PlastLIFE - Chemistry
Table of contents
Project description
Plastic materials can adsorb various substances, ranging from hormones to metal ions. The accumulation of these substances in plastic waste may increase the negative environmental impact of plastics. If plastic waste captures pollutants from the environment, this may increase the harmfulness of plastics when plastic material, such as microplastic particles, is consumed by organisms. On the other hand, the ability of plastics to bind various substances can be utilized to remove contaminants from an aqueous environment. Similarly, valuable substances can be recovered from the water using plastics as a raw material for selective adsorbents.
The JyU-Chemistry team aims to discover the adsorption abilities of different types of plastics and plastic waste fractions. The most potential materials will be used to manufacture selective scavenging filters. The primary tool in manufacturing the filters will be 3D printing. Printing provides a fast route to producing prototypes and even finished products of selective scavenging filters. The use of 3D printing opens up a new way of utilizing plastic waste.
Research work
Our first goal is to screen the adsorption properties of pristine plastics such as polyamide, polystyrene, polyurethane, polypropylene, etc. We are interested in the adsorption of metal ions as well as organic moieties, including pharmaceuticals, hormones, herbicides, pesticides, and organic compounds. The first steps have already been taken in this field [1-3]. We have shown that certain plastics can effectively adsorb metal ions and hormones, such as 17\beta-estradiol [3]. We are expanding our screening to a broader selection of metal ions and other chemical substances. Environmental conditions such as pH have an impact on adsorption. A study of the impact of environmental parameters on adsorption is also part of our project. If certain types of plastics tend to capture harmful substances from the environment, this may increase the negative effects of plastics when plastic material, such as microplastic particles, is consumed by organisms.
In the second stage, we will study the adsorption properties of actual plastic waste fractions. These waste materials will be obtained from our collaborators within the PlastLIFE consortium.
Based on the adsorption tests, we will select the best adsorbent materials for further processing. The goal is to use these materials to make selective adsorption filters using the powder-bed fusion 3D printing technique (Selective Laser Sintering, SLS).
Preparation of 3D Printed Filters
For SLS 3D printing, the plastic must be ground into particles of approx. 50-100 μ³¾. Therefore, we are assembling a grinding unit where plastic waste can be ground in stages. Depending on the adsorption properties, the plastic powder can be used as such, or it can be functionalized or used as a matrix for the actual adsorbent in the hybrid material. In functionalization, active groups capable of binding desired ions or compounds are chemically attached to plastic. In the fabrication of hybrid materials, a separate adsorbent and plastic that acts as a support material are simply printed together. In each case, the overall cost-effectiveness will also be considered.
Selective Laser Sintering (SLS) is a powder-bed fusion technique where small, typically 50–100 μ³¾, particles are fused by laser. The SLS technique allows, at least up to a point, control over the material's porosity by fine-tuning the printing parameters, including laser power, exposure time, printing temperature, and cooling rate. When the particles are sintered so that only their surfaces are partially melted, a solid structure containing accessible voids between the sintered grains is obtained. Such macroporous materials can be utilized directly in chemical applications. For example, if a porous filter disk is printed, a fluid (liquid or gas) can flow through the object, interacting with the surface of the partially fused particles.[2] The porous 3D-printed structures can be seen in Figure 1. Of course, it is also possible to print any kind of flow channels in the filters, which can be used to fine-tune the flow-through properties of the filter even further.
Figure 1. a) Helium Ion Microscope (HIM) image of the break surface of a 3D printed filter disk made of polyamide. b) HIM image of the break surface of a 3D printed MOF/polyamide hybrid disk. The grey particles are polyamide 12 particles, and the blue particles are MOF (HKUST-1) adsorbent crystals attached firmly to the polymer particles [4].
The Analytical Tools
Adsorption efficiency is monitored by analyzing the influent and effluent solution passing through the plastic material (powder bed or printed filter). The primary tools used for the analyses include GC, HPLC, ICP-OES, ICP-MS, mass spectrometer, NMR, IR, and Raman spectrometers.
The structure and composition of the printed filters will be studied by using thermochemical (TGA, DSC), microscopical (SEM, HIM), tomographical (X-ray tomography), XRD, and XRF techniques. The surface area of the printed filters is analyzed by the BET instrument.
The mechanical durability of the printed object will be analyzed by our collaborators.
The Research Team
| Prof. Matti Haukka | PI, supervisor | matti.o.haukka@jyu.fi |
| Dr. Rajendhraprasad Tatikonda | metal analyses, 3D printing adsorption testing | rp.tatikonda@jyu.fi |
| Mr. Janne Frimodig | 3D printing, organic analyses, metal analyses, adsorption testing | janne.v.frimodig@jyu.fi |
References
[1] Lahtinen, E.; Kivijärvi, L.; Tatikonda, R.; Väisänen, A.; Rissanen, K.; Haukka, M. ACS Omega, 2017, 2, 7299-7304
[2] Lahtinen, E.; Hänninen, M. M, Kinnunen, K.; Tuononen, H. M.; Väisänen, A.; Rissanen, K., Haukka M. *Adv. Sustaibale. Sys 2018, 2, 180048,
[3] Frimodig, J.; Autio, A.; Lahtinen, E.; Haukka, M. 3D printing and manufacturing, (Ahead of Print) 2022,
[4] Lahtinen, E.; Precker, R. L. M.; Lahtinen, M.; Hey-Hawkins, E.; Haukka, M. ChemPlusChem 2019, 84, 222-225,
Publications & Results
Frimodig, J. and Haukka, M. "Removal of estrogens from aqueous solutions using 3D printed polymers" Environ. Sci.: Adv. 2023, 2, 1739-1745,
Frimodig, J., Autio, A., Lahtinen, E., and Haukka, M. Recovery of 17β-Estradiol Using 3D Printed Polyamide-12 Scavengers. 3D Printing and Additive Manufacturing, 2023, 10(5), 1122-1129.
Reetta Mattila, Raskasmetallien adsorboituminen muoveihin, Pro gradu-tutkielma, Jyväskylän yliopisto, kemian laitos, 2024.
