Amphiphilic comb-block copolymers synthesized by photoinitiated polymerization for stabilization of oil–water emulsion by solution self-assembly

To enhance the stability of oil–water emulsions and expand their potential applications, we designed and synthesized a series of comb-block copolymers, hexadecyl methacrylate-co-poly (ethylene glycol) methyl ether methacrylate (HMA-PEGMA). By precisely adjusting the hydrophilic to hydrophobic block ratios, these copolymers demonstrated effective stabilization in both W/O and O/W emulsions. Characterization via cryogenic transmission electron microscopy (cryo-TEM) and scanning electron microscopy (SEM) confirmed their self-assembly into micellar structures. At a concentration of 1250 mg/L, HMA-PEGMA with block ratios of 3:1 and 1:2 stabilized emulsions for over 24 h, resisting centrifugal forces up to 2000 rpm and maintaining stability across a temperature range of 20–70 °C. The stability mechanisms of the dodecane/water emulsions were elucidated through macroscopic observation, dynamic light scattering (DLS), polarized optical microscopy (POM), interfacial tension measurements, and interfacial film rheology tests. A comparative analysis with commercial emulsifiers highlighted the superior performance of HMA-PEGMA, particularly in stabilizing crude oil emulsions from the Liaohe oilfield. Due to its efficient synthesis and eco-friendly characteristics, HMA-PEGMA presents significant potential for industrial applications.