The phase inversion parameters of membranes prepared from lab-synthesized poly(ether ether ketone) polymers BPAPEEK and TBPEEK are investigated to tune their performance towards nanofiltration. These PEEK polymers are suitable for producing phase inversion membranes as they are soluble in polar aprotic solvents, thanks to the presence of alkyl side groups. Firstly, the influence of polymer concentration on membrane performance was investigated and a volatile co-solvent was added to improve the retention. Evaporation time was then tuned, in addition to coagulation bath composition and casting thickness. The membranes were also tested with a smaller solute. Additional to this phase inversion study, stability of the membranes in alkaline conditions was investigated. The prepared polymers proved to have potential as solvent resistant nanofiltration membranes or as hydrophobic support materials for thin film composite membranes. (C) 2013 Elsevier B.V. All rights reserved