Structural characteristics and bonding environment of Ag nanoparticles synthesized by gamma irradiation within thermo‐responsive poly(N‐isopropylacrylamide) hydrogel

Abstract

To produce well‐defined metal clusters stabilized in protective matrix, poly(N‐isopropylacrylamide) (PNiPAAm) hydrogel with different initial concentration of polymer was used as nanoreactor. The in situ synthesis of well dispersed silver nanoparticles (AgNPs) was performed by gamma irradiation. The obtained AgNPs are spherical in shape with the diameter less than 20 nm. Crystalline properties of nanoparticles such as size, texture coefficient, strain, stress, lattice parameter, d‐spacing, and dislocation density have been calculated using XRD data. Results confirm that the changes of lattice parameter of crystalline AgNPs sensitively reflect their state of strain and stress depending on the formation conditions (i.e., on the concentration of PNiPAAm) and on the diameter of AgNPs. The negative lattice strain and compression stress were observed for the smaller AgNPs (lattice contraction), while for the larger AgNPs are positively strained and under tensile stress (lattice expansion). XPS spectra revealed the donor‐acceptor type of interaction between carbonyl oxygen from PNiPAAm and AgNPs (positive shift of high BE component of O 1s and negative shift of Ag 3d BE). The greater dislocation density of smaller AgNPs incorporated in more concentrated PNiPAAm, resulted in more binding sites and stronger interaction with polymer. POLYM. COMPOS., 38:1014–1026, 2017. © 2015 Society of Plastics Engineers

Intelligent Poly(N-Isopropylmethacrylamide) Hydrogels: Synthesis, Structure Characterization, Stimuli-Responsive Swelling Properties, and Their Radiation Decomposition

“…The p(NiPMAm) hydrogel sample with 1.5 mol% of EGDM, which was in gelatinous, paste-like state, was subjected to a γ-ray source, firstly with medium gamma-ray absorbed doses, based on analyzed literature [37][38][39].…”

“…N-isopropylacrylamide was successfully grafted onto chitosan via γ-radiation at a dose of 3-10 kGy [38]. The structural characteristics and bonding environment of Ag nanoparticles synthesized by gamma irradiation within thermo-responsive p(NiPAm) polymer composites were investigated [39]. A new superabsorbent hydrogel for diaper applications based on Tara gum and acrylic acid was synthesized by 14.5 kGy gamma irradiation in air at ambient temperature [40].…”

Green Synthesis of Silver Nanoparticles from Oxynema thaianum ALU PBC5 and their in vitro and in vivo Activity Against ESBL Producing MDR Escherichia coli and Klebsiella pneumoniae

“…These peaks signify face-centered cubic structures of silver and silver oxide (JCPDS 89-3722 and JCPDS 01-1164). The XRD pattern thus clearly confirmed that the biosynthesized AgNPs by O. thaianum ALU PBC5 were crystalline in nature [25].…”

A comprehensive review of the polymer‐based hydrogels with electrochemically synthesized silver nanoparticles for wound dressing applications

“…Most frequently applied methods in the literature are chemical reduction (with a strong reducing agent such as NaBH 4 ), 20 or γ-irradiation technique, which enables reduction of silver ions to Ag 0 with free radicals. 10,[21][22][23] Both of these methods have their advantages, but both also have their drawbacks. The chemical reduction method is attractive because it is relatively easy to perform, enables high yield of the synthesis and facilitates the control of AgNPs size and homogeneous distribution.…”