## 3 Results and Discussion  
### Surfner Synthesis and Analysis  
To study the influence of the oligoglycidol chain length on the surfactant properties of the oligoglycidol-functionalised styrene macromolecule, we synthesized surfmers with three different oligoglycidol chain lengths according to the previously reported procedure [27]. We used vinyl benzyl alcohol (VBA, see Figure S1) and ethoxy ethyl glycidyl ether (EEGE) in ring opening polymerisation to yield poly(ethoxy ethyl glycidyl ether) (PEEGE) **1a-c** with 6, 10 and 20 repeating units (Figure 1). The polymer chain length was controlled by adjusting the VBA:PEEGE ratio, and it was analysed by \({}^{1}\)H-NMR (see Figure S2). The oligoglycidol-functionalised surfmers **2a-c** were obtained via acidic deprotection of the PEEGE molecules. After removing the acetal protecting groups the oligoglycidol chain length was again determined via \({}^{1}\)H-NMR. For surfmers **2a-c** NMR analysis resulted in oligoglycidol chain lengths of 6, 10 and 20 repeating units, respectively (see Figure S3). Furthermore, we performed mass spectroscopy (MS) to analyse the polydispersity of the synthesized macromonomers of oligoglycidol **2a-c** (see Figures S4-S6). The MS analysis revealed that for all macromonomers not only one chain length was obtained but a distribution of chain lengths, and that the number of repeating units calculated from NMR are average values.  
Figure 1: Reaction scheme of oligoglycidol-functionalised styrene surfmer synthesis, and schematic representation of subsequent emulsion polymerisation of styrene and divinyl benzene (\(n=6\), 10 and 20, for **2a-c** respectively).  
To study the surfactant properties of the three synthesized oligoglycidol surfmers **2a-c** with 6, 10 and 20 repeating units, we performed pendant drop measurements on aqueous solutions at various concentrations of each macromolecule. Here it was important to prepare the solutions 2 h before measurement to reach stable surface tension values. For all three surfactants the surface tension decreased rapidly with increasing concentration before it reached values between 50 and 55 mN\(\cdot\)m\({}^{-1}\) at the CMC (Figure 2), where further increase in surfactant concentration only led to a small decrease in surface tension. With increasing oligoglycidol chain length the CMC was reached at a lower concentration. Therefore, the surfactant properties of oligoglycidol surfmer increased with increasing chain length. For the macromolecules **2a-c** with 6, 10 and 20 repeating units CMCs of 5.38, 1.55 and 0.69 mmol\(\cdot\)L\({}^{-1}\), respectively, were determined. The results obtained via surface tension measurements suggest that an increase in oligoglycidol chain length leads to an increase in hydrophobicity of the macromolecule, since according to [PERSON]'s rule an increase in hydrophobicity of the surfactant will lead to an increase in surface activity [30]. An increase in oligoglycidol chain length increased both the number of polar OH groups and the number of apolar CH\({}_{2}\) moieties in the surfmer. The results obtained via surface tension measurements suggest that the influence of the apolar moieties dominates, and therefore the overall hydrophobicity of the surfactant increased with increasing oligoglycidol chain length. The surfactant **2a** with the CMC at the highest concentration was used to study the influence of oligoglycidol surfmer concentration on the particle size below the CMC.