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1.
Journal of Thermal Analysis and Calorimetry - Coral wastes are produced during the construction of island. The use of coral wastes in concrete is beneficial to economy and environment. Coral waste...  相似文献   
2.
Sandwich-like mesoporous GS@Fe3O4@C nanosheets with a 2D nanoarchitecture have been successfully synthesized by one-step solvothermal treatment. Such type of 2D nanoarchitecture is made up of a number of Fe3O4 nanoparticles uniformly grown on a graphene sheet and an even amorphous carbon layer covering on their surface. The Li-cycling properties of GS@Fe3O4@C nanosheets have been evaluated by galvanostatic discharge-charge cycling and impedance spectroscopy. Results indicate that the GS@Fe3O4@C nanosheets with about 5 wt % of graphene content provides a very high discharge capacity of 913.2 mAh g−1 at a current densities of 200 mA g−1 after 100 cycles and reveals a stable discharge capacity of 483.2 mAh g−1 at a rate of 1600 mA g−1.  相似文献   
3.
针铁矿对焦磷酸根的吸附特征及吸附机制   总被引:1,自引:0,他引:1  
为深入了解自然水体中焦磷酸盐的迁移转化行为,以表生环境中广泛存在的稳定矿物-针铁矿为研究对象,系统研究了其对焦磷酸根的吸附过程,探索了不同实验条件下(p H值、电解质、时间、温度)针铁矿对焦磷酸根吸附的影响。结果表明,溶液p H值从6.27升至10.99时,总磷吸附量从3.00 mg/g降低至0.75 mg/g;电解质浓度越低越有利于针铁矿对焦磷酸根的吸附;吸附剂对焦磷酸根的吸附量在最初1 h内增长较快,随后渐渐达到吸附平衡;溶液温度的升高对吸附量提高具有增强作用。用动力学和热力学模型对吸附过程进行拟合,发现准二级动力学和Langmuir模型具有更好的适用性。结合材料吸附焦磷酸根前后的表征,推导出针铁矿对焦磷酸根的吸附机制可能是以表面配合和物理吸附为主导。  相似文献   
4.
Journal of Solid State Electrochemistry - A novel electrochromic polymer poly(2,3-dimethyl-2,3-dihydrothieno[3,4-b][1,4]dioxine) (PEDOT-Me2) based on 3,4-ethylenedioxythiophene (EDOT) with...  相似文献   
5.
盾构渣土基碳复合陶粒的制备及除磷性能   总被引:1,自引:0,他引:1  
以固体废弃物地铁盾构渣土、稻草秸秆和氧化镁为主要原料,通过烧结法制备了一种盾构渣土基碳复合陶粒。考察了陶粒吸附磷的主要影响因素及平衡吸附量,并采用模型对实验数据进行拟合分析。结果表明,当盾构渣土、稻草秸秆粉末和氧化镁质量比为7∶2∶1,在最佳烧结条件700℃烧结可得到除磷性能最佳的陶粒。当吸附pH=6.3时,陶粒具有较高的磷吸附性能。吸附在12 h内基本能达到吸附平衡,该过程适合准二级动力学方程。盾构渣土基碳复合陶粒对磷酸盐的吸附符合Temkin等温模型,随温度升高吸附量逐渐增大,40℃下最大吸附量为12.76 mg/g。热力学参数ΔH=5.64 k J/mol0,ΔS=8.00 J/(K·mol)0,ΔG=3.16 k J/mol0,呈吸热、非自发的热力学特征,陶粒吸附磷后可通过2.0 mol/L的氢氧化钠溶液重新解吸回收。  相似文献   
6.
