The surface energy of silica is correlated with topography and composition in micron thick films on polycarbonate visors for football, hockey, ski and scuba diving.

Use of visors can be limited by condensation that occurs in during athletic performance. Control of the hydro-affinity of the surface requires an understanding of hydrophobic/hydrophilic behavior as well as of condensation kinetics and surface contamination for up to several continuous hours

Combining Proton-Induced X-ray Emission (PIXE), Tapping Mode Atomic Force Microscopy (TMAFM) & the Sessile Drop Method with Contact Angle Analysis (CAA) using Young-Dupre Equation, yields insights into nucleation and ripening of water droplets. Real-time observation via optical microscopy of both reflected and transmitted light, PIXE, TMAFM and CAA with previous Rutherford Backscattering Spectrometry (RBS) results ca establish a model to predict surface energy and hydro-affinity of silicates, phospho-silicates and other compounds used for high impact resistance vision wear coatings. Ultimately, the goal is to control condensation on such coated polymers for applications in sport eyewear used in hockey, skiing, football and other contact sports, swimming goggles, and diving masks.

Surface characterization techniques in this research combine the 4.265 ± 0.035 MeV 12C(alpha, alpha)12C and the 3.05 ± 0.005 MeV 16O(alpha, alpha)16O MeV Oxygen Nuclear Resonance to increase light atoms detection with 2.8 MeV Hydrogen Elastic Recoil Detection for compositional analysis with depth profiling, and Tapping Mode Atomic Force Microscopy for surface topography. The water affinity of the solid surface is measured via contact angle analysis using the Sessile Drop method calibrated with standards such as OH(1x1)Si(100), 100 nm thermal oxides on Si(100), Si(100) amorphized by high dose Si ion implantation at 35-175 keV, alpha-quartz crystals, and the Young-Dupré equation to compute surface energy. The surface energy is then correlated with statistical analysis of Tapping Mode Atomic Force Microscopy topographs and PIXE/RBS analysis to predict and determine the mechanism and kinetics of water condensation. Polymer adsorption on these surfaces is used to alter the surface hydroaffinity and maintain clarity when condensation occurs by making it hydrophilic [1].

[1] US Patent pending "Molecular films for controlling hydrophobic, hydrophilic, optical, condensation and geometric properties of Si-based surfaces. Inventor(s): N. Herbots, J. D. Bradley, M. A. Hart, D. A. Sell, S. D. Whaley, Q. Bradley (filed: November 9, 2009)