CDSA kinetics are highly dependent on core chemistry, and to date, the majority of studies examining CDSA-mediated growth have focused on 1D fibers, with typically slow (hours to days) formation kinetics. However, limited attention has been given to the study of 2D platelet kinetics, which are characterized by relatively rapid self-assembly processes, distinct morphology, and ease of modification. Here, we chose poly(ε-caprolactone) (PCL)based polymers as the core-forming block for the preparation of well-defined 1D fibers and 2D platelets. Compared with other commonly used core materials, the biocompatibility and biodegradability of PCL make it an attractive starting point for a range of materials for biomedical applications. 11, In addition, the crystallinity of the core-forming PCL block plays an essential role in determining the morphology and kinetics of CDSA particles: High crystallinity (i.e., high degree of polymerization) contributes to fast crystallization rates, commonly accompanied by self-nucleation and agglomeration; whereas core-forming blocks with lower crystallinity typically exhibit slower crystallization rates, resulting in irregular assembly shapes and a prolonged assembly process. Here, PCL 45 was selected, as it provides a good balance between fast kinetics and tight morphological control. Using iS-CAT, we mapped the kinetics and morphology of fiber and platelet growth from mixtures of PCL and poly(ε-caprolactone)-b-poly(N,N -dimethylacrylamide) block copolymer, PCLb-PDMA.