Browsing by Author "Fazeli, Mahyar"

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Developing Self-Assembled Starch Nanoparticles in Starch Nanocomposite Films
(2022-12-13) Fazeli, Mahyar; Lipponen, Juha
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Starch nanoparticles (SNPs) are synthesized by different precipitation techniques using corn starch, and SNP films are prepared by the evaporation casting method. The morphological study is investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The distribution and sizes of precipitated SNPs after synthesizing are discovered by these methods as well. The crystallinity of the SNPs is studied by the X-ray diffractometry (XRD) method that demonstrates reduction compared to neat starch granules, and it is changed from A-style to VH-style after precipitation. The chemical bonding of different SNPs after the nanoprecipitation is analyzed by Fourier transform infrared spectroscopy (FT-IR). Thermogravimetric analysis (TGA) demonstrates the decomposition of starch nanoparticles and the starch matrix that is related to the depolymerization of carbon chains in the range of 260 to 350 °C. The mechanical properties of the SNP films versus the temperature changing are discovered by dynamic mechanical analysis (DMA). The water contact angles of SNP films are measured using a goniometer, and the results showed the hydrophobic surfaces of the prepared films. Our study indicates that SNPs have a promising impact on the properties of corn starch films, which would be useful in biodegradable packaging material.
Development and characterization of polylactic acid/starch biocomposites – From melt blending to preliminary life cycle assessment
(2024-11) Baniasadi, Hossein; Äkräs, Laura; Madani, Zahra; Silvenius, Frans; Fazeli, Mahyar; Lipponen, Sami; Vapaavuori, Jaana; Seppälä, Jukka
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This study presents a comprehensive analysis encompassing melt blending, characterization, life cycle assessment (LCA), and 3D printing of a range of polylactic acid (PLA)/starch biocomposites, with starch content varying from 0 to 50 wt%. To enhance compatibility between the starch particles and the PLA matrix, we utilized a solvent-free method to graft N-octadecyl isocyanate (ODI) molecules onto the surface of the starch particles, resulting in ODI-g-starch, which yielded several improved properties. Notably, toughness and elongation at break improved by approximately 170 % and 300 %, respectively. Moreover, the crystallinity increased from 11.6 % in plain PLA to 30.1 %, suggesting that the uniform dispersion of ODI-g-starch particles acted as nucleating sites for the crystallization of PLA chains. Additionally, viscosity decreased significantly with the introduction of ODI-g-starch particles, indicating their plasticizing effect, thereby enhancing the processability and ease of fabrication of the biocomposite. Crucially, our LCA analysis revealed a significant reduction in the carbon footprint of these biocomposites, up to 18 % and 63 %, compared to plain PLA and selected fossil-based plastics, respectively, upon the incorporation of ODI-g-starch. In summary, our research introduces the newly developed PLA/starch biocomposites as a sustainable and eco-friendly alternative to commercially available plain PLA and specific fossil-based plastics.
Development and characterization of pomegranate peel extract-infused carboxymethyl cellulose composite films for functional, sustainable food packaging
(2025-01) Baniasadi, Hossein; Fathi, Ziba; Lizundia, Erlantz; Cruz, Cristina D.; Abidnejad, Roozbeh; Fazeli, Mahyar; Tammela, Päivi; Kontturi, Eero; Lipponen, Juha; Niskanen, Jukka
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Our study explores the development and characterization of carboxymethyl cellulose (CMC)-based composite films integrated with clay particles and pomegranate peel extract (PE), aiming to inspire the films with natural antimicrobial and antioxidant properties for potential applications in food packaging. We conducted a comprehensive examination of the mechanical, barrier, surface, and degradation properties of these composite films, considering the impacts of incorporating clay particles and PE on their overall performance. Our findings reveal that the inclusion of clay particles enhances the mechanical strength and barrier properties of the films, while PE contributes to antioxidant and antibacterial effects. Namely, after the integration of 3 wt% clay, the tensile strength exhibited a remarkable increase of approximately 300%, accompanied by a notable reduction of 60% in water vapor permeability and 30% in oxygen transmission rate. Furthermore, the integration of PE into CMC films promoted antibacterial activity against 2 g-positive bacterial species, Staphylococcus aureus and Listeria monocytogenes. Additionally, we conducted a life cycle assessment (LCA) to quantify the cradle-to-gate environmental impacts of the developed bio-based active films. When normalized to the functional properties of the films, including mechanical and barrier performance, we observed significant benefits, with reductions of up to 59% after the concurrent incorporation of PE and clay nanosheets. Overall, our study underscores the potential of CMC-based composite films augmented with PE as a promising solution for sustainable food packaging, offering enhanced functionality while reducing environmental impact and increasing food safety.
