Antibacterial Activity of Silver‐Loaded “Green Zeolites”

Abstract

Green Zeolites" were prepared, without the use of organic structure-directing agents (OSDAs), by the seed-assisted method and were loaded with silver by a simple ion-exchange procedure. The silver-loaded zeolites were characterized by XRD, transmission electron microscopy and inductively coupled plasma atomic emission spectroscopy, which reveals that the ion-exchange procedure does not affect the structure of the zeolites and the presence of silver cations inside the aluminosilicate matrix. Two types of zeolites pres-[a]

Desenvolvimento e caracterização de filmes compósitos de quitosana e zeólitas com prata

“…Em função do pequeno raio iônico da prata, durante a lavagem houve troca iônica, por isso a quantidade de prata é quatro vezes maior do que a quantidade estequiométrica supostamente necessária para a troca de todo o sódio da zeólita, justificando o alto teor obtido pela análise de TXRF. A semelhança entre os diagramas das zeólitas de partida e as modificadas após o processo de troca com prata ou impregnação revela que estes processos não promovem qualquer modificação estrutural na zeólita [7,9,[17][18][19][20] . Não foram encontrados os picos característicos da prata metálica em 2θ = 38,21°, 44,51°, 64,51° e 77,51°.…”

“…Esse resultado indica uma boa troca iônica na amostra AgY-TI e que durante a calcinação não houve formação de aglomerados de Ag 2 O. Já na amostra impregnada, o baixo teor de prata e a alta dispersão dos critalitos explica sua não identificação. Inúmeros autores incorporaram diversos teores de prata na estrutura zeolítica por diversas metodologias diferentes e muitos deles também não verificaram a presença de cristais de prata em seus diagramas [7][8][9]19,[21][22][23] .…”

CO 2 adsorption–desorption properties of zeolite beta prepared from OSDA-free synthesis

“…Moreover, they have discovered that OSDA-free beta possessed high Al content in the *BEA framework (Si/Al <7) with a greater degree of well-defined microstructural features (crystallinity, micropore volume and morphology) as compared with conventional beta synthesized using OSDAs [12,13,31]. Since the reporting of OSDA-free synthesis, several important results have been published, in which OSDA-free beta showed enhanced performance in antibacterial [32], N 2 O decomposition [33], benzene alkylation [34], hexane cracking [23], selective catalytic reduction (SCR) of NO x [35] and NO sorption [36] applications when compared with conventional beta and other common zeolites.…”

Characterization and antibacterial activity of silver exchanged regenerated NaY zeolite from surfactant-modified NaY zeolite

“…01-087-0717 [50] were not observed, indicated that the silver ions were loaded onto the regenerated NaY zeolite via ion exchange reactions without the reduction of the silver species [51]. As the experiments were carried out in the absence of light, the reduction of silver ions into metallic silver was prohibited.…”

“…The concentrations of silver ions used in this study were low; thus, the silver ions were preserved and attached onto the regenerated AgY zeolite as Ag + . A high concentration of silver ions in ion exchange reactions tend to produce weakly bound silver ions on the zeolite surfaces, which are easily reduced to metallic silver when exposed to light [51].…”