| 1. |
- Apostolopoulou Kalkavoura, Varvara, 1988-, et al.
(author)
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In Situ Functionalisation and Upcycling of Post-Consumer Textile Blends into 3D Printable Nanocomposite Filaments
- 2024
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In: Advanced Sustainable Systems. - 2366-7486 .- 2366-7486.
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Journal article (peer-reviewed)abstract
- The linear lifecycle of the textile industry contributes to the enormous waste generation of post-consumer garments. Recycling or repurposing of post-consumer garments typically requires separation of the individual components. This study describes a novel and facile chemo-thermo-mechanical method for producing extrudable pellets, involving one-pot, 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation of post-consumer polycotton textiles, followed by mild mechanical treatment, all without isolating the constituents of the polycotton blend. The oxidized blend with high cellulose and carboxylate content of 1221 ± 82 mmol COO− per kg of cotton, is pelletised into a masterbatch and further in situ extruded into nanocomposite filaments for 3D printing. The carboxyl groups introduced on the polycotton-based filters enable cotton fibrillation into nanoscaled fibers during mechanical treatment and extrusion resulting to a variety of functional and high surface-finish quality models, including filters and fashion accessories. The electrostatic interactions with positively charged species, such as methylene blue (MB), facilitate their adsorption from water while exhibiting promising adsorption capacities. The adsorption of MB follows the Freundlich model and depends on the printed porosity of the filter. A “trash to treasure” concept for textile waste is further corroborated through the use of the developed 3D printing filament into commodity products.
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| 2. |
- Apostolopoulou Kalkavoura, Varvara, 1988-, et al.
(author)
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Trash to treasure: 3D printing of waste-based polycotton composite for the production of water filters and commodity products
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Other publication (other academic/artistic)abstract
- The recycling of polycotton without separating its constituents for high-performance applications has not yet been fully investigated. In this study, we propose a simple and efficient method involving one-pot, 2, 2, 6, 6 – tetramethylpiperdine-1-oxyl (TEMPO) - oxidation of post-consumer polycotton textile waste followed by lenient mechanical fibrillation. Successful chemical modification of the polycotton waste was confirmed by the Fourier-transform infrared (FT-IR) spectroscopy measurements, in which the presence of carboxyl groups introduced during the TEMPO-oxidation was observed. Moreover, the waste-based pellets were single-screw extruded into 3D printing filaments, which were further processed via desktop Fused Deposition Modelling (FDM) 3D printer.FDM processing was carried out without hindrance. The textile-based filament was used for the fabrication of a variety of high surface-finish quality models, which presented diverse geometries and porosity architectures. The versatility of the developed 3D printed models was demonstrated through both, their potential to be utilized as fashion accessories, and by evaluating their performance in water treatment applications. Taking advantage of the introduction of negatively charged carboxylic groups onto the polycotton-based materials, which was expected to facilitate the electrostatic interactions with positively charged species, the 3D printed filters were tested for removal of cationic dye methylene blue (MB) from water in a batch adsorption study. The adsorption followed Langmuir model, with a maximim adsorption capacity of 3 µmol/g. Overall, this work presents a novel approach for the upcycling of polycotton waste into functional filament suitable for a variety of 3D printing, and further, engineering applications. The development of composite filaments and their mechanical and adsorption properties pave the way for future research within valorisation of textile-based waste.
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| 3. |
- Fijoł, Natalia, et al.
(author)
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3D-printable biopolymer-based materials for water treatment : A review
- 2022
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In: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 430
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Research review (peer-reviewed)abstract
- The global environmental concerns drive scientists all over the world to develop eco-friendly and sustainable alternatives to techniques and materials commonly used until now for water treatment applications. The relatively novel Additive manufacturing (AM) technology allows to process materials in a custom optimized, cost and time effective manner, while use of biobased materials minimizes the secondary pollution issue. Combining three-dimensional (3D) printing technology and biopolymer-based materials refines the water treatment industry, as it provides tailored water filtration systems easily available in the disadvantaged areas at low environmental impact and cost due to the raw materials' bio-origin and abundance. This review highlights the combination of various 3D printing techniques such as Fused deposition modelling (FDM), Direct ink wetting (DIW) and Stereolitography (SLA) with nature-derived biopolymers and biopolymerbased materials including chitosan, Polylactic acid (PLA), alginate and Cellulose acetate (CA) for their potential application within the water treatment industry with emphasis on oil separation and metal removal. Moreover, the environmental impact of the revised biopolymers is briefly discussed.
