Removal of Amoxicillin Using a New Adsorbent: Silver Nanoparticle Modified With Poly(ε‐Caprolactone)‐Block‐Poly(L‐Lactide) Copolymer

Abstract

ABSTRACTThe aim of this study is to develop innovative hybrid materials with high adsorption capacity for removing amoxicillin from aqueous media. The study synthesized an AB‐type poly(ε‐caprolactone)‐block‐poly(L‐lactide) copolymer (PCL‐b‐PLLA) containing silver nanoparticles (Ag NP). A novel initiator, 2,4‐difluorobenzyl alcohol (1), was used to initiate the sequential ring‐opening polymerization (ROP) of ε‐CL and L‐LA, with tin octanoate Sn(Oct)2 as the catalyst. PCL (2) was synthesized by ROP of ε‐CL at 115°C, using (1) as an initiator and Sn(Oct)2 as the catalyst. Subsequently, PCL‐b‐PLLA (3) was obtained via ROP of L‐LA at 120°C in toluene, with (2) as a macroinitiator. The structures of the homo‐ and block copolymers were characterized using FT‐IR and 1H NMR. Ag NP was synthesized via a green method using Helichrysum arenarium extract. Polymer‐based composites containing Ag NPs possess functional surface properties that enhance selectivity and permeability, making them effective biocompatible adsorbents for removing contaminants from water. The nanoparticle content in the PCL‐b‐PLLA/Ag NP hybrid was analyzed by UV–Vis and TEM. For amoxicillin removal, both PCL‐b‐PLLA and PCL‐b‐PLLA/Ag NP were tested, achieving a maximum of 82% removal at pH 4.5 and 25°C. Adsorption studies were conducted in pure water and three wastewater samples to assess amoxicillin selectivity.