Despite the rapid development of nanomaterials and nanotechnology, it is still desirable to develop novel nanoparticle-based techniques which are cost-effective, timesaving, and environment-friendly, and with ease of operation and procedural simplicity, for assay of target analytes. In the work discussed in this paper, the dye fluorescein isothiocyanate (FITC) was conjugated to 1,6-hexanediamine (HDA)-capped iron oxide magnetic nanoparticles (FITC–HDA Fe3O4 MNPs), and the product was characterized. HDA ligands on the surface of Fe3O4 MNPs can bind 2,4,6-trinitrotoluene (TNT) to form TNT anions by acid–base pairing interaction. Formation of TNT anions, and captured TNT substantially affect the emission of FITC on the surface of the Fe3O4 MNPs, resulting in quenching of the fluorescence at 519 nm. A novel FITC–HDA Fe3O4 MNPs-based probe featuring chemosensing and magnetic separation has therefore been constructed. i.e. FITC–HDA Fe3O4 MNPs had a highly selective fluorescence response and enabled magnetic separation of TNT from other nitroaromatic compounds by quenching of the emission of FITC and capture of TNT in aqueous solution. Very good linearity was observed for TNT concentrations in the range 0.05–1.5 μmol?L?1, with a detection limit of 37.2 nmol?L?1 and RSD of 4.7 % (n?=?7). Approximately 12 % of the total amount of TNT was captured. The proposed methods are well-suited to trace detection and capture of TNT in aqueous solution.
Figure
Iron oxide magnetic nanoparticles-based selective fluorescent response and magnetic separation probe for 2,4,6-trinitrotoluene  相似文献   
7.
Irregular Bi2WO6 nanolaminars have been successfully synthesized via a rapid sonochemical approach using bismuth nitrate and tungstic acid as precursors in an aqueous solution. The characteristics of them were investigated in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption, pore value, PL spectroscopy and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). These irregular nanolaminars are of geometric shapes of orthorhombic Bi2WO6 with their basal plane being (0 0 1). They possess high crystallinity, lager surface area and pore value, which means fewer traps and stronger photocatalytic activity. The growth mechanism of such special nanolaminar was related to the sonochemical synthesis route, which played a key role in the formation of Bi2WO6 nanolaminar. Simultaneously, it was found that the formation of Bi2WO6 nanolaminar is a time dependent process. The Bi2WO6 nanolaminar has higher photocatalytic activity than bulk Bi2WO6 nanoparticle obtained by refluxing method for rhodamine B (Rh.B) degradation under visible light irradiation (λ > 400 nm).  相似文献   
8.
<正>A convenient and effective Paal-Knorr condensations of 2,5-hexanedione with most amines have been carried out at room temperature under solvent-free condition.Macroporous strongly acidic styrol resin(D001) as a novel,efficient,cost-effective,and reusable solid acid catalyst for the synthesis of pyrroles under the same conditions.The pyrroles were obtained in high yields in short reaction times.  相似文献   
9.
Polypropylene grafted silane and styrene (named PP-g-Si/St in this article) was successfully prepared by radical graft polymerization initiated by γ-ray irradiation. The influence of total absorbed dose on the graft ratio of vinyltrimethoxysilane onto PP and the melt flow rate (MFR) of the PP-g-Si/St product were studied. The effect of graft ratios of vinyltrimethoxysilane on the melting point and nonisothermal crystallization kinetics of PP-g-Si/St was investigated by the method of differential scanning calorimetry (DSC). With increasing vinyltrimethoxysilane and styrene (used as viscosity modifier and free radical source) grafted on PP, the melting point of PP-g-Si/St became lower. Several different analysis methods, including those of Avrami, Jeziorny, and Mo and colleagues, were employed to describe the nonisothermal crystallization process of the grafted samples. The results indicate that the peak temperature of crystallization of PP-g-Si/St sample was lower than that of virgin PP. Crystallization kinetics revealed that the rates of nucleation and growth were affected differently by the graft ratio of vinyltrimethoxysilane onto PP. The activation energy was calculated on the basis of the method of Kissinger, and the values were 253.6 and 215.7 kJ/mol for virgin PP and PP-g-Si/St, respectively.  相似文献   
10.
This paper reports a novel method to produce the graphite phase derived from polyimide using Ni(Ac)2 as catalyst at about 800 °C. The graphitization behavior was characterized by FTIR, X-ray diffraction, Raman spectra and N2 sorption measurements. The results showed that β-cyclodextrin promoted the catalytic effect of Ni(Ac)2 in graphitizing process, increased the degree of graphitization and micropore volume. The graphite structure was confirmed the pores distributed uniformly throughout by SEM.  相似文献   
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