Plant Protection Chemistry NZ Ltd, Rotorua, New Zealand.
Pest Manag Sci. 2011 Dec;67(12):1562-70. doi: 10.1002/ps.2213. Epub 2011 Jun 16.
Spray droplet adhesion is dependent not only on formulation and droplet parameters but also on the surface properties (physical and chemical) of the leaf. Quantifying these leaf surface properties would aid understanding and modelling of adhesion, helping to optimise spray formulations. Fractal dimensions (FDs) were used to quantify the relative leaf surface roughness of ten plant species. Static droplet contact angles were measured on each leaf surface, and wetting tension was calculated. Chemical profiles of the leaf surfaces were developed by evaluating contact angle behaviour relative to solution dielectric constants.
The FDs of Cryo-SEM micrographs taken at 300× magnification gave the best correlation with adhesion. The wetting tension intercept had a strong relationship with mean adhesion, and successfully accounted for the wettability of the outlier species.
The microroughness of the leaf surface, as revealed by Cryo-SEM, can be quantified by fractal dimension analysis. However, the wetting tension intercept is a more useful universal measure of the surface properties of the leaf (including roughness) as they pertain to adhesion. The slope of the wetting tension versus dielectric constant plot allowed preliminary quantification of the chemical contribution of leaf surface dielectric behaviour to adhesion.
喷雾液滴的附着不仅取决于配方和液滴参数，还取决于叶片的表面特性（物理和化学）。量化这些叶片表面特性将有助于理解和模拟附着，有助于优化喷雾配方。分形维数（FD）用于量化十种植物叶片的相对表面粗糙度。在每个叶片表面测量静态液滴接触角，并计算润湿张力。通过评估接触角行为相对于溶液介电常数来开发叶片表面的化学轮廓。
在 300×放大倍率下拍摄的 Cryo-SEM 显微照片的 FD 与附着性相关性最好。润湿张力截距与平均附着性有很强的关系，并成功解释了异常种的润湿性。
Cryo-SEM 揭示的叶片表面微观粗糙度可以通过分形维数分析来量化。然而，润湿张力截距是叶片表面特性（包括粗糙度）对附着性的更有用的通用度量。润湿张力与介电常数关系图的斜率允许初步量化叶片表面介电行为对附着性的化学贡献。
