Precise conductimetric studies on aqueous solutions of 2 : 2 electrolytes. Part 3.—Detailed study of individual electrolytes
作者:Alan D. Pethybridge、Shahab Soltani Taba
DOI:10.1039/f19827801331
日期:——
This paper reports precise conductance values for dilute (< 4 × 10–3 mol dm–3) aqueoussolutions of twenty-three 2:2 salts at 25 °C. Alkaline earth metal sulphates, thiosulphates, dithionates, tetrathionates, ethyl-, n-propyl-, n-butyl-disulphonates and acetylenedicarboxylates were studied. The results are analysed by means of the Lee–Wheaton conductance equation in terms of the limiting molar conductivity
Abstract Displacement reactions between calcium sulfates (gypsum and anhydrite) and aqueous solutions of Ba − , Sr − and Pb-salts were investigated by means of TG, DSC,microscopy and x-ray. The reactions can be followed directly by microscopy when cleavage plates of gypsum crystals are used. The first steps of crystallization are in some cases of a topotactical nature. The results presented in this
Surfactant mediated synthesis of barium sulfate, strontium sulfate and barium-strontium sulfate nanoparticles
作者:Prutviraj K.、Thimmasandra Narayan Ramesh
DOI:10.1080/24701556.2019.1603162
日期:2019.4.3
mixing metal chloride(s) (metal = barium/strontium/barium-strontium) with sodium dodecyl sulfate (SDS) as precursors. Barium dodecyl sulfate/strontium dodecyl sulfate/barium-strontium dodecyl sulfate obtained above on decomposition generates barium sulfate/strontium sulfate/barium strontium sulfate having different morphologies and nano sized particles. The samples were characterized using powder X-ray
Hydrothermal synthesis of the perovskite manganites Pr0.5Sr0.5MnO3 and Nd0.5Sr0.5MnO3 and alkali-earth manganese oxides CaMn2O4, 4H-SrMnO3, and 2H-BaMnO3
作者:Jeroen Spooren、Richard I. Walton
DOI:10.1016/j.jssc.2005.03.006
日期:2005.5
We report the synthesis of the perovskitemanganites Pr0.5Sr0.5MnO3 and Nd0.5Sr0.5MnO3 using mild hydrothermal conditions. Both are formed as polycrystalline powders from solutions of metal salts in aqueous potassium hydroxide at 240 °C, and crystallise as a tetragonal polymorph (space group I4/mcmI4/mcm). Scanning electron microscopy shows both materials to contain cuboid-shaped crystallites several
我们报道了使用温和的水热条件合成钙钛矿锰矿Pr 0.5 Sr 0.5 MnO 3和Nd 0.5 Sr 0.5 MnO 3。两者均由金属盐在240°C的氢氧化钾水溶液中形成多晶粉末,并结晶为四方多晶型物(空间群I4 / mcm I4 / mcm )。扫描电子显微镜显示两种材料都包含几微米尺寸的长方体形状的微晶,并且通过光散射测量来验证平均粒径。我们还报告了2H-BaMnO 3和4H-SrMnO 3的首次水热合成,以及第一个亚临界水热合成CaMn 2 O 4(白云石)。尽管在240°C下形成了这些碱土金属锰氧化物,但我们仍无法在相似的条件下分离出稀土金属锰氧化物Ln MnO 3。我们通过将我们的新结果与已经报道在水热条件下形成的锰铁矿相关联,讨论了在水热反应中钙钛矿型锰铁矿的形成,并通过考虑钙钛矿的耐受因子和A位金属半径的变化来合理化趋势。
Polysaccharide based scale inhibitor
申请人:Kesavan Subramanian
公开号:US20080277620A1
公开(公告)日:2008-11-13
A depolymerized-carboxyalkyl polysaccharide formed by de polymerizing a polysaccharide having from 0.5 to 3.0 degrees of substitution and reducing the molecular weight of said polysaccharide before or after said depolymerizing provides a biodegradable scale inhibitor useful to prevent deposition of scale comprising, for example, calcium, barium, sulfate and salts thereof. The depolymerized carboxyalkyl polysaccharide is particularly useful in off shore oil production squeeze treatments and in the treatment of scale formed in industrial water treatment.