Department of Chemistry, University of California, Irvine, CA, USA.
Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
Indoor Air. 2021 Nov;31(6):2070-2083. doi: 10.1111/ina.12854. Epub 2021 May 15.
Large surface area-to-volume ratios indoors cause heterogeneous interactions to be especially important. Semi-volatile organic compounds can deposit on impermeable indoor surfaces forming thin organic films. We developed a new model to simulate the initial film formation by treating gas-phase diffusion and turbulence through a surface boundary layer and multi-layer reversible adsorption on rough surfaces, as well as subsequent film growth by resolving bulk diffusion and chemical reactions in a film. The model was applied with consistent parameters to reproduce twenty-one sets of film formation measurements due to multi-layer adsorption of multiple phthalates onto different indoor-relevant surfaces, showing that the films should initially be patchy with the formation of pyramid-like structures on the surface. Sensitivity tests showed that highly turbulent conditions can lead to the film growing by more than a factor of two compared to low turbulence conditions. If surface films adopt an ultra-viscous state with bulk diffusion coefficients of less than 10 cm s , a significant decrease in film growth is expected. The presence of chemical reactions in the film has the potential to increase the rate of film growth by nearly a factor of two.
室内较大的表面积与体积比会导致非均相相互作用变得尤为重要。半挥发性有机化合物会沉积在不可渗透的室内表面上，形成薄的有机膜。我们开发了一种新的模型，通过在表面边界层中处理气相扩散和湍流，以及在粗糙表面上进行多层可逆吸附，同时解决薄膜中的体扩散和化学反应，来模拟初始薄膜形成。该模型应用一致的参数来再现二十一组由于多种邻苯二甲酸酯在不同室内相关表面上的多层吸附而导致的薄膜形成测量结果，表明薄膜最初应该是斑驳的，表面上形成金字塔状结构。敏感性测试表明，在高度湍流条件下，薄膜的生长速度比低湍流条件下快两倍以上。如果表面薄膜采用具有小于 10 厘米/秒的体扩散系数的超粘性状态，则预计薄膜生长会显著减少。薄膜中化学反应的存在有可能使薄膜生长速度提高近两倍。
