Ultra-low concentration of total organic carbon in ultrapure water using ion-exchange resin embedding silanized...

Regeneration of pure water is an important issue not only for the healthy life but also for the fine control of precise processes in various industries. One important issue in ultra-high purified water is to reduce the amount of total organic carbon (TOC). Herein, we introduce a new approach to reduce the TOC using the surface silanized nanoparticles, in which the magnetic nanoparticles (mNPs) are silanized and then complexed with ion exchange resin (IER) beads. The Fe₃O₄ mNPs are surface modified by using high concentrated vinyltrimethoxysilane (VTMS) and then adhered on the surface of IER beads. The surface modified mNPs have a thick-shell of polysiloxane layer varying from 5 to 22 nm depending on the amount of VTMS used, which leads the significant increase of specific surface area. The IER beads embedding VTMS-silanized mNPs achieves about 7 μg/L of the TOC level in ultrapure water system, which is two orders less than 228 μg/L of the feeding water and one order less than 96 μg/L from the system using pristine IER beads. This result is mainly attributed to the polysiloxane layer forming broccoli-like surface structure and some part by the vinyl group of VTMS exposed to the amines in the water.