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| 4. |
- Fijoł, Natalia, et al.
(author)
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3D-printed monolithic biofilters based on a polylactic acid (PLA) - hydroxyapatite (HAp) composite for heavy metal removal from an aqueous medium
- 2021
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In: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 11:51, s. 32408-32418
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Journal article (peer-reviewed)abstract
- High flux, monolithic water purification filters based on polylactic acid (PLA) functionalised with fish scale extracted hydroxyapatite (HAp) were prepared by solvent-assisted blending and thermally induced phase separation (TIPS), followed by twin-screw extrusion into filaments and processed via three-dimensional (3D) printing. The printed filters with consistent pore geometry and channel interconnectivity as well as homogenous distribution of HAp in the PLA matrix showed adsorption capabilities towards heavy metals i.e. cadmium (Cd) and lead (Pb) with maximum adsorption capacity of 112.1 mg gHAp−1 and 360.5 mg gHAp−1 for the metal salt of Pb and Cd, respectively. The adsorption was found to be driven by a combination of ion exchange, dissolution and precipitation on HAp and surface complexation.
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| 5. |
- Fijoł, Natalia, 1994-, et al.
(author)
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3D printed polylactic acid (PLA) filters reinforced with polysaccharide nanofibers for metal ions capture and microplastics separation from water
- 2023
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In: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 457
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Journal article (peer-reviewed)abstract
- The need for multifunctional, robust, reusable, and high-flux filters is a constant challenge for sustainable water treatment. In this work, fully biobased and biodegradable water purification filters were developed and processed by the means of three-dimensional (3D) printing, more specifically by fused deposition modelling (FDM).The polylactic acid (PLA) – based composites reinforced with homogenously dispersed TEMPO-oxidized cellulose nanofibers (TCNF) or chitin nanofibers (ChNF) were prepared within a four-step process; i. melt blending, ii. thermally induced phase separation (TIPS) pelletization method, iii. freeze drying and iv. single-screw extrusion to 3D printing filaments. The monolithic, biocomposite filters were 3D printed in cylindrical as well as hourglass geometries with varying, multiscale pore architectures. The filters were designed to control the contact time between filter’s active surfaces and contaminants, tailoring their permeance.All printed filters exhibited high print quality and high water throughput as well as enhanced mechanical properties, compared to pristine PLA filters. The improved toughness values of the biocomposite filters clearly indicate the reinforcing effect of the homogenously dispersed nanofibers (NFs). The homogenous dispersion is attributed to the TIPS method. The NFs effect is also reflected in the adsorption capacity of the filters towards copper ions, which was shown to be as high as 234 and 208 mg/gNF for TCNF and ChNF reinforced filters, respectively, compared to just 4 mg/g for the pure PLA filters. Moreover, the biocomposite-based filters showed higher potential for removal of microplastics from laundry effluent water when compared to pure PLA filters with maximum separation efficiency of 54 % and 35 % for TCNF/PLA and ChNF/PLA filters, respectively compared to 26 % for pure PLA filters, all that while maintaining their high permeance.The combination of environmentally friendly materials with a cost and time-effective technology such as FDM allows the development of customized water filtration systems, which can be easily adapted in the areas most affected by the inaccessibility of clean water.
