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■Bio-mathematics, Statistics and Nano-Technologies: Mosquito Control Strategies

anti-mosquito finishing protects people from the bite of mosquitos and, consequently, en-

sure safety from the infectious diseases they commonly spread (Amiri and Rahimi 2016,

Raja, ASM; Kawlekar, Sujata; Saxena, Sujata; Arputharaj, A; Patil 2015). Recently, inves-

tigations have been conducted to improve the properties of textile fabrics by incorporating

various finishes into the sol-gel coating to give them many important properties, such as

wear resistance, flame retardancy, UV protection, controlled release of oil and flavour, an-

timicrobial properties, bio-catalytic properties and washing fastness of dyestuffs, showing

no cytotoxicity (Plutino et al. 2017), thus the sol-gel technique resulting potentially attrac-

tive to develop anti-mosquito fabrics.

For example, this technique was used to immobilize permethrin molecules into cotton

fabrics by a silicon oxide nanocoating applied by conventional padding followed by cur-

ing (Ardanuy et al. 2014). The effect of the process parameters, such as silica precursor

content and permethrin/silica precursor ratio, on the insect-repellent activity, textile prop-

erties and stability during washing was studied. This new method provided the possibility

of fine-tuning the amount of insecticide incorporated, maintaining the maximum dosage

of permethrin in clothing less than 500 mg/m², according to the recommendation by the

World Health Organization (WHO).

The paper confirmed that silica-based coating, under experimental conditions, did not

influence mechanical properties of treated fabrics, maintaining the fabric softness and the

wrinkle resistance close to the untreated textile. The final result showed high washing fast-

ness of anti-mosquito coatings: after 50 laundering cycles, permethrin-containing sol–gel

finishing provided a total mosquitos mortality in one day of exposition, suggesting an al-

ternative to well-established treatments for textiles.

Furthermore, the lavender oil distilled from Lavandula Angustifolia was used as a core

material in combination with chitosan as a shell obtained by sol gel-emulsion method

with starch as a template (Mulyani and Sunendar 2013). The obtained microcapsules,

prepared at room temperature, showed a nanosizing structure in a rod shape that pro-

poses the lavender-containing silica coating as a good candidate to develop anti-mosquito

textiles. Unfortunately, no results were reported concerning the repellent properties of

the so obtained textile samples. A more recent paper (Abdelhameed et al. 2017) inves-

tigated a titanium-bearing metal-organic framework (MOF) with the chemical formula

Ti8O8(OH)4(BDC-NH2)6, built up from octahedral titanium units connected via oxygen

atoms to the organic linker 2-aminoterephthalic acid. For that investigation, MOF was

immobilized onto the silica modified fabrics via covalent bonding. With this goal, the

authors used 3-glycidyloxypropyltrimethoxysilane, as a sol-gel precursor, to finish plant-

based fibres (100% cotton, linen) or regenerated cellulosic fibres (viscose). The composites

were tested in the control of the adult stage of mosquitos. At low MOF concentration, the

mosquito mortality depends on the type of modified fabrics (cotton > linen > viscose),

and on NH2-MIL-125 concentration on the samples, high MOF content leading to higher

killing efficacy. Modified textiles show good washing resistance, surviving more than five