy resin(EPPU) was prepared by the reaction of isophorone diisocyanate (IPDI), poly (tetramethylene glycol)(PTMG), 2,2-dimethylolbutanoic acid(DMBA), γ-Aminopropyl triethoxysilane(γ-APTES), phoenix epoxy resin(E-44) and dibutyltindilaurate (T-12) as catalyst. The structure of the polyurethane was characterized by Fourier transform infrared (FTIR) spectrometer, X-ray diffraction (XRD) and transmission electron microscope(TEM). The effect of E-44 content on thermal stability, mechanical properties and water absorption of the membranes were measured. FTIR indicates that epoxy resin has been successfully introduced into the polymer main chain, and XRD shows that crystallinity of EPPU decreased with the addition of epoxy resin while the thermal stability has been improved. It was found that better mechanical properties of polyurethane were obtained when chemical networks formed after modification by epoxy resin. As the w(E-44) increases from 0 wt% to 10 wt%, the tensile strength increased from 5.19MPa to 6.99MPa and the water absorption of the membranes decreased from 19.81% to 4.865%.
  • The influence of Sr(NO3)2 on structure and properties of alkali-activated slag materials
    Xiao-Ying LI ;
    . 2015, 46(12-生态): 14-0.
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    To explore the performance of the alkali-activated slag (AAS) solidified body with Sr2+. AAS solidified body had been prepared using slag, water glass, water and strontium nitrate. The influence of strontium nitrate on the microstructure and properties of AAS had been researched. The results showed that Sr(NO3)2 decreased the crystallization degree and hydration heat release of AAS, which made the setting and hardening process of AAS paste delay. This was because Sr2+ damaged the formation of Si-O-Al groups and C-S-H. The 3-day compressive strength of AAS decreased while Sr2+ presence. However, the 28-day compressive strength of AAS increased with less than 0.4wt% of Sr2+ addition.
  • Study on Gas Sensing Properties of the SnO2-doped TiO2 Thick Film prepared by sol-gel Method
    Liu-mengmeng ;
    . 2015, 46(12-生态): 15-0.
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    Abstract:The SnO2-doped TiO2 nano-powders were prepared by the sol-gel method with precursors of stannic chloride、butyl titanate , and then with 300℃, 500℃, 700℃, 900℃ annealing process. SnO2-doped TiO2 thick film was prepared by the dipping pulling method on surface of Al2O3 ceramic tube.And the phase and morphology of the preparation powder were characterized by XRD and SEM, the gas sensitivities were tested by the method of static gas distribution,and based on theory of molecular orbital level, the gas-sensing mechanism was further discussed.The results show that the gas sensor prepared by after 700℃ annealing 4at% SnO2-doped TiO2 powder has a good selectivity to ethanol gas, when working temperature at 63℃, the sensitivity of ethanol gas is up to 1903, and the response and recovery time are 1s and 3s ,respectively, and it can be used in practical detection of ethanol gas.
  • Study on ethanol fermentation from green alga
    . 2015, 46(12-生态): 16-0.
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    The feasibility of using green alga as the substrate to ferment ethanol is discussed in this study by investigating the effect of alga type, acid concentration and ion concentration on ethanol yield. The results demonstrated that green alga Ulva sp. was rich of glucose which had great potential to be the substrate of ethanol fermentation. The maximum ethanol concentration was up to 30 g/L and ethanol production rate reached 0.63 g/(L?h) and ethanol yield was 37 g/Kg, which were obtained when green alga was hydrolyzed with 2% sulfuric acid and pH was adjusted to 5.5 with calcium hydroxide. In presence of enzyme, higher acid concentration practically had no help on dissolution of glucose, but had certain impact on dissolution of pentose. The concentration of sodium ion had significant effect on ethanol fermentation. A high concentration of sodium ion could inhibit ethanol production and ethanol production rate; low concentration of sodium ion could seriously inhibit ethanol production with the presence of chlorion.
  • The effect of stabilizer on phase composition and microstructure of ZrO2 sizing nozzle matrix before and after sintering
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    . 2015, 46(12-生态): 17-0.
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    ZrO2 sizing nozzle matrix was researched by adding stabilizer which were 2.8%MgO, 2.1%MgO and 2.2%MgO+1%Y2O3 respectively in the desilication zirconium powder. The effects of stabilizer on the composition of phase and the microstructure of ZrO2 sizing nozzle matrix before and after sintering were studied by XRD, SEM and EDS. Results showed that the content of cubic phase increased and the content of monoclinic phase decreased significantly for all samples after sintering at 1630℃, the specise and feed ratio of stabilizer in raw materials made cubic and monoclinic phase variation of each sample were not the same after sintering; After sintering at 1630℃, the solid solution was formed by MgO and ZrO2, with the location of MgO particle closer , the substitution degree of Mg2+ and Zr4+ was more obvious, but the diffusion and solid solution of the stabilizer were far from uniform state; For the sinteried sample combining MgO+Y2O3 stabilizer, cubic phase gained the most, and solid solution generated largest, the degree of stabilization was the highest and the combination between ZrO2 particles which have uniform size and angular shape is much close.
