Anti-microbial efficiency of nano silver–silica modified geopolymer mortar for eco-friendly green construction technology

Abstract

24A silver-silica nano composite based geopolymer mortar has been developed by 25 simple adsorption of silver in a suitable amount of colloidal silica suspension for anti-26 bacterial property development. The silver nanoparticles (3-7 nm) were attached on the 27 surface of 20-50 nm sized silica nanoparticle. The silver-silica nano-composite was 28 characterized by Transmission Electron Microscope (TEM), X-Ray Diffraction (XRD) and 29 Energy Dispersive X-ray Spectral analysis. Mechanical strength, durability and mechanistic 30 anti-bacterial activity of the silver-silica nano composite modified geopolymer mortar 31 (GM Ag-Si ) were investigated and compared to nano silica modified geopolymer mortar (GM Si ) 32 and control cement mortar (CM). To accesses the anti-microbial efficacy of the samples, 99% 33 mortality for the Gram positive and Gram negative bacteria were calculated. Minimum 34 Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values 35 were determined from batch culture. With the addition of 6% (w/w) of silver-silica nano 36 composite in the geopolymer mortar cured at ambient temperature shows substantial 37 improvement in mechanical strength, durability and anti-bacterial property. Reactive Oxygen 38 Species (ROS) generation and cell wall rapture as observed from fluorescence microscopy 39 and Field Emission Scanning Electron Microscopy (FESEM) may be possible reason behind 40 the anti-bacterial efficacy of silver-silica nano composite modified geopolymer mortar.41 42 43 44

Application of alkali-activated materials for water and wastewater treatment: a review

“…AAMs have many potential applications in water and wastewater treatment, including adsorbents/ion-exchangers, membranes and filtration media, photocatalysts, and solidification/stabilization of water and wastewater treatment residues. In addition, they can be used as antibacterial materials after the incorporation of copper (Hashimoto et al 2015) or silver (O'Connor et al 2010) through ion exchange or addition of nanoparticles (such as silver silica nanocomposites) into the aluminosilicate matrix of AAMs (Adak et al 2015). Although the aforementioned examples were intended as antimicrobial binders, there are numerous examples with similarly modified zeolites to indicate potential applicability for disinfection of wastewaters or groundwater (Akhigbe et al 2014;De la Rosa-Gómez et al 2008a, b;Dolic et al 2015;Mpenyana-Monyatsi et al 2012;Johari et al 2016).…”

A Review of Recent Developments and Advances in Eco-Friendly Geopolymer Concrete

“…In addition, the increase in alkali content from 35-45% of the total binder decreases the compressive strength of samples [53]. Likewise, the inclusion of nanoparticles enhances the compressive strength of geopolymer mortar at different curing age [136]. From Table 5, it is concluded that the strength development of FA-based GPC at ambient temperature enhanced due to the addition of external agents like superplasticizers or additives.…”

“…In addition, the increase in alkali content from 35-45% of the total binder decreases the compressive strength of samples [53]. Likewise, the inclusion of nanoparticles enhances the compressive strength of geopolymer mortar at different curing age [136].…”

Properties of Inorganic Polymers Based on Ground Waste Concrete Containing CuO and ZnO Nanoparticles

“…Hence, it is of great research interest to examine IPs composites with embedded -NPs as antimicrobial agents. The addition of nanosilver improved the mechanical strength, durability, and antibacterial properties of Ag-IPs composites [40][41][42]. Additionally, CuO and ZnO NPs can be included as reinforcement for IPs pastes [43,44] and also, generating antibacterial IPs surfaces [45,46].…”