Zinc oxide (ZnO) nanomaterials are used in various health-related applications, from antimicrobial textiles to wound dressing composites and from sunscreens to antimicrobial packaging. Purity, surface defects, size, and morphology of the nanoparticles are the main factors that influence the antimicrobial properties. In this study, we are comparing the properties of the ZnO nanoparticles obtained by solvolysis using a series of alcohols: primary from methanol to 1-hexanol, secondary (2-propanol and 2-butanol), and tertiary (tert-butanol). While the synthesis of ZnO nanoparticles is successfully accomplished in all primary alcohols, the use of secondary or tertiary alcohols does not lead to ZnO as final product, underlining the importance of the used solvent. The shape of the obtained nanoparticles depends on the alcohol used, from quasi-spherical to rods, and consequently, different properties are reported, including photocatalytic and antimicrobial activities. In the photocatalytic study, the ZnO obtained in 1-butanol exhibited the best performance against methylene blue (MB) dye solution, attaining a degradation efficiency of 98.24%. The comparative study among a series of usual model dyes revealed that triarylmethane dyes are less susceptible to photo-degradation. The obtained ZnO nanoparticles present a strong antimicrobial activity on a broad range of microorganisms (bacterial and fungal strains), the size and shape being the important factors. This permits further tailoring for use in medical applications.

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Influence of the Alcohols on the ZnO Synthesis and Its Properties: The Photocatalytic and Antimicrobial Activities

Abstract Screen-printing and spray-coating methods were used to produce photoluminescent, water-repellent, and antimicrobial films on textile fibers. The cotton fabrics were firstly finished with a flame-resistant agent. There are a number of functional agents that have been applied during the textile finishing process, including strontium aluminate pigment as antibacterial and photoluminescent agent, flame-retardant organophosphate, and water-repellent silicone rubber. The current research investigated the surface morphologies and chemical compositions of the screen-printed and spray-coated fabric cottons using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), wavelength dispersive X-ray fluorescence (WDXRF), and Fourier-transform infrared spectroscopy (FT-IR). According to morphological analysis, the phosphor nanoparticles had sizes ranging from 2 to 12 nm. After excitation at 399 nm, the generated colorless photoluminescent layer deposited onto cotton surface showed an emission profile at 516 nm. The luminescence spectra and CIE Lab characteristics confirmed that the phosphor-coated textiles displayed a white color in visible spectrum and green emission in the presence of UV light. It has been shown by analysis that the tested colors are very stable over time. The measurements of static water contact and sliding angles were also explored. The self-extinguishing activity of the coated fabrics retained their flame-retardant properties over 24 laundry cycles. Antimicrobial activity, hydrophobicity, and luminous properties were improved without affecting the intrinsic physical and mechanical features of the treated textiles. Details on the CIE Lab colorimetric measurements were discussed. The stiffness and air permeability were examined to explore the flexibility and breathability of the treated textile fibers. Excellent reversibility and photostability were seen in the phosphor-coated materials. 

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Imparting cotton textiles glow-in-the-dark property along with other functional properties: photochromism, flame-retardant, water-repellency, and antimicrobial activity

In this paper, we report the synthesis of ZnO nanoparticles (NPs) by forced solvolysis of Zn(CH3COO)2·2H2O in alcohols with a different number of –OH groups. We study the influence of alcohol type (n-butanol, ethylene glycol and glycerin) on the size, morphology, and properties of the obtained ZnO NPs. The smallest polyhedral ZnO NPs (<30 nm) were obtained in n-butanol, while in ethylene glycol the NPs measured on average 44 nm and were rounded. Polycrystalline particles of 120 nm were obtained in glycerin only after water refluxing. In addition, here, we report the photocatalytic activity, against a dye mixture, of three model pollutants: methyl orange (MO), methylene blue (MB), and rhodamine B (RhB), a model closer to real situations where water is polluted with many chemicals. All samples exhibited good photocatalytic activity against the dye mixture, with degradation efficiency reaching 99.99%. The sample with smallest nanoparticles maintained a high efficiency >90%, over five catalytic cycles. Antibacterial tests were conducted against Gram-negative strains Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, and Escherichia coli, and Gram-positive strains Enterococcus faecalis, Bacillus subtilis, Staphylococcus aureus, and Bacillus cereus. The ZnO samples presented strong inhibition of planktonic growth for all tested strains, indicating that they can be used for antibacterial applications, such as water purification.

/pdf/antibacterial-activity-of-solvothermal-obtained-zno-1vm100z5.pdf

Antibacterial Activity of Solvothermal Obtained ZnO Nanoparticles with Different Morphology and Photocatalytic Activity against a Dye Mixture: Methylene Blue, Rhodamine B and Methyl Orange

Md. Faisal Hossain

Papers

UV-blocking cotton fabric design for comfortable summer wears: factors, durability and nanomaterials