Development of Ioncell fibres reinforced bio-based epoxy composite via vacuum infusion technique
(2024-01-23) Islam, Shariful
Kemian tekniikan korkeakoulu | Master's thesis
The interest in composites reinforced with cellulose-based fibres is surging due to their eco-friendliness and cost-efficiency. However, their application in high-strength areas is limited, a domain where synthetic/inorganic fibres currently leading. The main concern with synthetic/inorganic fibre composites is their non-biodegradable nature and environmental unfriendliness. Composites made from regenerated cellulose fibres could potentially replace of synthetic/inorganic fibre composites, given their superior strength compared to other cellulosic fibres. “Ioncell fibre” was used in this study, a unique cellulose fibre developed by Aalto University and the University of Helsinki, to produce a composite for comparison with carbon, cellulosic, and glass fibre composites. The main objective is to assess the potential of the biodegradable composite produced from plain weave fabric of Ioncell fibres and a bio-based epoxy matrix via vacuum infusion technique. This thesis delves into the properties of fibres, including their mechanical attributes, degree of polymerization, and morphological structure. It also examines the mechanical and thermal characteristics, water absorption capacity, and hydrophilic/hydrophobic properties of the resulting composite. The study further explores its potential as a substitute for petroleum-based fibre composites, specifically carbon fibre composites. The findings reveal that while the strength of Ioncell fibre is four times less than that of carbon fibre, the strength of the Ioncell composite is nearly half that of the carbon fibre composite. These results could potentially lead to a wider acceptance of biobased Ioncell composites as alternatives to carbon and other synthetic as well as cellulosic fibre composites, contributing to a more sustainable future.
Elucidating the enduring transformations in cellulose-based carbon nanofibers through prolonged isothermal treatment
(2024-08) Nuge, Tamrin; Fazeli, Mahyar; Baniasadi, Hossein
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This study investigates the conversion of highly acetylated sugarcane bagasse into high-modulus carbon nanofibers (CnNFs) with exceptional electrical conductivity. By electrospinning the bagasse into nanofibers with diameters ranging from 80 nm to 800 nm, a cost-effective CnNFs precursor is obtained. The study reveals the transformation of the cellulose crystalline structure into a stable antiparallel chain arrangement of cellulose II following prolonged isothermal treatment, leading to a remarkable 50 % increase in CnNFs recovery with carbon contents ranging from 80 % to 90 %. This surpasses the performance of any other reported biomass precursors. Furthermore, graphitization-induced shrinkage of CnNFs diameter results in significant growth of specific surface area and pore volume in the resulting samples. This, along with a highly ordered nanostructure and high crystallinity degree, contributes to an impressive tensile modulus of 9.592 GPa, surpassing that of most petroleum-based CnNFs documented in the literature. Additionally, the prolonged isothermal treatment influences the d002 value (measured at 0.414 nm) and CnNFs degree of crystallinity, leading to an enhancement in electrical conductivity. However, the study observes no size effect advantages on mechanical properties and electrical conductivity, possibly attributed to the potential presence of point defects in the ultrathin CnNFs. Overall, this research opens a promising and cost-effective pathway for converting sugarcane biomasses into high-modulus carbon nanofibers with outstanding electrical conductivity. These findings hold significant implications for the development of sustainable and high-performance materials for various applications, including electronics, energy storage, and composite reinforcement.
