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81.
82.
LiFePO4 was synthesized using hydrothermal method and coated with different amounts of citric acid as carbon source.The samples were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscope(TEM),surface area measurement—Brunauer–Emmett–Teller(BET),discharge capability,cyclic voltammetry(CV),and electrochemical impedance spectroscopy(EIS).The results show that the quality and thickness of the carbon coating on the surface of LiFePO4 particles are very important.The optimum carbon content(about 30 wt%)can lead to a more uniform carbon distribution.Electrochemical results show that the samples containing 20 wt%,30 wt%,40 wt%,and50 wt% carbon deliver a discharge capacity of 105,167,151,and 112 mAhg-1,respectively,at the rate of 0.1C.The increase of carbon content leads to the decrease of discharge capacity of LiFePO4/C,owing to the fact that excess carbon delays the diffusion of Li+ through the carbon layers during charge/discharge procedure.The LiFePO4/C with low carbon content exhibits poor electrochemical performance because of its low electrical conductivity.Therefore,the amount of carbon must be optimized in order to achieve excellent electrochemical performance of LiFePO4/C for its application in a lithium ion battery. 相似文献
83.
Majid Ghashang Hadi Taghrir Mohammad Najafi Biregan Negar Heydari Fateme Azimi 《Journal of Sulfur Chemistry》2016,37(1):61-69
An eco-friendly procedure for synthesis of 2-(2-oxo-2H-chromen-4-yl)-3-arylthiazolidin-4-one derivatives by three-component reaction of 2-oxo-2H-chromene-4-carbaldehydes, aromatic amines and thioglycolic acid, with tetramethylbutane-1,4-diammonium acetate as a low-cost ionic liquid catalyst under reflux condition is described. The use of an ionic liquid as a catalyst has the advantages of high yields, short reaction time and environmentally friendly reaction media. 相似文献
84.
Effects of dynamic vulcanization on tensile,morphological, and swelling properties of poly(vinyl chloride) (PVC)/epoxidized natural rubber (ENR)/(Kenaf core powder) composites
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The effects of dynamic vulcanization on properties of poly(vinyl chloride) (PVC)/epoxidized natural rubber (ENR)/(kenaf core powder) composite were studied. Tensile properties indicated that the strength, elongation at break, and Young's modulus of the composites exhibited an increase for samples with dynamic vulcanization. Morphological analysis using scanning electron microscopy showed the interaction between ENR and PVC. There was no bonding between kenaf core powder and the PVC/ENR matrix owing to the different polarity of both components. Filler agglomerates increased, which leads to an increase of filler‐filler interaction and poor dispersion. Furthermore, swelling index indicated that the composite with dynamic vulcanization shows lower absorption of tolune compared with composites without dynamic vulcanization. J. VINYL ADDIT. TECHNOL., 22:206–212, 2016. © 2014 Society of Plastics Engineers 相似文献
85.
Mohammadreza Mahmoudi Sungjin Kim Arif M. Arifuzzaman Tomonori Saito Corson L. Cramer Majid Minary-Jolandan 《International Journal of Applied Ceramic Technology》2022,19(2):939-948
Preceramic polymer resins are attractive for the 3D printing of net-shaped ceramic components. Recently various processes have been demonstrated for 3D printing of polymer-derived ceramics (PDCs). Ultimately in these processes, the process outcomes strongly depend on the process parameters. In particular, for PDCs the ceramic density, and ceramic yield are affected by the catalyst concentration and cross-linking duration. Here, we use thermal analysis and FTIR to quantify the interrelation of the process parameters on the process outcome for polysilazanes and demonstrate 3D printing of PDC components based on the best-identified process parameters. The results of this work can be used as guidelines for future additive manufacturing of PDCs. 相似文献
86.
Velayati Mahin Sabouri Zahra Masoudi Abdolhossein Mostafapour Asma Khatami Mehrdad Darroudi Majid 《SILICON》2022,14(13):7541-7554
Silicon - In this research, epoxy polyurethane-nano silica nanocomposites have been synthesized using an in-situ method, for which SiO2 nanocomposites had been initially ready in N,... 相似文献
87.
Mirzaei Ahmad Navarchian Amir H. Tangestaninejad Shahram 《Iranian Polymer Journal》2020,29(6):479-491
Iranian Polymer Journal - Gas separation membranes with enhanced performance were developed by the introduction of nanosized palladium particles. In this study, gas separation performance of... 相似文献
88.
This paper reports on the synthesis of rice-like NiSe2 nanoparticles via a simple hydrothermal method by employing [bis(2-hydoxyacetophenato)nickle(II)], [Ni(HAP)2], as a novel nickel precursor. Effect of nickel source on morphology and size of nanostructures was also investigated. Moreover, the as-synthesized NiSe2 nanostructures were utilized as the photocatalyst for the degradation of methylene blue (MB) and as the counter electrode in dye-sensitized solar cells. The results showed that structures size and morphology have salient effect on solar cells and using rice-like NiSe2 nanoparticles leads to an increase in DSSCs efficiency compared to agglomerated sphere-like particles from 6.04 to 8.99?% (~49?% improvement). 相似文献
89.
Majid Soleimani Lope G. Tabil Catherine Niu 《American Institute of Chemical Engineers》2015,61(6):1783-1791
The kinetics of acid‐catalyzed hemicellulose removal and also alkaline delignification of oat hull biomass were investigated. All three operational parameters namely, catalyst concentration (0.10–0.55 N H2SO4), temperature (110–130°C), and residence time (up to 150 min) affected the efficiency of hemicellulose removal, with 100% of hemicellulose removed by appropriate selection of process parameters. Analysis of delignification kinetics (in the temperature range of 30–100°C) indicated that it can be expressed very well by a two‐phase model for the crude biomass and also for the hemicellulose‐prehydrolyzed material. The application of acid‐catalyzed prehydrolysis improved the capacity of lignin dissolution especially at lower temperatures (30 and 65°C) and accelerated the dissolution of lignin. This acceleration of delignification by prehydrolysis was possible at all levels of temperature in the bulk phase; however, results were more significant at the lower temperatures in the terminal phase. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1783–1791, 2015 相似文献
90.
Hadis Mohajerani Majid Kholghi Abolfazl Mosaedi Raziyeh Farmani Amir Sadoddin Markus Casper 《Water Resources Management》2017,31(6):1859-1879
This paper presents management of groundwater resource using a Bayesian Decision Network (BDN). The Kordkooy region in North East of Iran has been selected as study area. The region has been sub-divided into three zones based on transmissivity (T) and electrical conductivity (EC) values. The BDN parameters: prior probabilities and Conditional Probability Tables - CPTs) have been identified for each of the three zones. Three groups of management scenarios have been developed based on the two decision variables including “Crop pattern” and “Domestic water demand” across the three zones of the study area: 1) status quo management for all three zones represent current conditions; 2) the effect of change in cropping pattern on management endpoints and 3) the effect of future increased domestic water demand on management endpoints. The outcomes arising from implementing each scenario have been predicted by use of the constructed BDN for each of the zones. Results reveal that probability of drawdown in groundwater levels of southern areas is relatively high compared with other zones. Groundwater withdrawal from northern and northwestern areas of the study area should be limited due to the groundwater quality problems associated with shallow groundwater of these two zones. The ability of the Bayesian Decision Network to take into account key uncertainties in natural resources and perform meaningful analysis in cases where there is not a vast amount of information and observed data available – and opportunities for enabling inputs for the analysis based partly on expert elicitation,emphasizes key advantages of this approach for groundwater management and addressing the groundwater related problems in a data-scarce area. 相似文献