Solid-state 29Si NMR and FTIR analyses of lignin-silica coprecipitates

Yohanna Cabrera Orozco; Andrés Cabrera; Flemming Hofmann Larsen; Claus Felby

doi:10.1515/hf-2015-0165

Solid-state ²⁹Si NMR and FTIR analyses of lignin-silica coprecipitates

Yohanna Cabrera Orozco, Andrés Cabrera, Flemming Hofmann Larsen, Claus Felby

13 Citations (Scopus)

Abstract

When agricultural residues are processed to ethanol, lignin and silica are some of the main byproducts. Separation of these two products is difficult and the chemical interactions between lignin and silica are not well described. In the present study, the effect of lignin-silica complexing has been investigated by characterizing lignin and silica coprecipitates by FTIR and solid state NMR. Silica particles were coprecipitated with three different lignins, three lignin model compounds, and two silanes representing silica-in-lignin model compounds. Comparison of ²⁹Si SP/MAS NMR spectra revealed differences in the distribution of silanol hydroxyl groups among different coprecipitates. These differences are dependent on the lignin type. The results are interpreted that the underlying mechanism of the interactions is the formation of hydrogen bonds between lignin aliphatic hydroxyl or carboxyl groups and the silanols, but not a condensation of the silica-in-lignin among the silica particles and not the formation of C-O-Si bonds.

Original language	English
Journal	Holzforschung
Volume	70
Issue number	8
Pages (from-to)	709-718
Number of pages	10
ISSN	0018-3830
DOIs	https://doi.org/10.1515/hf-2015-0165
Publication status	Published - 2016

Keywords

C NMR
Si SP/MAS NMR
FTIR
lignin
lignin-silica-interactions
silans
silica
solid-state NMR

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10.1515/hf-2015-0165

http://www.degruyter.com/downloadpdf/j/hfsg.2016.70.issue-8/hf-2015-0165/hf-2015-0165.xml

Cite this

@article{a0fd284e47604907a0119c6ac0eba9af,

title = "Solid-state 29Si NMR and FTIR analyses of lignin-silica coprecipitates",

abstract = "When agricultural residues are processed to ethanol, lignin and silica are some of the main byproducts. Separation of these two products is difficult and the chemical interactions between lignin and silica are not well described. In the present study, the effect of lignin-silica complexing has been investigated by characterizing lignin and silica coprecipitates by FTIR and solid state NMR. Silica particles were coprecipitated with three different lignins, three lignin model compounds, and two silanes representing silica-in-lignin model compounds. Comparison of 29Si SP/MAS NMR spectra revealed differences in the distribution of silanol hydroxyl groups among different coprecipitates. These differences are dependent on the lignin type. The results are interpreted that the underlying mechanism of the interactions is the formation of hydrogen bonds between lignin aliphatic hydroxyl or carboxyl groups and the silanols, but not a condensation of the silica-in-lignin among the silica particles and not the formation of C-O-Si bonds.",

keywords = "C NMR, Si SP/MAS NMR, FTIR, lignin, lignin-silica-interactions, silans, silica, solid-state NMR",

author = "{Cabrera Orozco}, Yohanna and Andr{\'e}s Cabrera and Larsen, {Flemming Hofmann} and Claus Felby",

year = "2016",

doi = "10.1515/hf-2015-0165",

language = "English",

volume = "70",

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TY - JOUR

T1 - Solid-state 29Si NMR and FTIR analyses of lignin-silica coprecipitates

AU - Cabrera Orozco, Yohanna

AU - Cabrera, Andrés

AU - Larsen, Flemming Hofmann

AU - Felby, Claus

PY - 2016

Y1 - 2016

N2 - When agricultural residues are processed to ethanol, lignin and silica are some of the main byproducts. Separation of these two products is difficult and the chemical interactions between lignin and silica are not well described. In the present study, the effect of lignin-silica complexing has been investigated by characterizing lignin and silica coprecipitates by FTIR and solid state NMR. Silica particles were coprecipitated with three different lignins, three lignin model compounds, and two silanes representing silica-in-lignin model compounds. Comparison of 29Si SP/MAS NMR spectra revealed differences in the distribution of silanol hydroxyl groups among different coprecipitates. These differences are dependent on the lignin type. The results are interpreted that the underlying mechanism of the interactions is the formation of hydrogen bonds between lignin aliphatic hydroxyl or carboxyl groups and the silanols, but not a condensation of the silica-in-lignin among the silica particles and not the formation of C-O-Si bonds.

AB - When agricultural residues are processed to ethanol, lignin and silica are some of the main byproducts. Separation of these two products is difficult and the chemical interactions between lignin and silica are not well described. In the present study, the effect of lignin-silica complexing has been investigated by characterizing lignin and silica coprecipitates by FTIR and solid state NMR. Silica particles were coprecipitated with three different lignins, three lignin model compounds, and two silanes representing silica-in-lignin model compounds. Comparison of 29Si SP/MAS NMR spectra revealed differences in the distribution of silanol hydroxyl groups among different coprecipitates. These differences are dependent on the lignin type. The results are interpreted that the underlying mechanism of the interactions is the formation of hydrogen bonds between lignin aliphatic hydroxyl or carboxyl groups and the silanols, but not a condensation of the silica-in-lignin among the silica particles and not the formation of C-O-Si bonds.

KW - C NMR

KW - Si SP/MAS NMR

KW - FTIR

KW - lignin

KW - lignin-silica-interactions

KW - silans

KW - silica

KW - solid-state NMR

U2 - 10.1515/hf-2015-0165

DO - 10.1515/hf-2015-0165

M3 - Journal article

AN - SCOPUS:84983379444

SN - 0018-3830

VL - 70

SP - 709

EP - 718

JO - Holzforschung

JF - Holzforschung

IS - 8