Synthesis and bactericide activity of nanofiltration composite membranes – Cellulose acetate/silver nanoparticles and cellulose acetate/silver ion exchanged zeolites

Beisl, Stefan; Monteiro, Sílvia; Santos, Ricardo; Figueiredo, Ana Sofia; Sánchez-Loredo, María Guadalupe; Lemos, M.A.N.D.A.; Lemos, F.; Minhalma, Miguel; Pinho, Maria Norberta de

doi:10.1016/j.watres.2018.10.096

Cited by 70 publications

(36 citation statements)

References 29 publications

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“…Approximately 50-75% of Ag 0 in AgNPs was oxidized to Ag(I) as indicated by the XPS analysis ( Table 2). Both of the Ag oxidation states can, however, provide antimicrobial properties for filters 42,43 . Table 2.…”

Section: Modification Of Filters With Ag or Cu Both The Filter Prepamentioning

confidence: 99%

Ag- or Cu-modified geopolymer filters for water treatment manufactured by 3D printing, direct foaming, or granulation

Luukkonen

Sreenivasan

Ohenoja

et al. 2020

Sci Rep

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In this work, we compared the main characteristics of highly porous geopolymer components for water treatment applications manufactured by 3D printing, direct foaming, or granulation. Furthermore, different approaches to impregnate the materials with Ag or Cu were evaluated to obtain filters with disinfecting or catalytic properties. The results revealed that all of the investigated manufacturing methods enabled the fabrication of components that possessed mesoporosity, suitable mechanical strength, and water permeability, even though their morphologies were completely different. Total porosity and compressive strength values were 28 vol% and 16 MPa for 3D-printed, 70-79 vol% and 1 MPa for direct-foamed, and 27 vol% and 10 MPa for granule samples. Both the filter preparation and the metal impregnation method affected the amount, oxidation state, and stability of Ag and Cu in the filters. However, it was possible to prepare filters with low metal leaching between a pH of 3-7, so that the released Ag and Cu concentrations were within drinking water standards. Cellular ceramics have a high potential in water treatment applications, such as Ag impregnated point-of-use disinfecting filters 1 , slurry dewatering systems 2 , catalyst supports 3 , and micro-or ultrafiltration membranes 4. However, although ceramic materials have good chemical and physical stability, their higher price in comparison to organic polymers has hindered more widespread use in industrial water treatment 5,6. Geopolymers, on the other hand, are amorphous, low-calcium, aluminosilicate, ceramic-like materials with structural mesoporosity (i.e., pore diameter 2-50 nm) 7 ; good mechanical and chemical stability 8 ; and cation-exchange capacity 9. However, in contrast to conventional ceramics, geopolymers consolidate at (near) ambient conditions without high-temperature sintering. Consequently, geopolymer technology could offer a possibility for clean and low-cost production of ceramic-like filters, possessing better chemical stability, and a longer lifespan than polymeric components. In the context of water and wastewater treatment, geopolymers have already been investigated for a number of applications, such as adsorbents/ion exchangers, photocatalysts, and membranes, as summarized by Luukkonen et al. 10. Some of the outlined uses require modification of the geopolymers with metals. The proof-of-concept study for the use of geopolymers as antimicrobial materials was performed by O'Connor et al., who prepared an Ag +-exchanged, halloysite-based geopolymer and applied it successfully to inactivate Staphylococcus aureus on an agar plate 11. Metakaolin or fly ash geopolymers have also been modified with Ag-nanoparticles (AgNPs), and the resulting antimicrobial materials have been proposed to be used in construction 12,13. Furthermore, Cu 2+-exchanged metakaolin geopolymers have proved to be a promising antimicrobial material to be used against oyster mushroom hyphae 14. In (photo)catalytic water treatment applications, the successful impregnation of ca...

