Temperature Effect on Ionic Polymers Removal from Aqueous Solutions Using Activated Carbons Obtained from Biomass.

Area of Science:

• Materials Science
• Environmental Chemistry
• Polymer Science

Background:

• Activated carbons (AC) derived from natural herbs like nettle (NE) and sage (SA) offer sustainable adsorbent materials.
• Understanding polymer adsorption mechanisms is crucial for water treatment and material functionalization.

Purpose of the Study:

• To determine the influence of temperature on the adsorption of anionic poly(acrylic acid) (PAA) and cationic polyethylenimine (PEI) onto NE-AC and SA-AC.
• To investigate the adsorption-desorption behavior and polymer conformation changes with temperature.
• To analyze the thermodynamic parameters governing the adsorption processes.

Main Methods:

• Adsorption and desorption experiments were conducted at 15, 25, and 35 °C and pH 3.
• Viscosity measurements were used to determine the hydrodynamic radius and polymer conformation.
• X-ray Photoelectron Spectroscopy (XPS) was employed to analyze surface interactions.

Main Results:

• Maximum adsorption capacity for PAA on NE-AC was 198.12 mg/g at 25 °C.
• Temperature influenced polymer conformation and polymer-solvent interactions, affecting adsorption.
• XPS confirmed interactions in the PEI, PAA, and NE-AC system at 25 °C.

Conclusions:

• Temperature is a critical factor affecting polymer adsorption onto herb-derived activated carbons.
• The study provides insights into the thermodynamic feasibility and mechanisms of PAA and PEI adsorption.
• Optimized conditions, particularly temperature, are essential for maximizing adsorption efficiency.