摘要:
In this research,the wetting behavior of nonionic surfactant Triton X-100 on wheat leaf sunfaces at different developmental stages has been investigated based on the surface free energy,contact angle,adhesion tension,and liquid-solid interfacial tension.The results show that the contact angle remains constant with low adsorption at the liquid-air (ΓLv) and liquid-solid (Γ'SL) interfaces at low concentration,and the wetting state is in the Cassie-Baxter state.On increasing the concentration,the contact angle decreases sharply and the ratio of Γ'SL/FLv becomes more than 1.Meanwhile,the droplet overcomes the pinning effect to displace the air among three-dimensional wax layers and is in the Wenzel state.When the concentration becomes over critical micelle concentration (CMC),a saturated adsorption film forms at the interfaces,and the hemiwicking process occurs among microano structures because of the capillary effect,then the contact angle remains constant.%选择不同生长期小麦叶片,利用座滴法研究了非离子表面活性剂Triton X-1 00在小麦叶片表面接触角,考察浓度对接触角、粘附张力、固-液界面张力及润湿状态的影响.研究表明,在低浓度下,表面活性剂分子在气-液界面吸附量(ΓLV)和固-液界面吸附量(Γ'SL)相似,但吸附量较少形成了不饱和吸附层,接触角保持不变,其润湿状态为Cassie-Baxter状态;当浓度进一步增加,液滴突破叶片表面三维立体结构中存在的钉扎效应,取代空气层而处于Wenzel状态,接触角陡降,同时Γ'SL/ΓLV远大于1;当浓度超过临界胶束浓度(CMC)时,表面活性剂分子在气-液界面和固-液界面形成饱和吸附层,并产生毛细管效应,使溶液在小麦叶片三维立体结构中产生半渗透过程,此时接触角保持不变.