Dyes Adsorption onto Fe3O4‐Bis(trimethoxysilylpropyl)amine Composite Particles: Effects of pH and Ionic Strength on Electrostatic Interactions. Issue 2 (14th January 2019)

• Record Type: Journal Article
• Authors: Hu, Yaoqiang; Li, Kexin; Li, Yuting; Liu, Haining; Guo, Min; Ye, Xiushen; Wu, Zhijian; Lee, Kangtaek
• Is Part Of: ChemistrySelect. Volume 4:Issue 2(2019)
• Page Start: 617
• Page End: 622
• Publication Date: 2019-01-14
• Subjects: Dye -- Adsorption Mechanism -- Electrostatic Interaction -- pH -- Ionic Strength; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201803241
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: Hydrophobic, electrostatic interactions, and hydrogen bonding play important roles in dyes adsorption. Solution pH and ionic strength of aqueous solutions are important factors affecting dye adsorption by influencing the aforementioned interactions. In order to understand adsorption mechanism of dye on the mesoporous particles, Fe3 O4 ‐bis(trimethoxysilylpropyl)amine (Fe3 O4 ‐TSPA) composite particles were used to adsorb methyl orange (MO), methyl blue (MB), and neutral red (NR) from aqueous solutions. Fe3 O4 ‐TSPA particles were found to be effective in removing acidic dyes at pH < 8.5. The adsorption amount of MB was nearly 0.047 mmol/g at pH 2. The adsorptions of MO and MB were found to be significantly influenced by electrostatic interactions. Based on the effect of NaCl on the adsorption, it was concluded that the electrostatic attraction was suppressed by high ionic strength, but suppression was less significant when electrostatic attraction was strong. Abstract : The pH value and ionic strength of aqueous solutions are the important factors that affect dye adsorption by influencing the hydrophobic, electrostatic and hydrogen bonding interactions. During the adsorption process of three dyes on the Fe3 O4 ‐bis(trimethoxysilylpropyl)amine (Fe3 O4 ‐TSPA) composite particles, solution pH value affects the electrostatic interactions through the protonation and deprotonation of functional groups on the adsorbent. The electrostatic interaction was suppressed by high ionic strength, however, the suppression decreased when the electrostatic interaction became strong..