TY - JOUR
T1 - Single-chain folding and self-assembling of amphiphilic polyethyleneglycol-modified fluorinated styrene homopolymers in water solution
AU - Guazzelli, Elisa
AU - Masotti, Elena
AU - Calosi, Matteo
AU - Kriechbaum, Manfred
AU - Uhlig, Frank
AU - Galli, Giancarlo
AU - Martinelli, Elisa
PY - 2021/9/28
Y1 - 2021/9/28
N2 - Amphiphilic tetrafluorostyrene monomers (EFSn) carrying in the para position a polyethyleneglycol (PEG) chain with varied lengths (n = 3–13) were synthesized and polymerized by ARGET-ATRP to obtain the corresponding amphiphilic homopolymers pEFSn-x with controlled and tailored polymerization degrees (x = 8–135). All polymers presented a reversible thermoresponsive LCST-type behavior, in water/methanol mixture when n ≤ 4 or in pure water when n ≥ 8, with a cloud point (C
p) temperature in the range 30–40 °C strictly dependent on the length of the PEG side chain. Combined small angle X-scattering (SAXS) and dynamic light scattering (DLS) measurements were used to study the self-assembly behavior in water of the water-soluble amphiphilic homopolymers. SAXS confirmed the formation of compact-sized and spherical single-chain self-folded nanostructures below C
p, that generally presented small hydrodynamic diameters (D
h ≤ 11 nm) as proven by DLS analysis. Above C
p, much larger multi-chain aggregates were formed (D
h ≥ 800 nm), that reversibly turned back to collapsed nanostructures on cooling below the C
p temperature. By contrast, the polymers were not able to self-assemble in THF or DMF solutions, in which they adopted conventional random coil conformations.
AB - Amphiphilic tetrafluorostyrene monomers (EFSn) carrying in the para position a polyethyleneglycol (PEG) chain with varied lengths (n = 3–13) were synthesized and polymerized by ARGET-ATRP to obtain the corresponding amphiphilic homopolymers pEFSn-x with controlled and tailored polymerization degrees (x = 8–135). All polymers presented a reversible thermoresponsive LCST-type behavior, in water/methanol mixture when n ≤ 4 or in pure water when n ≥ 8, with a cloud point (C
p) temperature in the range 30–40 °C strictly dependent on the length of the PEG side chain. Combined small angle X-scattering (SAXS) and dynamic light scattering (DLS) measurements were used to study the self-assembly behavior in water of the water-soluble amphiphilic homopolymers. SAXS confirmed the formation of compact-sized and spherical single-chain self-folded nanostructures below C
p, that generally presented small hydrodynamic diameters (D
h ≤ 11 nm) as proven by DLS analysis. Above C
p, much larger multi-chain aggregates were formed (D
h ≥ 800 nm), that reversibly turned back to collapsed nanostructures on cooling below the C
p temperature. By contrast, the polymers were not able to self-assemble in THF or DMF solutions, in which they adopted conventional random coil conformations.
KW - Amphiphilic polymer
KW - LCST
KW - SAXS
KW - Single-chain nanoparticles
KW - Thermoresponsive polymer
UR - https://doi.org/10.1016/j.polymer.2021.124107
UR - http://www.scopus.com/inward/record.url?scp=85113298464&partnerID=8YFLogxK
U2 - 10.1016/j.polymer.2021.124107
DO - 10.1016/j.polymer.2021.124107
M3 - Article
SN - 0032-3861
VL - 231
JO - Polymer
JF - Polymer
M1 - 124107
ER -