Open AccessEffective Antiscaling Performance of Reverse-Osmosis Membranes Made of Carbon Nanotubes and Polyamide Nanocomposites
Author(s) -
Yukio Takizawa,
Shigeki Inukai,
Takumi Araki,
Rodolfo Cruz-Silva,
Josué OrtizMedina,
Aaron Morelos-Gómez,
Syogo Tejima,
Akihiro Yamanaka,
Michiko Obata,
Auppatham Nakaruk,
Kenji Takeuchi,
T. Hayashi,
Mauricio Terrones,
Morinobu Endo
Publication year - 2018
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.8b00601
Subject(s) - membrane , polyamide , chemical engineering , nanocomposite , materials science , interfacial polymerization , reverse osmosis , carbon nanotube , polymer chemistry , polymer , composite material , chemistry , biochemistry , monomer , engineering
The antiscaling properties of multiwalled carbon nanotube (MWCNT)-polyamide (PA) nanocomposite reverse-osmosis (RO) desalination membranes (MWCNT-PA membranes) were studied. An aqueous solution of calcium chloride (CaCl 2 ) and sodium bicarbonate (NaHCO 3 ) was used to precipitate in situ calcium carbonate (CaCO 3 ) to emulate scaling. The MWCNT contents of the studied nanocomposite membranes prepared by interfacial polymerization ranged from 0 wt % (plain PA) to 25 wt %. The inorganic antiscaling performances were compared for the MWCNT-PA membranes to laboratory-made plain and commercial PA-based RO membranes. The scaling process on the membrane surface was monitored by fluorescence microscopy after labeling the scale with a fluorescent dye. The deposited scale on the MWCNT-PA membrane was less abundant and more easily detached by the shear stress under cross-flow compared to other membranes. Molecular dynamics simulations revealed that the attraction of Ca 2+ ions was hindered by the interfacial water layer formed on the surface of the MWCNT-PA membrane. Together, our findings revealed that the observed outstanding antiscaling performance of MWCNT-PA membranes results from (i) a smooth surface morphology, (ii) a low surface charge, and (iii) the formation of an interfacial water layer. The MWCNT-PA membranes described herein are advantageous for water treatment.