Institute of Fundamental Technological Research

Nwaji N., Fikadu B. B., Osial M., Warczak M., Moazzami Goudarzi Z., Gniadek M., Asgaran S., Lee J., Giersig M., Advanced Functional NiCo 2 S4 @CoMo2 S4 Heterojunction Couple as Electrode for Hydrogen Production via Energy-Saving Urea Oxidation, Small, ISSN: 1613-6810, DOI: 10.1002/smll.202410848, Vol.2410848, pp.1-13, 2025

Abstract:
The urea oxidation reaction (UOR) is characterized by a lower overpotential compared to the oxygen evolution reaction (OER) during electrolysis, which facilitates the hydrogen evolution reaction (HER) at the cathode. Charge
distribution, which can be modulated by the introduction of a heterostructure, plays a key role in enhancing the adsorption and cleavage of chemical groups within urea molecules. Herein, a facile all-room temperature synthesis of functional heterojunction NiCo2 S4 /CoMo 2 S4 grown on carbon cloth (CC) is presented, and the as-prepared electrode served as a catalyst for simultaneous hydrogen evolution and urea oxidation reaction. The Density
Functional Theory (DFT) study reveals spontaneous transfer of charge at the heterointerface of NiCo 2 S4 /CoMo 2 S4 , which triggers the formation of localized electrophilic/nucleophilic regions and facilitates the adsorption of electron donating/electron withdrawing group in urea molecules during the UOR. The NiCo2 S4 /CoMo 2 S4 // NiCo 2 S4 /CoMo 2 S4 electrode pair required only a cell voltage of 1.17 and 1.18 V to deliver a current density of 10 and 100 mA cm−2 respectively in urea electrolysis cell and display very good stability. Tests performed in real urine samples show similar catalytic performance to urea electrolytes, making the work one of the best transition
metal-based catalysts for UOR applications, promising both efficient hydrogen production and urea decomposition.

Zaszczyńska A., Marzena Z., Kołbuk-Konieczny D., Denis P., Gradys A., Sajkiewicz P., On the Structural and Biological Effects of Hydroxyapatite and Gold Nano-Scale Particles in Poly(Vinylidene Fluoride) Smart Scaffolds for Bone and Neural Tissue Engineering, Molecules, ISSN: 1420-3049, DOI: 10.3390/molecules30051041, Vol.30, No.5, pp.1041-1-32, 2025

Abstract:
Piezoelectric materials, due to their ability to generate an electric charge in response to mechanical deformation, are becoming increasingly attractive in the engineering of bone and neural tissues. This manuscript reports the effects of the addition of nanohydroxyapatite (nHA), introduction of gold nanoparticles (AuNPs) via sonochemical coating, and collector rotation speed on the formation of electroactive phases and biological properties in electrospun nanofiber scaffolds consisting of poly(vinylidene fluoride) (PVDF). FTIR, WAXS, DSC, and SEM results indicate that introduction of nHA increases the content of electroactive phases and fiber alignment. The collector rotational speed increases not only the fiber alignment but also the content of electroactive phases in PVDF and PVDF/nHA fibers. Increased fiber orientation and introduction of each of additives resulted in increased SFE and water uptake. In vitro tests conducted on MG-63 and hiPSC-NSC cells showed increased adhesion and cell proliferation. The results indicate that PVDF-based composites with nHA and AuNPs are promising candidates for the development of advanced scaffolds for bone and neural tissue engineering applications, combining electrical functionality and biological activity to support tissue regeneration.

Keywords:
scaffolds, tissue engineering, bone tissue engineering, smart medicine, biodegradable polymers, regenerative medicine, poly(vinylidene fluoride)

Nabavian Kalat M., Ziai Y., Dziedzic K., Gradys A. D., Urbański L., Zaszczyńska A., Andrés Díaz L., Kowalewski Z. L., Experimental evaluation of build orientation effects on the microstructure, thermal, mechanical, and shape memory properties of SLA 3D-printed epoxy resin, EUROPEAN POLYMER JOURNAL, ISSN: 0014-3057, DOI: 10.1016/j.eurpolymj.2025.113829, Vol.228, pp.113829-1-18, 2025

Abstract:
Additive manufacturing (AM) methods, popularly known as 3D printing technologies, particularly the pioneering laser stereolithography (SLA), have revolutionized the production of complex polymeric components. However, challenges such as anisotropy, resulting from the layer-by-layer construction method, can affect the thermomechanical properties and dimensional stability of 3D-printed objects. Although anisotropy in SLA 3D printing is often overlooked due to the high precision of this technique, its impact on the properties and structural performance of the 3D-printed prototype becomes more significant when printing small devices designed for precise micro-mechanisms. This experimental study investigates the impact of the chosen printing surface – a less explored factor – on the performance of SLA 4D-printed thermo-responsive shape memory epoxy (SMEp) specimens. Two identical dog-bone specimens were printed from two distinct surfaces: edge and flat surface, to examine how variations in surface area and quantity of layers influence the microstructure, thermal behavior, mechanical properties, and shape memory performance. The results of this experimental investigation reveal that specimens printed from the edge, with a higher number of layers and smaller surface area, exhibit superior interlayer bonding, tensile strength, dimensional stability, and shape recovery efficiency compared to those printed from the flat surface. Conversely, specimens with fewer, larger layers demonstrated greater elongation and thermal expansion but reduced structural integrity and shape recovery performance. These results highlight the importance of experimentally investigating how different build orientations affect the properties and performance of SLA 3D-printed materials, especially before designing and employing them in applications demanding high precision and reliability.

