Synthesis and use for surfactant adsorption of hydrophobic poly[N-(diethylamino)ethylmethacrylate-co-N-vinly-2-pyrrolidone/octadecylacrylate]hydrogels

SYNTHESIS AND USE FOR SURFACTANT ADSORPTION OFHYDROPHOBIC POLY[N-(DIETHYLAMINO)ETHYLMETHACRYLATE -CO-N-VINYL-2-PYRROLIDONE/OCTADECYLACRYLATE] HYDROGELS(M.Sc. Thesis)Demet ZOLGAZI UNIVERSITYINSTITUTE OF SCIENCE AND TECHNOLOGYJanuary 2006ABSTRACTHydrophobically poly[N-(Diethylamino)ethylmethacrylate-co-N-vinyl-2-pyrrolidone/octadecylacrylate], [P(DEMA-co-VP/OA)], hydrogels weresynthesized by a free-radical crosslinking copolymerization of N-(Diethylamino)ethylmethacrylate (DEMA), N-vinyl-2-pyurolidone (VP)and different amounts of hydrophobic octadecyl acrylate (OA) in t-butylalcohol by using 1,2-ethyleneglycoldimethacrylate (EGDMA) ascrosslinker, ammonium persulfate (APS) as the initiator and N,N,N?,N?-tetramethylethylenediamine (TEMED) as the activator. The equilibriumswelling ratios of P(DEMA-co-VP/OA) hydrogels with different OAcontent were examined in pure water as a function of temperature. Theaverage molecular mass between crosslinks ( M c ), polymer-solventinteraction parameter ( χ ) and effective crosslinking density (ν eD ) werecalculated from the equilibrium swelling values. It was shown that theFlory-Rehner theory of swelling equilibrium provides a satisfactoryagreement to the experimental swelling data of the hydrogels. On theother hand, the equilibrium swelling ratio of P(DEMA-co-VP/OA)hydrogels with different OA content were examined as a function oftemperature in aqueous solutions of sodium dodecyl sulfate (SDS) anddodecyltrimethylammonium bromide (DTAB). It was shown that thevolume transition temperature increased with increasing of SDS orDTAB concentrations. In addition, the adsorption of these surfactantmolecules on the P(DEMA-co-VP/OA) hydrogels were determined byusing fluorescence emission spectrometer depending on OA content.The fluorescence probe studies showed that there is a good interactionbetween hydrophobic hydrogels and surfactants molecules. It wasfound that the adsorption of surfactant molecules on the P(DEMA-co-VP/OA) hydrogels increased with increasing OA content in thehydrogel.Science Code : 201.1.117Key Words : Hydrophobically P(DEMA-co-VP/OA) hydrogels,swelling, network parameters, surfactant,adsorption, fluorescencePage Number : 110Supervisor : Assoc. Prof. Dr. Tuncer ÇAYKARA