Modeling Pore Size Distribution in Cellulose Rolled Stationary Phases

Abstract

Rolled stationary phases are fabrics (i.e., nonparticulate phases) that rapidly separate proteins from salts on the basis of size exclusion. Pore size and pore size distributions in the stationary phase determine how different size molecules distribute between the stationary and mobile phases in liquid chromatography columns. The potential for size exclusion chromatography by fabrics is not initially obvious because their interlaced structures are atypical for size exclusion supports. A simple logistic model fits the pore size distribution of a rolled stationary phase when pore sizes were measured using PEG, Dextran, D2O, glucose, and NaCl probes. When the fabric is treated with cellulase enzymes, the water-accessible pores uniformly decrease and peak retention is lower. The logistic function model captures this result and enables comparison of pore size distribution curves between enzyme-treated and untreated fabrics in rolled stationary phase columns.

Effect of solvent exchange on the pore structure and dissolution behavior of cellulose

“…This value is lower than the usual one (about 0.60) previously found for this system 35 but corresponds to that found for PEG in water. 25 However, the exponent seems to coincide with the usual one when only high molecular weight fractions (above 25,000) are taken into account. Therefore, it is supposed that the reason for the relatively low exponent may be the inclusion of low molecular weight fractions, where the deviation from Gaussian statistics of chain dimension is assumed.…”

“…[15][16][17][18][19][20][21][22][23][24][25] However, the use of water as eluent is not suitable for our purpose, because the immersion of the DMAc-treated cellulose in water spoils the effect of the solvent exchange. For example, the solubility of the DMAc-treated cellulose in LiCl/DMAc is lowered by the immersion in water.…”

“…14 Size exclusion chromatography (SEC) also gives the information on the pore structure of cellulose and its derivatives. [15][16][17][18][19][20][21][22][23][24][25] This method has the advantage over other methods because it can investigate the pore structure of cellulose swollen in various kinds of liquids. However, previous studies focused only on the swelling of cellulose in water.…”

“…However, previous studies focused only on the swelling of cellulose in water. [15][16][17][18][19][20][21][22][23][24][25] On the other hand, investigation of the swelling behavior of cellulose in other non-aqueous media, which is required to clarify the effect of solvent exchange on the pore structure of cellulose, have not been performed yet. Therefore, we investigated the pore structure of cellulose in aqueous or nonaqueous media using SEC, DLS, and SAXS measurements.…”

Formation of a Low-Density Liquid Phase during the Dissociation of Gas Hydrates in Confined Environments

“…The calculated lattice parameters of confined hydrate and bulk hydrate. References [66][67][68][69][70][71][72][73][74][75][76][77] are cited in the supplementary materials.…”