嘧霉胺悬浮剂的润湿性能及其靶标表面性质研究

采用光学视频接触角测量仪对加入不同润湿分散剂(7227-A、SOPROPHOR FD和SC-4)的40%嘧霉胺悬浮剂的表面张力及其分量进行了测定,同时研究了作用靶标黄瓜和番茄叶片的表面自由能,以及药液在其上的润湿展布性能。结果显示:不同配方的嘧霉胺悬浮剂其表面张力在39~51 mN/m之间,且均以色散分量为主,其中加入SC-4的药剂表面张力最低(39~48 mN/m);黄瓜和番茄叶片的表面自由能均较小,在22 mJ/m2左右,不利于药液润湿,且以极性分量占主导;各配方药液的水稀释液在番茄叶面上的接触角在51~86°之间,在黄瓜叶面上的接触角在30~62°之间,药液在黄瓜叶面上更易附着,其中加入7227-A的药剂在黄瓜叶片上润湿性能最好,加入SOPROPHOR FD的药剂在番茄叶片上润湿性能最好;田间防治效果与药液的润湿性能呈正相关。表明嘧霉胺悬浮剂对靶标的润湿性能不仅与药液的表面张力有关,也与其分量有关,同时受到靶标表面性质的影响,通过研究药液对靶标润湿性能可分析评价其药效。

Study of wettability and target surface properties of pyrimethanil SC

The surface tension and its components,the surface free energy of cucumber and tomato leaves and the contact angle on cucumber and tomato leaves of pyrimethanil SC were measured by using optical contact angle measuring device.The results showed that the surface tension of different formula of pyrimethanil SC was around 39-51 mN/m,and the dominant component in surface tension was dispersion,the formula added SC-4 showed the lowest surface tension(39-48 mN/m);The surface free energy of cucumber and tomato leaves was about 22 mJ/m²,which was not conducive to liquid wetting,and the dominant component was polar force;The contact angle of different formula on tomato leaf ranged from 51° to 86°,and that on cucumber leaf ranged from 30° to 62°,suggesting that pyrimethanil SC was more easily adhered to cucumber leaf.The formula added 7227-A showed the best wettability on cucumber leaf,and the formula added SOPROPHOR FD showed the best wettability on tomato leaf;The results of field trial indicated that the liquid wetting properties were positively related to its field efficacy.The results showed that the wettability of pyrimethanil SC formula was not only related to surface tension,but also to its components,and was influenced by target surface properties,Using the wetting properties of the liquid on the target to analyze and evaluate its efficacy was feasible.