©Alexander Henn/Aalto University
Lignin nanoparticles form colourful coatings when they are applied as multilayer films.
RESEARCH BREAKTHROUGH
A Transparent Wood-Based Coating That Does Not Fog Up Edited by Aalto University Helsinki - Finland
Researchers have developed a way to turn a waste material from wood into a bio-based transparent film that can be used for anti-fogging or anti-reflective coatings on glasses or vehicle windows. In addition to offering an alternative to the toxic synthetic materials currently used, this approach transforms a waste product into a valuable carbon sink.
R
esearchers from the Finnish Aalto university have published a
films. “Optical coatings need to be transparent, but so far even rather
study demonstrating how to convert waste material from wood
thin lignin particle films have been visible. We knew that small particles
into a bio-based transparent film that can be employed for anti-
appear less turbid, so I wanted to see if I could make invisible particle
fogging or anti-reflective coatings on glasses or vehicle windows.
films by pushing the particle size to a minimum”, has stated Alexander
Lignin is an abundant waste product in paper and pulp production that
Henn, the doctoral researcher who led the study.
is very difficult to process, so it is usually burned to produce heat.
The team used acetylated lignin and developed an improved way to
Creating lignin nanoparticles to use for anti-fogging coatings is not a new
esterify it in a reaction that takes just a few minutes and happens
idea, but scientists have not yet been able to turn them into transparent
at the relatively low temperature of 60 °C. The lignin particles made
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N. 84 - NOVEMBER/DECEMBER 2023 - international PAINT&COATING magazine