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Abstract: This paper presents the evaluation of zinc and titanium nano-oxide silane/siloxane emulsions and their resistance to biofouling by algal colonisation. A culture streaming study was conducted to evaluate each treatment using mortar samples. Characterisation of the treatments included assessment of the porosity, surface roughness, sorptivity, hydrophobicity, treatment depth and visual alteration. The results showed that nanoparticulate incorporation did not adversely alter treatment penetration. Nanoparticulate treatments improved water repellence significantly while effectively conserving the morphology of the substrate. Treatments had negligible impact on visual aesthetics of the substrate making them ideal for future retrofit and heritage schemes. It was concluded that the reduced bioreceptivity observed primarily stemmed from the nanoparticulates ability to photocatalytically breakdown contaminants. [Copyright &y& Elsevier]

Silver nanoparticulate enhanced aqueous silane/siloxane emulsions and their efficacy against biofouling mechanisms are presented within this study. Different concentrations of silver nanoparticulates were added into viscous shear-thinning aqueous treatments and key attributes required for facade remedial applications assessed. Water repellence, biofouling resistance, and aesthetical alteration were studied to assess key treatment attributes. In addition, assessment of the porosity, sorptivity, and treatment depth was used to identify penetration and facade protection efficacy and morphological alteration of the masonry substrate. Results showed that silver nanoparticulate incorporation did not impede treatment penetration, better water repellent attributes were achieved with increased concentration while effectively conserving the morphology and aesthetics of the substrate. It was concluded that the reduced bioreceptivity observed primarily stemmed from the silver nanoparticulates ability to sanitise the surface, and that only small concentrations (<0.5%wt) were required to attain significantly beneficial improvements. Treatments were deemed practically and commercially viable for retrofit and heritage projects. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the evaluation of titanium dioxide and zinc oxide nano-particulate aqueous facade emulsions for water repellent and thermal insulation applications. Treated bricks were assessed by; thermal conductivity, water contact angle (WCA), water vapour permeation, water absorption and treatment depth measurements. In addition, a theoretical model was produced which was used to evaluate possible financial and energy saving potential of such treatments. Nano-particulate emulsions showed a 5% water beading improvement over the emulsion control. Thermal insulation of the treated samples improved significantly in wet conditions and was attributed to reduced water ingress. The titanium dioxide treatment showed approximately 45% lower sorptivity values compared to the emulsion control. Each emulsion achieved 13–14mm treatment penetration while still allowing water vapour permeation to occur. Theoretical modelling showed that all emulsions reduced energy consumption considerably allowing real financial savings to be made. Nano-particulate emulsions improved saving potential against the emulsion control by approximately 32%. [Copyright &y& Elsevier]