  • Research on water resistance and mechanism of magnesium oxychloride cement foam concrete with compound modifiers
    koubao FENG;wangluming
    . 2015, 46(12-生态): 18-0.
    Abstract ( ) Knowledge map Save
    On the basis of the research on the modification on magnesium oxychloride cement (MOC)foam concrete with phosphoric acid and calcium stearate respectively, then phosphoric acid,calcium stearate and styrene-acrylic emulsion were adopted to improve the water resistance of MOC foam concrete. The results show that, while adding 1wt% phosphoric acid and 1wt% calcium stearate to the foam concrete, comprehensive modification effect of MOC foam concrete were better than the one only modified by calcium stearate or phosphoric acid; Admixed with 1% styrene-acrylic emulsion, water resistance and compressive strength of MOC foam concrete were further improved. Its softening coefficient were up to 0.83.Compressive strength of specimen cured 3 days , 7 days and soaked in water 7 days could reach1.40MPa, 1.48MPa and 1.23MPa respectively, which were approaching and better than the blank. Comprehensive effect of compound modification is superior.
    • 工艺 技术
  • Preparation of TiO2/ZnO composite and its antimicrobial activity under different conditions
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    . 2015, 46(12-生态): 19-0.
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    TiO2/ZnO composite was prepared by hydrothermal synthesis method. The crystal structure and morphology of the TiO2/ZnO composite were characterized by XRD, SEM and EDX method. The antibacterial activity of the TiO2/ZnO composite was performed by the bacteriostatic circle test and bacterial suspensions exposure test, respectively. The results show that the TiO2/ZnO composite material is composed of anatase, rutile and hexagonal wurtzite. There is great amount of tiny lamellar structure on the surface of composite. TiO2/ZnO composite antibacterial activity is significantly better than TiO2. Under visible light irradiation, TiO2/ZnO composite could produce 22mm inhibition zone diameter to Escherichia coli. Exposure to bacteria suspensions, inactivation rate could achieve approximate 96% in 2 hours and 100% in 4 hours by TiO2/ZnO composite. Visible light irradiation will help improve inactivation rate during the early period of TiO2/ZnO composite exposure to bacteria solution. In the range from 4℃ to 30℃, higher temperature could promote the antibacterial activity of TiO2/ZnO composite.
  • Preparation and characterization of imidazole-1-acetic acid-grafted-chitosan
    . 2015, 46(12-生态): 20-0.
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    Chitosan used as target polymer and was modified with imidazole-1-acetic acid. 1-(3-dimethylamino propyl)-3-ethyl carbodiimide as initiator and N-hydroxysuccinimide as the coupler, the Imidazole-1-acetic acid was grafted to chitosan．A series of Imidazole-1-acetic acid modified chitosan (IACS) with different substitution degrees were prepared by using the method of freeze-casting and controlling the amount of Imidazole-1-acetic acid and other conditions. Chemical structure and morphology of IACS were characterized through Fourier transform infrared spectrometer(FT-IR),1H NMR spectroscopy, elemental analysis(EA), field emission scanning electron microscopy (FESEM) and other methods. The results showed that imidazole-1-acetic acid successfully grafted onto the amino groups of chitosan, with increasing of the imidazole-1-acetic acid dosage, the degree of substitution increased(5.52-7.76%), the pore size arranging in 50-150 μm, presenting three-dimensional structure. The Zeta value of IACS decreased from +64.2 mV to +24.2 mV with increase of pH value, which proved that IACS has pH responsibility. Based on the above results, it indicted that IACS could provide a good template for biomineralization and be applied in cartilage tissue engineering.
  • Performance and microscopic analysis of cement-based absorbing materials
    hong-wei liu; xiang gao;kai song
    . 2015, 46(12-生态): 21-0.
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    By double and triple designing, absorbing materials make it possible that match with space wave impedance, meanwhile, which has excellent electromagnetic loss characteristics. Testing the absorbing properties and mechanical properties of cement-based materials and having macro analysis about absorbing materials are necessary. Results show that with double and triple cement-based in 2-18GHz frequency range below-10dB, the effective bandwidth of absorbing panels are respectively 3.7GHz and 10.8GHz. Mechanical properties of double cement-based absorbing materials are superior to the three ones. And the mixing of 5% carbon nanotube will enhance the strength of resistance of cement paste effectively.
