Embark on a journey of discovery with BikiarisLab as we unveil our latest contributions to the ever-evolving landscape of polymers research. In this blog post, we are thrilled to share the diverse spectrum of our recent publications, each representing a milestone in our pursuit of knowledge. From cutting-edge developments in polymer chemistry to advancements in drug delivery systems and sustainable materials, BikiarisLab is committed to pushing the boundaries of innovation.
Topic: Biobased Polymers
In their Feature Letter, BikiarisLab addresses the environmental impact of plastics and the challenges associated with their waste management. Acknowledging the indispensable role of plastics and the EU Action Plan for circular economy, the letter emphasizes the need for reducing plastic usage, enhancing recycling efforts, and integrating more biobased and biodegradable plastics into the market. The authors highlight the increased use of mechanical recycling and the production of biobased conventional plastics like PE and PET. However, they also discuss the ongoing challenges in commercializing bioplastic products. The feature letter provides insights into the properties of bioplastics, the primary hurdles in their development, and the authors' perspective on their broader adoption in the market. Overall, it contributes to the ongoing dialogue on sustainable solutions for plastic usage in the transition to a circular economy.
The article, part of Johan Stanley's PhD thesis and published by BikiarisLab, explores the thermal decomposition kinetics and mechanisms of poly(ethylene 2,5-furan dicarboxylate) (PEF) based nanocomposites designed for food packaging applications.
In pursuit of enhanced antibacterial properties for food packaging applications, BikiarisLab, as part of Johan Stanley's PhD thesis, synthesized Poly(ethylene 2,5-furandicarboxylate) (PEF)-based nanocomposites via in situ polymerization. Ce–bioglass, ZnO, and ZrO2 nanoparticles were incorporated and extensively characterized. Confirming successful polymerization through attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, the nanocomposites displayed low-to-moderate color concentration increases compared to neat PEF. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) depth profiling provided insights into the nanocomposites' structure. Thermal analysis indicated a crystallinity shift from 0–5% in neat PEF to above 20% in annealed samples. Scanning electron microscopy (SEM) revealed well-dispersed nanoparticles, and contact angle measurements demonstrated reduced wetting angles. The nanocomposites exhibited a substantial increase in antimicrobial activity against Gram-positive and Gram-negative bacterial strains, with ZnO-based nanocomposites displaying improved hardness and elastic modulus values compared to neat PEF in nanoindentation tests. This research showcases promising developments in PEF-based nanocomposites for advanced food packaging solutions.
This research is funded under the project Advanced Research and Training Network in Food Quality, Safety, and Security—FoodTraNet—H2020-MSCA-ITN-2020. The authors acknowledge the Slovenian Research Agency (grant P2-0118). The project is cofinanced by the Republic of Slovenia, the Ministry of Education, Science and Sport, and the European Union under the European Regional Development Fund.
BikiarisLab, as part of Raphael Ioanndis's master thesis, presents a study on the synthesis and thermal investigation of poly(propylene terephthalate-co-2,5-furan dicarboxylate) (PPTF) copolyesters. The copolymers, featuring varying PT/PF molar fractions, were synthesized through a two-stage melt polycondensation reaction. Nuclear magnetic resonance spectroscopy confirmed the random structure and molar composition of the copolymers. XRD analysis revealed isodimorphism in the cocrystallization behavior, and DSC supported the random nature of the copolymers with a minimum melting temperature. Isothermal melt crystallization studies indicated a preferred incorporation of PF units into the PPT crystal, with higher PT content demonstrating increased crystallization rates. The effect of the furan ring was notable, influencing crystallization behavior. Polarized light microscopy was employed to examine the spherulitic morphology of the polymers. This research contributes valuable insights into the structure and thermal characteristics of PPTF copolyesters, offering potential applications in diverse fields.
