Radijaciono-hemijska sinteza termo-I pH-osetljivih antibakterijskih srebro/poli(N-izopropilakrilamid-ko- itakonska kiselina) nanokompozita

Abstract

U okviru ove doktorske disertacije izvedena je radijaciono-hemijska sinteza i karakterizacija novih nanokompozita na bazi umreţenih polimernih matrica N-izopropilakrilamida (NiPAAm) i itakonske kiseline (IK) i nanočestica srebra (Ag/P(NiPAAm/IK)). Za sintezu nanokompozita je korišćena radiolitička metoda koja omogućava umreţavanje i fino podešavanje svojstava nosača tj. polimerne matrice, ali i formiranje nanočestica srebra ţeljenih svojstava unutar polimerne matrice (in situ sinteza). Radiolitička metoda sinteze je izvedena pod dejstvom gama zračenja na kobaltnom (60Co) izvoru. Sintetisani uzorci su podvrgnuti detaljnoj fizičko-hemijskoj karakterizaciji u cilju dobijanja informacija o polimernim matricama kao nosačima i nanočesticama srebra kao nanopuniocima, ali i u cilju ispitivanja njihovog sinergističkog dejstva u nanokompozitnim sistemima.Morfologija umreţenih sistema je ispitana primenom skenirajuće elektronske mikroskopije (SEM) i mikro kompjuterizovane topografije (mikro-CT), a studija bubrenja praćenjem kinetike bubrenja u medijumima različitih pH-vrednosti i temperature, pri čemu su simulirani fiziološki uslovi. Utvrđeno je da prisustvo itakonske kiseline i inkorporacija nanočestica srebra utiču na morfologiju nanokompozita, parametre polimerne mreţe, kao i na kapacitet bubrenja.Optička svojstva nanokompozita su ispitana metodom spektroskopije u ultraljubičastoj i vidljivoj oblasti spektra (UV-Vis) i teorijskim modelovanjem primenom MiePlot 3.4 programskog paketa čiji je algoritam zasnovan na Mie-ovoj teoriji. U apsorpcionim spektrima je zapaţena karakteristična plazmonska apsorpcija sa maksimumom u opsegu od 390 nm do 412 nm, dok jemodelovanjem određeno da se vrednost prečnika nanočestica srebra kreće između 6,8 nm i 16,2 nm...

In this study, radiation-chemical synthesis and characterization of the novel nanocomposite systems based on silver nanoparticles (AgNPs) and crosslinked copolymer matrix of N-isopropylacrylamide (NiPAAm) and itaconic acid (IA) (Ag/P(NiPAAm/IA)) were performed. Radiolytic method, which is used for synthesis, enables fine tuning of properties of polymer matrix as a carrier, as well as formation of the silver nanoparticles with desired properties within polymer matrix (in situ synthesis). The radiolytic synthesis method is carried out by gamma irradiation at a cobalt (60Co) radiation facility. Synthesized samples were undergo to detailed physico-chemical characterization in order to obtain information about polymer matrix as a carrier and silver nanoparticles as a nanofillers, but also to examine their synergistic effects in the nanocomposite systems.Morphology of the crosslinked systems was performed by scanning electron microscopy (SEM) and micro computerized topography (micro-CT), while swelling study was performed by monitoring the swelling kinetics in the swelling media with different pH and temperature, i.e. in simulated physiological conditions. It has been shown that the addition of itaconic acid and incorporation of AgNPs have influences on the morphology, network parameters as well as on the swelling capacity.The optical properties of the nanocomposites were investigated by ultraviolet–visible spectroscopy (UV-Vis) and theoretical modeling using MiePlot 3.4 software package, with algorithm based on Mie's theory. Obtained absorption spectra exhibit the characteristic plasmon peak with maximabetween 390 nm and 412 nm, while the modeling has shown that the mean size of the silver nanoparticles was in the range between 6.8 nm and 16.2 nm...