Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Antimicrobial, starch based barrier coatings prepared using mixed silver/sodium exchanged bentonite
https://orcid.org/0000-0002-9566-5739
Abstract The effect of silver nitrate concentration, pre-washed bentonite (to remove extraneous salt) and back-exchange procedures have been explored to assess the type of silver species formed and their behaviour upon exposure to further salts. X-ray fluorescence was used to quantify the amount of silver present and whether in cation exchange sites, whereas X-ray diffraction and transmission electron microscopy identified the silver compounds present. A further objective was to assess the antimicrobial, barrier and dispersion properties of the silver/sodium bentonites when incorporated into a starch-plasticiser-clay coating used for packaging. The silver/sodium bentonites demonstrated very strong antimicrobial activity towards Escherichia coli, Kocuria rhizophila and Aspergillus niger. Incorporating just 0.03 wt% of silver/sodium bentonite in the coating (0.2 μmol/m2 Ag in dried coating with thickness of 14 μm) produced a > 4.4 log reduction against an initial loading of 2.1 × 105 CFU/object for E. coli. Water vapour barrier properties of coatings prepared on paper and containing the mixed silver/sodium bentonite were unaffected since water vapour transmission rate values of ~20–40 g/m2.day (23°C, 50% relative humidity) were maintained. Also the presence of silver did not adversely affect the clay dispersion. The Ag+ release profile from mixed silver/sodium clay upon addition of HNO3 and NaNO3 is discussed.
Highlights Silver/sodium-exchanged clay preparation investigated. Silver/sodium-clay used in sustainable, starch-based antimicrobial barrier coatings. High antimicrobial efficacy against E. coli, K. rhizophila and A. niger is observed. Silver ion release mechanism is highly dependent on ions in surrounding medium.
Antimicrobial, starch based barrier coatings prepared using mixed silver/sodium exchanged bentonite
https://orcid.org/0000-0002-9566-5739
Abstract The effect of silver nitrate concentration, pre-washed bentonite (to remove extraneous salt) and back-exchange procedures have been explored to assess the type of silver species formed and their behaviour upon exposure to further salts. X-ray fluorescence was used to quantify the amount of silver present and whether in cation exchange sites, whereas X-ray diffraction and transmission electron microscopy identified the silver compounds present. A further objective was to assess the antimicrobial, barrier and dispersion properties of the silver/sodium bentonites when incorporated into a starch-plasticiser-clay coating used for packaging. The silver/sodium bentonites demonstrated very strong antimicrobial activity towards Escherichia coli, Kocuria rhizophila and Aspergillus niger. Incorporating just 0.03 wt% of silver/sodium bentonite in the coating (0.2 μmol/m2 Ag in dried coating with thickness of 14 μm) produced a > 4.4 log reduction against an initial loading of 2.1 × 105 CFU/object for E. coli. Water vapour barrier properties of coatings prepared on paper and containing the mixed silver/sodium bentonite were unaffected since water vapour transmission rate values of ~20–40 g/m2.day (23°C, 50% relative humidity) were maintained. Also the presence of silver did not adversely affect the clay dispersion. The Ag+ release profile from mixed silver/sodium clay upon addition of HNO3 and NaNO3 is discussed.
Highlights Silver/sodium-exchanged clay preparation investigated. Silver/sodium-clay used in sustainable, starch-based antimicrobial barrier coatings. High antimicrobial efficacy against E. coli, K. rhizophila and A. niger is observed. Silver ion release mechanism is highly dependent on ions in surrounding medium.
Antimicrobial, starch based barrier coatings prepared using mixed silver/sodium exchanged bentonite
https://orcid.org/0000-0002-9566-5739
Abstract The effect of silver nitrate concentration, pre-washed bentonite (to remove extraneous salt) and back-exchange procedures have been explored to assess the type of silver species formed and their behaviour upon exposure to further salts. X-ray fluorescence was used to quantify the amount of silver present and whether in cation exchange sites, whereas X-ray diffraction and transmission electron microscopy identified the silver compounds present. A further objective was to assess the antimicrobial, barrier and dispersion properties of the silver/sodium bentonites when incorporated into a starch-plasticiser-clay coating used for packaging. The silver/sodium bentonites demonstrated very strong antimicrobial activity towards Escherichia coli, Kocuria rhizophila and Aspergillus niger. Incorporating just 0.03 wt% of silver/sodium bentonite in the coating (0.2 μmol/m2 Ag in dried coating with thickness of 14 μm) produced a > 4.4 log reduction against an initial loading of 2.1 × 105 CFU/object for E. coli. Water vapour barrier properties of coatings prepared on paper and containing the mixed silver/sodium bentonite were unaffected since water vapour transmission rate values of ~20–40 g/m2.day (23°C, 50% relative humidity) were maintained. Also the presence of silver did not adversely affect the clay dispersion. The Ag+ release profile from mixed silver/sodium clay upon addition of HNO3 and NaNO3 is discussed.
Highlights Silver/sodium-exchanged clay preparation investigated. Silver/sodium-clay used in sustainable, starch-based antimicrobial barrier coatings. High antimicrobial efficacy against E. coli, K. rhizophila and A. niger is observed. Silver ion release mechanism is highly dependent on ions in surrounding medium.
Antimicrobial, starch based barrier coatings prepared using mixed silver/sodium exchanged bentonite
Clegg, Francis (Autor:in) / Breen, Chris (Autor:in) / Muranyi, Peter (Autor:in) / Schönweitz, Claudia (Autor:in)
Applied Clay Science ; 179
22.05.2019
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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