Drying of colloidal droplets often develops versatile depositions.We study the drying deposition of both colloidal droplets containing silica nanoparticles and the silica colloidal droplets with polyethylene oxide(PEO...Drying of colloidal droplets often develops versatile depositions.We study the drying deposition of both colloidal droplets containing silica nanoparticles and the silica colloidal droplets with polyethylene oxide(PEO) additives.We focus on the effect of polymer additives on the deposition formation and the cracking dynamics by using in-situ microscope observation.With PEO additives,a transition from ring-like deposition to uniform deposition is observed,and the cracking dynamics is greatly reduced.The PEO additives enhance the adsorption of particles at the air-water interface,thus forming the network structure at the interface which blocks the outward capillary flow.This contributes to the uniform deposition.Meanwhile,the multi-distribution of the aggregates size enhances the non-homogeneity of the drying film and consequently results in multi-nucleation of cracks.This reduces the stress accumulation that drives the crack propagation and may be responsible for the sluggish cracking dynamics.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.51103117)Shaanxi Provincial Natural Science Foundation (Grant No.2012JQ1016)+2 种基金NPU Foundation for Fundamental Research (Grant Nos.JCY20130147 and JC201125)Specialized Research Fund for the Doctoral Program of Higher Education (Grant No.20126102120058)the Research Fund of the State Key Laboratory of Solidification Processing in NWPU (Grant No.SKLSP201217)
文摘Drying of colloidal droplets often develops versatile depositions.We study the drying deposition of both colloidal droplets containing silica nanoparticles and the silica colloidal droplets with polyethylene oxide(PEO) additives.We focus on the effect of polymer additives on the deposition formation and the cracking dynamics by using in-situ microscope observation.With PEO additives,a transition from ring-like deposition to uniform deposition is observed,and the cracking dynamics is greatly reduced.The PEO additives enhance the adsorption of particles at the air-water interface,thus forming the network structure at the interface which blocks the outward capillary flow.This contributes to the uniform deposition.Meanwhile,the multi-distribution of the aggregates size enhances the non-homogeneity of the drying film and consequently results in multi-nucleation of cracks.This reduces the stress accumulation that drives the crack propagation and may be responsible for the sluggish cracking dynamics.
