Synthesis and mussel-inspired polymerization of a new catechol monomer. The generated copolymer exhibits enhanced metal binding, due to the ligand nature of the new monomer, compared to polydopamine homopolymer.

The current methods used to impart flameretardant or fire-resistant properties to flexible polyurethane foams (PUFs) to meet fire safety requirements entail the use of halogenated phosphorus-based compounds. Whereas these are highly effective as flame retardants, the associated toxicity derived from halogens in the burning fumes are deadly. To address this problem, we herein present a facile and efficient method of fabricating highly fire-resistant flexible PUF using halogen-free nature-inspired coatings. All of the active ingredients used to fabricate the coatings originated from natural or widely available sources: chitosan from crustacean shells, acetic acid that is found in vinegar, and expandable graphite mined from mineral rocks, thus making this strategy environmentally friendly and sustainable. These coatings offer excellent flame-retardant properties; with a limiting oxygen index (LOI) value as high as 31%, the coated foam could potentially pass the highest levels within the British Standard 5852, which is a commonly accepted global industry standard for meeting the fire safety requirement of flexible PUF. Furthermore, cone calorimeter testing revealed the superior fire safety performance of the coated foam, including very low heat and smoke release upon burning. The flame retardancy of the coated PUFs is tunable depending on the amount of graphite employed in the coating solutions. It is anticipated that the coating strategy described here is applicable to other substrates.

Redox-facilitated self-polymerization can be performed with 5,6-dihydroxy-1H-benzimidazole to generate materials analogous to polydopamine, proving the possibility to expand the catecholamine-based chemistry to N-heterocyclic catechol derivatives.

This research aims to synthesize a dopamine-functionalized macromolecular anchor to perform surface modification on the target nanostructures. A molecular anchor, 3,4-dichloro-1-[2-(3,4-dihydroxyphenyl)ethyl]-1H-pyrrole-2,5-dione, was successfully synthesized from dopamine and 2,3-dichloromaleic anhydride. The anchor acted as a linkage to couple the chains of poly(pentafluorostyrene) (PPFS) which were synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization. Modification was successfully performed to silver nanoparticles (AgNPs) by deposition of the dopamine-functionalized coupled PPFS onto the surface of the particles. The modified AgNPs had demonstrated improved dispersibility in organic solvent due to the hydrophobic nature of PPFS. To modify the surface chemistry of the nanoparticles further, thioglucose was grafted onto the structure of the coupled PPFS via thiol-fluoro nucleophilic substitution at the para-position of the pentafluorophenyl groups on the monomer units. The presence of sugar moieties on the coupled PPFS increased its hydrophilicity, which allowed the modified AgNPs to be readily dispersed in aqueous solvent.