Capturing colloidal nano- and microplastics with plant-based nanocellulose networks

Abstract

Microplastics accumulate in various aquatic organisms causing serious health issues, and have raised concerns about human health by entering our food chain. The recovery techniques for the most challenging colloidal fraction are limited, even for analytical purposes. Here we show how a hygroscopic nanocellulose network acts as an ideal capturing material even for the tiniest nanoplastic particles. We reveal that the entrapment of particles from aqueous environment is primarily a result of the network’s hygroscopic nature - a feature which is further intensified with the high surface area of nanocellulose. We broaden the understanding of the mechanism for particle capture by investigating the influence of pH and ionic strength on the adsorption behaviour. We determine the nanoplastic binding mechanisms using surface sensitive methods, and interpret the results with the random sequential adsorption (RSA) model. These findings hold potential for the explicit quantification of the colloidal nano- and microplastics from different aqueous environments, and eventually, provide solutions to collect them directly on-site where they are produced.

Biobased Nanomaterials─The Role of Interfacial Interactions for Advanced Materials

“…Water interacts with cellulose both at molecular and supramolecular scales, and such water–cellulose interactions are commonly present in Nature (e.g., in wood). Understanding and tailoring those interactions can lead to new, advanced applications of cellulose-based materials . Fundamental studies on CNM dispersions using calorimetry, rheology and scattering techniques, and on CNM thin films using surface-sensitive methods like QCM-D, SPR, and AFM with modeling tools, have increased our understanding of how CNMs interact with water and are affected by ionic strength and pH.…”

“…Recently Leppänen et al demonstrated the advantage of the hygroscopicity of nanocellulose networks for the entrapment of nanoscaled plastic particles from aqueous dispersions. Interestingly the binding of the plastic nanoparticles was not dependent on any specific chemical interaction.…”

Effects of Weathering on Microplastic Dispersibility and Pollutant Uptake Capacity

“…Their general toxicity and overall impact on health are difficult to assess due to variability in their chemical makeup, size, origins, and degradation pathways over time. , MPs can be classified as primary when they are released into the environment as submillimeter-sized particles, for example, from commercial products in cosmetics, tires, and textiles. , Conversely, secondary MPs are formed from the breakdown of larger plastic waste . Both primary and secondary MPs can be anticipated to undergo physical and chemical changes when released in the environment. , However, there is a significant lack of understanding of the effect of parameters such as heat or sunlight irradiance on the physical properties of MPs that determine their long-term fate and interaction with the environment. Sustainability concerns regarding plastics are rendered more critical by the small size of MPs .…”

“…23 Both primary and secondary MPs can be anticipated to undergo physical and chemical changes when released in the environment. 24,25 However, there is a significant lack of understanding of the effect of parameters such as heat or sunlight irradiance on the physical properties of MPs that determine their long-term fate and interaction with the environment. Sustainability concerns regarding plastics are rendered more critical by the small size of MPs.…”

Spectro‐Microscopic Techniques for Studying Nanoplastics in the Environment and in Organisms

“…This lack of commercially available NPs other than PS particles led to a surge in research on the synthesis of fluorescent particles, and several groups reported protocols to generate traceable particles, either by integrating fluorescent organics or metals. [24,[68][69][70] Fluorescent particles have been used to track the capture of NPs in nanocellulose networks, [71] test the stability of NPs in digestion protocols, [72] and to study the uptake in organisms such as maize plants, [73] marine larvae, [68] diatom algae, [69] acorn barnacle, [70] daphnia magna, [74][75][76] mouse brain cells, [77] zebrafish, [78,79] and freshwater mussels. [80] It should be noted that leaching of the fluorescent dye (even from commercial particles) and autofluorescence in organic matrices might make the interpretation of results challenging or misleading, as was shown when the fluorophores alone agglomerated within zebrafish larvae and the fish larvae itself displayed green autofluorescence.…”