0
Article Tier 2 Detection Methods Nanoplastics Remediation Sign in to save

Photocatalytic aging process of Nano-TiO2 coated polypropylene microplastics: Combining atomic force microscopy and infrared spectroscopy (AFM-IR) for nanoscale chemical characterization

Journal of Hazardous Materials 2020 86 citations

AI summary Read the abstract

Researchers investigated the photocatalytic aging of nano-TiO2 coated polypropylene microplastics using AFM-IR nanoscale chemical characterization, finding that the TiO2 coating accelerated surface degradation and altered the physicochemical properties of the microplastics compared to pristine and conventionally aged counterparts.

Polymers

Microplastics (MPs) are considered to have greater environmental hazards than large plastics. Most MPs undergo different degrees of aging and aged MPs exhibit different physicochemical properties from pristine ones. This study successfully prepared a nano-TiO coated polypropylene MPs, and explored the nanoscale infrared, thermal, and mechanical properties of MPs before and after photo-aging using a combined AFM-IR technique. Surface height range of MPs was ± 25 nm. The signal intensity of the absorption peak at 1654 cm in terms of vinylidene end groups gradually increased as the irradiation time prolonged. The softening temperature of MPs decreased from 126.7 °C to 108.5 °C as the irradiation time increased from 0 h to 4 h. The MPs after photo-aging became stiffer, especially for the components surrounding the nano-TiO particle, indicating that photocatalytic reaction accelerated the aging process of MPs. The resonance frequency of MPs surrounding the nano-TiO particle was stronger after photo-aging and the stiffer components were uniformly distributed, confirming that the thermal and mechanical properties of MPs changed after photo-aging. These novel findings are essential to better understand the changes in the surface microstructures, physical properties, and chemical compositions of MPs during aging process.

More Papers Like This

Article Tier 2

Nanoscale infrared, thermal and mechanical properties of aged microplastics revealed by an atomic force microscopy coupled with infrared spectroscopy (AFM-IR) technique

AI summary Read the abstract

Researchers used atomic force microscopy coupled with infrared spectroscopy (AFM-IR) to characterize nanoscale infrared, thermal, and mechanical properties of TiO2-pigmented microplastics before and after aging, finding that weathering roughened surfaces and altered carbonyl and methylene band intensities.

Article Tier 2

Modelling the Photodegradation of Marine Microplastics by Means of Infrared Spectrometry and Chemometric Techniques

AI summary Read the abstract

Researchers modeled the photodegradation of polyethylene and polypropylene marine microplastics using infrared spectrometry and chemometric techniques, tracking structural and chemical changes during accelerated UV aging that simulated five years of solar exposure.

Article Tier 2

Characterizing photochemical ageing processes of microplastic materials using multivariate analysis of infrared spectra

AI summary Read the abstract

Researchers tracked how four common plastic types weather under UV light and sunlight over six months, using infrared spectroscopy and multivariate analysis to characterize surface chemistry changes. They found that polypropylene weathered fastest, while all plastics showed photooxidation at different rates depending on light source. The study proposes a multivariate spectral approach as a more broadly applicable method than the traditional carbonyl index for assessing microplastic aging.

Article Tier 2

Analysis of aged microplastics: a review

AI summary Read the abstract

This review looks at how microplastics change over time in the environment through exposure to sunlight, temperature changes, and biological activity. Aging alters the surface properties of microplastics, which can make them more toxic and change how they interact with other pollutants. Advanced techniques like infrared and Raman spectroscopy are the best current methods for identifying and tracking these aged microplastics in environmental samples.

Article Tier 2

Photoinduced Force Microscopy as an Efficient Method Towards the Detection of Nanoplastics

AI summary Read the abstract

Researchers used photoinduced force microscopy — a technique that overcomes the diffraction limit of conventional infrared spectroscopy — to detect and chemically characterize nanoplastic particles. The method revealed surface oxidation and chemical changes on polystyrene nanoplastics in salt water, demonstrating it can identify degraded nanoplastics that are too small for conventional IR detection.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper