CONCLUSION While cleaned silica-based glass surfaces have similar surface compositions, their susceptibility to strongly adsorbing organic contaminant s depends strongly on the glass composition and the cleaning procedure. For the three glass species exam-ined: silica, aluminoborosilicate, and sodalime glass , the glass surfaces behave similarly after chromic acid cleaning. They show significant differences in their properties followin g a dry cleaning procedure, such as pyrolysis or UV/ozone cleaning. The cleaned silica surfaces show a high susceptibility to adsorbing or-ganic contamination following pyrolysis cleaning, while the pyrolyzed sodalime glass appears to be virtually immune to strongly adsorbing organic molecules. Py-rolyzed aluminoborosilicate glass shows an intermediate susceptibility to adsorb-ing organic contaminants. The chromic acid cleaned glass surfaces all show an in-termediate susceptibility to contamination by adsorbed organic molecules. Thus, it may be an oversimplification to consider a clean glass surface as a high energy substrate that is bound to attract ambient organic contamination. The wettability behavior of the cleaned glass surfaces showed features associ-ated with their exposed chemical functions. The non-dispersive interaction energy between glass and water as a function of pH showed evidence of charging of the surface silanol groups. The point of zero charge for these surface chemical func-tions was observed at pH 3. An estimate of the non-dispersive interaction energy between glass and water at the point of zero charge enables a reasonable estima-tion of the density of surface silanol groups on the cleaned glass. The trends ob-served for the surface charge as a function of pH correlate with the observed sus-ceptibility for adsorbing organic contamination to the cleaned glass surfaces. Charge-adsorbed surfactant monolayers indicated a negative surface charge on the cleaned glass, as expected for silica-based glass surfaces at neutral pH. The wettability of grafted self-assembled octadecylsilane monolayers indicated high quality coatings on the cleaned glass surfaces. The coating quality was identical for all three glass species following chromic acid cleaning. The UV/ozone cleaned glass surfaces showed the highest coating quality on the silica surface, followed by the aluminoborosilicate surface and the sodalime glass surface. The trends in coating quality for all chromic acid cleaned surfaces and UV/ozone cleaned surfaces correlate with those seen for susceptibility to organic contamina-tion of the cleaned glass surfaces exposed to unpurified liquid octane. REFERENCES