APCNs swell in water and nonpolar organic solvents due to their amphiphilic nature and phase separation into hydrophobic and hydrophilic domains at the nanoscale. To analyze the effect of the HCNCs on the swelling, the volumetric degree of swelling (Svol) was measured by incubating the samples at room temperature in water and n-hexane. PHEA-l-(PBLA5-b-PDMS-b-PBLA5) APCNs without CNCs swelled to Svol = 3.13 ± 0.8 and 1.23 ± 0.2 in water and the organic solvent, respectively. This swelling response is significantly higher than that of similar APCNs investigated in our previous study, most likely because the peptide-reinforced APCNs investigated herein were synthesized in a different solvent at a lower concentration. Thus, the higher swelling of the peptidic APCNs in the present study is likely due to the less concentrated monomer mixture during synthesis, leading to less entangled polymer chains in the networks and, therefore, fewer additional physical crosslinking points. CNCs decreased the swellability significantly at all CNC concentrations (Figure ). Water swelled the CNC-containing APCNs to Svol = 1.3, independent of the concentration of CNCs. In n-hexane, the APCNs exhibited minimal swelling, possibly due to the CNCs inhibiting the adsorption of the n-hexane by hydrogen bond formation between the CNCs and the hydrophilic PHEA chain segments, as well as the peptide blocks. The error bars from Figure B look wider due the results being within the measurement error range.