Characterization of PLA Nanoplastics, and Their Effects on Daphnia magna
(2022) KASM15 20221Centre for Analysis and Synthesis
- Abstract
- As plastic pollution in aquatic environments keeps happening it has become more and more important to learn more about nanoparticles. Bio-based and biologically degradable plastics, such as polylactic acid (PLA), are gaining popularity and it is therefore important to determine whether they break down into nanoplastics or not. Should this be the case, it is of interest to characterize their size, morphology, surface charge, chemical composition, and determine if they are toxic to aquatic organisms.
The approach was to break down five different consumer PLA plastic products in Milli-Q water with an immersion blender. These products were a soup cup lid, coffee cup lid, plastic cup, plastic bag and 3D printer filament. The soup cup lid... (More) - As plastic pollution in aquatic environments keeps happening it has become more and more important to learn more about nanoparticles. Bio-based and biologically degradable plastics, such as polylactic acid (PLA), are gaining popularity and it is therefore important to determine whether they break down into nanoplastics or not. Should this be the case, it is of interest to characterize their size, morphology, surface charge, chemical composition, and determine if they are toxic to aquatic organisms.
The approach was to break down five different consumer PLA plastic products in Milli-Q water with an immersion blender. These products were a soup cup lid, coffee cup lid, plastic cup, plastic bag and 3D printer filament. The soup cup lid and coffee cup lid were also exposed to UV-C to see if that made any difference when characterizing them. Manufactured PLA nanoparticles were also purchased and studied. They were then characterized by using tools such as NTA, DLS, FTIR and TEM. To determine the toxicity of the particles, the zooplankton Daphnia magna was exposed to them.
The results showed that nanoplastics were formed, with an average size 145 - 230 nm in diameter depending on the product. The particles seemed to have different shapes, there were particles with sharp edges, and particles with round edges. The surface charge differed between the different products, all values indicated they should be unstable in Milli-Q water. However, when the stability was studied with the NTA, they seemed stable. The chemical composition of the soup cup lid, plastic cup and 3D printer filament matched that of pure PLA, while the coffee cup lid and the plastic bag seemed to be made of polystyrene and polyester, terephtalic acid (PET), respectively.
The toxicity was tested with the soup cup lid, the UV-C treated soup lid, the plastic bag and the manufactured nanoparticles in a short-term test where the plankton were not fed. They showed no sign of being toxic. On the contrary, the plankton seemed to live longer when exposed to breakdown PLA nanoplastics in the water. When exposed to the manufactured PLA, there was a toxic effect on the plankton. (Less) - Popular Abstract (Swedish)
- Nanoplaster: Hur ser de ut och är de farliga för vattenlevande organismer?
I detta projekt har polylaktid (PLA) brytits ner mekaniskt, för att undersöka om nanoplaster bildas och bestämma vilken storlek de blir. Dessa har sedan använts för att undersöka om de är toxiska för planktonet Daphnia magna. Även fabrikstillverkade PLA-nanopartiklar användes i experimenten.
Vi har alla hört talas om plastöarna i haven, och sett videon på en sköldpadda med ett sugrör i näsan. För att minska den stora påverkan plast har på miljön har biologiskt nedbrytbar plast, som PLA, blivit mer populära att använda.
En nanopartikel på storleken 100 nm är 400 gånger mindre än bredden på ditt hårstrå. På denna lilla skala kan de ha helt andra egenskaper än... (More) - Nanoplaster: Hur ser de ut och är de farliga för vattenlevande organismer?
I detta projekt har polylaktid (PLA) brytits ner mekaniskt, för att undersöka om nanoplaster bildas och bestämma vilken storlek de blir. Dessa har sedan använts för att undersöka om de är toxiska för planktonet Daphnia magna. Även fabrikstillverkade PLA-nanopartiklar användes i experimenten.
Vi har alla hört talas om plastöarna i haven, och sett videon på en sköldpadda med ett sugrör i näsan. För att minska den stora påverkan plast har på miljön har biologiskt nedbrytbar plast, som PLA, blivit mer populära att använda.
