Topic
Sodium sulfide
About: Sodium sulfide is a research topic. Over the lifetime, 2851 publications have been published within this topic receiving 27733 citations. The topic is also known as: disodium sulfide.
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TL;DR: In this paper, the properties of a nanoscale zero-valent iron (nZVI) with hydrogen sulfide dissolved in absolute ethanol were compared with S-nZVIs prepared through sulfidation of nZVI with aqueous hydrogen sulfides (S-nNZVI-H2S-Water).
16 citations
TL;DR: In this article, it was shown that the relative volume of zircon to cadmium sulfo-selenide has an important role on the complete encapsulation of colorants and the quality of pigment.
Abstract: Preparation of fire red cadmium sulfo- selenide pigments based on zircon via solid-state reactions encountered with some difficulties. Undesirable reactivity and inadequate homogeneity of components are two important problems, which counteracted on completely covering of color agents by zirconium silicate and so stable production of these materials. It has shown that by using a sol-gel method the above-mentioned problem will be eliminated and a desirable color shade can be obtained. In the sol-gel process, at first a precipitatant was prepared by mixing of Se (dissolved in sodium sulfide solution) and a cadmium sulfate-zirconium acetate solution. Gelation was occurred by adding a diluted sodium silicate solution into the washed and dried precipitant. The mineralizer was lithium fluoride, which was added to the washed/dried gel. Calcinations of the later compound were done at about 950°C. The experiments showed that the relative volume of zircon to cadmium sulfo selenide has an important role on a complete encapsulation of colorants and so on quality of pigment. According to our experiment, the optimum relative volume of colorant agent to zircon was determined as bout 40/60.
16 citations
Patent•
23 Mar 1973
TL;DR: In this article, the authors present an improvement in the BLEACHING of cylose pulp by the Alkaline OXYGEN GAS Process, in which a gas containing OXYgen is introduced into the cylose pulp in the presence of ALKALI.
Abstract: 1. IN THE BLEACHING OF CELLULOSE PULP BY THE ALKALINE OXYGEN GAS PROCESS, IN WHICH A GAS CONTAINING OXYGEN IS INTRODUCED INTO THE PULP IN THE PRESENCE OF ALKALI, WHICH CAN BE SELECTED FROM THE GROUP CONSISTING OF SODIUM HYDROXIDE AND SODIUM CARBONATE AND WHICH OPTIONALLY MAY CONTAIN SODIUM SULFIDE, THE IMPROVEMENT WHICH COMPRISES FIRST IMPREGNATED UNDER SUPERATMOSPHERE PRESSURE CELLULOSE PULP OBTAINED FROM A CONTINUOUS PULPING OR DIGESTION PROCESS AND CONTAINING SPENT PULPING LIQUOR WITH WASTE ALKALINE OXYGEN GAS BLEACHING LIQUOR IN ORDER TO DISPLACE A MAJOR PORPORTION OF THE PULPING CHEMICALS FROM THE CELLULOSE PULP BUT RETAIN A MINOR PROPORTION OF SUCH CHEMICALS, AND THEN IMPREGNATING UNDER SUPERATMOSSPHERIC PRESSURE THE RESULTING PULP WITH ALKALI TO BE EMPLOYED IN THE ALKALINE OXYGEN GAS BLEACHING.
16 citations
TL;DR: In this article, the phase transfer of catalyzed (PTC) polymerization of α,ω-dibromoalkanes with sodium sulfide was studied and it was shown that the participation of cyclic sulfides either facilitates cyclic formation or enhances polymer reactivity as controlled by the length of the dielectrophile.
Abstract: Some unexpected results were observed in the phase transfer of catalyzed (PTC) (two phase, aqueous-organic) polymerization of α,ω-dibromoalkanes with sodium sulfide. Alkane dielectrophiles containing fewer than six methylene units give rise to large, and sometimes quantitative, amounts of cyclic thioethers. These cyclic sulfides are formed under “polymerization” conditions and can be minimized by using only the monomer as the organic phase. Alkane dielectrophiles containing more than six methylene units yield only polymer. When a comonomer system composed of a 1:1 mixture of 1,4-dibromobutane (DBB) and 1,8-dibromooctane (DBO) is employed, the resulting copolymer's molecular weight and polydispersity are vastly improved compared to the corresponding homopolymerizations. Microstructurally, this copolymer is formed by complete consumption of DBO and partial incorporation of DBB. The remaining DBB forms tetrahydrothiophene (THT). These two odd and seemingly conflicting results could not be explained by “normal” or “inverse” PTC extraction mechanisms. Support of this new mechanism is given in the PTC polymerization of DBO with sodium sulfide in the presence of a catalytic amount of THT. The resulting polymer is of very high molecular weight and narrow polydispersity; it also does not contain tetramethylene sequences. Using this new mechanism, all results suggest the participation of cyclic sulfides either facilitates cyclic formation or enhance polymer reactivity as controlled by the length of the alkane dielectrophile.
16 citations
TL;DR: Tetrakis(2-thienyl)methane was synthesized for the first time by sodium sulfide induced cyclization of 5,5,5-tris( 2-THENYL)pentadiyne which was obtained from tris(1.5)methyl cation, and the molecular structure was elucidated by X-ray analysis for the tetrabromo derivative as mentioned in this paper.
16 citations