Why do nonpolar hydrocarbon ligands crystallize in nonpolar solvents? And why does the transition from disordered to ordered ligand structures coincide with a shift from repulsive to attractive interparticle interactions? For the first question, we propose that ordered packing of ligand head groups on the NC surface promotes tail-chain crystallization, even in favorable solvent environments. As for the second question, we hypothesize that in the disordered state, there are gaps between ligands that allow solvent molecules to penetrate and solvate the tail chains. However, once ligands crystallize into bundles, they exclude solvent molecules, causing the interparticle region to expel solvent and generate attractive forces.