Intercalation of graphite through sonochemical suspension copolymerization of styrene and methyl methacrylate for PSMMA/Graphene nanocomposite formation

This study presents a novel method for synthesizing poly(styrene-co-methyl methacrylate)/graphene (PSMMA/Graphene) nanocomposites via sonochemical suspension intercalative copolymerization of styrene and methyl methacrylate in the presence of graphite. The approach facilitates in-situ intercalation and exfoliation of graphite into few-layer graphene during copolymer formation. Comprehensive structural and morphological characterization using FTIR, UV–Vis, XRD, SEM, and TEM confirms successful transformation of graphite into functionalized graphene sheets embedded within the copolymer matrix. FTIR spectra reveal the presence of ester and aromatic functional groups from the copolymer, absent in pristine graphite. UV–Vis absorption and Tauc plot analysis indicate a reduced optical band gap (1.36 eV) for the nanocomposite, attributed to enhanced π–π interactions. XRD data show downshifted and broadened graphitic peaks, with calculated crystallite size and interlayer spacing suggesting the formation of ~5.6-layer graphene structures. SEM and TEM imaging demonstrate well-dispersed spherical polymer domains stabilized by wrinkled graphene sheets. This integrated synthesis strategy offers a scalable and eco-friendly route to engineer polymer/graphene hybrids with tailored optoelectronic and structural properties.