In this paper, thermal stability and stability for a carbonate reaction were examined to investigate the use of monosulphate (tetracalcium aluminate monosulphate 12-hydrate, 3CaO Al2O3·CaSO4· 12H2O) as a filler for papermaking. Monosulphate was synthesized by the use of chemical reagents in liquid-liquid systems. The product material was characterized by XRD, DTA-TG and IR after thermal decomposition and the carbonation reaction were carried out under humidity conditions from R.H.40% to R.H.90%. Obtained results suggest following. There are two endothermic peaks on the DTA curve from the dehydration of monosulphate through heating up to 300°C. A change in the crystal shape of Monosulfate is not observed during the heating up to 800°C. Calcium carbonate, gypsum, and aluminagel are formed, when monosulphate was carbonated in the wet condition. However, the progress of the reaction is slow in R.H.40% and R.H.70%, and there is only small change detected in the crystal shape. Results indicate that it is possible for monosulphate to be used as a filler for the paper.
Operating conditions, extruding pressure and extruding velocity, under extrusion moulding of cementitious materials produced by extrusion moulding are very important factor to control actual production facilities. A comprehensive predictive method for extruding pressure has been proposed on author's previous studies. However a predictive method for extruding velocity has not been clarified. Adjusting ratio, namely materials efficiency constants, of which conveying rate per revolution are adjusted by water content ratio are very important items for predicting extruding velocity. Because its items are correspond with productive efficiency. In this paper materials efficiency constants are confirmed to various experimental data under the various materials and mix proportions, such as sand cement ratio, the maximum size of fine aggregate, kinds of fiber additives and water content ratio. As results, the constants are clarified to be depended on materials and mix proportions as shown in the followings; 1) A relationship between the constants and sand cement ratio is a linear proportion. 2) The effects of aggregate size are small. 3) The effects of fiber kinds are different from each other.
A new ethylenediammonium monohydrogen-tetraoxophosphate, [NH3 (CH2) 2NH3] 2+ HPO42- has been hydrotherally synthesized and structurally characterized. The crystal structure of the compound consists of layers built up from [HPO4] 2- tetrahedra alternating with layers of the [NH3 (CH2) 2NH3] 2+ dications. In the inorganic layers, [HPO4] 2-groups link together by hydrogen bonds of O-H-O. The inorganic layers and [NH3 (CH2) 2 NH3] 2+ dications link adjacently, forming a network of hydrogen bonds, N-H-O.
Surface modification of glassy carbon powder was carried out in order to improve the electrochemical properties as anode materials for lithium ion secondary battery, in RF induction thermal plasma with the various reaction atmospheres. Glassy carbon powders treated in thermal plasmas showed characteristic surface morphology and compositional change. Nitrogen incorporation was recognized in the Ar-N2 plasma-treated powder. In addition, XRD measurement showed the thermal plasma treatment gave rise to advance in graphitaizarion. The electrochemical measurements of plasma treated samples also showed the increase of capacity (increase of inserted lithium content), change of the charge-discharge performance, and improvement of its cycle performance (lithium intercalation and de-intercalation). It was shown that the thermal plasma treatment should be feasible to the improvement of the electrochemical properties of carbonaceous materials.