Keywords:
Additive manufacturing, Laser stereolithography, Shape memory polymers, Materials processing, Anisotropy, Printing orientation

Niemczyk-Soczyńska B., Sajkiewicz P., Hydrogel-Based Systems as Smart Food Packaging: A Review, Polymers, ISSN: 2073-4360, DOI: 10.3390/polym17081005, Vol.17, No.8, pp.1005-1-30, 2025

Abstract:
In recent years, non-degradable petroleum-based polymer packaging has generated serious disposal, pollution, and ecological issues. The application of biodegradable food packaging for common purposes could overcome these problems. Bio-based hydrogel films are interesting materials as potential alternatives to non-biodegradable commercial food packaging due to biodegradability, biocompatibility, ease of processability, low cost of production, and the absorption ability of food exudates. The rising need to provide additional functionality for food packaging has led scientists to design approaches extending the shelf life of food products by incorporating antimicrobial and antioxidant agents and sensing the accurate moment of food spoilage. In this review, we thoroughly discuss recent hydrogel-based film applications such as active, intelligent packaging, as well as a combination of these approaches. We highlight their potential as food packaging but also indicate the drawbacks, especially poor barrier and mechanical properties, that need to be improved in the future. We emphasize discussions on the mechanical properties of currently studied hydrogels and compare them with current commercial food packaging. Finally, the future directions of these types of approaches are described.

Keywords:
hydrogels,bio-based polymers,active packaging,intelligent packaging,food packaging

Altangerel A., Miler O., Nirwan P., Rebecca H., Sajkiewicz P., Amir F., Facile Fabrication of Antibacterial 3D Fibrous Sponge via In Situ Protonation-Induced Direct Electrospinning, Advanced Materials Interfaces, ISSN: 2196-7350, DOI: 10.1002/admi.202400935, pp.1-12, 2025

Abstract:
A versatile, straightforward approach for direct fabrication of three-dimensional (3D) nanofibrous sponges via electrospinning is reported. The fabrication of porous 3D nanofibrous sponges is facilitated due to the protonation of dimethylamino ethyl (DMAE) groups in Eudragit E100 (EE). The generated 3D sponges are characterized by microscopy, thermal analysis, light scattering, and contact angle measurements to reveal their physicochemical properties. Additionally, antibacterial properties are confirmed via a colony-forming unit assay. Microscopy analysis demonstrated that the obtained nanofibers possessed uniform conformation without beads, and their overall diameter varies depending on the fraction of the blend composition. The protonation of DMAE groups is investigated via infrared spectroscopy and further confirmed via zeta potential measurements. The charged electrospun 3D sponges exhibited significant antibacterial properties, effectively combating E. coli even at a diluted extract of samples. Owing to their morphology, electrostatically charged surface, and significant antibacterial properties, these 3D nanofibrous sponges present themselves as an effective material for integration in filtering membranes or cartridges, which may minimize harmful substances suspended in the air.

Keywords:
electrospinning, antibacterial materials, 3D materials

Misiak M., Latko-Durałek P., Fernandez M., Olmedo-Martínez J., Kołbuk-Konieczny D., Górecka Ż., Malmir A., Kozera P., Müller A., Hatzikiriakos S., Boczkowska A., The relationship between thermal, rheological, and tack properties of copolyester-based hot melt adhesives, International Journal of Polymer Analysis and Characterization, ISSN: 1023-666X, DOI: 10.1080/1023666X.2025.2501584, pp.1-20, 2025

Abstract:
This paper studies the interrelationships between the molecular weight, rheology, crystallinity, and tackiness of three types of commercial thermoplastic hot melt adhesives. The hot melt adhesives employed here differ in their compositions and molecular weights, even though all are copolyesters primarily based on poly(butylene terephthalate). Differences in the composition were found to influence the adhesives’ crystallization and melting behavior. These structural variations can translate into different thermal responses and processing characteristics relevant for tailoring adhesive selection to application requirements. Furthermore, adhesives with higher molecular weight were observed to possess larger elasticity, leading to significantly enhanced tackiness properties, as evidenced by the higher values of tensile modulus, peak stress, and work of debonding. This elevated tackiness was linked to the increased fibrillation process observed in polymers with higher molecular weights. Additionally, all tested adhesives exhibited storage moduli below the Dahlquist threshold (G′ < 3.3 × 105 Pa), which supports their ability to achieve measurable tackiness during the initial bonding process. The results presented in this study underscore the diversity among hot melt adhesives and the critical properties that should be considered when selecting adhesives for specific applications.

Keywords:
Hot melt adhesives, copolyester, polybutylene terephthalate, tack properties, rheology, crystallinity