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| 6. |
- Fijoł, Natalia, 1994-
(author)
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3D printing of Green Water Purification Filters : Design towards Sustainable and Scalable Biocomposite Materials
- 2023
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Doctoral thesis (other academic/artistic)abstract
- The globally escalating water pollution and water scarcity necessitates the development of efficient and sustainable water treatment technologies. This thesis investigates the feasibility of utilizing renewable and waste materials in the form of green composites for the fabrication of water purification filters via Fused Deposition Modelling (FDM).The first system studied within this thesis is based on the biobased thermoplastic polymer - polylactic acid (PLA), which serves as a composite matrix that is reinforced and functionalized with an array of green materials including fish-scale extracted hydroxyapatite (HAp), 2,2,6,6 – tetramethylpiperdine-1-oxyl (TEMPO) - oxidized cellulose nanofibers (TCNF), chitin nanofibers (ChNF), and bioinspired metal-organic framework – SU-101. All the developed PLA-based biocomposites exhibited great design flexibility and excellent printability, leading to the development of high surface-finish quality water purification filters of various geometries and porosity architectures. The developed filters successfully removed various contaminants from water. High capability for removal of metal ions from both, model solutions (reaching removal capacity towards Cu2+ ions of 208 mg/gNF and 234 mg/gNF for ChNF/PLA and TCNF/PLA filters, respectively, compared to only 4 mg/g for PLA filters), as well as from an actual mine effluent, reaching removal efficiency towards i.a. Mn2+ ions of over 50 % was demonstrated. Moreover, the developed TCNF/PLA and ChNF/PLA filters successfully removed microplastics from laundry effluent with over 70 % separation efficiency. The PLA-based biocomposite filters surface-functionalized with SU-101 were also suitable for the removal of cationic dye, methylene blue (MB), from water with removal efficiencies of over 40 %.The second composite system explored the possibility of using post-consumer polycotton textile waste as a functional entity for the polyethylene terephthalate glycol (PETG) matrix, for the fabrication of 3D printing filaments, which can be further processed into highly functional water purification filters by the FDM. The conducted TEMPO-mediated oxidation of the polycotton garments introduced negatively charged carboxylic groups onto the 3D printing filament’s surface and consequently, onto the 3D printed structures, yielding filters suitable for removal of cationic dyes, such as MB, from water.Apart from being evaluated for their ability to remove various contaminants from water, the filters have been subjected to a series of tests to assess the homogeneity of the filler dispersion in the polymer matrix as well as the filters’ permeability and mechanical stability. The high throughput character of the filters was demonstrated, as e.g., for the HAp/PLA filters the calculated flux reached 2x106 Lm-2h-1bar-1. The reinforcing impact of the nanospecies on the polymer matrix in the gradient porosity filters was investigated and so, it was shown that the addition of ChNF and TCNF fibers into PLA increases their Young’s modulus value from 550.7 ± 2.8 MPa, to 622.7 ± 1.6 MPa and 702.9 ± 5.4 MPa, respectively. Moreover, the lifespan of the filters was assessed by subjecting them to an accelerated ageing procedure in water, which have shown that the TCNF/PLA and ChNF/PLA filters could serve up to eight and five months, respectively, while maintaining their functionality and good mechanical performance. Furthermore, the study revealed that the filters are indeed biodegradable, as after prolonged exposure to water at elevated temperatures, they have fully disintegrated.Overall, the obtained results demonstrate the feasibility of combining renewable and recycled materials with 3D printing technology to create water purification filters suitable for the removal of a wide variety of contaminants from water.
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| 7. |
- Fijoł, Natalia, et al.
(author)
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Accelerated ageing of 3D printed water purification filters based on PLA reinforced with green nanofibers
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Other publication (other academic/artistic)abstract
- This study investigates the ageing behavior of polylactic acid (PLA) and PLA-based biocomposites reinforced with either 2,2,6,6-tetramethylpiperidine 1-oxyl radical (TEMPO) - oxidized cellulose nanofibers (TCNF) or chitin nanofibers (ChNF) in water. Cuboid water filters, which were processed by the means of fused deposition modelling (FMD), were subjected to ageing tests in water at varying temperatures for 19 weeks. Thermomechanical results show that while the addition of TCNF and ChNF improves the mechanical performance of PLA-based filters in dry conditions, it has the opposite effect after exposure to water. Impact of the prolonged exposure to water on the Young’s modulus (YM) and toughness values on the aged biocomposite specimens was more significant than that on the unmodified PLA filters. Moreover, a significant drop in the glass transition temperature (Tg) of approximately 10 ℃ was observed for both, TCNF/PLA and ChNF filters, after just 3 weeks of ageing. In comparison, the Tg of the pure PLA remains unaffected for up to 7 weeks. The mechanical tests allowed to estimate the service life of the 3D printed filters using the Arrhenius model. It was shown that the TCNF/PLA and ChNF/PLA filters can be utilized at room temperature water for up to 8 and 5 months, respectively, until they lose 50 % of their initial ability to resist deformation. In the same conditions, PLA filters can serve for up to 3.5 years. In conclusion, this study highlights the importance of considering the degradation behaviour of biocomposites when developing sustainable materials for water treatment applications.
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| 8. |
- Fijoł, Natalia, 1994-, et al.
