充電されたコロイドの沈殿プロファイルに顕微鏡の電気場がある証拠
Mircea Raşa1, Albert P Philipse
1Van 't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Nature
|June 25, 2004
まとめ
充電粒子の超遠心分離は,沈着プロフィールを大幅に変化させるマクロスコピックな電場を明らかにします. この発見は,溶液中の有電荷コロイドの標準的な分子量決定に異議を唱えている.
科学分野:
- コロイドとインターフェースサイエンスの科学
- 物理化学 物理化学
- 生物物理分析とは
背景:
- 標準的な超遠心分離分析では,相互作用しない粒子の分子量の正確な決定を前提としています.
- 超遠心分離における電荷粒子は,歴史的に予期せぬ低分子量を生み出し,理解のギャップを示しています.
- 最近の観測では,充電粒子の沈着プロファイルが著しく拡大し,気圧測定の予測から逸脱していることが示されています.
研究 の 目的:
- 超遠心分離過程における電荷粒子分散におけるマクロスコープの電場の存在を実験的に検証する.
- この電場が沈殿プロファイルに与える影響を調査し,特に稀な電荷を持つ種について調査する.
- 充電されたシステムに対する超遠心分離分析の現在のモデルに挑戦し,精錬する.
主な方法:
- 充電されたコロイド性シリカ球体で超遠心分離実験を行った.
- 低イオン強度条件下で非常に稀薄な分散の沈殿プロファイルを分析した.
- バロメトリック沈殿予測からの量化偏差.
主要な成果:
- 超遠心分離中の電荷粒子の分散の中でマクロスコーピックな電場があるという実験的証拠を提供した.
- この電場が,薄くしたシステムでも,沈殿プロフィールに大きな影響を及ぼすことが実証されました.
- 充電されたシリカ球の実験結果と気圧測定予測の間の有意な不一致が観察されました.
結論:
- この研究は,電荷のある粒子の超遠心分離に影響を与えるマクロスコープの電場の存在を確認した.
- このフィールドは,表面上の浮力質量を大幅に減らし,非気圧積層化につながります.
- この発見は,電荷を持つマクロ分子やコロイドの超遠心分析方法の見直しを必要としている.
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