Gelation and decrystallization of cellulose by TAAHs/DMSO treatment and the role of anions and cations

• Published in: Cellulose (London) Vol. 22; no. 5; pp. 3013 - 3025
• Main Authors: Choe, Deokyeong, Shin, Chul Soo
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.10.2015; Springer Nature B.V
• Subjects: Anions; Basicity; Bioorganic Chemistry; bromides; Cations; Cellulose; Ceramics; Chemistry; Chemistry and Materials Science; chlorides; Composites; Crystalline cellulose; Dimethyl sulfoxide; Disruption; enzymatic hydrolysis; Fluorides; Fourier transform infrared spectroscopy; Gelation; gels; Glass; Halides; hydrogen bonding; Hydrogen bonds; hydrophobic bonding; Hydrophobicity; iodides; Natural Materials; Organic Chemistry; Original Paper; Physical Chemistry; Polymer Sciences; Sustainable Development; Swelling ratio; van der Waals forces; X-ray diffraction; Anions; Cations; Gelation; Cellulose; TAAHs/DMSO; Decrystallization
• ISSN: 0969-0239; 1572-882X
• DOI: 10.1007/s10570-015-0707-y

Compact crystalline cellulose was structurally transformed into a loose regenerated form using treatment with tetraalkylammonium halides in dimethyl sulfoxide (TAAHs/DMSO) and gel formation using water. Swelling of cellulose was affected by the TAAHs content in DMSO and the anion and/or cation type. The cellulose swelling ratio of TAAHs/DMSO was in the order of F⁻ > Cl⁻ > Br⁻ ≈ I⁻ due to differences between hydrogen bond basicity (β) values of TAAHs/DMSO. The swelling ratio varied with the cation size of tetraalkylammonium chlorides (TAACs). For tetraalkylammonium fluorides (TAAFs), swelling ratios were all high and independent of cation size. Decrystallization of cellulose varied with the TAAHs anion and/or cation type in a pattern similar to cellulose swelling ratios. Structural transformation of cellulose, which is due to disruption of hydrogen bonds and van der Waals and hydrophobic interactions in cellulose chains and sheets by anions and cations of TAAHs, was confirmed based on FT-IR, XRD, FE-SEM, TGA, and enzymatic hydrolysis reactions.