(author)
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Accelerated ageing of 3D printed water purification filters based on PLA reinforced with green nanofibers
- 2023
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In: Polymer testing. - 0142-9418 .- 1873-2348. ; 129
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Journal article (peer-reviewed)abstract
- This study investigates the ageing behavior of polylactic acid (PLA) and PLA-based biocomposites reinforced with either 2,2,6,6-tetramethylpiperidine 1-oxyl radical (TEMPO) - oxidized cellulose nanofibers (TCNF) or chitin nanofibers (ChNF) in water. Fused deposition modeling (FDM) was used to create water filters, which underwent aging tests at various temperatures over 19 weeks. Thermomechanical results show that while the addition of TCNF and ChNF improves the mechanical performance of PLA-based filters in dry conditions, it has the opposite effect after exposure to water. The impact of prolonged water exposure on Young's modulus and toughness was more significant in biocomposites than in unmodified PLA filters. The TCNF/PLA and ChNF/PLA filters saw a substantial ∼10 °C drop in glass transition temperature (Tg) after 3 weeks, while pure PLA remained nearly unaffected for up to 7 weeks. The mechanical tests allowed to estimate the service life of the 3D printed filters using the Arrhenius model. It was shown that the TCNF/PLA and ChNF/PLA filters can be utilized at room temperature water for up to 8 and 5 months, respectively, until they lose 50 % of their initial ability to resist deformation. In the same conditions, PLA filters can serve for up to 3.5 years. In conclusion, this study highlights the importance of considering the degradation behaviour of biocomposites when developing sustainable materials for water treatment applications.
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| 9. |
- Fijoł, Natalia, 1994-, et al.
(author)
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MOF@Cell : 3D printed biobased filters anchored with a green metal–organic framework for effluent treatment
- 2023
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In: Journal of Materials Chemistry A. - 2050-7488 .- 2050-7496. ; 11:23, s. 12384-12394
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Journal article (peer-reviewed)abstract
- Multifunctional, biobased materials processed by means of additive manufacturing technology can behighly applicable within the water treatment industry. This work summarizes a scalable and sustainablemethod of anchoring a green metal–organic framework (MOF) SU-101 onto the surface of 3D printed,biobased matrices built of polylactic acid (PLA)-based composites reinforced with TEMPO-oxidizedcellulose nanofibers (TCNFs). The two tested anchoring methods were hydrolysis via either concentratedhydrochloric acid treatment or via a photooxidation reaction using UV–ozone treatment. Stabledeposition of SU-101 distributed homogenously over the filter surface was achieved and confirmed byFT-IR, XPS and SEM measurements. The obtained 3D printed and functionalized MOF@PLA andMOF@TCNF/PLA (aka MOF@Cell) filters exhibit high efficiency in removing heavy metal ions from mineeffluent and methylene blue from contaminated water, as demonstrated through batch adsorptionexperiments. In addition to their potential for removal of contaminants from water, the MOF@Cell filtersalso exhibit excellent mechanical properties with a Young's modulus value of about 1200 MPa,demonstrating their potential for use in practical water treatment applications. The MOF@Cell filterswere able to maintain their structural integrity and filtration performance even after multiple cycles ofuse and regeneration. This study highlights the potential of multifunctional, biobased materials processedby additive manufacturing technology as a cost-effective alternative to traditional water treatmentmethods. The MOF@Cell filters presented in this study demonstrate high efficiency, durability, andreusability, making them promising candidates for practical applications in the modern water treatmentindustry.
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| 10. |
- Thomas, N. G., et al.
(author)
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Fish scale derived hydroxyapatite incorporated 3D printed PLA scaffold for bone tissue engineering
- 2024
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In: New Journal of Chemistry. - 1144-0546 .- 1369-9261. ; 48:24, s. 10841-10851
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Journal article (peer-reviewed)abstract
- Bone defect repair, particularly in the alveolar region, remains a significant hurdle in periodontics. In recent years, the spotlight in regenerative medicine has fallen on 3D-printed bone scaffolds, especially those constructed of polylactic acid (PLA) infused with hydroxyapatite. This research introduced a novel approach by developing a 3D-printed PLA scaffold enriched with hydroxyapatite derived from fish skin waste (FSHA). Mechanical compression tests revealed that the 3D-printed PLA-FSHA scaffolds had a compressive strength (13.4 ± 5.53 MPa) in the same ballpark as their reference PLA counterparts (20.3 ± 1.08 MPa). Scanning electron micrographs highlighted an average pore size in the scaffold (572 ± 33 μm) conducive to angiogenesis and facilitating cell migration and proliferation. In vitro, cytotoxicity was ascertained using the MTT assay on L929 fibroblast cells. Further in vitro cytocompatibility assessments through actin-DAPI staining and measurements of bone regeneration markers - alkaline phosphatase, osteocalcin and osteopontin-demonstrated that the PLA-FSHA scaffolds not only were biocompatible but also showcased performance on par with the commercial graft, osseograft. This lays the foundation for future in vivo evaluations of bone regenerative capabilities.
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