No abstract

Microplastic pollution is omnipresenthaving been found in our land, air, food, and water. Over the last two decades, both identifying microplastics and sleuthing their sources has been a major research focus. Moving forward, the next goal should be remediation. Although removing microplastics from the environment is impractical, developing methods that prevent their release into the environment is essential. Herein, we report an approach for removing microplastics from water using a pressuresensitive adhesive. Specifically, we demonstrate that shaking zirconium silicate beads coated with poly(2-ethylhexyl acrylate) in aqueous suspensions containing polystyrene microplastics (10 μm) can remove up to 99% of the microplastics within 5 min. We show that the adhesive molar mass (ranging from 93−950 kg/ mol) is invariant with respect to removal efficiency at 5 min, as quantified by flow cytometry. Preliminary results suggest these adhesives can bind other microplastics as well, including nonpolar polymers (e.g., polyethylene, micronized rubber) and polar polymers (e.g., nylon, polyethylene terephthalate). Overall, this proof-of-concept study demonstrates a promising approach for remediating microplastics from aqueous suspensions using adhesives.

Fiber materials and textiles are topics of much research and study today, with efforts being made to produce fibers that are stronger, more durable, more breathable, and better for the environment. However, the production of fibers at the laboratory scale is uncommon and difficult past the prototype phase, and to a commercial fiber production level. Most current fiber spinning systems are too large to be operated anywhere outside of a designated facility and are prohibitively expensive. Here we present the build for a simple and affordable fiber collection device adept for demonstrations, student laboratories, and early research prototyping. This paper describes a nearly laboratory ready, functional fiber collection device that was designed, built, and evaluated during the COVID pandemic. It is constructed of an Arduino microcontroller, a toy motor, and basic circuit components with an assembled cost of ∼$60. The developed spinner's rotational speed ranged from ∼120−960 rpm. Spinner functionality was tested via fiber winding, solution spinning, and melt spinning. It is estimated that the spinner could hold ∼3.5 g worth of fiber before unloading and restarting with a fresh spool. Melt spun fibers produced by the unit were measured to have an average diameter of 31 ± 6 μm. Ultimately, this system was designed to be a low-cost entry point to fiber spinning for research and more primarily for education purposes. The parts list and system design are included and could be expanded upon as part of a learning laboratory exercise around the design/build/test paradigm. The current system works effectively as a demonstration to produce low-to moderate-quality fibers. The design would need to be augmented with a higher-torque motor, and certain components would need to be replaced if higherquality fibers are desired.

No abstract

Inadvertent consumption of latent microplastics is a lethal challenge for developing creatures in aquatic environments. There are compelling needs to classify which kinds of plastics are most likely to be encountered by sea creatures and to develop mitigation strategies to reduce exposure. We analyzed an ensemble of microplastic particle fragments isolated from sea turtle post-hatchlings to identify their composition and other features and attributes. These microplastic particles were likely consumed by post-hatchlings because of the adsorbed biofilm formation mimicking normal food sources. Of the hundreds of particles that were collected, 30 were selected for analysis using differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy and density assessment to identify them compared with other compositional libraries. These thermophysical measurements were also compared with observational assessments via optical microscopy. Of the particles tested, nearly all were polyolefins such as polyethylene and polypropylene. The melting points of the extracted polymers were typically lower than for product grades of these resins, indicative of some level of degradation. Spectral analysis by FTIR often showed absorption indicative of new chemistries likely from both hydrolysis and biofilm growth observed on the surface that was subsequently investigated through surface abrading. Separate assessments of density of these particles were conducted and tended to reinforce identification via FTIR and DSC. The density results can be misleading if additives, fillers or biofilms that form alter the particle density relative to those of the neat resins. We suggest that since post-hatchlings commonly feed in the neritic or nearshore environment, less dense polymers are more likely to convey, thereby threatening sea turtle hatchlings who consume them inadvertently.