Development and optimization study of porous PVDF/Ag/BaTiO 3 /Gr nanocomposite foams for effective electromagnetic interference shielding applications using statistical and machine learning approaches

With the rapid expansion of technology and industrialization, the use of modern wireless electronic devices and household appliances has risen sharply. As a result, electromagnetic pollution, or electromagnetic interference (EMI), has surged globally. Therefore, to overcome this issue, the demand for lightweight, flexible EMI shielding materials has opened new avenues in material research. In this study, porous-structured polyvinylidene Fluoride (PVDF) nanocomposite foams were fabricated via a sacrificial template removal method, and their shielding performance was tested over the X -band frequency range of 8–12 GHz. To enhance the surface roughness, conductivity, and β -phase characteristics, various compositions and loadings of silver (Ag), barium titanate (BaTiO3), and graphene (Gr) nanofillers were incorporated into a PVDF matrix. A systematic central composite design based on response surface methodology (RSM) and a gradient descent algorithm (GDA) was used to predict the shielding effectiveness (SE) and identify the optimal filler combinations. Based on the experimental results, it is observed that the PVDF foam sample (S14) with 2.5 g of Ag, 2.5 g of BaTiO 3 , and 0.2 g of Gr with a porosity of 95.6%–64.9% fraction of crystallinity has achieved the maximum EMI SE of 35.9 dB in the X -band frequency range of 8–12 GHz. RSM and GDA predictions matched the experimental results, with mean absolute percentage errors of less than 2%, respectively. These results demonstrate that the porous PVDF/Ag/BaTiO 3 /Gr nanocomposite foam is a promising lightweight, flexible, biocompatible EMI-shielding material suitable for casings and enclosures in wearables, smartphones, and 5G equipment.