    • 综述 进展
  • Synthesis and Application of 1,3,5-Triazine-Based Intumescent Flame Retardants
    丽 马
    . 2015, 46(12-生态): 22-0.
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    1,3,5-triazine-based intumescent flame retardants exhibit excellent potential applications in the field of halogen-free retarded polymers, owing to their good characteristics like smoke suppression, low toxicity, no corrosion, high flame retardant efficiency, etc. Their recent researches and developments were reviewed on the synthesis and application of 1,3,5-triazine-based intumescent flame retardants, the compounds/derivatives based on melamine and cyanuric chloride. Finally, the developing trend of 1,3,5-triazine-based intumescent flame retardants was prospected.
    • 研究 开发
  • Study on conductive characters of ABS/stainless steel fiber/graphite conductive composites
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    . 2015, 46(12-生态): 24-0.
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    ABS/Stainless steel fiber/graphite composites were made by acrylonitrile/butadiene/styrene copolymer (ABS) as matrix and stainless steel fiber (SSF) and graphite as conducting medium. The association of conductive percolation behavior and rheological characteristic of conductive composites were studied, and the resistance-temperature properties and conductive mechanism were studied under DMA multifrequency strain mode and micro- dynamic force field. The results showed that the addition of graphite can obviously improve the seepage conductive ability of compound system. Resistivity showed the strong dependence of vibration frequency and temperature: resistance positive temperature effect (PTC) and resistance negative temperature effect (NTC) were appeared with increased temperatures. And the higher frequency, the lower content of SSF, the higher composite PTC transition temperature of the system.
  • Effect of Titanium Slag Nucleation Agent on Properties of Red Mud and Fly Ash Glass-ceramics
    Chao-Yi CHEN
    . 2015, 46(12-生态): 25-0.
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    The high content of red mud and fly ash glass ceramics was prepared by sintering process, using titanium slag to replace titanium dioxide as Nucleation Agent. The effect of titanium slag content on physicochemical properties, phase composition and microstructure of glass ceramics products were researched mainly. The results show that the main crystalline phase is gehlenite, and the secondary crystalline phase is hedenbergite and anorthite. The crystallinity increases with titanium slag content, but the titanium slag content is high, the crystal will occur condensation phenomenon. When titanium slag content is 6.6%, the compressive strength, flexural strength, microhardness, acid resistance, alkali resistance is 89.43Mpa, 53.13Mpa, 637.27kgf/mm2, 0.041%, 0.15%, respectively. Product performance is meet standard of JC/T 872-2000 with building decoration glass-ceramics.
  • The preparation and property of N-halamine modified chitosan/PVA antibacterial composite film
    ;;;;;Rong LIXuehong Ren
    . 2015, 46(12-生态): 26-0.
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    Chitosan has attracted researchers' wide attention due to its excellent properties such as biodegradability, biocompatibility and antibacterial property. Based on our preliminary studies, composite films in different proportions were prepared by physically mixing N-halamine modified chitosan (CTS-GH) and polyvinyl alcohol (PVA) to improve practical application of composite films. The miscibility of the mixed solution was examined by atomic force microscopy (AFM). The miscibility of the composite films was characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD). The antimicrobial property of the chlorinated composite film was evaluated. The results showed that the miscibility of CTS-GH/PVA composite film is perfect with the exception of CTS-GH/PVA = 10/90. After the chlorination treatment, the composite film with chlorine content of 0.86 × 1018 atoms/cm2 (CTS-GH/PVA = 20/80) can kill 98.92% Staphylococcus aureus and 100% Escherichia coli within 5min, and 100% Staphylococcus aureus within 60min.
  • Influence of Silanized Polycarboxylate Superplastizers on Fluidity of Cement-Silica fume pastes and its mechanism
    Yue GU ;
    . 2015, 46(12-生态): 27-0.
    Abstract ( ) Knowledge map Save
    Abstract: Silica fume is the hardest dispersing component in ultra high strength concrete (UHSC), and improvement of UHSC performance need effective dispersion of silica fume. In this study, Silanized Polycarboxylate Superplastizer (PCES)was synthesized through radical copolymerization，which Vinyltriethoxysilane was introduced to backbone structure of polymer.The influence of PCES on fluidity of cement-silica fume pastes was analysed by mini-slumps method. Adsorption properties of PCES on surface of cement and silica fume were investigated by TOC. Results shows: Compared with traditional polycarboxlate， PCES showed a higher dispersing capability in cement-silica fume pastes, Adsorption amount increased marginally in cement, while sharply in silica fume. The surface of silica fume existed hydroxyl, chemical adsorption and electrostatic adsorption of PCES happened simultaneously. Owing to additional chemical adsorption，more molecules exists in surface of particles,they can offer stronger steric hindrance repulsive force, this may be a mechanism that PCES possessed high dispersion effectiveness in cement-silica fume pastes. Compared to traditional polycarboxlate, PCES was more suitable for ultra high strength concrete.
