Antifouling properties of dendritic polyglycerols against marine macro-fouling organisms.

Abstract

Dendritic polyglycerols (PGs) were synthesized and post-modified by grafting of polyethylenglycol (PEG) and polypropyleneglycol (PPG) diglycidyl ether (DGE) groups and their antifouling and fouling-release properties were tested. Coatings characterization by spectroscopic ellipsometry, contact angle goniometry, ATR-FTIR, and AFM showed brush-like morphologies with a high degree of micro-scale roughness and the ability to absorb large amounts of water within seconds. PGs with three different thicknesses were tested in laboratory assays against settlement of larvae of the barnacle Balanus improvisus and against the settlement and removal of zoospores of the alga Ulva linza. Very low coating thicknesses, e.g. 11nm, reduced the settlement of barnacles, under static conditions, to 2% compared to 55% for an octadecyltrichlorosilane reference surface. In contrast, zoospores of U. linza settled readily but the vast majority were removed by exposure to a shear force of 52 Pa. Both PEG and PPG modification increased the antifouling properties of the PG films, providing a direct comparison of the ultra-low fouling properties of all three polymers. Both, the modified and the non-modified PGs are promising components for the incorporation into amphiphilic fouling-resistant coatings.