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排序方式: 共有327条查询结果,搜索用时 31 毫秒
91.
Green approaches have the potential to significantly reduce the costs and environmental impact of chemical syntheses. Here, the authors used green tea (GT) leaf extract to synthesise and anchor palladium nanoparticles (PdNPs) to silica. The synthesised PdNPs in GT extract were characterised by ultraviolet–visible spectroscopy, Fourier‐transform infrared spectroscopy, X‐ray diffraction, and transmission electron microscopy. PdNPs primarily formed as capped NPs dispersed in GT extract before reduction completed after 24 h. This capped phytochemical solution was employed as a green precursor solution to synthesise PdNP‐embedded solid supports. The morphology of PdNPs anchored to silica differed to that of PdNPs in solution. Silica‐embedded PdNPs was employed as a new ligand exchanger to isolate trace polycyclic aromatic sulphur heterocycles from a hydrocarbon matrix. The isolation efficiency of the new, greener ligand exchanger was the same as an efficient chemical ligand exchanger and may, therefore, hold promise for future applications.Inspec keywords: nanofabrication, palladium, visible spectra, transmission electron microscopy, nanoparticles, reduction (chemical), ultraviolet spectra, X‐ray diffraction, Fourier transform infrared spectra, surface morphologyOther keywords: ultraviolet–visible spectroscopy, Fourier‐transform infrared spectroscopy, transmission electron microscopy, phytochemical solution, green precursor solution, PdNP‐embedded solid supports, solid support‐embedded PdNPs, green tea leaf extract, chemical ligand exchanger, anchor palladium nanoparticles, X‐ray diffraction, isolate trace polycyclic aromatic sulphur heterocycles, hydrocarbon matrix, green synthesis, time 24.0 hour, Pd 相似文献
92.
Habiba Bejbouj Laurence Vignau Jean Louis Miane Thomas Olinga Guillaume Wantz Azzedine Mouhsen El Moustafa Oualim Mouhammed Harmouchi 《Materials Science and Engineering: B》2010,166(3):185-189
We have studied the use of water and solvent-based polyaniline (PANI) dispersions as a transparent hole-injecting layer in polymer light emitting diodes (PLEDs). We have investigated the effects of the pH, the conductivity, the work function and the nature of the solvent and the dopant on the hole-injection properties. The water-dispersed PANI at a low pH (pH 1.8) showed an efficiency similar to that of PEDOT-based devices due to its high HOMO level and high conductivity. For the solvent-based PANI dispersions, the influence of the nature of the solvent and the dopant on the crystallinity, the conductivity of the PANIs and on the performances of the light emitting devices is discussed. 相似文献
93.
94.
We investigate the existence of nontrivial solutions for a multi-point boundary value problem for fractional differential equations. Under certain growth conditions on the nonlinearity, several sufficient conditions for the existence of nontrivial solution are obtained by using Leray–Schauder nonlinear alternative. As an application, some examples to illustrate our results are given. 相似文献
95.
Eltai Nahla O. Mahmoud Nouf N. Zakaria Zain Z. Abdelrahman Hana Moustafa Ala-Eddin Al Al-Asmakh Maha 《Journal of Inorganic and Organometallic Polymers and Materials》2022,32(7):2527-2537
Journal of Inorganic and Organometallic Polymers and Materials - Gold nanorods (AuNRs) were synthesized by the seed-mediated wet chemical method using a binary surfactant system. AuNRs were... 相似文献
96.
97.
I. Aiad Samy M. Shaban H. Y. Moustafa Ahmed Hamed 《Protection of Metals and Physical Chemistry of Surfaces》2018,54(1):135-147
Three Gemini cationic surfactants named N1,N1,N3,N3-tetramethyl-N1,N3-bis(3-octanamidopropyl) propane-1,3-diaminium bromide (C8-S3-C8), N1,N1,N3,N3-tetramethyl-N1,N3-bis(3-dodecanamidopropyl) propane-1,3-diaminium bromide (C12-S3-C12) and N1,N1,N3,N3-tetramethyl-N1,N3-bis(3-hexadecanamidopropyl) propane-1,3-diaminium bromide (C16-S3-C16) were evaluated as corrosion inhibitors for mild steel in 1.0 M HCl. The corrosion rate of mild steel in 1.0 M HCl at three different temperatures 25, 45 and 60oC was investigated gravimetrically. The corrosion rate of mild steel was confirmed electrically at 25oC. The corrosion inhibition efficiency directly proportionally with the hydrophobic chain length of inhibitors. The inhibition efficiency exhibit a positive trend with raising the solution temperatures. The potentiostatic polarization study revealed that the tested gemini cationic surfactants act as mixed type inhibitors with predominant control of cathodic reaction. The Villamil isotherm provide the best describing of the adsorption process on the selected steel in 1.0 M HCl. The adsorption of the tested inhibitors on the steel surface is a mixture of chemical and physical adsorption. 相似文献
98.
Dissolved pharmaceuticals were removed by adsorption on some natural and synthetic polymers. Cellulose, chitosan, and sodium alginate were selected as examples of natural polymers while a synthetic copolymer of epichlorohydrin and urea was prepared for comparison. Water contaminated with some antibiotics was treated with these polymers using stirred flask and column methods. The particles size of the investigated materials was increased up to 2 mm diameter by converting them into beads. Combinations of polymers, natural or synthetic, were used together to improve their behavior. The synthetic polymer has shown better removal effect than that of natural ones. It has removed up to 75% of the drug in 6 h. Chitosan was the best natural polymers in removing dissolved drugs; up to 13% of the drug has been removed by it. The recycling properties of the polymers loaded with drugs were examined and up to 9% of the drug was successfully restored. In addition, fully loaded dry beads with drugs were grounded and recycled in an ointment as blends. Moreover, the swelling behavior of the beads in different mediums and under different conditions was examined. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40458. 相似文献
99.
Full as well as half generations of dendritic poly(amido amine)s (PAMAMs) were introduced onto urea‐formaldehyde (UF) wood adhesive system as modifiers to increase its stability and enhance the performance of the bonded wood joints with it. The effect of the modifiers on the physical properties and mechanical performance was discussed on the light of gel times, curing exotherms using differential scanning calorimetry (DSC), infra‐red (IR), and shear strength measurements. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
100.
Hisham M. Aly Moustafa E. Moustafa Ehab A. Abdelrahman 《Advanced Powder Technology》2012,23(6):757-760
Mordenite is a zeolite that has been used as a selective adsorbent and as a catalyst. Mordenite zeolite with crystal diameter 65 nm and crystal length 7 μm was successively synthesized in the absence of organic template by hydrothermal method at 180 °C for 5 days after stirring at high speed and aging in the synthesis mixture with the molar composition of 12Na2O:100SiO2:2Al2O3:500H2O. The produced samples were investigated using XRD, SEM, FT-IR, EDS, DTA/TG and BET surface area. The prepared sample, crystallized in needle shape crystals. Total (BET) surface area was 52.14 m2/g whereas, total pore volume was 0.2 cm3/g. Average pore diameter was 24.16 Å. Thermogravimetry analysis (DTA/TG) showed that, at room temperature to 800 °C, mordenite mass loss is 6%. 相似文献