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Section: Modification Of Filters With Ag or Cu Both The Filter Prepamentioning

confidence: 99%

Ag- or Cu-modified geopolymer filters for water treatment manufactured by 3D printing, direct foaming, or granulation

Luukkonen

Sreenivasan

Ohenoja

et al. 2020

Sci Rep

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“…Technical and medicinal textiles, pharmaceutical drug coatings, microparticles for controlled drug release, sensors (immune-, chemical-, biochemical- and photosensors) and polymer membranes are some examples of engineered CA products in the market [ 6 ]. Regarding polymer membranes for industrial separation-processes, CA membranes have played an important role in drinking and wastewater treatment [ 7 ], gas separation [ 8 ], blood purification [ 9 , 10 ], ultra/nanofiltration and various other bio-separation processes [ 11 , 12 ], due to their high efficacy and cost effectiveness [ 13 ]. However, extreme operating conditions, such as high temperatures and/or low pH values, may promote the hydrolysis of the CA polymer, compromising the chemical, mechanical and thermal stability of the CA membranes.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Novel Integral Asymmetric Monophasic Cellulose–Acetate/Silica/Titania and Cellulose–Acetate/Titania Membranes

2020

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Two series of novel integral asymmetric monophasic hybrid membranes, cellulose acetate/silica/titania (CA/SiO2/TiO2—series 1) and cellulose acetate/titania (CA/TiO2—series 2), were developed by the coupling of sol-gel technology and a modified version of the phase inversion technique. SEM micrographs confirmed the integral asymmetric structure of all membranes. ATR-FTIR and ICP-OES results showed that, for the membranes in series 1, TiO2 is covalently bound to SiO2, which, in turn, is covalently bound to CA, while for the membranes in series 2, TiO2 is directly and covalently bound to the CA matrix. Permeation experiments revealed that the permeation performance of the membranes in series 1 is unaffected by the introduction of TiO2. In contrast, the introduction of TiO2 in the series 2 membranes increased the hydraulic permeability by a factor of at least 2 when compared to the pristine CA membrane and that incremental additions of TiO2 further increased the Lp.

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“…Moreover, it has been reported that NPs conjugated with antibiotics show synergistic effects against bacteria [5,8]. Therefore, metallic NPs could offer an effective solution for infection control by incorporating them on the contact surfaces of medical devices, textiles, food packages, and membrane filters employed in water treatment [5,9,10], or by being applied topically to treat skin and wound infections [11].…”

Section: Introductionmentioning

confidence: 99%

Metallic Nanoparticles—Friends or Foes in the Battle against Antibiotic-Resistant Bacteria?

et al. 2021

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The rapid spread of antibiotic resistances among bacteria demands novel strategies for infection control, and metallic nanoparticles appear as promising tools because of their unique size and tunable properties that allow their antibacterial effects to be maximized. Furthermore, their diverse mechanisms of action towards multiple cell components have suggested that bacteria could not easily develop resistance against nanoparticles. However, research published over the last decade has proven that bacteria can indeed evolve stable resistance mechanisms upon continuous exposure to metallic nanoparticles. In this review, we summarize the currently known individual and collective strategies employed by bacteria to cope with metallic nanoparticles. Importantly, we also discuss the adverse side effects that bacterial exposure to nanoparticles may have on antibiotic resistance dissemination and that might constitute a challenge for the implementation of nanoparticles as antibacterial agents. Overall, studies discussed in this review point out that careful management of these very promising antimicrobials is necessary to preserve their efficacy for infection control.

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Synthesis and bactericide activity of nanofiltration composite membranes – Cellulose acetate/silver nanoparticles and cellulose acetate/silver ion exchanged zeolites

Cited by 70 publications

References 29 publications

Ag- or Cu-modified geopolymer filters for water treatment manufactured by 3D printing, direct foaming, or granulation

Ag- or Cu-modified geopolymer filters for water treatment manufactured by 3D printing, direct foaming, or granulation

Synthesis and Characterization of Novel Integral Asymmetric Monophasic Cellulose–Acetate/Silica/Titania and Cellulose–Acetate/Titania Membranes

Metallic Nanoparticles—Friends or Foes in the Battle against Antibiotic-Resistant Bacteria?

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