Colloidal Stability, Sedimentation, and Aggregation of Crystalline Two-Dimensional Crumpled Birnessite Flakes, Their Dye Adsorption and Immune Cell Response.

ABSTRACT: Highly crystalline two-dimensional (2D) flakes of birnessite, a polymorph of manganese oxide with a MnO₂ chemistry, were synthesized by reacting manganese oxide, Mn₃O₄, at 80 °C with aqueous solutions of tetramethylammonium hydroxide (TMAH) for tens of hours. Their colloidal stability, aggregation, and sedimentation were studied as a function of ionic strengths of Na⁺ and Li⁺ cations. After reaction, a water-based stable colloidal suspension (ζ-potential ∼ -31 ± 1 mV) was obtained. Mixing the colloidal suspension with a LiCl or NaCl aqueous solution resulted in the sedimentation of crumpled flakes, as evidenced by electron microscopy (transmission and scanning). Concomitant with the sedimentation, the TMA⁺ cations present af

SUBMITTER: Hassig MQ 

PROVIDER: S-EPMC11866922 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature