论文部分内容阅读
The self-diffesion of water, ethanol and water-ethanol mixtures in chitosan (CS) membranes crosslinked byaqueous H_2SO_4 solution and uncrosslinked membrane was measured using pulsed-field gradient (PFG) nuclear magneticresonance (NMR) spectroscopy to obtain the partial solubilities and self-diffusion coefficients. An attempt was made toexplain the transport properties of water and ethanol through the CS membrane. It was concluded that there are two types ofchannel water and ethanol diffesate transfer. The water was localized in the hydrophilic ionic region formed by the ionizedgroups, and the ethanol was localized in the hydrophobic amorphous network of the polymer. There was a good agreementbetween the separation fastors estimated from PFG-NMR data and those obtained by pervaporation testing.
The self-diffesion of water, ethanol and water-ethanol mixtures in chitosan (CS) membranes crosslinked by aqueous H 2 SO 4 solution and uncrosslinked membrane was measured using pulsed-field gradient (PFG) nuclear magnetic resonance (NMR) spectroscopy to obtain the partial solubilities and self- diffusion constants. An attempt was made to explain the transport properties of water and ethanol through the CS membrane. It was concluded that there are two types of channel water and ethanol diffesate transfer. The water was localized in the ionic ionic region formed by the ionized groups, and the ethanol was localized in the hydrophobic amorphous network of the polymer. There was a good agreement between the separation fastors estimated from PFG-NMR data and those obtained by pervaporation testing.