Optimization of superhydrophilic coatings for enhanced aerosol sampling efficiency

Atmospheric aerosols contain various pathogenic microorganisms and allergens, which pose significant threats to public health and safety. Traditional wet-wall cyclone aerosol sampling methods are widely used for the sampling and enrichment of aerosol particles owing to their decent enrichment efficiency and good microbial survivability. However, due to the poor inherent wettability of the sampling cup material itself, incomplete coverage and easy rupture of the liquid film during sampling result in suboptimal enrichment, posing a challenge to improving the enrichment efficiency of wet-walled cyclone aerosol sampling. In this work, a robust and durable superhydrophilic coating of functionalized nanoparticles composite SBS adhesive (SC-SBS) was prepared and applied to the inner wall of the aerosol sampler. The coating facilitates the formation of a stable and uniform liquid film due to the interaction between the superhydrophilic surface and the two-phase centrifugal flow, minimizing wall losses and enhancing enrichment efficiency. Under flow rate gradients ranging from 100 to 300 L/min, the device achieved more than double the enrichment efficiency for non-biological aerosol particles of various sizes. For biological aerosol particles ( Bacillus subtilis ), the enrichment enhancement rates exceeded 300 %. This demonstrates its important application prospects in the fields of occupational health and air aerosol sampling.