Incorporation of well-defined functional filler into a polymer matrix to form inorganic/organic composites with tailored properties represents new chemical feedstock advancement. In this work, functionalized polyhedral oligomeric silsesquioxane (functional silsesquioxane) and quaternary ammonium compound immobilized metal graphene oxide (functional graphene oxide) hybrids with defined architectures were synthesized by wet chemical methods. The synthesized functional fillers were thoroughly characterized by using various techniques including electronic absorption (UV-Vis), X-ray diffraction, scanning electron microscopy (SEM), optical microscopy, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Raman Spectroscopy, and dynamic laser light scattering (DLS). Functional silsesquioxane was incorporated into two polymer matrices, non-reactive and reactive, to achieve inorganic/organic composites. Poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) as non-reactive polymer matrix and poly(pyromellitic dianhydride-co-4, 4′-oxydianiline), amic acid solution as reactive polymer matrix were used. Functional graphene oxide was incorporated in poly(methyl methacrylate)/poly(ethylene glycol) (PMMA/PEG) blend matrix to achieve inorganic/organic composite. All the composites were prepared by low cost solution casting method. The physiochemical properties of the prepared composites were examined by using different techniques. The prepared composites analysis by FTIR, XRD, TGA, differential scanning calorimetry (DSC), and SEM indicated that the functional fillers were bonded through different set of interactions including electrostatic, van der Waal and hydrogen bonding and dispersed uniformly into the polymer matrices. The prepared composites showed excellent antifouling and antibacterial performances for bovine serum albumin (BSA) protein and Escherichia coli (E. coli) bacteria, respectively. In addition, the prepared composites performance was checked with pure water flux and gas permeability/selectivity studies. The present study would be providing advantages over existing methods to prepare nanofiller/polymer composites such as low cost, proper dispersion of fillers that would allow obtaining excellent structural, thermal, optical and surface properties of polymer nanocomposite/nanohybrids for applied water treatment and other environmental applications.