Investigation of the Structure of Cellulose in LiCl/DMAc Solution and Its Gelation Behavior by Small‐Angle X‐Ray Scattering Measurements

Ishii, Daisuke; Tatsumi, Daisuke; Matsumoto, Takayoshi; Murata, Kazuki; Hayashi, Hisao; Yoshitani, Hiroshi

doi:10.1002/mabi.200500231

Cited by 62 publications

(48 citation statements)

References 32 publications

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“…Of numerous cellulose solvents, several are known to give translucent gels with little shrinkage from solution. Such solvents are aqueous calcium thiocyanate (Kuga 1980;Jin et al 2004), LiCl/dimethyl acetamide (DMAc) (Ishii et al 2006;Nishio and Hirose 1992;Miyashita et al 1996), NaOH aqueous Budtova 2007, 2008), and aqueous alkali-urea (Cai et al 2008). The recently-found cellulose solvent, LiCl/dimethyl sulfoxide (DMSO) (Wang et al 2009(Wang et al , 2010 is analogous to LiCl/DMAc in composition, and therefore attracts attention regarding gelation behavior.…”

Section: Introductionmentioning

confidence: 98%

Cellulose gel and aerogel from LiCl/DMSO solution

et al. 2012

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Recently-discovered lignocellulosic solvent, 8%(w/w) lithium chloride/dimethyl sulfoxide (LiCl/DMSO), was found to dissolve cellulose of varied crystal forms and degree of polymerization. Cellulose samples could be activated for dissolution by complexation with ethylenediamine (EDA), giving EDA contents of 20-23% (w/w) in the complex irrespective of the cellulose type. The cellulose solution gave well-resolved 13 C NMR spectrum, confirming molecular dispersion. Cellulose could be coagulated by ethanol to give translucent cellulose gels, which could be converted to highly porous aerogels via solvent exchange drying. Nitrogen adsorption analysis gave their specific surface areas of 190-213 m 2 /g, with typical mesopore sizes of 10-60 nm. Scanning electron microscopy revealed the network structure of aerogel composed of relatively straight fibril segments, approx. 20 nm wide and 100-1,000 nm long. X-ray diffraction showed that the material is poorly crystalline cellulose II.

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Section: Introductionmentioning

confidence: 98%

Cellulose gel and aerogel from LiCl/DMSO solution

et al. 2012

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“…Pure cellulose is also capable of forming gels, however, in order to produce hydrogels it requires the use of special solvents, such as alkali-urea (Cai and Zhang 2006;Qin et al 2013), DMAc-LiAc (Ishii et al 2006) or ionic liquid (Kadokawa et al 2008) systems.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of cellulose derivative based superabsorbent hydrogels by radiation induced crosslinking

et al. 2014

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Hydrogels with high water uptake were prepared by ionizing radiation induced crosslinking in aqueous solutions of four cellulose derivatives (carboxymethylcellulose sodium salt-CMC-Na, methylcellulose-MC, hydroxyethylcellulose-HEC and hydroxypropylcellulose-HPC). The gel fraction increased with absorbed dose, while water uptake decreased. At high polymer concentrations lower gel fractions were found due to the lower polymer chain mobility and inhomogeneity at low water content. The swelling rate gradually slowed down after 4-5 h. CMC and HEC gels reached equilibrium after 24 h, while HPC and MC gels required longer immersion times. Gels showed second-order swelling kinetics in water. The mechanism of the water diffusion proved to be anomalous. In pure water, CMC gels showed the highest, while HPC and MC gels the lowest water uptake. The derivatives had different sensitivities to ionic strength in the swelling solution. The salt type also proved to be a significant factor at uniform ionic strength. Thus different cellulose derivative based gels may be preferred at various applications depending on the environment.

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“…Similar behavior has been observed in the LiCl/DMAc system, and the influence of the water was attributed to competitive hydrogen bonding. 13,14 The aim of the present paper is two-fold: to elucidate the mechanism of dissolution of cellulose in TBAF/DMSO and to explain the gelation that occurs on addition of water. The intermolecular interactions are monitored by 19 F NMR and 1 H NMR.…”

Section: Introductionmentioning

confidence: 99%

Dissolution and Gelation of Cellulose in TBAF/DMSO Solutions: The Roles of Fluoride Ions and Water

et al. 2009

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Solutions of cellulose in a mixture of tetrabutylammonium fluoride and dimethyl sulfoxide (TBAF/DMSO) containing small and varying amounts of water were studied by nuclear magnetic resonance (NMR). By measuring the composition dependences of 19 F NMR and 1 H NMR chemical shifts and line widths, details on the dissolution and gelation mechanisms for cellulose in TBAF/DMSO were elucidated. Our results suggest that the strongly electronegative fluoride ions act as hydrogen bond acceptors to cellulose hydroxyl groups, thus dissolving the polymer by breaking the cellulose-cellulose hydrogen bonds and by rendering the chains an effective negative charge. It was found that the fluoride ions also interact strongly with water. Small amounts of water remove the fluoride ions from the cellulose chains and allow reformation of the cellulose-cellulose hydrogen bonds, which leads to formation of highly viscous solutions or gels even at low cellulose concentrations.

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Investigation of the Structure of Cellulose in LiCl/DMAc Solution and Its Gelation Behavior by Small‐Angle X‐Ray Scattering Measurements

Cited by 62 publications

References 32 publications

Cellulose gel and aerogel from LiCl/DMSO solution

Cellulose gel and aerogel from LiCl/DMSO solution

Synthesis of cellulose derivative based superabsorbent hydrogels by radiation induced crosslinking

Dissolution and Gelation of Cellulose in TBAF/DMSO Solutions: The Roles of Fluoride Ions and Water

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