mindyhausler
7 posts
Jun 19, 2025
6:33 PM
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Dimethicone was utilized as a non-ionic surfactant to stabilize water-in-oil (W/O) miniemulsions for the one-pot synthesis of gold nanoparticles (AuNPs) and their encapsulation into polymer matrices. To prepare the oil phase, 1?g of dimethicone was dissolved in 25?g of cyclohexane. The aqueous phase consisted of 3?g of an aqueous HAuCl? solution mixed with either 1-vinylpyrrolidone (VP) or 2-hydroxyethyl methacrylate (HEMA), with or without the crosslinker N,N'-methylenebisacrylamide (MBAAm).
The two phases were first stirred at 25?°C for 1 hour to form a macroemulsion, followed by ultrasonication (200?W, 10?min, ice bath) to generate nanodroplets, serving as confined reactors. Gold ions were reduced directly within the droplets due to the presence of dimethicone, producing 10-20?nm AuNPs.
For polymer encapsulation, an oil-soluble initiator (V-601) was added to the oil phase, and the emulsion was stirred under an inert atmosphere at 65?°C for 5?h. Alternatively, a water-soluble initiator (VA-061) was preloaded into the aqueous phase for HEMA-based systems. Adjusting initiator and crosslinker concentrations improved gelation and encapsulation efficiency.
This process enabled the uniform production of AuNP-loaded polymer nanoparticles, showcasing dimethicone's dual role as emulsifier and reductant in functional nanomaterial synthesis.
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