Microstructures of cellulose coagulated in water and alcohols from 1-ethyl-3-methylimidazolium acetate: contrasting coagulation mechanisms

Hedlund, ArturRISE,IVF,Chalmers University of Technology, Sweden,Swerea IVF, Biobased Fibers, Argongatan 30, S-43153 Molndal, Sweden.;Chalmers Univ Technol, Forest Prod & Chem Engn, Gothenburg, Sweden.,Chalmers tekniska högskola (författare)

Microstructures of cellulose coagulated in water and alcohols from 1-ethyl-3-methylimidazolium acetate : contrasting coagulation mechanisms

QC 20190326
Abstract: Coagulation of cellulose solutions is a process whereby many useful materials with variable microstructures and properties can be produced. This study investigates the complexity of the phase separation that generates the structural heterogeneity of such materials. The ionic liquid, 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), and a co-solvent, dimethylsulfoxide (DMSO), are used to dissolve microcrystalline cellulose in concentrations from 5 to 25 wt%. The solutions are coagulated in water or 2-propanol (2PrOH). The coagulated material is then washed and solvent exchanged (water → 2PrOH → butanone → cyclohexane) in order to preserve the generated microstructures upon subsequent drying before analysis. Sweep electron microscopy images of 50 k magnification reveal open-pore fibrillar structures. The crystalline constituents of those fibrils are estimated using wide-angle X-ray spectroscopy and specific surface area data. It is found that the crystalline order or crystallite size is reduced by an increase in cellulose concentration, by the use of the co-solvent DMSO, or by the use of 2PrOH instead of water as the coagulant. Because previous theories cannot explain these trends, an alternative explanation is presented here focused on solid–liquid versus liquid–liquid phase separations. Graphical abstract: [Figure not available: see fulltext.].

NATURVETENSKAP Kemi hsv//swe
NATURAL SCIENCES Chemical Sciences hsv//eng
NATURVETENSKAP Kemi Oorganisk kemi hsv//swe
NATURAL SCIENCES Chemical Sciences Inorganic Chemistry hsv//eng
NATURVETENSKAP Kemi Fysikalisk kemi hsv//swe
NATURAL SCIENCES Chemical Sciences Physical Chemistry hsv//eng
NATURVETENSKAP Kemi Annan kemi hsv//swe
NATURAL SCIENCES Chemical Sciences Other Chemistry Topics hsv//eng
TEKNIK OCH TEKNOLOGIER Materialteknik Pappers-, massa- och fiberteknik hsv//swe
ENGINEERING AND TECHNOLOGY Materials Engineering Paper, Pulp and Fiber Technology hsv//eng
NATURVETENSKAP Kemi Materialkemi hsv//swe
NATURAL SCIENCES Chemical Sciences Materials Chemistry hsv//eng
Cellulose
Co-solvent
Ionic liquid
Microstructure
Non-solvent
Regeneration
Coagulation
Crystallite size
Ionic liquids
Ketones
Phase separation
Praseodymium compounds
Solvents
X ray spectroscopy
1-ethyl-3-methylimidazolium acetates
Cosolvents
Electron microscopy images
Micro-crystalline cellulose
Microstructures and properties
Non-solvents
Structural heterogeneity
Cellulose
Co-solvent
Ionic liquid
Microstructure
Non-solvent
Regeneration

Köhnke, TobiasRISE,IVF,Swerea IVF, Biobased Fibers, Argongatan 30, S-43153 Molndal, Sweden.(Swepub:ri)tobiasko@ri.se (författare)
Hagman, JoelLund University,Lunds universitet,Fysikalisk kemi,Enheten för fysikalisk och teoretisk kemi,Kemiska institutionen,Institutioner vid LTH,Lunds Tekniska Högskola,Physical Chemistry,Physical and theoretical chemistry,Department of Chemistry,Departments at LTH,Faculty of Engineering, LTH(Swepub:lu)fkem-jhn (författare)
Olsson, UlfLund University,Lunds universitet,Fysikalisk kemi,Enheten för fysikalisk och teoretisk kemi,Kemiska institutionen,Institutioner vid LTH,Lunds Tekniska Högskola,Physical Chemistry,Physical and theoretical chemistry,Department of Chemistry,Departments at LTH,Faculty of Engineering, LTH(Swepub:lu)fk1-uol (författare)
Theliander, HansKTH Royal Institute of Technology,KTH,Wallenberg Wood Science Center,Chalmers Univ Technol, Forest Prod & Chem Engn, Gothenburg, Sweden.;Chalmers Univ Technol,,Chalmers University of Technology, Sweden; KTH Royal Institute of Technology, Sweden,Chalmers tekniska högskola(Swepub:cth)hanst (författare)
RISEIVF (creator_code:org_t)

Ingår i:Cellulose: Springer Science and Business Media LLC26:3, s. 1545-15630969-02391572-882X

Av författaren/redakt...: Hedlund, Artur; Köhnke, Tobias; Hagman, Joel; Olsson, Ulf; Theliander, Hans

Om ämnet

TEKNIK OCH TEKNOLOGIER: TEKNIK OCH TEKNO ...; och Materialteknik; och Pappers massa oc ...

Av lärosätet: RISE; Kungliga Tekniska Högskolan; Chalmers tekniska högskola; Lunds universitet

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