Elasticity‐Dependent Fast Underwater Adhesion Demonstrated by Macroscopic Supramolecular Assembly

Abstract

Macroscopic supramolecular assembly (MSA) is a recent development in supramolecular chemistry to associate visible building blocks through non‐covalent interactions in a multivalent manner. Although various substrates (e.g. hydrogels, rigid materials) have been used, a general design rule of building blocks in MSA systems and interpretation of the assembly mechanism are lacking and are required. Herein we design three model systems with varied elastic modulus and correlated the MSA probability with the elasticity. Based on the effects of substrate deformability on multivalency, we have proposed an elastic‐modulus‐dependent rule that building blocks below a critical modulus of 2.5 MPa can achieve MSA for the used host/guest system. Moreover, this MSA rule applies well to the design of materials for fast underwater adhesion: Soft substrates (0.5 MPa) can achieve underwater adhesion within 10 s with one order of magnitude higher strength than that of rigid substrates (2.5 MPa).

Supramolecular silicone coating capable of strong substrate bonding, readily damage healing, and easy oil sliding

“…Comparison of shear strengths between DOSS coatings and reported adhesive materials/commercial glues. (A)The shear strength between the DOSS coating and various substrates (blue columns) and, as a comparison, the results of reported adhesive materials/commercial glues (black columns) are listed(32,33,(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52). The shear strength reported in this work is competitive with the results of reported adhesive materials/commercial glues.…”

“…Quantitative tests show that a shear strength above 20 MPa is recorded (Fig. 3A) for cellulose (paper) and all tested metal substrates and about 10 MPa for Teflon, outstanding among the commercial glues and other adhesive materials that have ever been reported (32,33,(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52). This high shear strength can be ascribed to the high mechanical strength of the siloxane oligomers and the high-density H-bonds between the urea and UPy motifs, especially the dissociated UPy motifs at the DOSS coatings/substrate interface, which can form hydrogen bonding with either the hydroxyl groups of hydrophilic surfaces or the fluorine groups of the hydrophobic Teflon surface (Fig.…”

Ultra-strong bio-glue from genetically engineered polypeptides

“…This is achieved by in situ polymerization or crosslinking of reactive monomers that form permanent, non-adaptive covalent bonds or networks 7 , 8 . Recently, systems based on supramolecular interfacial bond formation, such as catechol or host-guest motifs, were introduced 9 – 11 . However, they failed to deliver strong adhesion strengths under ambient conditions and moreover often require hard-to-prepare or irritating components.…”

Recent progress in polymer hydrogel bioadhesives

“…Hydrogel adhesives have great potentials in clinical applications, [5][6][7][8] implantable devices 9,10 and electronic skin. [11][12][13] Many non-covalent secondary forces like hydrogen bonding, [14][15][16] dipole-dipole interactions, 17,18 host-guest interaction 19 and electrostatic forces 20 between the adhesive and the substrate have been utilized to achieve strong and reversible adhesion. 3,21 Different mechanisms have been proposed to explain the adhesion to substrates.…”