Cellulose hollow fibers for organic resistant nanofiltration

Abstract

Cellulose is the most abundant biopolymer, but it is difficult to process due to its low solubility in most of the solvents. In this work, we demonstrate the preparation, of self-standing and defect-free cellulose hollow fiber membranes made by a sustainable process for filtration in organic solvent medium. The hollow fibers were made by the simple spinning technique using ionic liquids as a solvent. The spun solutions were prepared with three different ionic liquids, having imidazoliumbased cations and acetate or phosphates as anions. We used X-ray diffraction to evaluate the influence of the different ionic liquids on the crystallinity of the cellulose and the membrane solvent stability. We used cryo-scanning electron microscopy to investigate the porous structure of the hydrated membranes, distinguishing it from that of the dry membranes. The hollow fiber membrane performance was studied using dyes in water and ethanol solutions. The rejection of Congo Red (696 g/mol) was higher than 90% in ethanol and even closer to 100% in water. The best results were obtained by using 1-ethyl-3-methyimidazolium diethyl phosphate and 1,3dimethylimidazolium dimethyl phosphate. Our results indicate that by using greener process is possible to obtain solvent resistant cellulose hollow fibers.

Carbon hollow fiber membranes for a molecular sieve with precise-cutoff ultramicropores for superior hydrogen separation

“…Although cellulose membranes and its derived CMS membranes have been reported in the literature 19 , 20 , 26 , asymmetric cellulose-based carbon hollow fiber membranes have never been reported for gas separation. Cellulose has strong inter- and intra-chain hydrogen bonds, which prevents solubility in most common solvents.…”

“…Thus, it is difficult to control the membrane formation phase inversion process for such a system, which ultimately determines the structure and morphology of regenerated hollow fiber cellulose precursors. Furthermore, it has been found that water-filled cellulose membranes experience morphology collapse when dried directly from water 26 . Accordingly, a proper drying process to maintain the formed pore structure is required.…”

Recent Advances in Biopolymer-Based Dye Removal Technologies

“…For instance, Li et al reported the fabrication of permeable and antifouling UF membranes using bacterial cellulose with mussel-inspired dopamine and graphene oxide [ 106 ]. Graphene-oxide nanosheet functionalized phosphorylated chitosan (PCS) NF membranes also exhibited high flux, separation efficiency and antifouling performance [ 107 ]. Therefore, due to their unique characteristics such as high mechanical strength, tunable weight, surface properties, strong networking abilities and antifouling, biopolymers and their derivatives have been used to devise pressure-driven membranes.…”

Green Approaches for Sustainable Development of Liquid Separation Membrane

“…This proves the feasibility of using ionic liquids for cellulose dissolution, as well as the practicability of cellulosic membrane in various applications involving a solvent medium. On the other hand, ionic liquids such as 1-ethyl-3-methyimidazolium diethyl phosphate, 1,3-dimethylimidazolium dimethyl phosphate, and 1-butyl-3-methylimidazolium chloride were also employed by other groups of researcher as the solvent to prepare cellulosic membrane for dye, protein, and oil retentions [ 107 , 108 , 109 ]. The membrane performances showed that all ionic liquids can be good solvents for cellulose.…”