Polyether‐segmented nylon hemodialysis membrane. VII. Studies on surface structures of various poly(ethylene oxide)‐segmented nylon membranes

Abstract

The relationships of the surface morphologies to the surface chemical compositions in poly(ethylene oxide)-segmented nylon (PEO–Ny) membranes prepared by the phase-inversion method were studied using scanning electron microscopy (SEM), electron spectroscopy for chemical analysis (ESCA), and static secondary ion mass spectrometry (SSIMS). The PEO–Ny's used were high semicrystalline PEO-segmented polyiminosebacoyliminohexamethylene (PEO–Ny610), low semicrystalline PEO-segmented poly(iminosebacoylimino-m-xylylene) (PEO–NyM10), and amorphous PEO- segmented poly(iminoisophthaloyliminomethylene-1,3-cyclohexylenemethylene) (PEO–NyBI). SEM observation showed that the surfaces of the PEO–Ny610 and PEO–NyM10 membranes were composed of crystalline spherulite and that the PEO–NyBI membrane surface had a nodular structure. ESCA analysis exhibited the enrichment of the PEO segment at the surfaces of the PEO–Ny610 and PEO–NyM10 membranes. On the other hand, the enrichment of the Ny segment was observed in the case of the PEO–NyBI membrane. SSIMS analysis revealed that the outermost surfaces of the PEO–Ny membranes except the PEO–NyBI membrane were almost covered with the PEO segment. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 517–528, 2000