Chitin Nanowhisker/Gold\nNanocluster Hybrids with an\nExcellent Dispersion Stability via Poly(ethylene glycol) Grafting

Hybrid\nnanoparticles composed of chitin nanowhiskers\n(ChNWs) and\ngold nanoclusters (AuNCs) having an improved stability were prepared.\nThe grafting of monomethoxypoly(ethylene glycol) (mPEG) and subsequent\nsurface adsorption of AuNCs enabled the steric stabilization of ChNW/AuNC\nhybrids. mPEGs with terminal formyl groups and diethylacetal protecting\ngroups were grafted via in situ deprotection and reductive amination\nwith the surface amino groups (SAGs) of ChNWs. The treatment of chitin\nwith a 30% sodium hydroxide solution improved the SAG contents of\nthe ChNWs obtained from acid hydrolysis, resulting in an enhancement\nin mPEG grafting. The obtained sterically stabilized ChNW/AuNC hybrids\nexhibited remarkable dispersion stability at higher AuNC and electrolyte\nconcentrations.