Spinodal decomposition of partially miscible polymer blends has the potential to generate well-defined polymeric nanostructured materials, with precise control of length scale and connectivity, and applications ranging from membranes and scaffolds to photovoltaics. In this review, we briefly summarize the theoretical basis for describing spinodal decomposition in binary polymer blends, and the parameters that determine the accessible demixing length scales and the timescales over which they develop. We then examine experimentally the validity of the classical Cahn-Hilliard (CH) theory prediction for the initial spinodal length scale, $\text{Λ}\equiv 2\pi /\sqrt{-G^{″}/\left(4k\right)}$ where G′′ is the second derivative of the free energy of mixing with respect to composition, and k is the ‘square gradient’ parameter, accounting for changes in free energy arising from concentration gradients. Benefitting from the perspective of over 40 years of neutron and light scattering data, and noting (remaining) misconceptions in the literature when analyzing phase separation, we examine a large collection of Λ measurements, and independent -G′′(T) and k experimental estimates. Overall, we find the CH prediction for Λ to be remarkably accurate for all blends and self-consistent conditions examined. We then summarize design considerations for generating polymeric materials via spinodal decomposition, bound by thermodynamics of available polymer systems, coarsening kinetics governed by rheology, as well as by engineering constraints. The fulfillment of the potential of this approach in the development of real functional materials demands, however, improved thermodynamic theories for polymer blends, able to quantitatively predict G′′(T) and k in terms of molecular structure and interactions.

部分混溶的聚合物共混物的旋节线分解具有产生明确定义的聚合物纳米结构材料的潜力，可以精确控制长度尺度和连接性，其应用范围从膜，支架到光伏电池。在这篇综述中，我们简要总结了描述二元聚合物共混物中旋节线分解的理论基础，以及确定可达到的混合长度尺度及其发展时间尺度的参数。然后，我们通过实验检验经典Cahn-Hilliard（CH）理论预测对初始旋节线长度尺度的有效性，$\text{Λ}\equiv \mathrm{2个}\pi /\sqrt{-G^{\text{'}\text{'}}/（4ķ）}$其中G''是混合自由能相对于成分的二阶导数，k是“平方梯度”参数，说明了浓度梯度引起的自由能变化。受益于40多年来中子和光散射数据的观点，以及在分析相分离时注意到（遗留）误解的文献，我们研究了大量的Λ测量值，以及独立的-G ′ （T）和k实验估计。总体而言，我们发现，对于所考察的所有掺混物和自洽条件，CH的Λ预测都非常准确。然后，我们总结了通过旋节线分解生成聚合物材料的设计注意事项，并受可用聚合物系统的热力学，流变学和工程约束控制的粗化动力学约束。为了实现这种方法在开发实际功能材料中的潜力，需要改进聚合物共混物的热力学理论，能够从分子结构和相互作用方面定量预测G''（T）和k。