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Fabrication and characterization of polysaccharide ion gels with ionic liquids and their further conversion into value-added sustainable materials.

Takada A, Kadokawa J - Biomolecules (2015)

Bottom Line: The resulting ion gels have been characterized by suitable analytical measurements.Characterization of a pregel state by viscoelastic measurement provided the molecular weight information.Furthermore, the polysaccharide ion gels have been converted into value-added sustainable materials by appropriate procedures, such as exchange with other disperse media and regeneration.

View Article: PubMed Central - PubMed

Affiliation: Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga Koen 6-1, Kasuga, Fukuoka 816-8581, Japan. takada@mm.kyushu-u.ac.jp.

ABSTRACT
A review of the fabrication of polysaccharide ion gels with ionic liquids is presented. From various polysaccharides, the corresponding ion gels were fabricated through the dissolution with ionic liquids. As ionic liquids, in the most cases, 1-butyl-3-methylimidazolium chloride has been used, whereas 1-allyl-3methylimidazolium acetate was specifically used for chitin. The resulting ion gels have been characterized by suitable analytical measurements. Characterization of a pregel state by viscoelastic measurement provided the molecular weight information. Furthermore, the polysaccharide ion gels have been converted into value-added sustainable materials by appropriate procedures, such as exchange with other disperse media and regeneration.

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Procedure for fabrication of cellulose ion gel with 1-butyl-3-methylimidazolium chloride (BMIMCl).
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biomolecules-05-00244-f004: Procedure for fabrication of cellulose ion gel with 1-butyl-3-methylimidazolium chloride (BMIMCl).

Mentions: When solutions of cellulose in BMIMCl (9.1–13.0 wt%), which were prepared by heating the mixtures, were left standing at room temperature for seven days, the gelation was progressed with exclusion of excess BMIMCl from the gel matrix (Figure 4) [27]. The resulting gel was purified by washing with ethanol and dried under reduced pressure. Thus, a flexible and manipulatable gel was obtained, which was characterized by powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), and elemental analysis measurements. The XRD profile of the ion gel indicated that the crystalline structure of cellulose was mostly disrupted, but still slightly remained. The TGA profile of the ion gel showed two step weight losses at temperatures below 100 °C and higher than 250 °C. The former and latter are reasonably attributed to evaporation of water and degradation of cellulose, respectively. This data strongly indicated that the ion gel was composed not only of cellulose and BMIMCl, but also of water (ca. 15 wt%). The elemental analysis result also supported the presence of the large amount of water in the gel. The analytical results suggested the fact that the absorption of water into the solution, due to the strong hygroscopic nature of BMIMCl, probably caused the gelation of cellulose with BMIMCl. Because BMIMCl does not dissolve cellulose perfectly from a molecular point of view, aggregates of crystalline parts partially present among cellulose molecules were formed by gradually absorbing water into the solution, owing to its insolubility in water. Indeed, the colorless solution tuned into turbid during the gelation because of the formation of the aggregates. The aggregates probably acted as cross-linking points for the formation of the ion gel (Figure 5).


Fabrication and characterization of polysaccharide ion gels with ionic liquids and their further conversion into value-added sustainable materials.

Takada A, Kadokawa J - Biomolecules (2015)

Procedure for fabrication of cellulose ion gel with 1-butyl-3-methylimidazolium chloride (BMIMCl).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4384121&req=5

biomolecules-05-00244-f004: Procedure for fabrication of cellulose ion gel with 1-butyl-3-methylimidazolium chloride (BMIMCl).
Mentions: When solutions of cellulose in BMIMCl (9.1–13.0 wt%), which were prepared by heating the mixtures, were left standing at room temperature for seven days, the gelation was progressed with exclusion of excess BMIMCl from the gel matrix (Figure 4) [27]. The resulting gel was purified by washing with ethanol and dried under reduced pressure. Thus, a flexible and manipulatable gel was obtained, which was characterized by powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), and elemental analysis measurements. The XRD profile of the ion gel indicated that the crystalline structure of cellulose was mostly disrupted, but still slightly remained. The TGA profile of the ion gel showed two step weight losses at temperatures below 100 °C and higher than 250 °C. The former and latter are reasonably attributed to evaporation of water and degradation of cellulose, respectively. This data strongly indicated that the ion gel was composed not only of cellulose and BMIMCl, but also of water (ca. 15 wt%). The elemental analysis result also supported the presence of the large amount of water in the gel. The analytical results suggested the fact that the absorption of water into the solution, due to the strong hygroscopic nature of BMIMCl, probably caused the gelation of cellulose with BMIMCl. Because BMIMCl does not dissolve cellulose perfectly from a molecular point of view, aggregates of crystalline parts partially present among cellulose molecules were formed by gradually absorbing water into the solution, owing to its insolubility in water. Indeed, the colorless solution tuned into turbid during the gelation because of the formation of the aggregates. The aggregates probably acted as cross-linking points for the formation of the ion gel (Figure 5).

Bottom Line: The resulting ion gels have been characterized by suitable analytical measurements.Characterization of a pregel state by viscoelastic measurement provided the molecular weight information.Furthermore, the polysaccharide ion gels have been converted into value-added sustainable materials by appropriate procedures, such as exchange with other disperse media and regeneration.

View Article: PubMed Central - PubMed

Affiliation: Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga Koen 6-1, Kasuga, Fukuoka 816-8581, Japan. takada@mm.kyushu-u.ac.jp.

ABSTRACT
A review of the fabrication of polysaccharide ion gels with ionic liquids is presented. From various polysaccharides, the corresponding ion gels were fabricated through the dissolution with ionic liquids. As ionic liquids, in the most cases, 1-butyl-3-methylimidazolium chloride has been used, whereas 1-allyl-3methylimidazolium acetate was specifically used for chitin. The resulting ion gels have been characterized by suitable analytical measurements. Characterization of a pregel state by viscoelastic measurement provided the molecular weight information. Furthermore, the polysaccharide ion gels have been converted into value-added sustainable materials by appropriate procedures, such as exchange with other disperse media and regeneration.

Show MeSH