Programmable polymer-based supramolecular temperature sensor with a memory function.
A new class of polymeric thermometers with a memory function is reported that is based on the supramolecular host-guest interactions of poly(N-isopropylacrylamide) (PNIPAM) with side-chain naphthalene guest moieties and the tetracationic macrocycle cyclobis(paraquat-p-phenylene) (CBPQT(4+)) as the host. This supramolecular thermometer exhibits a memory function for the thermal history of the solution, which arises from the large hysteresis of the thermoresponsive LCST phase transition (LCST = lower critical solution temperature). This hysteresis is based on the formation of a metastable soluble state that consists of the PNIPAM-CBPQT(4+) host-guest complex. When heated above the transition temperature, the polymer collapses, and the host-guest interactions are disrupted, making the polymer more hydrophobic and less soluble in water. Aside from providing fundamental insights into the kinetic control of supramolecular assemblies, the developed thermometer with a memory function might find use in applications spanning the physical and biological sciences.
Université Lille Nord de France, ENSCL, Unité des Matériaux et Transformations, UMR CNRS 8207, Equipe Ingénierie des Systèmes Polymères (ISP), 59655 Villeneuve d'Ascq Cedex (France).
Léna
L
Sambe
Victor R
VR
de La Rosa
Khaled
K
Belal
François
F
Stoffelbach
Joel
J
Lyskawa
François
F
Delattre
Marc
M
Bria
Graeme
G
Cooke
Richard
R
Hoogenboom
Patrice
P
Woisel
D011108:Polymers; D066244:Proton Magnetic Resonance Spectroscopy; D013056:Spectrophotometry, Ultraviolet; D013821:Thermometers
D011108:Polymers
host-guest systems; memory; phase transitions; supramolecular chemistry; thermometer