Naslov
Factors influencing one-step γ-irradiation synthesis of Ag and Au nanocomposite hydogels

Autori
Pustak, Anđela ; Marić, Ivan ; Mihaljević, Monika ; Gotić, Marijan ; Jurkin, Tanja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
32nd Miller Conference on Radiation Chemistry : Book of abstracts / - , 2023, 76-76

Skup
32nd Miller Conference on Radiation Chemistry

Mjesto i datum
Korzika, Francuska, 03.06.2023. - 08.06.2023

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
silver nanoparticles ; gold nanoparticles : hydrogel nanocomposite, hydrogel, PEO/Ag nanocomposite ; gamma-irradiation ; one step synthesis

Sažetak
Nanocomposite gels are usually synthesized by two- step methods, while the one step synthesis of nanocomposite hydrogels is much less investigated. One-step synthesis takes an advantage of simultaneous crosslinking of polymer chains and reduction of metal cations, which is quicker and simpler, but finding optimal conditions for these reactions to occur simultaneously is crucial. The aim of this study was to investigate the influence of various experimental factors on the ability of the irradiation technique to synthesize PEO/Ag and PEO/Au nanocomposite hydrogels in a single-step, and thus on the properties of synthesized gels. PEO and Ag+ or Au3+ aqueous solutions were γ- irradiated without addition of a scavenger. The dose, atmosphere, pH, concentration of metal salts, and polymer molecular mass and concentration were varied and optimised. The pH and concentration of metal salts were crucial factors in determining the formation of nanocomposite gels vs. suspensions. Neutral pH let to the formation of stable AuNPs colloid solutions, whereas unstable suspensions and bigger AuNPs were obtained at acidic pH. Alkaline conditions and lower metal salt concentrations favored the formation of Ag and Au nanocomposite hydrogels. Synthesis at elevated pH (pH 11 vs. 9), more concentrated PEO solution and inert atmosphere enabled the formation of hydrogels with higher NPs concentration. AgNPs (AuNPs) were embedded within PEO network with homogenous distribution. Smaller NPs were formed at lower concentration of metal salt, higher pH (pH 11 vs. 9) and under nitrogen atmosphere. In addition to the above, dose was significant factor affecting the PEO crosslinking density ; influence of atmosphere was also visible. At 100 kGy nearly amorphous composite gels with significantly reduced melting and crystallization temperatures were obtained. Smaller amount of NPs did not significantly affect the polymer network, with composite gels having slightly higher degree of crystallinity compared to pure PEO gels. The optimal amount was 1 wt% Au3+ to incorporate AuNPs into the gel and maintain or even improve the rheological properties (firmer gels, higher storage moduli, higher yield points and flow points and better recovery) compared to pure PEO gel. Higher amount of AuNPs (5 wt%, 10 wt%) lead to deterioration of gel properties and significant weakening of gel. The synthesized gels were also tested for their catalytic activity for the degradation/reduction of organic contaminants. The gels were showed to be promising catalysts for the reduction of toxic pollutant 4 nitrophenol to 4- aminophenol. Depending on the amount of NPs synthesized within gels the reduction can be completed almost instantaneously. Acknowledgments: This work has been supported by the Croatian Science Foundation under the project UIP-2017-05- 7337 (POLRADNANOP).

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA