@article{TAI2026, 
author = {Hao-Yun TAI and Bo ZHANG and Hao REN and Yuan LIANG and Feng WANG and Zong-He HUANG and Rong-Gang WANG and Qi LI},
title = {Preparation of Carboxyl-Functionalized Core–Shell Magnetic Nanoparticles and Their Forward Osmosis Desalination Performance},
year = {2026},
journal = {Advanced Ceramics},
volume = {47},
number = {4},
pages = {396-411},
keywords = {Forward Osmosis, Seawater Desalination, Magnetic Nanoparticles, Carboxyl Functionalization},
url = {https://www.sciopen.com/article/10.16253/j.cnki.37-1226/tq.2026.04.008},
doi = {10.16253/j.cnki.37-1226/tq.2026.04.008},
abstract = {Forward osmosis (FO) technology has garnered considerable attention in seawater desalination owing to its low energy consumption and pressure-free operation. However, the lack of efficient and recoverable draw solutions has limited its practical application. In this study, Fe3O4 magnetic nanoparticles prepared via a hydrothermal method were used as cores, coated with a SiO2 shell through the Stöber method, and then surface-functionalized with D-xylose and sodium citrate to yield two magnetic nanoparticle draw solutions of Fe3O4@SiO2/D-Xylose and Fe3O4@SiO2-COOH, respectively. The structure and magnetic properties of the materials were characterized by TEM, XRD, FT-IR, and VSM, and their desalination performance was evaluated using a self-built FO apparatus. The results demonstrated that the SiO2 shell (thickness ~10 nm) effectively protected the Fe3O4 core. In a pH 4.5 acidic solution, the iron ion leakage was merely 0.07 mg/L, far below that of the uncoated sample (0.60 mg/L). After carboxyl functionalization, Fe3O4@SiO2-COOH exhibited a saturation magnetization of 37 emu/g, enabling magnetic separation. When the draw solution concentration was 5 g/L and ultrapure water served as the feed solution, the water flux of Fe3O4@SiO2-COOH reached 4.58 LMH, which was higher than those of Fe3O4@SiO2 (2.98 LMH) and Fe3O4@SiO2/D-Xylose (3.02 LMH). As the concentration increased to 50 g/L, the water flux rose to 20.32 LMH. Using 50 g/L Fe3O4@SiO2-COOH as the draw solution and 35 g/L NaCl simulated seawater as the feed solution, an average water flux of 0.75 LMH was obtained in FO mode, and the diluted draw solution could be rapidly recovered by a permanent magnet. This study offers new insights into the application of magnetic nanomaterials in forward osmosis seawater desalination.}
}