機械的処理による水和物のメカノケミカル脱水と物性変化

概要

論文の詳細を見る
Mechanochemical behaviors of several hydrated crystals having such three types of crystallization water as H_2O, OH radical and hydrogen bond were investigated. Mechanochemical dehydration progressed in accordance with the corder of thermal stability of the hydrates. Typical structural changes of the hydrates during grinding process were as follows ; (1) CaSO_4・2H_2O→CaSO_4・1/2H_2O→IICaSO_4, (2) Mg(OH)_2→brucite gel (in the air), (3) Mg(OH)_2→MgO (in vacuum), (4) Al(OH)_3 gibbsite→κ-Al_2O_3→α-Al_2O_3, (5) CaHPO_4・2H_2O→CaHPO_4→Ca_2P_2O_7 (almost amorphous phase), (6) TiO_2・nH_2O gel→anatase→rutile. It was found that most of the mechanochemical dehydrates except (5) existed as aggregation of fine crystals (1/100 μ order) and did not transform into amorphous phase contrary to the phenomena observed in general products of grinding. Surface properties of the dehydrates, distorted by shear stress, were discussed in terms of their acidity and heat of wetting.
社団法人日本材料学会の論文
1973-07-15