Linear and nonlinear viscoelasticity of water-in-oil emulsions: Effect of droplet elasticity
Linear and nonlinear viscoelasticity of water-in-oil emulsions: Effect of droplet elasticity
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DOI：
10.1016/j.colsurfa.2013.05.057
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发表时间：
2013-10
期刊：
影响因子：
--
通讯作者：
Ruiwen Shu;Weixiang Sun;Tao Wang;Chaoyang Wang;Xinxing Liu;Zhen Tong
中科院分区：
文献类型：
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作者：
Ruiwen Shu;Weixiang Sun;Tao Wang;Chaoyang Wang;Xinxing Liu;Zhen Tong
通过比较两种乳液（一种以纯水为液滴，另一种以锂皂石粘土悬浮液为液滴），研究了液滴弹性对油包水乳液线性和非线性粘弹性的影响。由于粘土悬浮液的凝胶化，粘土填充的乳液具有高的液滴弹性。随着水油体积比的增大，乳状液由类液态向类固态转变，液滴形成堵塞状态。液滴弹性的影响是最显着的堵塞状态，其中粘土填充的乳液表现出比无粘土的一个更高的平台模量。大振幅振荡剪切流变学观察到非线性粘弹性。Lissajous曲线被分解为笼屈服和笼重构部分，并且由于液滴弹性的贡献，填充粘土的乳液在非线性粘弹性区域中的笼模量G高于堵塞状态下的无粘土乳液。液滴的弹性被发现有助于乳液的非线性粘弹性。
The effect of droplet elasticity on the linear and nonlinear viscoelasticity of water-in-oil emulsions was studied by comparing two kinds of emulsions: one with pure water as droplets, the other with a suspension of hectorite clay as droplets. The clay-filled emulsion had high droplet elasticity due to the gelation of the clay suspension. As the water-to-oil volume ratio ϕ increased, the emulsions changed from liquid-like state to solid-like state as the droplets formed a jammed state. Effect of droplet elasticity was most significant in the jammed state, where the clay-filled emulsion showed a much higher plateau modulus than the clay-free one. Nonlinear viscoelasticity was observed by the large amplitude oscillatory shear (LAOS) rheology. The Lissajous curve was dissected into the cage-yielding and cage-restructuring parts, and the cage modulus Gkin the nonlinear viscoelastic regime was higher for clay-filled emulsion than the clay-free one in the jammed state due to the contribution of the droplet elasticity. The droplet elasticity was found to contribute to the nonlinear viscoelasticity of the emulsions.