Quantitative 1 H NMR spectroscopy confirmed the presence of higher-order aggregates with solid-like properties for co-formulations a -j at 2.78 mM, in a 19:1 D2O:EtOH solution. Here SSA co-formulation was found to result in the production of higher-order aggregated species which demonstrated increased variation in dH (determined through DLS studies) and stability (determined through zeta potential studies) compared to the homogenous SSA aggregates produced under analogous experimental conditions. In general, the incorporation of 5 led to aggregates with a smaller dH (99 nm, 105 nm, 84 nm), unless combined with 3, in which case this trend was reversed as this combination of SSAs led to the production of the largest heterogenous SSA aggregates identified (dH = 690 nm). However, we believe that this size of aggregate may be produced through the aggregation of smaller species present in solution. Zeta potential measurements showed the presence of 3 (increased hydrophobicity and potential to stabilise intermolecular π-π stacking interactions) and 4 (a sulfonate squaramide based SSA) to increase the stability of the heterogenous aggregates to the greatest extent, with the most stable aggregates formed when combining 4 and 5, which we hypothesise to be due to enhanced intermolecular hydrogen bonding strength, provided through the presence of the squaramide moiety (Table ). Tensiometry experiments showed that all SSA co-formulations retained the surfactant nature of the homogenous solutions, although solubility prevented calculation of accurate CAC values.