Exploring the potential of regenerated Ioncell fiber composites: a sustainable alternative for high-strength applications
(2024-07-07) Fazeli, Mahyar; Islam, Shariful; Baniasadi, Hossein; Abidnejad, Roozbeh; Schlapp-Hackl, Inge; Hummel, Michael; Lipponen, Juha
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Cellulose-based fiber-reinforced composites are gaining attention for their eco-friendly attributes and cost-effectiveness. However, their application in high-strength domains remains limited due to the dominance of synthetic and inorganic fibers. This study explores the potential of composites utilizing “Ioncell fiber”, a unique cellulose fiber, in comparison to carbon, cellulosic, and glass fiber composites. Our findings reveal that Ioncell fiber composites exhibit earlier thermal degradation compared to carbon fiber composites according to thermogravimetric analysis (TGA). Analysis via scanning electron microscopy (SEM) highlights exceptional interaction between Ioncell fiber and bio-based epoxy, surpassing other fibers. Additionally, assessment of composite hydrophilicity or hydrophobicity through contact angle measurements reveals distinctive surface characteristics, with Ioncell exhibiting a contact angle of 80°, comparable to carbon fiber's contact angle of 75°, while glass transition results demonstrate Ioncell fiber's transformation closely resembling that of carbon fiber composites. Although Ioncell fiber exhibits lower strength (approximately 50 cN per tex) compared to carbon fiber (222 cN per tex), Ioncell composites demonstrate promising strength levels nearly half that of carbon fiber composites (approximately 230 MPa for Ioncell fiber composite compared to 500 MPa for carbon fiber composite). These results underscore the potential of Ioncell composites as sustainable alternatives to petroleum-based and synthetic fiber composites, thus contributing to a more environmentally sustainable future.
Increase mechanical performance in bio-based 3D printed honeycomb structures. A numerical approach
(2024-03-11) Gupta, Tirtha
Insinööritieteiden korkeakoulu | Master's thesis
Owing to their enormous potential for weight savings in a variety of applications, ultralight sandwich structures—which combine stiffening parts with a low-density core—have attracted a lot of research interest. With an emphasis on improving strength, stiffness, and weight reduction, this thesis utilizes finite element analysis to optimize additively manufactured sandwich constructions with a non-regular hexagon honeycomb core built from bio epoxy-based materials and plywood face sheets. The research identifies crucial design considerations and validates the structural integrity of the bio-based sandwich panels by methodically examining parameters like face thickness, core height, panel width, and cell size. These methods are combined with experimental three-point bending tests and theoretical models integrating honeycomb mechanics and classical beam theory. The beam's stiffness and strength are increased by increasing the panel's width, adding a layer of printing core, and thickening the face material. Failures such top face indentation, bottom face fracture, and core fracture were noted during three-point bending testing. As the size of the hexagonal cells with-in the honeycomb core varied, the sandwich panels' strength and stiffness stayed relatively constant. Additionally, a study was done on sandwich panels made with bio epoxy to evaluate their ultimate load capacity and bending stiffness. The utilization of ABAQUS/EXPLICIT for analysis provided valuable insights into performance optimization, with implications for the furniture application. These industries can benefit from sustainable engineering solutions that are driven by high-performance, environmentally friendly materials and manufacturing techniques.
Innovations in hydrogel-based manufacturing: A comprehensive review of direct ink writing technique for biomedical applications
(2024-02) Baniasadi, Hossein; Abidnejad, Roozbeh; Fazeli, Mahyar; Lipponen, Juha; Niskanen, Jukka; Kontturi, Eero; Seppälä, Jukka; Rojas, Orlando J.
