Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA.
Langmuir. 2013 Feb 26;29(8):2588-94. doi: 10.1021/la400032u. Epub 2013 Feb 13.
We explore the role of polymer chains on deposition of colloidal particles at solid surfaces from drying aqueous drops and show that the kinetics of phase separation of colloids and polymers can be explained by spinodal decomposition of binary systems. Concentrations of polymer solutions and polymer chain lengths were varied to understand the aggregation dynamics of colloidal particles via a polymer bridging mechanism. We show that when polymer concentration in the droplet is increased, particles spatially order upon drying due to a combination of the phase separation of highly bridged particles and the Marangoni flow effect. The demonstrated effect of particle-adsorbing, water-soluble polymers on the coffee-ring formation opens up new ways of creating highly ordered, long-range patterned surfaces using a facile, template-free approach.
我们探讨了聚合物链在从含水液滴中干燥时胶体颗粒在固体表面上沉积的作用，并表明胶体和聚合物的相分离动力学可以用二元系统的旋节分解来解释。通过聚合物桥接机制，我们改变聚合物溶液的浓度和聚合物链长度来理解胶体颗粒的聚集动力学。我们表明，当液滴中的聚合物浓度增加时，由于高度桥接颗粒的相分离和马兰戈尼流效应的结合，颗粒在干燥时会发生空间有序排列。所展示的具有吸附粒子作用的水溶性聚合物对咖啡环形成的影响为使用简单、无模板的方法来制造高度有序、长程图案化表面开辟了新途径。
