AVS 52nd International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP11
The Effect of Solid Surface Tension on Biofilm Adhesion

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Biomaterial Interfaces Poster Session
Presenter: R.A. Brizzolara, NSWC, Carderock Division
Authors: R.A. Brizzolara, NSWC, Carderock Division
R.M. Lennen, NSWC, Carderock Division
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The effect of material properties on the biofouling of a surface is of great practical importance. Biofouling is a chronic and costly problem in the maritime industry as well as being a significant issue for the medical community. This study investigates the effect of solid surface tension on microbial biofilm adhesion and accumulation. The experimental approach was designed to isolate the effects of solid surface tension on the biofilm from the effects of other material properties such as elastic modulus and surface topography, as well as to isolate biofilm accumulation from biofilm adhesion. Covalently bound monolayers of organosilanes were prepared on native titanium oxide surfaces. The solid surface tension was varied through the choice of the terminal group, using hexadecyltrichlorosilane, 1H,1H,2H,2H-perfluorooctyltrichlorosilane and 3-chloropropyltrichlorosilane precursors. This resulted in surfaces with a wide range of solid surface tensions, while retaining the original topography and modulus. Monolayer deposition was verified using contact angle/solid surface tension measurements and x-ray photoelectron spectroscopy (XPS). Biofilm accumulation and adhesion measurements were performed by growing Pseudomonas fluorescens biofilms under gentle agitation (~120 RPM shaker) and performing a Bradford protein assay before and after exposing the coupons to hydrodynamic shear stresses of 3.7 N m-1 in a turbulent flow cell. It is expected that the results of this study will assist in the design of advanced coatings and surfaces by defining the optimum solid surface tension for reduced biofouling. This work was funded by the NSWC, Carderock Division In-House Laboratory Independent Research (ILIR) program.