consumed during the polymerization.265 It is also interesting to notice for MIP3 the appearance of

a broad absorbance peak in the 3400-3600 cml region that corresponds to the stretching

vibration of O-H bonds from carboxylic acid groups, which confirms the successful inclusion of

the MAA monomers in the nanoparticles during miniemulsion polymerization.266


 h EGMA t1640 cm-l
 3100 cm-l 4 1





 I I,





 4000 3000 2000 1000

 Wavenumber (cm l)

Figure 7-3. IR absorbance spectra of EGDMA, MIP1, and MIP3.

 The apparent hydrodynamic diameters of the nanoparticles were determined by dynamic

light scattering (DLS) just after miniemulsion polymerization and after high dilution to avoid

interparticle aggregation. All the samples show monodisperse distributions with average particle

diameters around 220 nm + 50 nm, independent of the nanocapsule composition. The DLS size

distribution of MIP6 is shown as an example in Figure 7-4. The ability to design particles through

miniemulsion polymerization with diameters in the nanometer range and with therefore large

surface-to-volume ratios is essential for drug detoxification therapy, because it has been

previously shown that increasing the available contact surface by decreasing the size of the

encapsulation entities significantly enhanced the uptake of toxic drugs, probably resulting from a

surface adsorption phenomena. In the present work, the amount of surfactant