The development of low-cost materials and efficient methods for the fractionation of water and ethanol in binary mixtures is of great interest for food processing and biofuels production. Herein, we report a systematic study of a series of linear and branched starch-based biopolymers along with their modified forms via cross-linking with epichlorohydrin (EPI) at variable EPI composition. The fractionation properties of these adsorbent materials were studied in binary ethanol water solutions and compared against those of neat solvents. H-1 NMR spectroscopy was used to assess the binary solvent composition for the study of isotherms for the respective solvent components. The monolayer adsorption capacity (Q(m)) for starch and its cross-linked forms varied from 0.01 to 2.70 g.g(-1) for water and ethanol in binary mixtures according to the Sips isotherm model. The fractionation selectivity [R-selectivity; Q(m)(W)/Q(m)(E)] of starch-EPI adsorbents for water (W) and ethanol (E) in binary mixtures ranges from 3.8 to 80. At saturative conditions in binary W E mixtures, the R-selectivity isotherm parameter reveals unique solvent selective uptake that depends on the amylose versus amylopectin composition and the EPI content of these cross-linked materials. The unique water uptake properties of starch and its cross-linked forms illustrate the role of textural properties and relative hydrophobic character of the polymer network based on the selective adsorption properties. Starch and its modified forms represent a promising class of adsorbent materials and a sustainable technology for the adsorptive-based fractionation of W E binary mixtures.