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. Author manuscript; available in PMC: 2011 Dec 28.
Published in final edited form as: Phys Rev E Stat Nonlin Soft Matter Phys. 2011 Sep 12;84(3-1):031911. doi: 10.1103/PhysRevE.84.031911

FIG. 9.

FIG. 9

(Color online) Fresnel-normalized reflectivity data for a Si-Ni-Si substrate [green (light gray)] and with a VSD-OG monolayer tethered to its surface [red (gray)] via the SA approach in (a) moist He, (b) aqueous Tris buffer environment. The corresponding absolute electron density profiles (c) for Si-Ni-Si substrate itself in moist He (black) and aqueous buffer [blue (dark gray)] environments. (d) The absolute difference electron density profile for the VSD-OG monolayer in moist helium (black), referenced to the substrate profile in moist helium (left ordinate scale), compared with the relative (or excess) difference electron density profile of the same VSD-OG monolayer in aqueous buffer [blue (dark gray)], referenced to the substrate profile in the buffer (right ordinate scale; note that 0.000 e−/Å3 on this relative scale is 0.333 e−/Å3 on an absolute scale). The inset in (c) depicts the simple cartoon for the Si-Ni-Si substrate in moist He versus aqueous buffer.