Correlative microscopy across standalone systems for investigation of crystal growth and nanoscale morphology in PLA

A workflow for multimodal characterization across individual microscopy systems is shown. This is of high importance because different microscopy methods complement each other and provide complementarily data regarding contrast and resolution. The utilization of individual systems confers a number of advantages, chief among them being the ability to employ these systems in their totality without the encumbrance of restrictions imposed by elaborate setups. Correlation is implemented by means of manual coordinate transformation, thereby providing unlimited flexibility to integrate any device equipped with a coded XY-stage. The precision of the correlation is validated through comparison of acquired images using PLA crystallization as object of investigation. Dynamic in situ microscopy is employed to characterize the density of spherulites at varying crystallization temperatures. Subsequently, light microscopy with sophisticated contrasts is applied. This, correlated with scanning electron and atomic force microscopy allows for the acquisition of high-resolution three-dimensional data. Crystalline lamellae can be differentiated and PLA spherulites are characterized in depth. The method applied here facilitates the examination of nanoscale characteristics in multimodal contrast, thereby establishing a foundation for a comprehensive understanding of tailoring polymer crystallization, e.g. by means of additives. The implemented method for correlating individual microscopy systems additionally holds large potential for process control and inspection of samples with large contrast variations in different microscopy systems.