6533b871fe1ef96bd12d1bec

RESEARCH PRODUCT

Preparation of pH sensitive poly(vinilydenefluoride) porous membranes by grafting of acrylic acid assisted by supercritical carbon dioxide

Loredana FerroAlessandro GaliaOnofrio Scialdone

subject

PH-dependentGrafting proceGeneral Chemical EngineeringRadical polymerizationpH-sensitive polymersMass fractionPoly(vinylidene fluoride)Free radical graftingGrafting degreeCarboxylic acidRelease experimentAcrylic acidSupercritical fluid extraction Grafting (chemical)chemistry.chemical_compoundCrystallinityPVDF membraneFree radicalPolymer chemistrypH sensorPhysical and Theoretical ChemistryFluid-phasepH sensitiveAcrylic acidCrystallinitieDecompositionSupercritical carbon dioxideFree radical polymerizationChemistrySupercritical carbon dioxides Carbon dioxideSettore ING-IND/27 - Chimica Industriale E TecnologicaCondensed Matter PhysicsGraftingSolventMembraneSpectroscopic analysiPorous membraneNuclear chemistry

description

Free radical grafting of acrylic acid (AA) on poly(vinilydenefluoride) (PVDF) porous membranes was studied at 65°C using supercritical carbon dioxide (scCO 2) as a solvent and delivery agent. The process was initiated by the thermal decomposition of benzoylperoxide (BPO). Spectroscopic analyses confirmed the presence of poly(AA) chains linked to treated membranes. The mass fraction of grafted AA increased with grafting time and BPO concentration while it decreased when the density of the fluid phase was enhanced. A not-monotonic trend was obtained when the effect of the initial AA concentration was studied. The grafting process was accompanied by a reduction of the crystallinity of the PVDF matrix. Flow measurements and caffeine release experiments performed using PVDF membranes with proper grafting degree exhibited a pH dependent behaviour. © 2011 Elsevier B.V.

yearjournalcountryeditionlanguage
2012-06-01The Journal of Supercritical Fluids
https://doi.org/10.1016/j.supflu.2011.09.004