A2 Katsausartikkeli tieteellisessä aikakauslehdessä
Direct ink writing (DIW) stands as a pioneering additive manufacturing technique that holds transformative potential in the field of hydrogel fabrication. This innovative approach allows for the precise deposition of hydrogel inks layer by layer, creating complex three-dimensional structures with tailored shapes, sizes, and functionalities. By harnessing the versatility of hydrogels, DIW opens up possibilities for applications spanning from tissue engineering to soft robotics and wearable devices. This comprehensive review investigates DIW as applied to hydrogels and its multifaceted applications. The paper introduces a diverse range of printing techniques while providing a thorough exploration of DIW for hydrogel-based printing. The investigation aims to explain the progress made, challenges faced, and potential trajectories that lie ahead for DIW in hydrogel-based manufacturing. The fundamental principles underlying DIW are carefully examined, specifically focusing on rheological attributes and printing parameters, prompting a comprehensive survey of the wide variety of hydrogel materials. These encompass both natural and synthetic variations, all of which can be effectively harnessed for this purpose. Furthermore, the review explores the latest applications of DIW for hydrogels in biomedical areas, with a primary focus on tissue engineering, wound dressing, and drug delivery systems. The document not only consolidates the existing state of DIW within the context of hydrogel-based manufacturing but also charts potential avenues for further research and innovative breakthroughs.
Lignin beyond the status quo: Recent and emerging composite applications
(2024-01-21) Fazeli, Mahyar; Mukherjee, Sritama; Baniasadi, Hossein; Abidnejad, Roozbeh; Mujtaba, Muhammad; Lipponen, Juha; Seppälä, Jukka; Rojas Gaona, Orlando
A2 Katsausartikkeli tieteellisessä aikakauslehdessä
The demand for biodegradable materials across various industries has recently surged due to environmental concerns and the need for the adoption of renewable materials. In this context, lignin has emerged as a promising alternative, garnering significant attention as a biogenic resource that endows functional properties. This is primarily ascribed to its remarkable origin and structure that explains lignin's capacity to bind other molecules, reinforce composites, act as an antioxidant, and endow antimicrobial effects. This review summarizes recent advances in lignin-based composites, with particular emphasis on innovative methods for modifying lignin into micro and nanostructures and evaluating their functional contribution. Indeed, lignin-based composites can be tailored for superior physicomechanical characteristics, biodegradability, and surface properties, thereby making them suitable for applications beyond typical, for instance, in ecofriendly adhesives and advanced barrier technologies. Herein, we provide a comprehensive overview of the latest progress in the field of lignin utilization in emerging composite materials.
Lignocellulosic biomass from agricultural waste to the circular economy: a review with focus on biofuels, biocomposites and bioplastics
(2023-05-20) Mujtaba, Muhammad; Fernandes Fraceto, Leonardo; Fazeli, Mahyar; Mukherjee, Sritama; Savassa, Susilaine Maira; Araujo de Medeiros, Gerson; do Espírito Santo Pereira, Anderson; Mancini, Sandro Donnini; Lipponen, Juha; Vilaplana, Francisco
A2 Katsausartikkeli tieteellisessä aikakauslehdessä
Industries are working to minimize their reliance on petrochemicals and petroleum-based industrial components and replace them with biobased, sustainable, and environmentally friendly alternatives due to the global warming emergency caused by the uncontrolled production of greenhouse gases. The agricultural waste provides large volumes of lignocellulosic biomass, a sustainable resource material to develop a wide portfolio of bioproducts. Recent developments in integrated biorefineries have enhanced the utilization of waste lignocellulose components to generate biofuels, platform chemicals, resins, bioplastics, additives, and other biobased materials for a variety of applications. Here in this review, we have summarized recent advancements in the processing of lignocellulosic biomass from agricultural waste. Additionally, this review thoroughly discussed the recent technological advancements in the utilization of various lignocellulose biomass constituents for biofuels, biocomposites, and bioplastics. Finally, an assessment of the currently existing literature gaps and prospective future perspectives for the development of lignocellulosic biomass from agricultural waste has been conducted.
