Graphene Quantum Dots-Ornamented Waterborne Epoxy-Based Fluorescent Adhesive via Reversible Addition–Fragmentation Chain Transfer-Mediated Miniemulsion Polymerization: A Potential Material for Art Conservation

Abstract

Epoxy-based adhesives have gotten significant attention in the conservation of antiquities and repair or reconstruction of artifacts due to their excellent adhesion strength. However, it has become hard to detect repaired work in artifacts due to the transparent nature of epoxy-based adhesives. Hence, the making of fluorescent adhesives has become an exciting topic for art conservators. Here, we have synthesized a new kind of waterborne epoxy-based fluorescent adhesive decorated with graphene quantum dots (GQDs) via reversible addition–fragmentation chain transfer (RAFT)-mediated surfactant-free miniemulsion polymerization. In this case, a new block copolymer (BCP), poly­(1-vinyl-2-pyrrolidone)-block-poly­(glycidyl methacrylate), has been synthesized via surfactant-free RAFT-mediated miniemulsion polymerization using a polymerization-induced self-assembly technique. The GQDs were prepared from citric acid by a hydrothermal process, and this was used for making a fluorescence-active BCP/GQD nanocomposite emulsion. The obtained BCP/GQD nanocomposite adhesive was transparent and showed blue fluorescence under ultraviolet–visible light, indicating the easy detection of its mark on the artifacts. The BCP and BCP/GQD emulsions were applied to adhere ceramic and glass substrates, and their adhesion strength was evaluated by lap shear tests. The BCP/GQDs showed better adhesion strength than the BCP only, indicating better adhesive performance. Additionally, the synthesis process was carried out in aqueous media, indicating the sustainability and environment-friendliness of the process. We believe that this kind of new waterborne epoxy-based fluorescent adhesive will provide a new contrivance among art conservators to repair or reconstruct artifacts.

Silicon-Doped Graphene Oxide Quantum Dots as Efficient Nanoconjugates for Multifunctional Nanocomposites

“…These results suggest that deposition of the Si-GOGQs on the top surface yielded films that were less stiff, likely as a result of stabilization at an interphase region at the nanodot/polymer interface. The enhanced ductility of the film with the incorporation of the Si-GOQDs could also be explained by physisorption between the PDMS and Si-GOQDs . When an external mechanical stress is applied, the nanodot domains act as highly stable associations to transfer the load across the interfacial region, resisting external damage.…”

“…The enhanced ductility of the film with the incorporation of the Si-GOQDs could also be explained by physisorption between the PDMS and Si-GOQDs. 60 When an external mechanical stress is applied, the nanodot domains act as highly stable associations to transfer the load across the interfacial region, resisting external damage.…”

RAFT-mediated polymerization-induced self-assembly (RAFT-PISA): current status and future directions

“…The work by Singha et al presented a waterborne epoxy-based fluorescent adhesive ornamented with graphene quantum dots (GQDs). 237 The GQDs were prepared by hydrothermal process, then mixed with the poly(1-vinyl-2-pyrrolidone) (PVP) macro-RAFT agent and glycidyl methacrylate monomer to undergo surfactant-free miniemulsion PISA. The carboxyl and hydroxyl groups on the surface of GQD nanoparticles interacted with the nitrogen of the PVP block via noncovalent interaction, resulting in a honeycomb-like structure.…”

Bioactive Graphene Quantum Dots Based Polymer Composite for Biomedical Applications

“…Mini-emulsion polymerization is one of the simplest and most common methods for encapsulating QDs in hydrophobic sub-micron polymer particles. A polymerization monomer produces an aqueous dispersion of nanoparticles where the surface of the coated QDs is compatible [ 203 , 204 , 205 , 206 , 207 ]. The creation of polymer nanoparticles containing QDs is achieved through the polymerization of a dispersion nanodroplet.…”