# Transparent wood: take out the lignin, fill in a matching polymer

> A staircase of four wood blocks: natural wood, the white cellulose template left when the light-absorbing lignin is removed, the template filled with a polymer whose refractive index matches the cell walls, and transparent wood that passes up to 90 % of the light. Above the steps, why it turns clear; below them, what it brings: low haze, a third of glass’s thermal conductivity and far more work of fracture, for light-transmitting buildings and solar-cell windows.

- Page: https://www.labcanvas.com/templates/graphical-abstracts/transparent-wood-take-out-lignin-fill-matching-polymer
- Open in the LabCanvas editor (LabCanvas account): https://www.labcanvas.com/editor.html?template=transparent-wood-delignify-and-fill
- Updated: 2026-10-14
- Category: Graphical abstracts
- Method: Graphical abstract
- Starting materials: A block of natural wood (balsa is among the most used)
- Product: Transparent wood: a cellulose template filled with an index-matched polymer
- Key result: Transmittance 85 %, haze 71 % (Li et al. 2016); 90 % and 10 % (Jia et al. 2019); 0.35 W m⁻¹ K⁻¹ against ~1 for glass (Jia et al. 2019); work of fracture 1.2 MJ m⁻³, an order of magnitude above glass (Li et al. 2017)
- Figure: 1920 × 1080 px, 99 editable layers (4 generated objects with settings)

## Steps

1. **Natural wood**: Lignin absorbs light, and the cell walls (refractive index about 1.53) scatter it at the air-filled cells (index 1) (Li et al. 2016; Pugliese & Malucelli 2025)
2. **Remove lignin**: Delignification takes out around 30 wt % of the wood and leaves a white, nanoporous cellulose template with the cell structure kept (Li et al. 2017; Li et al. 2016)
3. **Infiltrate**: A refractive-index-matched prepolymerized monomer (MMA) fills the lumens and the nanopores of the cell walls (Li et al. 2016)
4. **Transparent wood**: Up to 85 % transmittance at 71 % haze (Li et al. 2016); clear wood reaches 90 % with 10 % haze and conducts heat at a third of glass’s rate (Jia et al. 2019)

## Uses

- Graphical abstracts on transparent wood and cellulose materials
- Talks on bio-based optical materials and energy-saving buildings
- Teaching refractive-index matching

## References

1. Li, Fu, Yu, Yan & Berglund, “Optically Transparent Wood from a Nanoporous Cellulosic Template: Combining Functional and Structural Performance”, Biomacromolecules 2016. https://doi.org/10.1021/acs.biomac.6b00145 (method origin)
2. Li et al., “Lignin-Retaining Transparent Wood”, ChemSusChem 2017. https://doi.org/10.1002/cssc.201701089 (primary)
3. Jia et al., “Clear Wood toward High-Performance Building Materials”, ACS Nano 2019. https://doi.org/10.1021/acsnano.9b00089 (primary)
4. Pugliese & Malucelli, “Toward the Optimization of the Optical Behavior of Transparent Wood: Current State of the Art and Perspectives”, Polymers 2025. https://doi.org/10.3390/polym17243276 (review)

Credit: Drawn by LabCanvas after Li et al., Biomacromolecules 2016 (doi:10.1021/acs.biomac.6b00145); Li et al., ChemSusChem 2017 (doi:10.1002/cssc.201701089); Jia et al., ACS Nano 2019 (doi:10.1021/acsnano.9b00089) and Pugliese & Malucelli, Polymers 2025 (doi:10.3390/polym17243276).

## Questions

**What does the “Transparent wood: take out the lignin, fill in a matching polymer” template show?** A staircase of four wood blocks: natural wood, the white cellulose template left when the light-absorbing lignin is removed, the template filled with a polymer whose refractive index matches the cell walls, and transparent wood that passes up to 90 % of the light. Above the steps, why it turns clear; below them, what it brings: low haze, a third of glass’s thermal conductivity and far more work of fracture, for light-transmitting buildings and solar-cell windows.

**What are the steps shown in “Transparent wood: take out the lignin, fill in a matching polymer”?** 1. Natural wood: Lignin absorbs light, and the cell walls (refractive index about 1.53) scatter it at the air-filled cells (index 1) (Li et al. 2016; Pugliese & Malucelli 2025). 2. Remove lignin: Delignification takes out around 30 wt % of the wood and leaves a white, nanoporous cellulose template with the cell structure kept (Li et al. 2017; Li et al. 2016). 3. Infiltrate: A refractive-index-matched prepolymerized monomer (MMA) fills the lumens and the nanopores of the cell walls (Li et al. 2016). 4. Transparent wood: Up to 85 % transmittance at 71 % haze (Li et al. 2016); clear wood reaches 90 % with 10 % haze and conducts heat at a third of glass’s rate (Jia et al. 2019).

**What are the starting materials and the product?** Starting materials: A block of natural wood (balsa is among the most used). Product: Transparent wood: a cellulose template filled with an index-matched polymer.

**Which papers is “Transparent wood: take out the lignin, fill in a matching polymer” based on?** Li, Fu, Yu, Yan & Berglund, “Optically Transparent Wood from a Nanoporous Cellulosic Template: Combining Functional and Structural Performance”, Biomacromolecules 2016 (doi:10.1021/acs.biomac.6b00145); Li et al., “Lignin-Retaining Transparent Wood”, ChemSusChem 2017 (doi:10.1002/cssc.201701089); Jia et al., “Clear Wood toward High-Performance Building Materials”, ACS Nano 2019 (doi:10.1021/acsnano.9b00089); Pugliese & Malucelli, “Toward the Optimization of the Optical Behavior of Transparent Wood: Current State of the Art and Perspectives”, Polymers 2025 (doi:10.3390/polym17243276).

**Can I edit the “Transparent wood: take out the lignin, fill in a matching polymer” template?** Yes. Open it in the LabCanvas editor: all 99 layers are editable, including 4 generated objects (structures, plots, equipment) with their own settings. Change the text, colours and layout, then export PNG, TIFF, SVG or PDF.

**Do I need an account to use this template?** Not to view it here. To open and edit it, sign in to LabCanvas or create a free account (the free plan keeps up to 3 designs). Downloading the figure is part of LabCanvas Pro (US$19 a month or US$199 a year).