  • Study on the Preservation Effect of Potato Starch-based Antimicrobial Edible Films on the Chilled Meat
    Li-Qiang WANG
    . 2015, 46(12-生态): 28-0.
    Abstract ( ) Knowledge map Save
    Abstract:Potato starch-based antimicrobial edible films were obtained by using potato starch, pullulan, gelatin as film-forming material, glycerol as plasticizer, calcium chloride as cross-linking agent, calcium propionate and cinnamaldehyde as antibacterial agent, the preservation effect of the antimicrobial edible films on the chilled meat was investigated. The results showed that antimicrobial edible films can effectively inhibit the growth and reproduction of microorganisms on the chilled meat surface, and the total number of colonies of chilled meat surface gradually reduced with the increase of antibacterial agents. Antimicrobial edible films can maintain the a* of chilled meat effectively. At later stage of chilled meat storage, water loss rate of chilled meat wrapped by antimicrobial edible films is smaller, which indicatedantimicrobial edible films has some water retention capacity.The pH of chilled meat wrapped by antimicrobial edible films is lower than the pH of chilled meat wrapped by edible films don’t contain antibacterial agents, which indicated calcium propionate and cinnamaldehyde had antibacterial activity during the storage of chilled meat, inhibited the growth of microorganisms effectively, reduced the rate of microbial decomposition on protein, and played a certain role in preservation.
  • Effect of composite set-accelerator on the performance of ultra-lightweight foamed concrete
    Jun JIANG ;
    . 2015, 46(12-生态): 29-0.
    Abstract ( ) Knowledge map Save
    Motivated by the requirement for low cost, fire resistant, inorganic thermal insulation materials with high performance, ultra-lightweight foamed concrete (porosity>90%) was prepared by introducing preformed foam into Portland cement slurries containing different dosages of composite set-accelerator, air-voids structure and the composition of foamed concrete were analyzed by SEM, XRD, and Image-pro Plus , and the workability of fresh foamed concrete, compressive strength, thermal conductivity and air-void structure of harden foamed concrete were studied. The results indicate that the relative plastic viscosity and the relative yield stress of fresh foamed concrete increase with the dosage of set-accelerator, and the slump flow reduces. With the increase of set-accelerator, the amount of small air-voids (<0.2mm) increases, D50 reduces and pore size distribution becomes uniform significantly, which improve the thermal insulating property, the mechanical property improves at first, and then becomes poor slightly. At 4% of set-accelerator, the apparent density is 175.2kg/m3, the compressive strength at 7D and 28D achieves 0.25MPa and 0.33MPa, and the thermal conductivity is 0.0516 W/(m·k).
    • 工艺 技术
  • The Mechanical Properties Analysis of SBS Modified Asphalt Mortar under Salt Freezing Cycle
    Ji-Wei HAN ;;
    . 2015, 46(12-生态): 30-0.
    Abstract ( ) Knowledge map Save
    De-icing salt was often used when the road was covered by snow and ice in cold area, which would cause erosion to asphalt mixture. Asphalt mortar, as an important part of asphalt pavement materials, plays an extremely important role in the mechanical properties of asphalt concrete. The three routine indicators (penetration, softening point and ductility) of the SBS modified asphalt was tested before and after the salt freezing. Uniaxial compression creep test of SBS modified asphalt mortar specimens were conducted after different salt freezing cycles. And the SEM (scanning electron microscope) was used to observe the microstructure of SBS modified asphalt mortar. The analysis results showed that the freeze-thaw cycle and load stress would cause the loss of mechanical properties of SBS modified asphalt mortar. So It is necessary to restrict traffic and overloading and the use of de-icing salt in cold area，in order to reduce the damage of pavement structure.
    • 研究 开发
  • Room Temperature Synthesis and Characterization of Metal-organic Framework Cu3(BTC)2
    . 2015, 46(12-生态): 31-0.
    Abstract ( ) Knowledge map Save
    By converting 1,3,5-benzenetricarboxylic acid into potassium 1,3,5-benzenetricarboxylate, Cu3(BTC)2, one of the most well-known metal-organic frameworks, was synthesized rapidly at room temperature. SEM was use to investigate the formation of Cu3(BTC)2 particles. Powder XRD pattern indicates that the product is in pure form with a high crystallinity. The TGA data reveal that the crystal structure is stable up to 300 °C. N2 sorption measurements indicate large BET surface areas and total pore volumes. This research provides a straight forward and energy saving method for the preparasion of Cu3(BTC)2.
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