Multi-tunable aggregation behaviors of thermo/pH-responsive toothbrush-like and jellyfish-like copolymers

Abstract

Rational design of comb-like and linear conjugates comprising PNIPAM and PDMAEMA segments allows the construction of a multi-tunable hierarchical self-assembly platform and insight into the topology effect.

Impact of cyclization and dendronization on multi-tunable thermoresponsive behaviors of polyacrylamide copolymers

“…After the ring-opening reaction, the signals related to the ATL unit completely shifted from 4. 74 1 H NMR spectrum (Fig. S4b †).…”

“…Upon heating, the type and strength of intra/intermolecular interactions such as HBs and electrostatic interactions (EIs) continuously changed, and the variation of packing parameters drove the reassembly of copolymer assemblies. 40,52,53,[72][73][74] To reveal the reversibility of morphological changes, copolymer assemblies formed at 25 °C upon cooling were also subjected to TEM analysis. The TEM results (d and h of Fig.…”

Multitunable LCST and UCST Behaviors of Y-Junction-Bearing Polyacrylamides

“…Rational integration of thermosensitive groups in architectural polymers allows on-demand control over types and temperatures of phase transitions. − ,− Among them, the heterofunctional Y junction is a promising building block to construct multistimulus-responsive systems; especially, the incorporation of multifunctional Y junctions into polyacrylamides can endow the resultant Y-junction-bearing polymers (YJPs) with multitunable LCST/UCST phase transitions. − Meanwhile, thermoresponsive polymers can serve as ideal choices to achieve shape-shifting nano-objects . As a consequence of thermoresponsiveness, abundant morphological transformations among spheres, worms, nanocapsules (e.g., vesicles and nanobowls), and lamellae can occur upon heating, in which the shape shifts are driven by the variation of the packing parameter. − Given the promising multi-in-one functions of Y junctions, it is desirable to rationally design YJPs to achieve on-demand phase transitions and nanostructures.…”

Rational design of a multi-in-one heterofunctional agent for versatile topological transformation of multisite multisegmented polystyrenes

“…6–8 With the incorporation of reversible or irreversible covalent linkers, polymer segments can be subjected to stimuli-triggered cleavage and rearrangement, leading to the formation of other polymers with distinct topology, composition or molar mass ( M n ). Representative reversible covalent linkers comprise thermoresponsive Diels–Alder (DA) adduct 9–12 and alkoxyamine, a photo/thermoresponsive anthracene dimer (AntD) 13–16 and a redox-sensitive disulfide group, and typical irreversible covalent linkers mainly include a UV-cleavable o -nitrobenzyl group, 17 a thermo-labile azo group, and pH-labile ester, 18 acetal 19 and thioketal 20–23 groups. Rational incorporation of smart linkers leads to versatile topological transformations among linear, cyclic and branched polymers.…”