Christoph Hötte
Research interests
- chemical wood modification
- impregnation
- wood drying and curing
- development and optimization of wood modification processes
Projects
- ZitroWood - Bio-based and environmentally friendly modification of wood based on sorbitol and citric acid
Publications

Excellent! Next you can
create a new website with this list, or
embed it in an existing web page by copying & pasting
any of the following snippets.
JavaScript
(easiest)
PHP
iFrame
(not recommended)
<script src="https://bibbase.org/show?bib=https://owncloud.gwdg.de/index.php/s/Q5ML8nhrPoIyEl9/download&jsonp=1&jsonp=1"></script>
<?php
$contents = file_get_contents("https://bibbase.org/show?bib=https://owncloud.gwdg.de/index.php/s/Q5ML8nhrPoIyEl9/download&jsonp=1");
print_r($contents);
?>
<iframe src="https://bibbase.org/show?bib=https://owncloud.gwdg.de/index.php/s/Q5ML8nhrPoIyEl9/download&jsonp=1"></iframe>
For more details see the documention.
This is a preview! To use this list on your own web site
or create a new web site from it,
create a free account. The file will be added
and you will be able to edit it in the File Manager.
We will show you instructions once you've created your account.
To the site owner:
Action required! Mendeley is changing its API. In order to keep using Mendeley with BibBase past April 14th, you need to:
- renew the authorization for BibBase on Mendeley, and
- update the BibBase URL in your page the same way you did when you initially set up this page.
2025
(2)
Fire behavior of thermally modified pine (Pinus sylvestris) treated with DMDHEU and flame retardants: from small scale to SBI tests.
Wu, M.; Hötte, C.; Karthäuser, J.; and Militz, H.
Holzforschung, 0(0). April 2025.
Publisher: De Gruyter Section: Holzforschung
Paper
doi
link
bibtex
abstract
@article{wu_fire_2025, title = {Fire behavior of thermally modified pine ({Pinus} sylvestris) treated with {DMDHEU} and flame retardants: from small scale to {SBI} tests}, volume = {0}, copyright = {De Gruyter expressly reserves the right to use all content for commercial text and data mining within the meaning of Section 44b of the German Copyright Act.}, issn = {1437-434X}, shorttitle = {Fire behavior of thermally modified pine ({Pinus} sylvestris) treated with {DMDHEU} and flame retardants}, url = {https://www.degruyterbrill.com/document/doi/10.1515/hf-2025-0021/html}, doi = {10.1515/hf-2025-0021}, abstract = {In this study, thermally modified Scots pine ( Pinus sylvestris L.) was impregnated with DMDHEU (1,3-dimethylol-4,5-dihydroxyethyleneurea) monomers combined with a flame retardant (FR) based on monoguanidine phosphate salt. Fire performance was assessed using ignitability tests (ISO 11925-2, 2020), mass loss calorimetry test (ISO 13927, 2015), and single burning item (SBI) tests (EN 13823, 2020). Results showed enhanced flame retardancy, reaching Class B in the SBI test. Small-scale ignitability tests revealed minor differences in flame spread across samples, unlike the SBI results. Fire growth rate and ignition time from mass loss calorimetry strongly correlated with burning suppression in the SBI test.}, language = {en}, number = {0}, urldate = {2025-04-25}, journal = {Holzforschung}, author = {Wu, Muting and Hötte, Christoph and Karthäuser, Johannes and Militz, Holger}, month = apr, year = {2025}, note = {Publisher: De Gruyter Section: Holzforschung}, file = {Full Text PDF:/home/maicher/Zotero/storage/YQQDMZXV/Wu et al. - 2025 - Fire behavior of thermally modified pine (Pinus sy.pdf:application/pdf}, }
In this study, thermally modified Scots pine ( Pinus sylvestris L.) was impregnated with DMDHEU (1,3-dimethylol-4,5-dihydroxyethyleneurea) monomers combined with a flame retardant (FR) based on monoguanidine phosphate salt. Fire performance was assessed using ignitability tests (ISO 11925-2, 2020), mass loss calorimetry test (ISO 13927, 2015), and single burning item (SBI) tests (EN 13823, 2020). Results showed enhanced flame retardancy, reaching Class B in the SBI test. Small-scale ignitability tests revealed minor differences in flame spread across samples, unlike the SBI results. Fire growth rate and ignition time from mass loss calorimetry strongly correlated with burning suppression in the SBI test.
Investigating the Efficacy of Established Chemical Wood Modifications on Large-Diameter Pine: Durability Against Basidiomycetes.
Martin, L. S.; Stolze, H.; Hötte, C.; and Militz, H.
Materials, 18(13): 2985. June 2025.
