This study reports on the structural characterization and physicochemical properties of surface modified starch particles (SPs). The surface of the SPs was patterned via controlled deposition of cetylpyridinium bromide (CPB) at the solid−solution interface with incremental CPB loadings, denoted as SP-CPBX, where X = 0.5, 2.5, or 5.0 mM CPB. The surface-patterned SPs were characterized by several complementary methods: spectroscopic (NMR, FT-IR, Raman, and SEM), thermoanalytical (DSC and TGA), powder X-ray diffraction (PXRD), gravimetric-based solvent swelling, zeta-potential (ζ), and particle size distribution (PSD). NMR spectral results reveal that CPB is bound at the starch−solvent interface via the pyridyl headgroup, whereas the tertiary structure of the SPs was maintained over the range of CPB doping, as revealed by SEM and PXRD results. The ζ-value results of the SP-CPBX systems reveal negative ζ-values at the starch surface, where tunable surface properties occur at variable levels of CPB surface patterning, as evidenced by the variable adsorptive affinity with water. Solvent swelling in water for the SP-CPBX systems reveal a dependence of the hydration properties on the level of CPB surface patterning, as highlighted by the unique physicochemical properties for the SP-CPB0.5 system, according to the relative accessibility of the active surface sites. The DSC/TGA and Raman/NMR spectral results of the SP-CPBX systems further support that variable surface coverage of CPB governs the interfacial adsorption of water according to Sabatier's principle. Furthermore, the SP-CPB0.5 system was compared among a variety of common bacterial strains for its antibacterial activity that met or exceeded the activity of SPs imbibed with conventional antibiotic agents. This study highlights that surfactant-modified starch is a sustainable material with unique adsorption properties that are switchable upon surfactant patterning. CPB-coated SPs possess improved antibacterial stability and functional versatility with potential utility as sustainable carrier systems for diverse applications that involve adsorption-based processes.