Stratification during evaporative assembly of multicomponent nanoparticle films
Stratification during evaporative assembly of multicomponent nanoparticle films
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DOI：
10.1016/j.jcis.2018.01.005
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发表时间：
2018-04-01
影响因子：
9.9
通讯作者：
Bhatia, Surita R.
中科院分区：
文献类型：
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作者：
Liu, Xiao;Liu, Weiping;Bhatia, Surita R.
假设：具有不同功能层的多组分涂层对各种应用都很感兴趣，包括电子设备，能量存储和生物材料。而不是使用多个沉积步骤来创建这样的薄膜，我们探索一种单步方法，通过改变粒子佩莱特数，Pe来创建这样的薄膜。基于最近对分层过程的理论描述，我们的假设是，通过改变颗粒大小和蒸发速率，使Pe的大小颗粒高于或低于1，我们可以创建聚合物和无机颗粒的分层膜。实验：我们展示了由聚苯乙烯纳米颗粒（直径25-90 nm）和二氧化硅纳米颗粒（直径8-14 nm）组成的薄膜表面组成的原子力显微镜。先前对含有无机和聚合物颗粒的薄膜的研究对应于较大的Pe值（例如，120-460），而我们使用类似于0.3-4的Pe，使我们能够测试针对不同Pe体系开发的理论。研究结果：我们证明了分层和Pe比率影响的证据，尽管我们的结果仅与理论定性一致。我们的研究结果也验证了最近对薄膜干燥过程的理论描述，这些理论描述预测了大顶部和小顶部分层的不同制度。(C) 2018爱思唯尔公司版权所有。
Hypothesis: Multicomponent coatings with layers comprising different functionalities are of interest for a variety of applications, including electronic devices, energy storage, and biomaterials. Rather than creating such a film using multiple deposition steps, we explore a single-step method to create such films by varying the particle Peclet numbers, Pe. Our hypothesis, based on recent theoretical descriptions of the stratification process, is that by varying particle size and evaporation rate such that Pe of large and small particles are above and below unity, we can create stratified films of polymeric and inorganic particles.Experiments: We present AFM on the surface composition of films comprising poly(styrene) nanoparticles (diameter 25-90 nm) and silica nanoparticles (diameter 8-14 nm). Previous studies on films containing both inorganic and polymeric particles correspond to large Pe values (e.g., 120-460), while we utilize Pe similar to 0.3-4, enabling us to test theories that have been developed for different regimes of Pe.Findings: We demonstrate evidence of stratification and effect of the Pe ratio, although our results agree only qualitatively with theory. Our results also provide validation of recent theoretical descriptions of the film drying process that predict different regimes for large-on-top and small-on-top stratification. (C) 2018 Elsevier Inc. All rights reserved.