Paper
doi
link
bibtex
abstract
@article{martin_investigating_2025, title = {Investigating the {Efficacy} of {Established} {Chemical} {Wood} {Modifications} on {Large}-{Diameter} {Pine}: {Durability} {Against} {Basidiomycetes}}, volume = {18}, copyright = {https://creativecommons.org/licenses/by/4.0/}, issn = {1996-1944}, shorttitle = {Investigating the {Efficacy} of {Established} {Chemical} {Wood} {Modifications} on {Large}-{Diameter} {Pine}}, url = {https://www.mdpi.com/1996-1944/18/13/2985}, doi = {10.3390/ma18132985}, abstract = {In Germany, Pinus sylvestris is a dominant tree species, and many trees with large diameters are not utilised due to difficulties with processing. However, older pines have larger volumes of sapwood, and boards with a high sapwood content can be produced. The durability of boards from large-diameter ({\textgreater}50 cm) P. sylvestris trees, treated with furfurylation, acetylation, DMDHEU (1.3-dimethylol-4.5-dihydroxyethyleneurea), and SorCA (Sorbitol/Citric Acid), was assessed. The samples were taken from different sections along the longitudinal axis and the cross-section. The durability was tested against Coniophora puteana, Rhodonia placenta, and Trametes versicolor, according to the EN 113-2 standard. All treatments had a median mass loss {\textless} 5\%, so classed as “highly durable” (Durability Class 1) against all fungi. DMDHEU had a large deviation in mass loss against Coniophora puteana and could potentially be classified as “moderately durable” (Durability Class 3), if based on the mean mass loss. The inner part of the end section had a higher mass loss, indicating that there was poorer retention of the treatment at this location. Overall, chemical modifications on large-diameter pine trees were effective at increasing durability. Utilising large-diameter pine trees can help to make use of regional resources and potentially reduce reliance on imported timber. With favourable mechanical properties and easy-to-treat sapwood, large-diameter P. sylvestris trees could be used for commercial treatments.}, language = {en}, number = {13}, urldate = {2025-06-25}, journal = {Materials}, author = {Martin, Lucy S. and Stolze, Hannes and Hötte, Christoph and Militz, Holger}, month = jun, year = {2025}, pages = {2985}, file = {PDF:/home/maicher/Zotero/storage/C2R3QCT9/Martin et al. - 2025 - Investigating the Efficacy of Established Chemical Wood Modifications on Large-Diameter Pine Durabi.pdf:application/pdf}, }
In Germany, Pinus sylvestris is a dominant tree species, and many trees with large diameters are not utilised due to difficulties with processing. However, older pines have larger volumes of sapwood, and boards with a high sapwood content can be produced. The durability of boards from large-diameter (\textgreater50 cm) P. sylvestris trees, treated with furfurylation, acetylation, DMDHEU (1.3-dimethylol-4.5-dihydroxyethyleneurea), and SorCA (Sorbitol/Citric Acid), was assessed. The samples were taken from different sections along the longitudinal axis and the cross-section. The durability was tested against Coniophora puteana, Rhodonia placenta, and Trametes versicolor, according to the EN 113-2 standard. All treatments had a median mass loss \textless 5%, so classed as “highly durable” (Durability Class 1) against all fungi. DMDHEU had a large deviation in mass loss against Coniophora puteana and could potentially be classified as “moderately durable” (Durability Class 3), if based on the mean mass loss. The inner part of the end section had a higher mass loss, indicating that there was poorer retention of the treatment at this location. Overall, chemical modifications on large-diameter pine trees were effective at increasing durability. Utilising large-diameter pine trees can help to make use of regional resources and potentially reduce reliance on imported timber. With favourable mechanical properties and easy-to-treat sapwood, large-diameter P. sylvestris trees could be used for commercial treatments.
2024
(2)
Esterification of wood with citric acid and sorbitol: effect of the copolymer on the properties of the modified wood. Part 1: macroscopic changes, fixation of chemicals and impact bending properties.
Hötte, C.; and Militz, H.
Holzforschung, 78(11-12): 673–682. December 2024.
