Robust, Reusable, and Antioxidative Supramolecular Adhesive to Inorganic Surfaces Based on Water-Stimulated Hydrogen Bonding

Abstract

Reusable adhesives able to bond and debond to a surface as needed in response to stimuli are eagerly sought. Despite recent advances in catechol-derived adhesives, achieving strong and switchable adhesion persists as a challenge because easy catechol-to-quinone oxidation invariably reduces the adhesive catechol units which induce the formation of irreversible cross-linked networks. For this study, a supramolecular adhesive carrying a hydrophobic tetramethylcyclotetrasiloxane (TMCS) core surrounded by hydrophilic groups including four peripheral catechol groups (Cat) and four carboxyl groups (CGs) was demonstrated to have good oxidation resistance and strong and reusable adhesion to inorganic surfaces upon contacting water. The hydrophobic TMCS core supplied a hydrophobic environment for oxidation resistance. Once water was added to the materials, TMCS expelled water to expose more catechol units outward for sufficient contact with the substrate surface. The supramolecule was found to have a remarkably high complex viscosity of up to 2.6 × 108 mPa·s at 1 Hz, which is 105 times that of the TMCS core. These unique properties make the supramolecular material a promising candidate for extensive applications such as marine adhesives.

Highly Adhesive and Tough Thermoplastic Polyurethanes Using a Furandicarboxamide Rigid Chain Extender with Noncovalent Interactions

“…The curves of G ′ and G ″ will intersect, and the film transits from an elasticity-dominated solid-like state to a viscosity-dominated melt state. With the increase of HO–FDAM–OH amount, the intersection point temperature gradually increases and they are 54 °C for PUFD-0.5, 82 °C for PUFD-1, and 84 °C for PUFD-1.5, PUFD-1, and PUFD-1.5, which is related to the enhanced hydrogen-bonding interactions and the elevated rigidity of the chain segments . However, it needs to be noted that due to the lower molar mass and wider molar mass dispersity of PUFD-2, its low molar mass component indeed acts as a plasticizer and the intersection temperature of PUFD-2 shifts to a lower temperature of about 75 °C.…”

Debonding-on-demand adhesives based on photo-reversible cycloaddition reactions

“…[9][10][11][12][13] The most attractive mechanism for developing DoD adhesives that are reversibly detachable on demand is incorporating a system of reversible bond breaking and forming into the material design. [3][4][5] Dynamic covalent bonds, which are distinguished by their reversibility and responsiveness to external stimuli such as heat, light, electricity, and pH, can control the degree of polymerization, crosslink density, and viscoelastic properties of polymeric materials. [14][15] Recently, stimulus-responsive dynamic covalent bonding has been shown to be applicable to adhesives in terms of controlling adhesiveness.…”

“…Over the past decade, debonding-on-demand (DoD) systems with a variety of bond strengths according to requirements have been developed in the medical, automotive, micro, and soft electronics fields. [1][2][3][4][5] These DoD adhesives are required to possess switchable adhesiveness, that is, they should be sufficiently strong to hold and bond adherends when in use, while decreasing in strength sufficiently to be peeled off from the adherends after use. For example, acrylic-and silicone-based adhesives are mainly used as peelable wound dressings in the biomedical field.…”

“…Four-arm monomers are known to induce macromolecular architectural transformations (MAT) by increasing the number of dynamic covalent bonding sites, forming denser and more reproducible polymer networks. [51][52][53][54][55] To achieve MAT, two features are important: (i) flowability (ability to be fluidized); and (ii) intermolecular bonding (ability to form networks). In the molecule we synthesized (SS1, Fig.…”

Metallization of Polyphenylene Sulfide by Low-Cost Mussel-Inspired Catechol/Polyamine Surface Modification

“…Recently, dopamine has received much attention due to its high adhesion, good hydrophilicity, and bioactivity. − Dopamine contains much catechol and amine groups, which can undergo autoxidative polymerization under weak alkaline conditions to form polydopamine (PDA) coatings and adsorb to various substrate surfaces through covalent- and noncovalent-bonding interactions. − In addition, PDA coatings can be used as a secondary functionalization platform because the phenolic hydroxyl and amine groups in PDA coatings can be used for molecular modification and loading transition-metal ions. − However, the high price of dopamine severely limits its development in the industrial field. − Fortunately, it has been shown that the cross-linked network formed by the phenolic hydroxyl groups and autoxidative polymerization is the key to the outstanding adhesion of PDA. − Wang et al used inexpensive catechol (CA)/polyamine (PA) to modify the aramid fibers and further bridged the silane coupling agent, which significantly improved the interfacial adhesion of the modified aramid fibers to the rubber matrix. Gu et al modified aramid fibers with catechol/polyamine (CPA), and the wet shear strength of the prepared aramid fiber-reinforced SPI-based adhesive was increased by 133.3%.…”