%N 1 %V 11 %J Crystals %P 1-12 %T Synthesis and Characterization of Polystyrene/CuO-Fe₂O₃ Nanocomposites from Natural Materials as Hydrophobic Photocatalytic Coatings %I MDPI %A Ratnawulan Ratnawulan %A Ramli Ramli %A Ahmad Fauzi %A Sukma Hayati AE %X This study reports on the synthesis, characterization of polystyrene (PS)/CuO-Fe₂O₃ nanocomposites, and their application as hydrophobic coatings. CuO and Fe₂O₃ materials were synthesized from natural materials by the milling method. Meanwhile, the PS/CuO-Fe₂O₃ nanocomposites were synthesized by the sol-gel method. Furthermore, the hydrophobic coating on the glass substrate was made by spin-coating. To obtain the highest value of contact angle, the composition of both CuO and Fe₂O₃ in nanocomposite as well as calcination temperatures were varied. Sample characterization was conducted using XRD, SEM, and UV-Vis spectrophotometry. The sessile drop method was used to determine the contact angle. Results showed that PS/CuO-Fe₂O₃ nanocomposite was successfully obtained with a crystal size between 40–52 nm and grain size of 92 nm. The highest contact angle was 125.46° at 3:1 composition and calcination temperature of 200 °C. The composite was hydrophobic, but photocatalyst activity was very small at 0.24%. %L repounp38395 %K Composite, Calcination Temperature, Contact Angle, Hydrophobic, Photocatalytic Coating %D 2020