OPTICAL ASSESSMENT OF A FOULING-RESISTANT SURFACE (PHEMA BENZALKONIUMCHLORIDE) AFTER EXPOSURE TO A MARINE-ENVIRONMENT

A hydrogel based on poly(a-hydroxyethyl methacrylate) (PHEMA) containi ng benzalkonium chloride (BAK) can be used as an environmentally accep table, fouling-resistant material in the marine environment. The loade d hydrogel system is transparent and has the potential to be used in t he protection of optical ports in underwater instruments. Ultraviolet- visible (UV-vis) spectroscopy was used to study the optical properties of the material after a marine exposure period. The optical transmitt ance of PHEMA/BAK was higher for 10 weeks than that detected for poly( methyl methacrylate) (PMMA), a material currently used in commercial i nstruments, which confirmed the superior fouling resistance of the PHE MA/BAK combination. The UV-vis spectroscopic method was quick, relativ ely cheap and accurate enough to allow the effects of the development of marine fouling on transparent surfaces for use in marine underwater optical applications to be monitored. (C) 1998 John Wiley & Sons, Ltd .