Cellulose nanocrystals (CNCs) are natural, sustainable, and renewable – in a word, eco-friendly – and what’s more, they can play a direct role in cleaning up pollution!
Nanocellulose-based materials are being increasingly explored as sustainable materials for environmental remediation. CNCs have proven to be highly effective adsorbents for various contaminants and pollutants, including dyes, heavy metals, pharmaceuticals, oils, and toxic gases.
Cellulose nanocrystals carry anionic surface groups that have high affinity toward dyes and heavy metals. This post examines the use of CNCs in the removal of dyes and heavy metals from wastewater and contaminated aquatic environments:
Raj et al. have found cellulose nanocrystals to be effective adsorbents for methylene blue dye due to their surface chemistry – hydroxyl groups can interact with dye molecules through hydrogen bonding and van der Waals forces, enhancing dye adsorption – and their high specific surface area.
Cellulose nanocrystals and modified charcoal were combined by Rahman et al. to create a composite adsorbent to remove methyl orange dye from wastewater. The composite demonstrated a high uptake capacity and selectivity for dyes and heavy metals including nickel, lead, chromium, cadmium, and cobalt, owing to the interaction between the CNCs and the charcoal, which created a high surface area for adsorption. The composite also maintained stability and efficiency across different pH levels and contaminant concentrations.
Li et al. modified CNCs with nano zero-valent iron (nZVI; see figure above) and used them to degrade tetrabromobisphenol A (TBBPA), a persistent environmental contaminant, showing removal efficiency of 96.5%. The enhanced performance was once again attributed to the increased adsorption capacity and efficient electron delivery facilitated by the CNC/nZVI interface. Cellulose nanocrystals also facilitate the dispersion of nZVI and provide active sites for anchoring the nZVI, increasing the surface area available for TBBPA adsorption.
Finally, cellulose nanocrystal-modified bentonite was found by Deng et al. to enhance Cr(VI) removal through a synergistic combination of ion exchange, hydrogen bonding, electrostatic interactions, and steric hindrance which improves the adsorption capacity of the mineral. CNC modification of the mineral increased its surface area and created a porous structure, allowing for more efficient adsorption of the chromium ions.
Cellulose nanocrystals’ properties such as their high specific surface area and electrostatic interactions with both substrates and contaminant molecules can lead to synergistic effects, enabling them to effectively remove a wide range of contaminants. Their ability to be further chemically modified and combined with other materials also enhances their adsorption capacities and functional properties, making them promising candidates to target more pollutants for various environmental remediation applications.
Test cellulose nanocrystals in your applications and order a free CelluRodsTM sample now!
For more information, please consult the full articles:
Cellulose nanocrystals intercalated clay biocomposite for rapid Cr(VI) removal.
About CelluForce
CelluForce manufactures and commercialises cellulose nanocrystals and formulated nanocellulose solutions to help manufacturers around the world improve the environmental footprint and the technical performance of their products.
