Conditioning of self-assembled monolayers at two static immersion test sites along the east coast of Florida and its effect on early fouling development

Abstract

Among the first events after immersion of surfaces in the ocean is surface ‘conditioning’. Here, the accumulation and composition of the conditioning films formed after immersion in the ocean are analyzed. In order to account for different surface chemistries, five self-assembled monolayers that differ in resistance to microfouling and wettability were used. Water samples from two static immersion test sites along the east coast of Florida were collected at two different times of the year and used for experiments. Spectral ellipsometry revealed that conditioning films were formed within the first 24 h and contact angle goniometry showed that these films changed the wettability and rendered hydrophobic surfaces more hydrophilic and vice versa. Infrared reflection adsorption spectroscopy showed that the composition of the conditioning film depended on both the wettability and immersion site. Laboratory and field assays showed that the presence of a conditioning film did not markedly influence settlement of microorganisms.

Keywords:

• static immersion
• conditioning film
• self-assembled monolayers
• field experiments
• protein adsorption
• Ulva linza

Acknowledgements

The authors acknowledge the financial support from ONR (grant number N00014-08-1-1116 and N00014-12-1-0498 to MG and AR and N00014-08-1-0010 to JAC and MEC) and the POF Biointerfaces of the Helmholtz Society for support of this work. The generous help of the whole Swain team during the experiments at FIT is kindly acknowledged, as well as the kind support during the IRRAS measurements by S. Heissler at IFG, KIT.