En nanopartikel på storleken 100 nm är 400 gånger mindre än bredden på ditt hårstrå. På denna lilla skala kan de ha helt andra egenskaper än partiklar i mikrostorlek, som mikroplaster, och därför är nanopartiklarna otroligt viktiga att studera. Fem konsumentprodukter av PLA bröts i detta projekt ned med en stavmixer för att simulera mekanisk nedbrytning i naturen. Av detta bildades nanoplaster i storlekarna 145-230 nm, och i mikroskop kunde man se att några av partiklarna hade vassa kanter medan andra var mer rundade.
När den kemiska sammansättningen av produkterna analyserades var soppskålslocket, plastmuggen och 3D-printer filamenten identiska med ren PLA, medan plastpåsarna liknade polyester, och kaffemuggslocken liknade polystyren. Efter nedbrytning tappade partiklarnas sammansättning likhet med sina respektive hela produkter, men blev istället lika varandra.
Toxixciteten hos D. magna testades med partiklar av sopplock, UV-exponerat sopplock, plastpåse och tillverkade PLA-nanopartiklar. I testen hade planktonen ingen mat i vattnet. De tillverkade nanopartiklarna var de enda som påvisade toxicitet. Med nebrutna PLA-partiklar i vattnet levde planktonen längre än kontrollplanktonen, som inte hade någonting alls i vattnet. En gissning till varför detta hände är att bakterier kunde föröka sig på plastpartiklarna tillräckligt mycket för att planktonen skulle kunna livnära sig på dem. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9087081
- author
- Rydberg, Melinda LU
- supervisor
- organization
- course
- KASM15 20221
- year
- 2022
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Polylactic acid, Polylactide, PLA, Nanoplastic, Daphnia magna, Toxicity, Polymer Technology
- language
- English
- id
- 9087081
- date added to LUP
- 2022-06-17 13:28:05
- date last changed
- 2022-06-17 13:28:05
@misc{9087081,
abstract = {{As plastic pollution in aquatic environments keeps happening it has become more and more important to learn more about nanoparticles. Bio-based and biologically degradable plastics, such as polylactic acid (PLA), are gaining popularity and it is therefore important to determine whether they break down into nanoplastics or not. Should this be the case, it is of interest to characterize their size, morphology, surface charge, chemical composition, and determine if they are toxic to aquatic organisms.
The approach was to break down five different consumer PLA plastic products in Milli-Q water with an immersion blender. These products were a soup cup lid, coffee cup lid, plastic cup, plastic bag and 3D printer filament. The soup cup lid and coffee cup lid were also exposed to UV-C to see if that made any difference when characterizing them. Manufactured PLA nanoparticles were also purchased and studied. They were then characterized by using tools such as NTA, DLS, FTIR and TEM. To determine the toxicity of the particles, the zooplankton Daphnia magna was exposed to them.
The results showed that nanoplastics were formed, with an average size 145 - 230 nm in diameter depending on the product. The particles seemed to have different shapes, there were particles with sharp edges, and particles with round edges. The surface charge differed between the different products, all values indicated they should be unstable in Milli-Q water. However, when the stability was studied with the NTA, they seemed stable. The chemical composition of the soup cup lid, plastic cup and 3D printer filament matched that of pure PLA, while the coffee cup lid and the plastic bag seemed to be made of polystyrene and polyester, terephtalic acid (PET), respectively.
The toxicity was tested with the soup cup lid, the UV-C treated soup lid, the plastic bag and the manufactured nanoparticles in a short-term test where the plankton were not fed. They showed no sign of being toxic. On the contrary, the plankton seemed to live longer when exposed to breakdown PLA nanoplastics in the water. When exposed to the manufactured PLA, there was a toxic effect on the plankton.}},
author = {{Rydberg, Melinda}},
language = {{eng}},
note = {{Student Paper}},
title = {{Characterization of PLA Nanoplastics, and Their Effects on Daphnia magna}},
year = {{2022}},
}