R.M. Dorin, D.S. Marques, H. Sai, U. Vainio, W.A. Phillip, K.-V. Peinemann, S.P. Nunes, U. Wiesner
ACS Macro Letters, 1, 614-617, (2012)
Small-angle X-ray scattering (SAXS) analysis of the diblock copolymer poly(styrene-b-(4-vinyl)pyridine) in a ternary solvent system of 1,4-dioxane, tetrahydrofuran, and N,N-dimethylformamide, and the triblock terpolymer poly(isoprene-b-styrene-b-(4-vinyl)pyridine)
in a binary solvent system of 1,4-dioxane and tetrahydrofuran, reveals a
concentration-dependent onset of ordered structure formation.
Asymmetric membranes fabricated from casting solutions with polymer
concentrations at or slightly below this ordering concentration possess
selective layers with the desired nanostructure. In addition to rapidly
screening possible polymer solution concentrations, solution SAXS
analysis also predicts hexagonal and square pore lattices of the final
membrane surface structure. These results suggest solution SAXS as a
powerful tool for screening casting solution concentrations and
predicting surface structure in the fabrication of asymmetric
ultrafiltration membranes from self-assembled block copolymers.