Tritium labelling to study humic substance-nanodiamond composites

Area of Science:

• Environmental Science
• Materials Science
• Nanotechnology

Background:

• Detonation nanodiamonds are utilized in various applications, including lubricants and composites.
• Understanding nanodiamonds' surface properties is crucial for predicting their environmental behavior.
• Interaction with natural organic matter influences nanoparticle fate and transport.

Purpose of the Study:

• To investigate the adsorption of humic substances onto nanodiamonds.
• To determine how nanodiamond surface properties affect this interaction.
• To assess the impact of these interactions on nanodiamond uptake by plants.

Main Methods:

• Utilized tritium-labelled humic substances for quantitative adsorption analysis.
• Measured nanodiamond zeta potential in aqueous solutions.
• Quantified nanodiamond uptake by wheat seedlings.

Main Results:

• Humic substance adsorption onto nanodiamonds caused fractionation, dependent on nanodiamond zeta potential.
• Nanodiamond uptake by wheat seedlings was not significantly affected by humic substance adsorption.
• Plant uptake of nanodiamond particles was primarily governed by the surface functional groups of the nanodiamonds.

Conclusions:

• Nanodiamond surface properties, specifically zeta potential, significantly influence interactions with natural organic matter.
• While humic substance interactions occur, they do not impede nanodiamond uptake by wheat seedlings.
• The functional composition of nanodiamond surfaces is the key determinant for plant uptake.