نتایج جستجو برای: solventless modification
تعداد نتایج: 127538 فیلتر نتایج به سال:
The novel synthesis of monodisperse magnetite Fe(3)O(4) nanoparticles of varying sizes using a solventless synthetic method was developed. Iron salt was treated in excess oleylamine and oleic acid as ligands. The effect of the reaction temperature and time on the particle size was investigated and the particle sizes were easily tuned from 5.3 to 20.4 nm by changing the reaction temperature and ...
The catalytic ability of ZrO(2)/SO(4)(2-) to promote solventless three-component condensation reactions of a diversity of aromatic aldehydes, urea or thoiurea and ethyl acetoacetate was studied. Products resulting from Hantzsch and/or Biginelli multi-component reactions are obtained in the presence of solid acid catalysts using the same reactants but different temperature conditions. The sulfat...
Liquid-liquid extraction or solid-phase extraction followed by gas chromatography (GC) or high-performance liquid chromatography are traditional herbicide residue determination methods for environmental samples. Solid-phase microextraction (SPME) is a solventless, fast, and sensitive alternative herbicide residue extraction method that can be applied to numerous environmental matrices. The obje...
An efficient solventless protocol for the preparation of a wide variety of ionic liquids is described, which requires a simple exposure of admixed 1-methylimidazole and alkyl halides to microwave irradiation in open glass containers. The details of this clean process using a common household microwave oven, which exploits the newer inverter technology system for better power attenuation, are de...
Growing public concern over protecting our environment obligates chemists, including analytical chemists, to change chemical activity in such a way that it will be conducted in an environmentally friendly manner. The article provides an overview of green chemistry issues relating to sample preparation techniques, concentrating especially on the green advantages of so-called solventless sample p...
A low-cost bimetallic bifunctional 5-5 wt% FeNi/H-Beta-300 catalyst was investigated in solventless hydrodeoxygenation of lignin-derived model compounds isoeugenol or dihydroeugenol the batch and continuous mode. The characterized...
Syngenite (K2Ca(SO4)2 ⋅ H2O) presents an effective hydration activator (accelerator) for anhydrite (CaSO4) applied in construction systems. The current synthesis relies on co-precipitation of K2SO4 and CaSO4 2H2O produces large amounts waste water holding excess potassium sulfate. Therefore, this method is deemed ineffective, uneconomical environmentally unfriendly. Moreover, it crystals (ℓ ∼5-...
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