Evaluation of characterization and disinfection efficacy of chlorocresol nanoemulsion disinfectant

Abstract

The aim of this study is to evaluate the characterization and disinfection efficacy of chlorocresol nanoemulsion disinfectant (CND). The characterization of CND was examined by observing the appearance with the naked eye, identifying the structure type with dye tests and dilution tests, investigating the morphology with transmission electron microscopy, and measuring droplet size with a laser particle size analyzer. Conductivity, viscosity and pH values were separately measured and the stability was assessed by centrifugation tests and accelerated tests. The disinfection efficacy of CND was investigated with quantitative bactericidal tests of a bacteria suspension of E. coli 8099 and on-the-spot disinfection tests of the object surface. The results showed that the appearance of CND was transparent and no phase separation occurred after centrifuging, the structure type was an O/W nanoemulsion, the morphology was spherical droplets and the mean droplet size was 27.43 nm with normal distribution. The conductivity, viscosity and pH values were 479.67 μs cm⁻¹, 204.33 cp and 2.52, respectively. CND showed good stability and could be stored for 2 years. In addition, CND exhibited strong bactericidal activity increasing with the increase of the disinfectant concentrations and disinfection time. Moreover, the bactericidal ability of CND was stronger than that of chlorocresol aqueous solution (P < 0.01). In conclusion, the results suggested that CND was an effective novel nanoemulsion disinfectant.