TY - JOUR
T1 - Morphology of thin film composite membranes explored by small-angle neutron scattering and positron-annihilation lifetime spectroscopy
AU - Pipich, Vitaliy
AU - Dickmann, Marcel
AU - Frielinghaus, Henrich
AU - Kasher, Roni
AU - Hugenschmidt, Christoph
AU - Petry, Winfried
AU - Oren, Yoram
AU - Schwahn, Dietmar
N1 - Funding Information:
Funding: This work was funded by the German–Israeli Foundation for Scientific Research and Development (GIF), grant No: I-101-307.4-2013.
Funding Information:
This work was funded by the German?Israeli Foundation for Scientific Research and Development (GIF), grant No: I-101-307.4-2013.
Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2020/3/1
Y1 - 2020/3/1
N2 - The morphology of thin film composite (TFC) membranes used in reverse osmosis (RO) and nanofiltration (NF) water treatment was explored with small-angle neutron scattering (SANS) and positron-annihilation lifetime spectroscopy (PALS). The combination of both methods allowed the characterization of the bulk porous structure from a few Å to µm in radius. PALS shows pores of ~ 4.5 Å average radius in a surface layer of about 4 μm thickness, which become ~ 40% smaller at the free surface of the membranes. This observation may correlate with the glass state of the involved polymer. Pores of similar size appear in SANS as closely packed pores of ~ 6 Å radius distributed with an average distance of ~ 30 Å. The main effort of SANS was the characterization of the morphology of the porous polysulfone support layer as well as the fibers of the nonwoven fabric layer. Contrast variation using the media H2O/D2O and supercritical CO2 and CD4 identified the polymers of the support layers as well as internal heterogeneities.
AB - The morphology of thin film composite (TFC) membranes used in reverse osmosis (RO) and nanofiltration (NF) water treatment was explored with small-angle neutron scattering (SANS) and positron-annihilation lifetime spectroscopy (PALS). The combination of both methods allowed the characterization of the bulk porous structure from a few Å to µm in radius. PALS shows pores of ~ 4.5 Å average radius in a surface layer of about 4 μm thickness, which become ~ 40% smaller at the free surface of the membranes. This observation may correlate with the glass state of the involved polymer. Pores of similar size appear in SANS as closely packed pores of ~ 6 Å radius distributed with an average distance of ~ 30 Å. The main effort of SANS was the characterization of the morphology of the porous polysulfone support layer as well as the fibers of the nonwoven fabric layer. Contrast variation using the media H2O/D2O and supercritical CO2 and CD4 identified the polymers of the support layers as well as internal heterogeneities.
KW - Chemistry and internal structures
KW - Detection of the order of Å to micrometer large pores in RO membranes
KW - Fibers of nonwoven fabric support layer
KW - Positron-annihilation lifetime spectroscopy
KW - Small-angle neutron scattering using contrast variation
UR - http://www.scopus.com/inward/record.url?scp=85082024003&partnerID=8YFLogxK
U2 - 10.3390/membranes10030048
DO - 10.3390/membranes10030048
M3 - Article
C2 - 32197524
AN - SCOPUS:85082024003
SN - 2077-0375
VL - 10
JO - Membranes
JF - Membranes
IS - 3
M1 - 48
ER -