陆军, 金天澍, 张红涛. 溴氰菊酯乳油液滴在蕹菜叶面的叠加凝并行为研究[J]. 农药学学报, 2019, 21(4): 514-522. DOI: 10.16801/j.issn.1008-7303.2019.0069
    引用本文: 陆军, 金天澍, 张红涛. 溴氰菊酯乳油液滴在蕹菜叶面的叠加凝并行为研究[J]. 农药学学报, 2019, 21(4): 514-522. DOI: 10.16801/j.issn.1008-7303.2019.0069
    LU Jun, JIN Tianshu, ZHANG Hongtao. Deltamethrin emulsifiable concentrates droplets superposition and coagulation behavior on water spinach leaf surface[J]. Chinese Journal of Pesticide Science, 2019, 21(4): 514-522. DOI: 10.16801/j.issn.1008-7303.2019.0069
    Citation: LU Jun, JIN Tianshu, ZHANG Hongtao. Deltamethrin emulsifiable concentrates droplets superposition and coagulation behavior on water spinach leaf surface[J]. Chinese Journal of Pesticide Science, 2019, 21(4): 514-522. DOI: 10.16801/j.issn.1008-7303.2019.0069

    溴氰菊酯乳油液滴在蕹菜叶面的叠加凝并行为研究

    Deltamethrin emulsifiable concentrates droplets superposition and coagulation behavior on water spinach leaf surface

    • 摘要: 为了探究溴氰菊酯乳油液滴在蕹菜Ipomoea aquatica Forsk叶片表面的叠加凝并行为及其动态接触角变化规律,采用纤维细度分析仪和光学接触角测量仪,观测蕹菜各分割部分的叶面形貌特征,测定了25 mg/L溴氰菊酯乳油的表面张力、液滴叠加凝并前后动态接触角及铺展直径等润湿参数,并依据幂次法则对液滴叠加铺展驱动力成因进行分析。结果显示:25 mg/L溴氰菊酯乳油的表面张力为29.02 mN/m;当垂直方向碰撞速率为0.082 6 m/s时,蕹菜叶面5 μL等体积液滴会以2种方式发生叠加凝并,即滚入底部吸入凝并和直接顶部吸入凝并,两种方式从叠加开始至凝并形成新液滴的时间分别为0.035 2 s和0.025 1 s;前者凝并成新液滴后接触角减小12.9%,而后者的接触角均有不同程度的增加,最大增幅达27.4%;两种方式叠加凝并形成新液滴的铺展直径随时间的变化分别呈线性关系和符合幂函数关系 (幂值α < 0.1),据此推测前者(滚入底部吸入凝并方式)是完全由表面张力梯度导致的超铺展行为,后者(直接顶部吸入凝并方式)是由动态表面张力主导驱动的铺展行为,前者药液在蕹菜叶片表面的铺展效果优于后者。

       

      Abstract: In order to investigate the superposition behavior of 25 mg/L emulsion deltamethrin emulsifiable concentrates droplets on the surface of water spinach (Ipomoea aquatica Forsk) leaves and the change of dynamic contact angle, fiber fineness analyzer and optical contact angle measuring instrument ware used to observe the leaf surface morphology of water spinach and measure the surface tension of deltamethrin emulsifiable concentrates droplets, dynamic contact angle, spreading diameter and other wetting parameters. According to the power law, the causes of droplets superposition spreading driving force were analyzed. The result showed that the surface tension of deltamethrin emulsifiable concentrates was 29.02 mN/m. There were two kinds of different behavior happen in the overlying process of the same volume (5 μL) droplets on water spinach leaves surface. The former behavior was to roll into the bottom and the latter behavior was to inhale directly at the top. The time for the superposition to condense and form a new droplet were 0.035 2 s and 0.025 1 s, respectively. The former condensed into a new droplet and the contact angle decreased by 12.9%. As for the latter, the contact angles all increased and the maximum increase rate was 27.4%. The spreading diameters of the new droplets formed by the two superposition methods showed linear relationship with time and in accordance with the power function relationship (power α < 0.1). Those results demonstrated that the former was a super spreading behavior caused by the surface tension gradient, and the latter was the spreading behavior driven by the dynamic surface tension. And the former was superior to the latter in terms of spreading effect.

       

    /

    返回文章
    返回