An overview of bio-based composite development
(2023-05-29) Roivas, Jenni
Kemiantekniikan korkeakoulu | Bachelor's thesis
Recycled carbon fiber reinforced composites: Enhancing mechanical properties through co-functionalization of carbon nanotube-bonded microfibrillated cellulose
(2024-05) Fazeli, Mahyar; Jayaprakash, Siddharth; Baniasadi, Hossein; Abidnejad, Roozbeh; Lipponen, Juha
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
The imperative challenge of repurposing recycled carbon fiber (rCF) in composite structures, due to its cost-effectiveness and eco-friendly attributes, has spurred innovative research. This study introduces a scalable processing technique, integrating carbon nanotube (CNT)-bonded microfibrillated cellulose (MFC) onto randomly oriented rCF mats, focusing on enhancing mechanical properties. Employing electrophoretic deposition (EPD), rCF surfaces are effectively functionalized with CNT/MFC, probed through X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Modified fiber surfaces exhibit reduced contact angles, indicating improved wettability. Epoxy-based composites, fabricated via vacuum infusion, show up to 32% and 27% improvements in tensile and flexural strength. Dynamic mechanical analysis (DMA) confirms elevated storage modulus and energy dissipation capability. SEM analysis of fracture surfaces illustrates robust adhesion between coated fibers and the matrix, supporting the proposed approach's efficacy. This study unveils an innovative pathway to enhance recycled carbon fiber composite properties, extending their application potential in diverse engineering domains.
Structure of cellulose and its effect on optical properties
(2024-06-11) Huotari, Viivi
Kemian tekniikan korkeakoulu | Master's thesis
This thesis aims to prove that materials with cavities in the range of 200 to 300 nm have high opacity and appear white. This range has been deemed as an optimal diameter for scattering centres also by literature sources. The aim of the experimental part of the thesis was to produce white materials with a porous inner structure with cavities in the chosen range. Regenerated cellulose films were produced with air drying and freeze drying. This resulted in highly transparent films and highly opaque films. Porous microcrystalline cellulose (MCC) particles were generated by mixing sodium hydroxide with MCC, which resulted in promising porous structures for further testing. β-1,3-glucan particles were tested due to their interesting lamellar structure. Unfortunately, this lamellar structure was shown to collapse more easily during freeze drying in comparison to the MCC structure. Therefore, air cavities inside the particles were compromised, lowering the effective scattering of the particles. The particles (untreated MCC, porous MCC, and β-1,3-glucan) and the freeze-dried regenerated cellulose films were characterized with different methods. Results from Fourier-transform infrared (FTIR) spectroscopy showed differences in amounts of cellulose I and cellulose II polymorph structures. The ratio of cellulose II to cellulose I was estimated to be greater in porous MCC and regenerated cellulose films than in untreated MCC. X-ray diffraction was used to analyse the crystallinity of the samples. All samples except untreated MCC had high crystallinity values between 87 to 92%. The cellulose films, MCC particles and β-1,3-glucan particles were treated with transparent lacquer in order to test the materials’ behaviour in paint systems. UV-Vis spectroscopy was used to observe the transmittance values of the cellulose films treated with lacquer and the particle-lacquer mixtures. The transmittance values were constant between 350 to 800 nm wavelengths. The best opacity (98%) was calculated for freeze-dried cellulose films which had a transmittance value close to that of titanium dioxide-lacquer mixture. Titanium dioxide was used as a comparison due to its common usage as an opacifying pigment by the paint industry. The results were linked with the films’ porous inner structure that had a high number of air-filled pores with a diameter of 200 to 300 nm. Additionally, the dense outer structure of the films was thought to protect the inner structure from the lacquer penetration which could lower the refractive index difference. These findings support the hypothesis that the inner structures of materials are crucial for effective light scattering. Based on results and literature, scattering centres in the range of 200 to 300 nm, which in this thesis were air-filled pores, increase opacity. Contrary to what the hypothesis leads to believe, the distance between the scattering centres can differ from the 200 to 300 nm range. The next step would be to define the optimal filling fraction for the scattering centres in the material. In addition, further optimization of the particle structure needs to be done to produce particles that can form a barrier between themselves and the lacquer to keep the inner porous structure separate from the lacquer and maintain the refractive index difference.