A Rapidly Self‐Healing Supramolecular Polymer Hydrogel with Photostimulated Room‐Temperature Phosphorescence Responsiveness

Abstract

Development of self-healing and photostimulated luminescent supramolecular polymeric materials is important for artificial soft materials. A supramolecular polymeric hydrogel is reported based on the host-guest recognition between a β-cyclodextrin (β-CD) host polymer (poly-β-CD) and an α-bromonaphthalene (α-BrNp) polymer (poly-BrNp) without any additional gelator, which can self-heal within only about one minute under ambient atmosphere without any additive. This supramolecular polymer system can be excited to engender room-temperature phosphorescence (RTP) signals based on the fact that the inclusion of β-CD macrocycle with α-BrNp moiety is able to induce RTP emission (CD-RTP). The RTP signal can be adjusted reversibly by competitive complexation of β-CD with azobenzene moiety under specific irradiation by introducing another azobenzene guest polymer (poly-Azo).

A Cucurbit[7]uril Based Molecular Shuttle Encoded by Visible Room‐Temperature Phosphorescence

“…In addition, aJ ob'sp lot wasu sed to further validate the bindings toichiometry between IQC [5] and CB [7] and the UV absorbance maximizinga tan umerical value of 0.5 for [Guest]/[Host + Guest] ( Figure 3). These data could be best fitted to a1 :1 binding model to obtain the associationc onstant, whichwas found to be (5.73 AE 0.07) 10 3 Lmol…”

“…[5] Room-temperature phosphorescence induced by cyclodextrin (CD-RTP), firstly introduced by Turro et al [6] and used as au seful method to acquire optical signal, possesss everal merits such as longerl uminescence lifetime, less influence from short-lived fluorescencea nd scattering light, superior selectivity and obvious Stokes' shift. [7] Several phosphor/CD systems have been recently discovered, exhibitinga pplication potentials in numerousf ields including molecular switches, [8] logic gates, [9] luminescence materials, [10] and so forth. Similar to cyclodextrins, cucurbit[n]urils (CB [n]) are af amily of macrocyclic hostm olecules with ah ydrophobic cavity to fabricate stable inclusionc omplexes with guest molecules.…”

Supramolecular Polymeric Materials Containing Cyclodextrins

“…Self-healable materials based on various kinds of polymer backbones cross-linked by CD-guest interactions have been developed so far. [48][49][50][51] Therefore self-healing materials based on reversible host-guest interaction may be a versatile concept suitable for various applications.…”

Intrinsic Self-Healing Polymers Based on Supramolecular Interactions: State of the Art and Future Directions

“…This effect generated mobility in the material and enabled healing (e.g., crack healing in a coated polymer film). Chen et al investigated the host-guest interactions between β-CD and α-bromonaphthalene (α-BrNp) in a hydrogel based on a polyacrylamide backbone [243]. After cutting the material into pieces and placing the surfaces together, rapid self-healing behavior was observed (1 min).…”