Solution Behavior of POM Macroions Soluble but Still Aggregate

SOLUTION BEHAVIOR OF POM MACROIONS SOLUBLE BUT STILL AGGREGATE 

POM macroions allow a connection between simple ions and colloidal systems to be established. Similar to simple ions, POM macroions are highly soluble, thermodynamically stable, and form real solutions. However POMs macroanions are significantly larger than common simple ions, leading to a large size disparity between cations and anions. At the same time, the sizes of POM are close to some small colloids. Colloidal systems are insoluble, thermodynamically unstable, and form suspensions, but POMs do not display any of these characteristics. Instead, they form stable real solutions. 

FIGURE 3. SEM and TEM images obtained from POM blackberry solutions, (a) TEM image of M0154 in aqueous solution. (Reprinted with permission from ref. 23.) (b) SEM image of M0132 in water/acetone mixture (Reprinted with permission from ref. 25.) 

FIGURE 4. Typical Zimm plot based on measurements of a SLS study. Three different solution concentrations (0.03,0.015, 0.01 mg/mL) all at pH 2.3 are measured. The Rg and can be calculated from the plot. Inset Typical CONTIN results from a DLS study of 0.01 mg/mL aqueous POM solution at pH 2.3, scattering angle of 60°. Here Ri, = 45 nm, with a very narrow size distribution (Reprinted with permission from ref. 23.) 

Bilayer vesicle structures are very common in surfactant solutions, driven by the hydrophobic interaction due to the surfactant tails. Here the vesicle-like POM supramoelcular structures are completely different from surfactant bilayer vesicles because the POM macroions are fully hydrophilic. Furthermore, the POM macroions do not touch each other in the assemblies due to the electrostatic repulsions. We have given the new structure the nickname blackberry because of the similar shapes of the blackberry fruit and the self-assembled structures formed by POM macroions. 

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Solution Behavior of POM Macroions Soluble but Still Aggregate 39... 

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