Standard interfacial polymerization and phase inversion based-membranes are complex, sensitive to small changes, susceptible to residual chlorine, and have rough surfaces enabling unfavorable adsorption. There is an urgent need to improve synthetic membrane filtration performance for systems which recover biofuels in energy production and desalinize sea and brackish water for potable use. This technology includes a new class of tunable, selective, synthetic membranes and process of making thereof, which outperform commercially available membranes. The membranes include a hydrophobic polymer layer located on a polymeric membrane support layer, which includes a plurality of polymer units covalently bonded to the polymeric membrane support layer, and each polymer unit comprises a polymerized plurality of vinyl monomers. The reproducible, scalable production method eliminates the need for graphene oxide or carbon nanotubes, which combined with the improved selectivity performance, results in an overall advantage in cost savings. Multiple applications of this technology include pervaporation, reverse osmosis, nanofiltration and gas separation processes used in petroleum refining, wastewater treatment, chemical and biochemical production, electrodialysis, desalination, volatile compound treatment and recovery and more.