PTA analysis for samples at (8.5 cm/s) (Figure ) showed a shift to larger size ranges when compared to samples incubated at 0.85 cm/s and 2-hour static (Figure ) conditions across all particle surface modifications. Further PTA analysis showed a widening of the particle size distribution span for unmodified nanoparticles with a baseline span of 0.42, which increased to 0.62 (isolated), and 0.49 (in-situ) following 2-hour incubation. Under shear flow conditions an increase in particle size distribution span to 0.45 (in-situ), and 0.56 (isolated) was observed following incubation at (0.85 cm/s). A similar increase was seen for particles incubated at (8.5 cm/s) with a particle size distribution span increase to 0.65 (in-situ) and 0.78 (isolated). Amineand carboxylate-modified nanoparticles showed a decrease in particle size span in comparison to static incubation (2 hours) following incubation under shear flow conditions (0.85 cm/s, 8.5 cm/s) (see supplementary information).