ガラス表面における珪酸マグネシウム水和物皮膜の生成

スポンサーリンク

概要

• 論文の詳細を見る

• It has been known that Mg2+ has a marked tendency to form the lustrous flake (spicule) in the water stored in glass containers. In order to elucidate the role of Mg2+ in the flake-formation, the reaction in the Mg2+-SiO2-H2O system in a glass container has been studied.Slightly alkaline aqueous solutions, with or without SiO2, which contained Mg2+ less than 16ppm and adjusted to pH range from 7.5 to 9.4, were heated in a silica glass flask at temperatures below 90°C, within 72h. The measurment of changes of the Mg2+- and SiO2-concentration and the observation of the flake-formation were carried out. The reaction products formed in the state of film on the glass surface were identified as magnesium silicate hydrates, which were similar in composition to sepiolite but had very low crystallinity, by means of chemical analysis, X-ray diffraction, DTA and IR absorption spectra.The Mg2+ concentration decreased with heating time, and approached finally to almost zero in the solution at pH 9.0 as most of the Mg2+ were consumed for formation of the film on glass surface. The SiO2 concentration increased in contrast to the Mg2+ concentration by dissolving of silica from the glass surface. The concentrations of Mg2+ and SiO2 depended on both the pH value and temperature of the solution. No flake-formation was observed at pH below 8.0.The role of Mg2+ in the flake-formation might be considered as follows;1) The hydrated silica layer formed in gel-state on glass surface by the action of OH-, is tightened due to the formation of magnesium silicate hydrate film and therefore the durability of the gel-layer to water increases.2) OH- and Mg2+ remaining in the water can enter into inner side of the film through small openings of the film, and the thickness of the film increases successively.3) The break-down of the film is directly or indirectly caused by its own contractile force as a whole, with increasing of the thickness.

• 社団法人日本セラミックス協会の論文
• 1976-02-01

著者

• 赤木 三郎

  大阪市立工業研究所

関連論文

• SiO_2-Fe_2O_3-K_2O系ガラスから生成したFe-leucite結晶の転移温度
• SiO_2-Fe_2O_3-K_2O系ガラスの高膨張性とFe-leucite生成との関係
• SiO_2-Al_2O_3-K_2O-Na_2O系ガラスにおける白榴石の生成と熱膨張
• 6.銅赤ガラスの発色について, 第1報 : ガラス組成と発色との関係(研究発表講演要旨)
• 魔法びんの保温性能とその試験方法に関する考察
• ソーダ・石灰・ケイ酸ガラスびん内のアルコール溶液における固相の生成
• ガラス表面におけるマンガン化合物皮膜の生成
• 脱アルカリ処理されたソーダ・石灰・珪酸ガラス壜の化学的耐久性
• 魔法壜におけるフレークの生成
• ガラス表面における珪酸マグネシウム水和物皮膜の生成

スポンサーリンク