Abstract
Solution rheology of cellulose in 1-butyl-3-methyl imidazolium chloride ([BMIm]Cl) is reported using oscillatory and steady shear for cellulose concentrations from 0.1 to 10 wt %, spanning the dilute, semidilute unentangled, and entangled regimes. Although pure [BMIm]Cl is a crystalline solid at room temperature with a melting temperature of 65 °C, all solutions prepared at 75 °C are transparent and visually homogenous at 25 °C, and these supercooled solutions, with of order 0.1 wt % water, show no sign of crystallizing for months in either calorimetry or rheology measurements, allowing the potential for room temperature solution processing of native cellulose, such as fiber spinning. The overlap concentration of our cellulose in [BMIm]Cl is 0.5 wt % and the entanglement concentration is a factor of 4 larger (2 wt %). For semidilute unentangled solutions (between 0.5 and 2 wt %), the specific viscosity, relaxation time, and terminal modulus exhibit concentration dependences ηsp ∼ c2, τ∼c, and G∼c, respectively, while for entangled solutions (between 2 and 10 wt %) we find ηsp ∼ c14/3, τ∼ c2.3, and G∼ c 2.3, consistent with scaling predictions for neutral polymers in a θ solvent. However, failure of the Cox-Merz rule with steady shear viscosity larger than complex viscosity and the observed internal mode structure of dilute and semidilute unentangled solutions suggest that cellulose in [BMIm]Cl is not simply a flexible polymer in a θ solvent.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 485-494 |
| Number of pages | 10 |
| Journal | Journal of Rheology |
| Volume | 55 |
| Issue number | 3 |
| DOIs | |
| State | Published - May 1 2011 |
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All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
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Solution rheology of cellulose in 1-butyl-3-methyl imidazolium chloride. / Chen, Xun; Zhang, Yumei; Wang, Huaping; Wang, Shih Wa; Liang, Siwei; Colby, Ralph H.
In: Journal of Rheology, Vol. 55, No. 3, 01.05.2011, p. 485-494.Research output: Contribution to journal › Article
TY - JOUR
T1 - Solution rheology of cellulose in 1-butyl-3-methyl imidazolium chloride
AU - Chen, Xun
AU - Zhang, Yumei
AU - Wang, Huaping
AU - Wang, Shih Wa
AU - Liang, Siwei
AU - Colby, Ralph H.
PY - 2011/5/1
Y1 - 2011/5/1
N2 - Solution rheology of cellulose in 1-butyl-3-methyl imidazolium chloride ([BMIm]Cl) is reported using oscillatory and steady shear for cellulose concentrations from 0.1 to 10 wt %, spanning the dilute, semidilute unentangled, and entangled regimes. Although pure [BMIm]Cl is a crystalline solid at room temperature with a melting temperature of 65 °C, all solutions prepared at 75 °C are transparent and visually homogenous at 25 °C, and these supercooled solutions, with of order 0.1 wt % water, show no sign of crystallizing for months in either calorimetry or rheology measurements, allowing the potential for room temperature solution processing of native cellulose, such as fiber spinning. The overlap concentration of our cellulose in [BMIm]Cl is 0.5 wt % and the entanglement concentration is a factor of 4 larger (2 wt %). For semidilute unentangled solutions (between 0.5 and 2 wt %), the specific viscosity, relaxation time, and terminal modulus exhibit concentration dependences ηsp ∼ c2, τ∼c, and G∼c, respectively, while for entangled solutions (between 2 and 10 wt %) we find ηsp ∼ c14/3, τ∼ c2.3, and G∼ c 2.3, consistent with scaling predictions for neutral polymers in a θ solvent. However, failure of the Cox-Merz rule with steady shear viscosity larger than complex viscosity and the observed internal mode structure of dilute and semidilute unentangled solutions suggest that cellulose in [BMIm]Cl is not simply a flexible polymer in a θ solvent.
AB - Solution rheology of cellulose in 1-butyl-3-methyl imidazolium chloride ([BMIm]Cl) is reported using oscillatory and steady shear for cellulose concentrations from 0.1 to 10 wt %, spanning the dilute, semidilute unentangled, and entangled regimes. Although pure [BMIm]Cl is a crystalline solid at room temperature with a melting temperature of 65 °C, all solutions prepared at 75 °C are transparent and visually homogenous at 25 °C, and these supercooled solutions, with of order 0.1 wt % water, show no sign of crystallizing for months in either calorimetry or rheology measurements, allowing the potential for room temperature solution processing of native cellulose, such as fiber spinning. The overlap concentration of our cellulose in [BMIm]Cl is 0.5 wt % and the entanglement concentration is a factor of 4 larger (2 wt %). For semidilute unentangled solutions (between 0.5 and 2 wt %), the specific viscosity, relaxation time, and terminal modulus exhibit concentration dependences ηsp ∼ c2, τ∼c, and G∼c, respectively, while for entangled solutions (between 2 and 10 wt %) we find ηsp ∼ c14/3, τ∼ c2.3, and G∼ c 2.3, consistent with scaling predictions for neutral polymers in a θ solvent. However, failure of the Cox-Merz rule with steady shear viscosity larger than complex viscosity and the observed internal mode structure of dilute and semidilute unentangled solutions suggest that cellulose in [BMIm]Cl is not simply a flexible polymer in a θ solvent.
UR - http://www.scopus.com/inward/record.url?scp=79955383564&partnerID=8YFLogxK
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U2 - 10.1122/1.3553032
DO - 10.1122/1.3553032
M3 - Article
VL - 55
SP - 485
EP - 494
JO - Journal of Rheology
JF - Journal of Rheology
SN - 0148-6055
IS - 3
ER -