Figure 1.10 И
Schematic of the diffuse electric double layer formed over a negatively charged
surface. The red dots represent positive counterions. The density of the counterions
close to the surface is higher than in the bulk. This cloud of positive counterions is the
diffuse electric double layer.
Figure 2.1 19
(Top Left) 3D schematic diagram, (Top Right) Finite Element Domains I to IV, not
to scale. (Bottom) Portion of the mesh generated while solution is computed.
Figure 2.2 22
The lipid membrane charge densities determined by applying Equation 2.1 to
the experimental force curves. The data do not follow the expected trend with
DOPS mole fraction.
Figure 2.3 23
Comparing data and simulation results. Each solid, colored line represents
the computationally simulated force curve obtained by using various guesses as
to the lipid surface charge density. Note that the data is fit to the model only in the
long-range region (1-4 Debye lengths).
Figure 2.4 24
(a) Lipid membrane charge densities and, (b) surface potentials determined
by a numerical analysis of the experimental force curves. The data (squares) follow
the curves predicted by the Gouy-Chapman-Stem model (line).
Figure 3.1 27
Schematic of AFM tip-induced mobile charge regulation. Neutral lipids are
shown in yellow and the anionic lipids are shown in white, (a) In an unperturbed
lipid bilayer, the neutral and the anionic lipids are distributed homogenously,
(b) The close proximity of the negatively charged AFM tip induces the negative
lipid molecules to move away and results in a patch of mostly neutral lipids
forming underneath the AFM tip.
Figure 3.2 28
(a) The fixed charged density model is a good fit for the data for D > 11 nm.
(b) A closer view of the same data shown in (a) reveals that the simulation deviates
from the data when D < 11 run. The data is for a 1:5, DOPCrDOPS mixture.
Figure 3.3 31
Fluid AFM topography image of a 1:9, DMPC:DMPS lipid patch. We are able to
identify the lipid bilayer patch from its cross-sectional height which is 5nm.
The scan size is Ixl μm.
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