Soluble colloidal manganese dioxide: Formation, identification and prospects of application

Md Aminul Islam, M. Muhibur Rahman

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

Soluble colloidal MnO2 was prepared by the reduction of KMnO4 by three reducing agents as MnSO4, Na 2S2O3 and HCOOH in neutral aqueous solutions at 25 C. Under suitable conditions, these solutions were dark brown in color and found to remain stable and transparent for several weeks. The obtained colloid was characterized by spectrophotometric and coagulation methods. The spectral behavior of soluble colloidal MnO2 was studied. The λmax was 390 nm when MnO2 was prepared by the reduction of KMnO4 by MnSO4. Both the λ max and the molar extinction coefficient depended on the method of preparation of colloidal MnO2. The formation of MnO2 was confirmed by the determination of the oxidation state of Mn-species in MnO 2. The behavior of as-prepared colloidal solution obeys Beer Lambert law, if the concentrations of the colloidal particles are assumed to be equal to [MNO 4 - ]0. Both spectral analysis and that using Rayleigh's law confirmed the existence of colloidal MnO2. The observed coagulating efficiency depends not only on the concentration of electrolyte but also on the charge carried by the cation of the electrolyte. Stability of the colloidal particles in the aqueous solutions is determined by the negative charge on the surface of the colloidal particles.

Original languageEnglish
Pages (from-to)538-542
Number of pages5
JournalColloid Journal
Volume75
Issue number5
DOIs
StatePublished - Sep 2013
Externally publishedYes

ASJC Scopus subject areas

  • Surfaces and Interfaces
  • Physical and Theoretical Chemistry
  • Colloid and Surface Chemistry

Fingerprint

Dive into the research topics of 'Soluble colloidal manganese dioxide: Formation, identification and prospects of application'. Together they form a unique fingerprint.

Cite this