Senses Erkan, Tyagi Madhusudan, Pasco Madeleine, Faraone Antonio
NIST Center for Neutron Research, National Institute of Standards and Technology , Gaithersburg , Maryland 20899-8562 United States.
Department of Materials Science and Engineering , University of Maryland , College Park , Maryland 20742-2115 , United States.
ACS Nano. 2018 Nov 27;12(11):10807-10816. doi: 10.1021/acsnano.8b02514. Epub 2018 Oct 11.
We present nanocomposite materials formed by using glassy star-shaped polymers as nanofillers and dispersing them in soft matrices. The resulting "architecturally engineered" polymer nanocomposites structurally reside between the linear homopolymer blends and the conventional polymer nanocomposites with inorganic fillers, inducing reinforcement, which can be as strong as that of solid nanoparticles, or softening depending on the compactness and concentration of the nanoparticles. Such behavior can be traced back to the dynamical features at the local segmental and the chain level, which we investigated using neutron scattering over a wide range of time and length scales in the glassy and melt states of the nanocomposites. The local and segmental dynamics as well as the degree of chain-chain entanglements are all modified by the star-shaped fillers. The presented approach to tuning the physical properties of all-polymer-based nanocomposites is readily adaptable to other polymer architectures with immediate applications in numerous areas including gas separation membranes, tissue engineering, drug delivery, and functional coatings.
我们展示了通过使用玻璃态星形聚合物作为纳米填料并将其分散在软质基质中形成的纳米复合材料。所得的“结构工程化”聚合物纳米复合材料在结构上介于线性均聚物共混物和具有无机填料的传统聚合物纳米复合材料之间，可产生增强作用，其增强效果可与固体纳米颗粒一样强，或者根据纳米颗粒的致密性和浓度而软化。这种行为可以追溯到局部链段和链水平的动力学特征，我们在纳米复合材料的玻璃态和熔体状态下，通过在广泛的时间和长度尺度上使用中子散射对其进行了研究。星形填料改变了局部和链段动力学以及链-链缠结程度。所提出的调节全聚合物基纳米复合材料物理性能的方法很容易适用于其他聚合物结构，并可立即应用于包括气体分离膜、组织工程、药物递送和功能涂层在内的众多领域。
