N. Verko
Tehniska fakulteta
Oddelek za kemijsko tehnologijo
62000 Maribor, Smetanova 17
C. Stropnik, K. Ribic, Tehniska fakulteta, Maribor
G. Jonsson, Institut for kemiteknik, Lyngby, Danmark Tekniske
Universitet
Membrane iz polisulfona so bile pripravljene s postopkom fazne
inverzije s potopitvijo plasti raztopine polisulfona v obarjalno
kopel. Pri membranski filtraciji s krozenjem retentata po
povrsini membrane so bile dolocene zadrzevalne lastnosti membrane
za polietilenglikola (PEG) razlicnih molekulskih mas in
koeficienti prenosa snovi. Uporabljena je bila metoda variacije
hitrosti krozenja retentata. Za izracun koeficienta prenosa snovi
in dejanskega zadrzevanja membrane je bil uporabljen model
teorije filma. Povrsina membran je bila modificirana z reakcijo
po Friedel-Craftsu s propilenoksidom in katalizatorjem
aluminijevim trikloridom. Na povrsino vezane hidroksilne skupine
so bile dokazane z ATR-FTIR spektroskopijo. Pretoki in
zadrzevanje molekul PEG so bili izmerjeni na isti membrani pred
modifikaciji in po njej. Po modifikaciji so bili pretoki vode
skozi membrano vecji, membrane pa so v manj{i meri prepuscale
molekule PEG. Pretoki vode in prepuscanje molekul PEG so bili
nespremenjeni za membrane, ki so bile le kondicionirane v topilih
na enak nacin kot modificirane membrane, a brez reakcije.
Kljucne besede: polisulfon, membrane, kemijska modfikacija,
reakcije po Friedel-Craftsu, membranska filtracija s krozenjem
retentata, zadrzevalne lastnosti
Polysulfone membranes were obtained by phase inversion by
immersion precipitation. Retention characteristics for different
PEG's and mass transfer coefficients were determined by velocity
variation method in crossflow membrane filtration. Film theory
model was used for calculating the mass transfer coefficients and
true membrane retention. The membrane surface was modified by
Friedel-Crafts reaction with propyleneoxide and catalyst
aluminium trichloride. Surface bonded hydroxilic groups were
detected by ATR-FTIR spectroscopy. Waterflux and retention of
PEG's were measured on the same membrane before and after surface
chemical modification. After modification, membranes had higher
waterflux and higher retention of PEG. Waterflux and retention of
PEG's for the membranes which were conditioned in solvents in the
same way as modified membranes but without following surface
reaction were unchanged.
Key words: polysulfone, membranes, chemical modification,
Friedel-Crafts reactions, cross-flow membrane filtration,
rejection properties