Laboratory of Plastics and Rubber Technology, Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, P.O. Box 91, H-1521 Budapest, Hungary.
Nanoscale. 2012 Mar 21;4(6):1919-38. doi: 10.1039/c2nr11442a. Epub 2012 Feb 20.
This feature article discusses the main factors determining the properties of polymer nanocomposites with special attention paid to structure and interactions. Usually more complicated structure develops in nanocomposites than in traditional particulate filled polymers, and that is especially valid for composites prepared from plate-like nanofillers. Besides the usually assumed exfoliated/intercalated morphology, i.e. individual platelets and tactoids, such nanocomposites often contain large particles, and a network structure developing at large extent of exfoliation. Aggregation and orientation are the most important structural phenomena in nanotube or nanofiber reinforced composites, and ag-gregation is a major problem also in composites prepared with spherical particles. The surface characteristics of nanofillers and interactions are rarely determined or known; the related problems are discussed in the paper in detail. The surface of these reinforcements is modified practically always. The goal of the modification is to improve dispersion and/or adhesion in nanotube and spherical particle reinforced composites, and to help exfoliation in nanocomposites containing platelets. However, modification decreases surface energy often leading to decreased interaction with the matrix. Very limited information exists about interphase formation and the properties of the interphase in nanocomposites, although they must influence properties considerably. The properties of nanocomposites are usually far from the expectations, the main reason being insufficient homogeneity, undefined structure and improper adhesion. In spite of considerable difficulties nanocomposites have great potentials especially in functional applications. Several nanocomposite products are already used in industrial practice demonstrated by a few examples in the article.
这篇专题文章讨论了决定聚合物纳米复合材料性能的主要因素，特别关注结构和相互作用。通常，纳米复合材料的结构比传统的颗粒填充聚合物更为复杂，对于由片状纳米填料制备的复合材料尤其如此。除了通常假设的剥离/插层形态，即单个薄片和原纤，这种纳米复合材料通常还包含大颗粒和在很大程度上剥离时形成的网络结构。在纳米管或纳米纤维增强复合材料中，聚集和取向是最重要的结构现象，在使用球形颗粒制备的复合材料中，聚集也是一个主要问题。纳米填料的表面特性和相互作用很少被确定或了解；本文详细讨论了相关问题。这些增强剂的表面实际上总是被修饰的。修饰的目的是改善纳米管和球形颗粒增强复合材料中的分散性和/或附着力，并帮助含有薄片的纳米复合材料进行剥离。然而，修饰通常会降低表面能，从而导致与基体的相互作用减弱。关于纳米复合材料的相间形成和相间性质的信息非常有限，尽管它们必须对性能有很大的影响。纳米复合材料的性能通常远低于预期，主要原因是不均匀性、结构不明确和附着力不当。尽管存在相当大的困难，纳米复合材料仍具有很大的潜力，特别是在功能应用方面。本文通过几个例子说明了一些纳米复合材料产品已经在工业实践中得到应用。
