The importance of specific surface interactions increases as the NPs get smaller, and the forces originating at the NP-solvent interface are often dominant and intrinsically short-range . In the <50 nm regime, the classic DLVO theory is often insufficient to explain the NP self-assembly since the interactions become non-additive and highly dependent on the NP surface structure and chemical specificity. Indeed, a feature that can lead to directional interactions between NPs is their surface patchiness . The complexity of the aggregate can be controlled by having a finite number of adhesive patches corresponding to the maximum number of possible junctions. For instance, Janus NPs, whose surface is divided into two well-distinct domains, can be the building blocks of colloidal polymers .