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Title: Effect of Ionic Liquid Treatment on the Structures of Lignins in Solutions: Molecular Subunits Released from Lignin

Abstract

The solution structures of three types of isolated lignin—organosolv (OS), Kraft (K), and low sulfonate (LS)—before and after treatment with 1-ethyl-3-methylimidazolium acetate were studied using small-angle neutron scattering (SANS) and dynamic light scattering (DLS) over a concentration range of 0.3–2.4 wt %. The results indicate that each of these lignins is comprised of aggregates of well-defined basal subunits, the shapes and sizes of which, in D 2O and DMSO-d 6, are revealed using these techniques. LS lignin contains a substantial amount of nanometer-scale individual subunits. In aqueous solution these subunits have a well-defined elongated shape described well by ellipsoidal and cylindrical models. At low concentration the subunits are highly expanded in alkaline solution, and the effect is screened with increasing concentration. OS lignin dissolved in DMSO was found to consist of a narrow distribution of aggregates with average radius 200 ± 30 nm. K lignin in DMSO consists of aggregates with a very broad size distribution. In conclusion, after ionic liquid (IL) treatment, LS lignin subunits in alkaline solution maintained the elongated shape but were reduced in size. IL treatment of OS and K lignins led to the release of nanometer-scale subunits with well-defined size and shape.

Authors:
 [1];  [1];  [2];  [1];  [1];  [3];  [1];  [4];  [2];  [1];  [1]
  1. Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States). Deconstruction and Technology Divisions; Sandia National Lab. (SNL-CA), Livermore, CA (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biology and Soft Matter Division
  3. Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States). Deconstruction and Technology Divisions
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1049200
DOE Contract Number:  
AC05-00OR22725; AC02-05CH11231
Resource Type:
Journal Article
Journal Name:
Langmuir
Additional Journal Information:
Journal Volume: 28; Journal Issue: 32; Journal ID: ISSN 0743-7463
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Cheng, Gang, Kent, Michael S., He, Lilin, Varanasi, Patanjali, Dibble, Dean, Arora, Rohit, Deng, Kai, Hong, Kunlun, Melnichenko, Yuri B., Simmons, Blake A., and Singh, Seema. Effect of Ionic Liquid Treatment on the Structures of Lignins in Solutions: Molecular Subunits Released from Lignin. United States: N. p., 2012. Web. doi:10.1021/la300938b.
Cheng, Gang, Kent, Michael S., He, Lilin, Varanasi, Patanjali, Dibble, Dean, Arora, Rohit, Deng, Kai, Hong, Kunlun, Melnichenko, Yuri B., Simmons, Blake A., & Singh, Seema. Effect of Ionic Liquid Treatment on the Structures of Lignins in Solutions: Molecular Subunits Released from Lignin. United States. doi:10.1021/la300938b.
Cheng, Gang, Kent, Michael S., He, Lilin, Varanasi, Patanjali, Dibble, Dean, Arora, Rohit, Deng, Kai, Hong, Kunlun, Melnichenko, Yuri B., Simmons, Blake A., and Singh, Seema. Tue . "Effect of Ionic Liquid Treatment on the Structures of Lignins in Solutions: Molecular Subunits Released from Lignin". United States. doi:10.1021/la300938b.
@article{osti_1049200,
title = {Effect of Ionic Liquid Treatment on the Structures of Lignins in Solutions: Molecular Subunits Released from Lignin},
author = {Cheng, Gang and Kent, Michael S. and He, Lilin and Varanasi, Patanjali and Dibble, Dean and Arora, Rohit and Deng, Kai and Hong, Kunlun and Melnichenko, Yuri B. and Simmons, Blake A. and Singh, Seema},
abstractNote = {The solution structures of three types of isolated lignin—organosolv (OS), Kraft (K), and low sulfonate (LS)—before and after treatment with 1-ethyl-3-methylimidazolium acetate were studied using small-angle neutron scattering (SANS) and dynamic light scattering (DLS) over a concentration range of 0.3–2.4 wt %. The results indicate that each of these lignins is comprised of aggregates of well-defined basal subunits, the shapes and sizes of which, in D2O and DMSO-d6, are revealed using these techniques. LS lignin contains a substantial amount of nanometer-scale individual subunits. In aqueous solution these subunits have a well-defined elongated shape described well by ellipsoidal and cylindrical models. At low concentration the subunits are highly expanded in alkaline solution, and the effect is screened with increasing concentration. OS lignin dissolved in DMSO was found to consist of a narrow distribution of aggregates with average radius 200 ± 30 nm. K lignin in DMSO consists of aggregates with a very broad size distribution. In conclusion, after ionic liquid (IL) treatment, LS lignin subunits in alkaline solution maintained the elongated shape but were reduced in size. IL treatment of OS and K lignins led to the release of nanometer-scale subunits with well-defined size and shape.},
doi = {10.1021/la300938b},
journal = {Langmuir},
issn = {0743-7463},
number = 32,
volume = 28,
place = {United States},
year = {2012},
month = {6}
}