Recent progresses of genome-wide chromatin conformation capture techniques have shown that the genome is segmented into hierarchically organized spatial compartments. In particular, these nuclear compartments have been associated to epigenomics and may play an important role in gene regulation. Formation of these compartments have been associated to the micro-phase separation of genomic loci sharing the same chromatin state and of their associated chromatin-binding proteins. However, the mechanisms leading to this (micro) phase-separation are still unclear. In my presentation, I will present our last efforts to understand the physical driving forces of chromatin compartmentalization like liquid or copolymer phase separation.