Scattering behavior interface

An alternative approach is the use of pH-sensitive fluorophores (Lichtenberg and Barenholz, lOSS). These probes are located at the lipid-water interface and their fluorescence behavior reflects the local surface pH, which is a function of the surface potential at the interface. This indirect approach allows the use of vesicles independent of their particle size. Recently, techniques to measure the C potential of Liposome dispersions on the basis of dynamic light scattering became commercially available (Muller et al., 1986). 

Zhou, Z Chu, B, Light-Scattering Study on the Association Behavior of Triblock Polymers of Ethylene Oxide and Propylene Oxide in Aqueous Solution, Journal of Colloid and Interface Science 126, 171, 1988. 

Dynamic Behaviors of Molecules at Liquid-Liquid Interfaces Using the Time-Resolved Quasi-Elastic Laser Scattering Method... 

Zhou, Z. and B. Chu. 1988. Light-scattering study on the association behavior of triblock polymers of ethylene oxide and propylene oxide in aqueous solutubrColloid Interface Sci. 126 171-180. 

The Porod behavior ( q 4) at low q values arises from residual interfacial scattering from the silica surfaces. This is still present despite the solvent composition, which was chosen to exactly match the scattering density of silica by immersing the pure silica particles in different mixtures of H20 and D20. We determined this matched solvent composition to have a D20 volume fraction of 0.65. However, due to the large amount of silica in the samples (ca. 50 w/w-%) only a slightly mismatched solvent composition leads to a significant scattering from the interfaces of the silica particles. 

Figure 9 shows a comparison of the scaling function F(x) for several polymer mixtures [36,180] and small molecules [181]. The data show clear evidence for Porod s law [182,183], S(q > qm(t)) ocq-4, which describes the scattering from sharp interfaces between the co-existing A-rich and B-rich regions. While the behavior F(x 1) ocx4 also has been predicted theoretically [184-186], a theoretical calculation of the scaling function F(x) which would be fully satisfactory for all x is still a problem [187-190]. 

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