Industrial Technology Research Institute

Hsiao-Fen Cheng

Kon-Tsu Kin

Pei-Lin Chang

Farhang F Shadman

Chiou-Mei Chen

The present invention discloses a method for removing impurities from a porous material by flowing a supercritical fluid with or without a modifier therein over a to-be-cleaned porous material having pores at the nanometer level under suitable temperatures and pressures, so that the supercritical fluid migrates into the pores at the nanometer level and removes impurities entrapped therein. The method of the present invention uses the physical and chemical properties of the supercritical fluid and optionally the modifier to clean the porous material without using an acid or alkaline solvent. The method of the present invention conserves water, and is both a highly efficient and environmentally friendly cleaning technique.

Method for removing impurities from porous materials

In order to reduce a total organic carbon (TOC) in ultrapure water to a level less than 1 ppb, several cycles of ozone contact/UV irradiation treatments are carried out in sequence. Preferably, the first cycle further includes an ion exchange treatment which is applied to the resulting UV irradiation water.

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Hsinchu, Taiwan

Hsiao-Fen Cheng