## 4 Conclusions  
Novel amphiphilic homopolymers composed of a poly(pentafluorostyrene) modified in the para position with an oligo(ethyleneglycol) side chain containing eight CH\({}_{2}\)CH\({}_{2}\)O units on average were synthesized by ARGET-ATRP. By taking advantage of the controlled nature of the polymerization, two homopolymers with different lengths were prepared and their self-assembling and thermoresponsive behavior in water was investigated by DLS, turbidimetry, and n-DSC. All the analytic techniques pointed out for both polymers the existence of an LCST-type phase transition at which nanostructures with a low \(D_{\rm h}\) of 6-7 nm, consistent with a polymer single chain, self-assembled into much larger multichain aggregates whose dimensions depended on the polymer concentration. The cloud point temperatures (\(T_{\rm cp}\)) at 50% transmittance were generally in between the calorimetric \(T_{\rm onset}\) and \(T_{\rm max}\). Moreover, \(T_{\rm cp}\), \(T_{\rm onset}\), and \(T_{\rm max}\) were found to be lower for the shorter than for the longer homopolymer. n-DSC measurements revealed, in any case, the presence in heating scans of a broad endothermic peak mainly due to the dehydration process of the polymer single chains and their collapse into aggregates. However, the LCST behavior associated with this unimer-aggregate transition was found to be reversible up to a specific homopolymer-dependent temperature (\(T_{\rm rev}\)), which was higher than \(T_{\rm max}\) in both cases. On the other hand, when heating above \(T_{\rm rev}\), the transition was no longer reversible, causing the shift of \(T_{\rm onset}\) and \(T_{\rm max}\) at lower values, which was indicative of the increase in hydrophobicity of the polymer systems. This was interpreted by assuming a temperature-dependent dehydration process, resulting in significant changes in unimer and aggregate conformations.  
To the best of our knowledge, the obtained results contribute, for the first time, to drawing a general picture to describe the thermoresponsive behavior, and its reversibility, of novel amphiphilic tetrafluorostyrene-based homopolymers in aqueous solutions.  
**Supplementary Materials:** The following are available online at [[https://www.mdpi.com/2076-341](https://www.mdpi.com/2076-341)]([https://www.mdpi.com/2076-341](https://www.mdpi.com/2076-341)) 7/11/6/2711/s1, Figure S1: DSC thermal profiles of the polymer pEFS8-46 performed in aqueous solution at concentrations of 0.5 g/L (a), 1 g/L (b), and 5 g/L (c). Figure S2. Reversibility of the aggregation process for pEFS8-46 aqueous solutions (1 g/L), studied by n-DSC. The first 3 scans were carried out at 1 \({}^{\circ}\)C/min, and the last two at 0.5 \({}^{\circ}\)C/min. Figure S3. Reversibility of the aggregation  
Figure 7: Schematic representation of the self-aggregation process of the amphiphilic homopolymers pEFS8-x below and above \(T_{\rm rev}\).  
process for pEFS8-46 aqueous solutions studied by n-DSC (changing the final temperature of the scan every two heating scans) (a) and by turbidity measurements (b).  
Conceptualization, M.R.T., C.D., and E.M.; methodology, C.P., M.C., and E.G.; software, C.P. and M.C.; validation, L.B., C.D., and E.M.; formal analysis, L.B., C.D., and E.M.; investigation, E.M., E.G., M.C., C.P., and C.D.; resources, L.B., M.R.T., C.D., and E.M.; data curation, M.C., C.P., and E.G.; writing--original draft preparation, C.P. and M.C.; writing--review and editing, E.M. and C.D.; visualization, E.M. and C.D.; supervision, L.B., C.D., and E.M.; project administration, E.M. and C.D.; funding acquisition, M.R.T., L.B., and E.M. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the University of Pisa (Progetti di Ricerca di Ateneo, PRA_2020_27 and PRA_2020_32) and by Regione Toscana (Project Ecopool Smart Filter 2017 POR CREO FESR).  
Not applicable.  
The authors declare no conflict of interest.