1大気圏のシリケート溶融のアニオン構成:1大気圏のシリケート溶融のアニオン構成:岩性溶融の構造への影響
まとめ
この研究では,シリケート溶液中のポリマー単位をモデル化し,モノマー,ジマー,チェーン,シート,3D単位などのアニオン種を特定しています. これらの構造は,非橋渡し性酸素とシリコンの比率 (NBO/Si) に依存しています.
科学分野:
- 地質化学 地質化学
- 材料科学 材料科学とは
- スペクトル顕微鏡検査です.
背景:
- シリケート溶液は,多様なポリマー構造を持つ複雑な混合物です.
- これらの構造を理解することは,地質学と材料科学にとって極めて重要です.
- 以前の研究では,シリケート系における様々なアニオン単位が特定されました.
研究 の 目的:
- シリケート溶液におけるポリマー単体の構造モデルを提案する.
- 特定されたアニオン種と,橋渡しでない酸素とシリコンの比率 (NBO/Si) を相関させる.
- 異なる溶融組成におけるアニオン種の均衡を解明する.
主な方法:
- ラーマン光譜を用いてアニオン種を特定した.
- 構造モデリングは,消火したシリケート溶液に適用されました.
- ノンブリッジングオキシゲンと四面体協調カチオン (NBO/Si) の比率を分析した.
主要な成果:
- 特定されたアニオン単位には,SiO(4)(4-) モノマー,Si(2)O(7)(6-) ダイマー,SiO(3)(2-) チェーン/リング,Si(2)O(5)(2-) シート,SiO(2) 3D単位が含まれています.
- NBO/Siの特定の範囲は,共存する異なるアニオン種と相関しています.
- 不均衡反応は,アルカリ・シリケート,アルミ・シリケート,多成分溶液におけるアニオン種を支配する.
結論:
- NBO/Si比に基づくシリケート溶融の包括的な構造モデルが提示されています.
- アニオンの種の均衡と共存は,溶融の組成に基づいて予測可能である.
- このモデルは,天然の岩石溶融の構造についての洞察を提供します.
関連する概念動画
Molecular and Ionic Solids
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Ionic Association
The ionic association is the association of oppositely charged ions in an electrolyte solution to form ion pairs. Bjerrum defined ion pairs as two oppositely charged ions whose electrostatic attraction exceeds the thermal energy of the system, typically expressed as 2kT. Electrostatic attraction depends on ionic charge, separation distance, and the dielectric constant of the medium. Thermal energy, represented by kT, reflects the tendency of ions to move independently due to molecular motion.
Ionic Bonding and Electron Transfer
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
Ionic Strength: Overview
The ionic strength of a solution is a quantitative way of expressing the total electrolyte concentration of a solution. This concept was first introduced in 1921 by two American physical chemists, Gilbert N. Lewis and Merle Randall, while describing the activity coefficient of strong electrolytes. During the calculation of ionic strength (I or μ), all the cations and anions are considered. However, the concentration (c) of an ion with a greater charge number (z) has a greater contribution to...
Ionic Strength: Effects on Chemical Equilibria
The addition of an inert ionic compound increases the solubility of a sparingly soluble salt. For example, adding potassium nitrate to a saturated solution of calcium sulfate significantly enhances the solubility of calcium sulfate. Le Châtelier's principle cannot predict this shift in the equilibrium. Instead, this could be explained in terms of changes in the effective concentration of the ions in solution in the presence of added inert salt.
In this solution, the primary cation—the calcium...
In this solution, the primary cation—the calcium...


