title: Online SAXS investigations of polymeric hollow fibre membranes.
abstract: Polymeric membranes are used in industrial and analytical separation techniques. In this study small-angle X-ray scattering (SAXS) with synchrotron radiation has been applied for in-situ characterisation during formation of polymeric membranes. The spinning of a polyetherimide (PEI) hollow fibre membrane was chosen for investigation of dynamic aggregation processes during membrane formation, because it allows the measurement of the dynamic equilibrium at different distances from the spinning nozzle. With this system it is possible to resolve structural changes in the nm-size range which occur during membrane formation on the time-scale of milliseconds. Integral structural parameters, like radius of gyration and pair-distance distribution, were determined. Depending on the chosen spinning parameters, e.g. the flow ratio between polymer solution and coagulant water, significant changes in the scattering curves have been observed. The data are correlated with the distance from the spinning nozzle in order to get information about the kinetics of membrane formation which has fundamental influence on structure and properties of the membrane.
authors.affiliation: GKSS Research Centre, Institute for Materials Research, Max-Planck-Str., 21502, Geesthacht, Germany. pranzas@gkss.de
authors.forename: P Klaus
authors.initials: PK
authors.lastname: Pranzas
authors.forename: Arndt
authors.initials: A
authors.lastname: Knöchel
authors.forename: Klemens
authors.initials: K
authors.lastname: Kneifel
authors.forename: Helmut
authors.initials: H
authors.lastname: Kamusewitz
authors.forename: Thomas
authors.initials: T
authors.lastname: Weigel
authors.forename: Rainer
authors.initials: R
authors.lastname: Gehrke
authors.forename: Sérgio S
authors.initials: SS
authors.lastname: Funari
authors.forename: Regine
authors.initials: R
authors.lastname: Willumeit
mesh_terms: D008420:Manufactured Materials; D008567:Membranes, Artificial; D008968:Molecular Conformation; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D012542:Scattering, Radiation; D017356:Synchrotrons; D014961:X-Ray Diffraction / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D011108:Polymers; C433673:polyetherimide