Paper
doi
link
bibtex
abstract
@article{hotte_esterification_2024, title = {Esterification of wood with citric acid and sorbitol: effect of the copolymer on the properties of the modified wood. {Part} 1: macroscopic changes, fixation of chemicals and impact bending properties}, volume = {78}, issn = {0018-3830, 1437-434X}, shorttitle = {Esterification of wood with citric acid and sorbitol}, url = {https://www.degruyter.com/document/doi/10.1515/hf-2024-0070/html}, doi = {10.1515/hf-2024-0070}, abstract = {Wood modification processes based on citric acid in combination with various copolymers have gained in importance in recent years. These processes also include modification with citric acid (CA) and sorbitol, a sugar alcohol, which is currently in the industrial realisation phase in Germany (SorCA) and Norway (CIOL). The modification of wood with sorbitol and citric acid (SorCA) can significantly improve the dimensional stability and durability of the wood. It is hypothesised that the addition of a copolymer may improve the fixation of the chemicals within as well as the flexibility of the modified wood matrix. In this study, the macroscopic changes, the fixation of the chemicals and the impact bending properties of wood modified with CA and SorCA are compared. Both modifications cause a permanent increase in mass (WPG) and volume (CWB). The fixation of the chemicals was comparable for both modifications; at high chemical concentrations, the SorCA polyester fixed slightly better within the wood matrix. Both modifications led to embrittlement of the wood, measured by a decrease in the impact bending strength (IBS). This embrittlement was clearly concentration-dependent and slightly more pronounced for the modification with CA.}, language = {en}, number = {11-12}, urldate = {2024-12-16}, journal = {Holzforschung}, author = {Hötte, Christoph and Militz, Holger}, month = dec, year = {2024}, pages = {673--682}, file = {Hötte and Militz - 2024 - Esterification of wood with citric acid and sorbit.pdf:/home/maicher/Zotero/storage/WBBU678Z/Hötte and Militz - 2024 - Esterification of wood with citric acid and sorbit.pdf:application/pdf}, }
Wood modification processes based on citric acid in combination with various copolymers have gained in importance in recent years. These processes also include modification with citric acid (CA) and sorbitol, a sugar alcohol, which is currently in the industrial realisation phase in Germany (SorCA) and Norway (CIOL). The modification of wood with sorbitol and citric acid (SorCA) can significantly improve the dimensional stability and durability of the wood. It is hypothesised that the addition of a copolymer may improve the fixation of the chemicals within as well as the flexibility of the modified wood matrix. In this study, the macroscopic changes, the fixation of the chemicals and the impact bending properties of wood modified with CA and SorCA are compared. Both modifications cause a permanent increase in mass (WPG) and volume (CWB). The fixation of the chemicals was comparable for both modifications; at high chemical concentrations, the SorCA polyester fixed slightly better within the wood matrix. Both modifications led to embrittlement of the wood, measured by a decrease in the impact bending strength (IBS). This embrittlement was clearly concentration-dependent and slightly more pronounced for the modification with CA.
Modification of different European hardwood species with a bio-based thermosetting resin on a semi-industrial scale.
Hötte, C.; and Militz, H.
In 11th Hardwood Conference Proceedings, volume 11, pages 557–563, Sopron, Hungary,, May 2024. University of Sopron Press
link bibtex
link bibtex
@inproceedings{hotte_modification_2024, address = {Sopron, Hungary,}, title = {Modification of different {European} hardwood species with a bio-based thermosetting resin on a semi-industrial scale}, volume = {11}, booktitle = {11th {Hardwood} {Conference} {Proceedings}}, publisher = {University of Sopron Press}, author = {Hötte, Christoph and Militz, Holger}, month = may, year = {2024}, pages = {557--563}, }
2023
(1)
Investigation of oil curing as an alternative curing procedure for Scots pine modified with sorbitol and citric acid.
Rabke, J.; Hötte, C.; and Militz, H.
In Proceedings of the 19th Meeting of the Northern European Network for Wood Science and Engineering (WSE), pages 13–15, Ås, Norway, October 2023.
link bibtex
link bibtex
@inproceedings{rabke_investigation_2023, address = {Ås, Norway}, title = {Investigation of oil curing as an alternative curing procedure for {Scots} pine modified with sorbitol and citric acid}, booktitle = {Proceedings of the 19th {Meeting} of the {Northern} {European} {Network} for {Wood} {Science} and {Engineering} ({WSE})}, author = {Rabke, Joshua and Hötte, Christoph and Militz, Holger}, month = oct, year = {2023}, pages = {13--15}, }
2022
(1)
Holzmodifizierung mit Zitronensäure und Zuckeralkoholen – Optimierung des Trocknungs- und Aushärtungsprozesses.
Hötte, C.
Technical Report Wood Biology and Wood Products, Faculty of Forest Sciences and Forest Ecology,University of Goettingen, Göttingen, Germany, November 2022.
link bibtex
link bibtex
@techreport{hotte_holzmodifizierung_2022, address = {Göttingen, Germany}, type = {Master thesis}, title = {Holzmodifizierung mit {Zitronensäure} und {Zuckeralkoholen} – {Optimierung} des {Trocknungs}- und {Aushärtungsprozesses}}, language = {ger de}, institution = {Wood Biology and Wood Products, Faculty of Forest Sciences and Forest Ecology,University of Goettingen}, author = {Hötte, Christoph}, month = nov, year = {2022}, pages = {152}, file = {Hötte - 2022 - Holzmodifizierung mit Zitronensäure und Zuckeralko.pdf:/home/maicher/Zotero/storage/CIY9IALI/Hötte - 2022 - Holzmodifizierung mit Zitronensäure und Zuckeralko.pdf:application/pdf}, }