## 3 Results
### Characterization of Dispersions of Pluronic-F-127-Decorated Silica Nanoparticles
Therefore, based on the DLS results, a very efficient adsorption of Pluronic F-127 on the surface of silica nanoparticles can be assumed, which is consistent with previous results  
Figure 1: DLS results for mixed dispersions of silica nanoparticles (concentration, \(1\%\omega/w\)) and Pluronic F-127, with increasing concentrations of the latter: (**a**) intensity autocorrelation functions; (**b**) intensity–apparent hydrodynamic diameter distributions obtained from the analysis of the intensity autocorrelation functions in (**a**). The color code is the same in both panels (concentrations refer to Pluronic F-127): (**\(\blacksquare\)**, \(\blacksquare\)**) 0.2 mg/mL, (\(\bullet\)**, \(\blacksquare\)**) 1 mg/mL g/L, (\(\blacktriangle\)**, \(\blacksquare\)**) 3 mg/mL, and (\(\blacktriangledown\)**, \(\blacksquare\)**) 10 mg/mL. reported by [PERSON] et al. [17]. It should be noted that average size obtained by DLS for decorated silica nanoparticles is higher than that expected for Pluronic F-127 chains, and that in the case of Pluronic F-127 solutions above the cmc, DLS shows a multimodal system where two different types of species (i.e., single chains and micelles) are involved, leading to more complex DLS results [17]. For a deeper understanding of the formation of Pluronic-F-127-decorated silica nanoparticles, Figure 2 shows the dependence on the average apparent hydrodynamic diameter (obtained as the maximum of the intensity-apparent hydrodynamic diameter distribution) on the concentration of the Pluronic F-127 included in the dispersion (\(c_{\text{Pluronic F-127}}\)) for dispersions with two different concentrations of silica nanoparticles (\(c_{\text{NP}}\)). It should be noted that the reported apparent hydrodynamic diameter is a concentration-dependent quantity, with this dependence resulting from interparticle interactions, and is therefore different from the true hydrodynamic diameter reported in Section 3.1 [35; 36]. The addition of Pluronic F-127 to the silica nanoparticle dispersions results in a significant increase in the apparent hydrodynamic diameter of the nanoparticles when dispersions with a fixed nanoparticle concentration are considered. In fact, the apparent hydrodynamic diameter (\(d_{h}^{PPp}\)) increases from approximately \(20\,\text{nm}\) for the unmodified particles to roughly \(60\,\text{nm}\) for dispersions containing a \(0.1\%\,w/w\) nanoparticle concentration, and up to values of about \(30\,\text{nm}\) when the concentration of the dispersions is increased by a factor of \(10\) (\(1\%\,w/w\)). These observations strongly suggest the adsorption of Pluronic F-127 molecules onto the silica nanoparticle surfaces. At lower Pluronic F-127 concentrations, the copolymer molecules are likely to be adsorbed individually, adopting a flat conformation that becomes increasingly disordered with increasing copolymer concentration, as a result of an increase in the number of polymer segments protruding into the aqueous phase--and the consequent increase in \(d_{h}^{PPp}\). However, once the critical micelle concentration (cmc) of Pluronic F-127 is overcome, micelles of the copolymer are expected to adsorb directly onto the nanoparticle surfaces. These micelles can be deformed as their number increases to maximize their adsorption on the surface. This is particularly important at the lowest nanoparticle concentration, where the dimensions of the Pluronic F-127 capping layer exceed the average apparent hydrodynamic diameter of the Pluronic F-127 micelles (approximately \(15\)-\(20\,\text{nm}\)) [17]. The adsorption of Pluronic F-127 micelles on silica surfaces is consistent with previous reports suggesting that the micellization of Pluronic copolymers on hydrophilic surfaces is preferential compared to the micellization process occurring in bulk aqueous phases [37; 38]. Figure 2: (**a**) Dependence of the average apparent hydrodynamic diameter on the concentration of Pluronic F-127 for the mixed dispersions. (\(\blacksquare\)) \(c_{\text{NP}}=0.1\%\,w/w\) and (\(\bullet\)) \(c_{\text{NP}}=1\%\,w/w\).