This article is a layman adaptation of the TRANSLATE publication “Nanowood: A Unique Natural Nanomaterial That Can Be Obtained Using Household Chemicals”, from the UCC TRANSLATE team.
Nedrygailov, I., O’Brien, D., Monaghan, S., Hurley, P., Biswas, S., & Holmes, J. D. (2024). Nanowood: A Unique Natural Nanomaterial That Can Be Obtained Using Household Chemicals. Journal of Chemical Education. DOI: 10.1021/acs.jchemed.4c00166
Why Fluids Behave Differently at the Nanoscale
At the nanoscale, fluids do not behave as they do in bulk form. Their electrical conductivity, viscosity, and even their ionic composition can shift dramatically when confined within nanochannels. These effects are largely due to interactions between the fluid and the walls of the nanostructure. In particular, due to the formation of an electric double layer (EDL)—a charged interface that can influence ion transport. The study of such confined fluids falls under the emerging field of nanofluidics, which has applications in energy harvesting, bioanalysis, and lab-on-a-chip devices.
One of the main challenges in studying nanofluidics, however, is that fabricating nanofluidic structures usually requires highly specialised equipment and cleanroom conditions. This limits its accessibility, particularly in teaching environments.
Related read: In the nanochannel, heat is converted into electricity
A Natural Alternative: Turning Wood into a Nanofluidic Membrane
This research introduces ‘nanowood’, a natural material containing a network of nanochannels which can be produced from a simple chemical treatment. By removing lignin—the glue-like component that holds wood fibres together—the researchers create a membrane consisting mostly of cellulose fibres, leaving behind well-aligned nanochannels.
(Figure, left) (a) A log of natural wood, used as a raw material for the manufacturing of nanowood membranes. (b) Wood blocks measuring 20×20×6 mm, after cutting the log with a saw. (c) Wood blocks on the first day after being placed in the household bleach solution. (d) Delignified wood blocks (nanowood membranes) in DI water.
Figure from Nedrygailov et al. (2024). Source: DOI: 10.1021/acs.jchemed.4c00166.
This study demonstrates that this delignification process can be performed using common household bleach, making nanowood an accessible platform for nanofluidics research and education.
Testing Nanowood’s Nanofluidic Properties
To confirm that nanowood exhibits nanofluidic behaviour, the researchers investigated its ionic conductance in different concentrations of sodium chloride (NaCl) solution. Conductance measurements were carried out using electrochemical impedance spectroscopy (EIS)—a technique that examines how ions move through a material by applying an AC voltage and measuring the response.
Key Findings: Conductance Changes at Low Ion Concentrations
- At high NaCl concentrations, the conductance of nanowood behaves similarly to a bulk electrolyte solution—following classical models where more ions lead to higher conductance.
- At low NaCl concentrations, however, conductance stops depending on bulk ion concentration and instead becomes governed by surface charge effects in the nanochannels. This suggests that the nanochannels selectively influence ion transport, a hallmark of nanofluidic behaviour.
Implications and Future Applications
- Educational potential: Nanowood provides a low-cost way to study nanofluidics in university labs, helping students visualise nanoscale fluid behaviour without expensive fabrication methods.
- Sustainable nanomaterials: The ability to create functional nanomaterials from wood, a renewable resource, opens pathways for eco-friendly applications in filtration, sensing, and energy harvesting.
- Further research: The study paves the way for more advanced research into modifying nanowood’s properties for specific applications, such as ion-selective membranes or bio-inspired nanofluidic devices.
(Figure, right) Schematic illustration of the manufacturing of nanowood membranes. After lignin is removed, a nanowood is formed, which is a matrix of cellulose fibres forming a system of well-aligned nanofluidic channels
Figure from Nedrygailov et al. (2024). Source: DOI: 10.1021/acs.jchemed.4c00166.
Conclusion: A Simple Yet Powerful Nanomaterial
This study highlights nanowood as a practical and sustainable nanofluidic material. By leveraging the natural structure of wood and applying basic chemical treatment, the researchers have created a platform that enables further exploration of nanoscale ion transport. This work not only deepens our understanding of nanofluidics but also provides an innovative approach to making nanoscience more accessible to students and researchers alike.
You may also be interested in: Harvesting Electricity from Wood: The NXTGENWOOD-TRANSLATE Link
