Keywords Hydrophobic association · Micelles · Pluronic F127 · Responsiveness ·
Shape morphing · Soft actuator · Tough hydrogels · Triblock copolymer
Abbreviations
2D
Two dimension
β-CD
β-Cyclodextrin
AAm
Acrylamide
AMPS
2-Acrylamide-2-methylpropanesulfonic acid
AZO
4-(Phenylazo)benzoic acid
CC gels
Chemically crosslinked hydrogels
DC
Direct current
DLS
Dynamic light scattering
DMAEA-Q
(2-(Acryloyloxy)ethyl)trimethylammonium chloride
DMAEMA
2-(Dimethylamino)ethyl methacrylate
DMSO
Dimethyl sulfoxide
F127
Pluronic F127, poly(ethylene oxide-propylene oxide-ethylene
oxide)
F127DA
Pluronic F127 diacrylate
HAAD
Hydrazine-modified hyaluronic acid
HEMA
2-Hydroxyethyl methacrylate
IS
Ionic strength
NaMAA
Sodium methacrylate
PAAm
Polyacrylamide
PAMPS
Poly(2-acrylamide-2-methylpropanesulfonic acid)
PDMAEA-Q Poly((2-(acryloyloxy)ethyl)trimethylammonium chloride)
PEG
Poly(ethylene glycol)
PNIPAM
Poly(N-isopropylacrylamide)
SAXS
Small-angle X-ray scattering
SEM
Scanning electron microscopy
TEM
Transmission electron microscopy
1 Introduction
Among the non-covalent interactions used to crosslink hydrophilic polymer chains
into networks, hydrophobic association has been very widely and successfully used
as the mechanism for crosslinking and energy dissipation [1–3]. Okay et al. used
micelles of small molecular surfactants to create a nanometer-sized spot for the local
polymerization and association of hydrophobic monomers to form hydrophobic
crosslinks [4]. The nanometer-sized hydrophobic crosslinks could be mediated by
using salt and other monomers [5]. It even allows for the formation of crystalline
domains that further toughen the hydrogels and impart shape memory effects
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J. Fu