BikiarisLab, as part of the KYKA project, presents research on fully biobased composite materials composed of poly(ethylene succinate) (PESu) and hemp fibers derived from agricultural waste. The study explores different hemp fiber (HF) incorporation levels, ranging from 10% to 75%, and investigates the impact of Joncryl ADR® 4400 (JC) as a compatibilizer. The materials' chemical structure, thermal behavior, crystallization, mechanical properties, antioxidant activity, hydrophilicity, and soil degradation were analyzed. Initially, mechanical properties showed improvement up to 20–50% HF, declining with higher fiber content. Antioxidant activity and soil degradation increased proportionally with HF content. Surprisingly, hydrophobicity increased with HF incorporation, potentially due to non-cellulosic hydrophobic compounds in the polymeric matrix. JC was found to enhance fiber/polymeric matrix adhesion, resulting in overall improved properties. This study contributes valuable insights into the development of fully biobased materials with enhanced thermal and biodegradation properties, fostering sustainable composite materials.
This research was co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship, and Innovation, under the call RESEARCH- CREATE-INNOVATE (project code: T2EDK–00008).
BikiarisLab explores the structure-properties relationships in novel polymer nanocomposites using renewable poly(butylene succinate) (PBSu) filled with low amounts of 1-3D nanoparticles (NP). The study highlights the direct impact of NPs on crystallization, facilitating nucleation and increasing the crystalline fraction. Additionally, indirect effects are observed through crystallization, influencing molecular mobility and macroscopic performance. The alterations in semicrystalline morphology have notable consequences on electrical and heat transport, as well as mechanical properties. The research provides insights into the intricate interplay between the structure and properties of PBSu nanocomposites, showcasing the influence of both direct and indirect effects of 1-3D nanoparticles on various aspects, contributing to the understanding of their potential applications and performance.
Topic: Polymers for biomedical applications
BikiarisLab, in collaboration with the Centre for Research and Technology Hellas, Information Technologies Institute, published an article focusing on the exploration of methodologies for developing antimicrobial fused filament fabrication (FFF) parts through composite 3D printing filaments. These filaments, integrating antimicrobial nanoparticles, aim to provide inherent microbial resistance, particularly for medical applications such as implants, offering cost-effective alternatives to metal options. A PLA-based filament with 5% TiO2 nanoparticles and 2% Joncryl as a chain extender was formulated to exhibit antimicrobial properties. Comparative analysis involved PLA 2% Joncryl filament and a TiO2 coating for 3D-printed specimens, evaluating mechanical and thermal properties, wettability, and antimicrobial characteristics. The study demonstrated that the filaments with 5 wt.% embedded TiO2 significantly reduced the viability of both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli after 3D printing. This research aims to contribute to the optimal approach for achieving antimicrobial and medical 3D printing outcomes.
BikiarisLab presents a study on the synthesis of novel interpenetrated networks (IPNs) using [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide) (SBMA) and poly(vinyl alcohol) (PVA) for ocular co-administration of glaucoma drugs, timolol maleate (TIM), and dorzolamide hydrochloride (DORZ). The polymerization of SBMA in the presence of PVA resulted in semi-interpenetrated pSBMA-PVA networks (IPNs) with intrinsic antimicrobial properties. Characterization techniques, including FTIR, contact angle, and water sorption measurements, confirmed the successful synthesis and significant hydrophilicity, making them suitable for ocular applications. DSC revealed PVA as a plasticizer, and water sorption capacity assessments indicated sufficient hydrophilicity for ocular use. The optimal pSBMA-PVA IPN was used to encapsulate TIM and DORZ, and irritation tests confirmed their safety for ophthalmic use. Co-release studies demonstrated sustained drug release controlled by diffusion, showcasing the potential of these IPNs for ocular drug delivery.
