Development of a polyallylamine hydrochloride hydrogel imprinted with xylose for the purification of xylose from sugar mixture

Abstract

A novel molecularly imprinted hydrogel (X-MIP) was developed with poly (allylamine hydrochloride) as monomer and epichlorohydrin as crosslinker. After optimising preparation conditions including reaction temperature, the amount of NaOH and template xylose, the X-MIP was characterised through Fourier transform infrared spectroscopy, scanning electron microscope and swelling ratio. Xylose and glucose were employed to evaluate the adsorption capacity and selectivity of the X-MIP. Its adsorption to xylose followed pseudo-second-order rate kinetics and the adsorption process was multilayer adsorption based on the matched Freundlich isotherm model. Its adsorption capacity to xylose was up to 398.68 mg g −1 . The similar adsorption abilities in five successive runs and the good desorption rate (98.9%) verified its reusability. The selectivity for xylose and glucose could reach 4.70, and their separation factors in simulated xylitol production feedstocks were 591.05 (xylose:glucose, 99:1) and 15.42 (xylose:glucose, 3:1), respectively. Results indicated the prepared X-MIP has good potential in industrial xylose purification.