Kinetics of conditioning layer formation on stainless steel immersed in seawater

Abstract

Adhesion of microorganisms to surfaces in marine environments leads to biofouling. The deleterious effects of biofilm growth in the marine environment are numerous and include energy losses due to increased fluid frictional resistance or to increased heat transfer resistance, the risk of corrosion induced by microorganisms, loss of optical properties, and quality control and safety problems. Antifouling agents are generally used to protect surfaces from such a biofilm. These agents are toxic and can be persistent, causing harmful environmental and ecological effects. Moreover, the use of biocides and regular cleaning considerably increase the maintenance costs of marine industries. An improved knowledge of biofilm adhesion mechanisms is needed for the development of an alternative approach to the currently used antifouling agents. The aim of this study is to characterise the chemical composition of the molecules first interacting with stainless steel during the period immediately following immersion in natural seawater and to elucidate the kinetics of the adsorbtion process. Proteins are shown to adhere very rapidly, closely followed by carbohydrates. The distribution on the surface of organic molecules is also examined. The adsorbate on the surface is not a continuous film but a heterogeneous deposit, whose average thickness varies widely. The cleaning procedures used affect the adsorption kinetics. In particular, cleaning with hexane results in slower adsorption of nitrogen-containing species than does cleaning in acetone.

Microbial Surface Colonization and Biofilm Development in Marine Environments

“…Proteins and glycoproteins are usually the major constituents of conditioning films (571,572), although lipids, polysaccharides, nucleic acids, aromatic amino acids, uronic acids, humic acids, and some other biomolecules may also be present (573). The conditioning film affects the surface nutritional conditions and physicochemical properties, usually causing a convergence of surfaces that initially vary strongly in hydrophobicity and roughness (6,7,572).…”

Adsorption and self-assembly of bio-organic molecules at model surfaces: A route towards increased complexity

“…On the other hand, adsorption of peptides and proteins is a preliminary step for the further growth of bio-films on solid surfaces [5] and must be prevented when addressing fouling, hygiene and bio-corrosion issues. As tangible example of application, we mention the deposition and immobilization of fullerene molecules on a template formed by a self-assembled glycine layer on Cu(111) [6].…”

Biofilm development on acrylic coupons during the initial 24 hour period of submersion in a tropical coastal environment

“…Proteins showed higher concentration than carbohydrates during the 24 hour study period. Compere et al (2001) suggested that proteins were the first to adsorb on the surfaces, followed by carbohydrates. However, D'Souza et al In the present study also these compounds showed an increasing trend with time.…”