BikiarisLab, in collaboration with McGill University, Montreal, presents a study on the synthesis of novel interpenetrated networks (IPNs) for the ocular co-administration of glaucoma drugs, timolol maleate (TIM), and dorzolamide hydrochloride (DORZ). The IPNs, composed of [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide) (SBMA) and poly(vinyl alcohol) (PVA), exhibited antimicrobial properties due to SBMA. Confirmation of successful IPN synthesis was achieved through Fourier-transform infrared spectroscopy (FTIR). The resulting sponges demonstrated significant hydrophilicity, essential for ocular applications, as revealed by contact angle and water sorption measurements. Differential scanning calorimetry (DSC) indicated PVA's plasticizing effect, while water sorption assessments suggested sufficient hydrophilicity for ocular use. The optimized pSBMA-PVA IPN successfully encapsulated TIM and DORZ, with irritation tests confirming their safety for ophthalmic use. Co-release studies demonstrated a sustained release pattern controlled primarily by diffusion. This research introduces promising IPNs for the ocular co-administration of glaucoma drugs, showcasing their safety and sustained drug release potential.
Topic: Microplastics
BikiarisLab, as part of Nina-Maria Ainali's PhD thesis, addresses the pressing concern of microplastics (MPs) formation through a multi-tiered study evaluating the UV aging processes of commonly used polymers, including PET, PC, and PA. The extent of polymer degradation is found to be influenced by both the aging mechanism and the specific material. The study introduces Pyrolysis‒Gas Chromatography/Mass Spectrometry (Py‒GC/MS) as a potential tool to indicate oxidation, a key factor in the formation of MPs during UV aging. The research emphasizes the urgent need for assessing UV-induced oxidation phenomena, as it poses challenges to the reliability of quantifying MPs. This work contributes valuable insights into the physicochemical alterations of UV-aged polymers, shedding light on the intricate processes leading to microplastics formation and offering a comprehensive approach to address this environmental concern.
The research work was supported by the Hellenic Foundation for Research and Innovation (HFRI) under the 3rd Call for HFRI PhD Fellowships (Fellowship Number: 6567).
Part of this study was financially supported by the Greek Ministry of Development and Investments (General Secretariat for Research and Technology) through the research project “Intergovernmental International Scientific and Technological Innovation-Cooperation. Joint declaration of Science and Technology Cooperation between China and Greece” (Grant no: T7ΔKI-00220) and it is gratefully acknowledged.
Topic: Improvement of commodity polymers
1. Structural Characteristics and Improved Thermal Stability of HDPE/Calcium Pimelate Nanocomposites
As part of the REDONDO project, BikiarisLab conducted research on enhancing the thermal stability of high-density polyethylene (HDPE) through the incorporation of calcium pimelate (CaPim) as an additive. Nanocomposites with CaPim content ranging from 0.1% to 1% were successfully prepared, resulting in homogeneous white materials. Infrared spectroscopy confirmed the chemical structure and incorporation of CaPim, while scanning electron microscopy examined the surficial morphology and additive distribution. Differential scanning calorimetry and X-ray diffraction revealed that the thermal transitions and crystal structure of HDPE remained unaffected by CaPim, preserving overall mechanical properties. The study focused on the thermal degradation of HDPE nanocomposites, employing various analytical methods to investigate the degradation mechanism and kinetic parameters. Isoconversional techniques, including the Friedman method and Vyazovkin analysis, were used to calculate activation energies (Eα). Multivariate non-linear regression determined the degradation mechanism and kinetic triplet. The presence of CaPim increased the Eα of thermal degradation, contributing to the improved thermal stability of the HDPE matrix. This research provides valuable insights into the structural characteristics and enhanced thermal stability of HDPE/CaPim nanocomposites, showcasing their potential for advanced applications.
This research was funded by the European Union’s Horizon Europe Framework Programme under Grant Agreement No. 101058449.
In wrapping up our discussion on BikiarisLab's recent research endeavors, we invite you to reflect on the diverse facets of polymer science explored in our latest publications. These papers delve into the realms of biobased polymers, biomedical polymers, microplastics, and commodity polymers, offering insights into the complexities of these materials. Our focus remains steadfast on contributing to the collective understanding of these topics, without losing sight of the broader implications for the scientific community. Stay tuned for more news from BikiarisLab!