Active dressings based on natural polymers are becoming increasingly popular on the market. One of such polymers is alginate, which is characterized by biodegradability, resorbability, has no carcinogenic properties, does not have allergenic or hemostatic properties, and has a confirmed lack of toxicity. However, this polymer does not show biocidal and biostatic properties, therefore the purpose of this research was to select the appropriate conditions for the production of calcium alginate fibers modified with nano titanium dioxide and nano zinc oxide. It was assumed that the presence of nano metal oxide fillers will give antibacterial properties to formed fibers, which were used to form nonwovens. The following article presents a comparative analysis of nonwovens made of alginate fibers, without nano additives, with nonwovens made of alginate fibers containing in their structure 7% titanium dioxide and nonwovens made of alginate fibers containing 2% ZnO. The selection of the nano additive content was determined by the spinning ability of the developed polymer solutions. Based on the results contained in the article, it was found that the introduction of modifiers in the structure of fibers increases the diameter of the fiber pores, which improves the sorption and retention properties of the obtained fibers, and also gives differentiated antibacterial properties to the obtained nonwovens depending on the type of nano additive used. Greater activity against Escherichia coli, Staphylococcus aureus strains and Aspergillus Niger molds was shown in nonwovens made of 2% ZnO modified fibers compared to nonwovens made from TiO₂ modified fibers.

Plastic products, especially in the packaging industry, have become the main commodities penetrating virtually every aspect of our lives. Unfortunately, their omnipresence is not neutral to the natural environment. Pollution in the form of microplastics is a global problem. Therefore, green technologies that enter into the circular economy become an important topic. As part of the research work, the modification of poly(lactic acid) has been studied for use in the packaging industry. Due to its intrinsic rigidity, plasticizing substances had to be introduced in PLA in order to improve its plastic deformability. Both high-molecular compounds such as ethoxylated lauryl alcohol, block copolymer of ethylene oxide and propylene oxide, and ethoxylated stearic acid as well as low-molecular compounds such as di-2-ethylhexyl adipate, di-2-ethylhexyl sebacate, and triethyl citrate were used. The samples extruded from plasticized polymers were characterized using differential scanning calorimetry, thermal gravimetric analysis, and mechanical properties including Young’s modulus. The melt flow rate (MFR) and molar mass distribution were determined. For all modified samples the glass transition temperature, depending on the plasticizer used, was shifted towards lower values compared to the base polymer. The best result was obtained for di-2-ethylhexyl adipate (ADO) and di-2-ethylhexyl sebacate (SDO). The elongation at break increased significantly for ADO at about 21%. The highest elongation was obtained for SDO (about 35%), although it obtained a higher glass temperature. The degradation of the polymer was not observed for both plasticizers. For these plasticizers (ADO and SDO) it also lowered Young’s module by about 26%, and at the infrared spectrum deformation of peaks were observed, which may indicate the interaction of the ester carbonyl group of PLA with plasticizers. Therefore it can be concluded that they are good modifiers. The selected plasticizers that are used in the production of food contact materials, in particular in the production of PVC (polyvinyl chloride) food films, also exhibited great potential to be applied to PLA food films, and exhibit better properties than the citrate, which are indicated in many publications as PLA plasticizers.

Chitosan, a well-established biomaterial known for its biocompatibility, biodegradability, and bioactivity, has been the focus of extensive research in recent years. This study explores the enhancement of chitosan fibers’ properties through wet impregnation with either ursolic acid (UA) or cross-linking with tripolyphosphate (TPP). In the first experiment, chitosan fibers were treated with UA, for varying immersion set points (1, 2, 4, 6, and 8 h). FTIR, SEM, and UV-Vis spectroscopy analyses demonstrated a chemical reaction between chitosan and UA, with stability reached after 2 h of immersion. Antibacterial testing revealed that chitosan fibers impregnated with UA exhibited significant antibacterial activity against Gram-positive bacteria, notably Staphylococcus aureus. The second experiment involved modifying chitosan fibers’ surfaces with a 1% w/v TPP solution for the same periods of time (1, 2, 4, 6, and 8 h). Subsequently, the investigation involved FTIR, SEM, and dynamometry analyses, which revealed successful cross-linking between chitosan and TPP ions, resulting in improved tensile strength after 2 h of immersion. This dual-approach study highlights the potential of chitosan fibers for diverse applications, from wound-healing dressings to antibacterial materials against Gram-positive bacteria.

Polymers derived from renewable sources which are additionally subject to degradation processes are currently an interesting alternative to conventional polymers of petrochemical origin. One of such polymers is poly(lactic acid) (PLA), which can be used in the packaging, textile and also medical industries. Its great advantage is the susceptibility to biodegradation and the nontoxicity of the degradation products. Because of high brittleness and stiffness, the modification of PLA is necessary to improve its plastic deformability, which can expand the new application possibilities. As part of the research work, the modification of PLA by plasticisation was undertaken to improve its plastic deformability properties. The low molecular mass esters from the citrate group and glycerol triacetate were used. The samples extruded from plasticised polymer were characterised using Differential Scanning Calorimetry (DSC) and Gel Permeation Chromatography/Size Exclusion Chromatography (GPC/SEC). The mechanical properties and melt flow rate after modification were determined. The aim of the research was to determine the relationship between the structure of a plasticiser and its ability to reduce the interactions in the polymer chain in order to develop an optimal polymer-plasticiser arrangement. Based on this research, there was no relationship between the efficiency of the plasticisation process and the increasing molecular mass of the plasticiser. The additional chemical (acetyl) group in the plasticiser also does not increase the efficiency of the PLA plasticisation process. In the next steps of the research, functional forms will be produced, i.e. fibers, films, and fittings from the selected polymer-plasticiser systems.

Due to the deteriorating state of surface waters and the resulting reduction in their availability for the population, efforts have been undertaken to develop a biodegradable or compostable water filtration system capable of reducing the amount of harmful bacteria in this environment. The aim of this research was to develop nonwovens using the classic needle-punching method with commercially available polylactide (PLA) polymer, and subsequently, to select appropriate concentrations of modifiers to create systems with antibacterial properties. The resulting composites could potentially serve as filtration materials for the purification of surface waters. Nanoparticles such as zinc oxide, titanium dioxide, and silver were employed in this research. These compounds exhibit antibacterial properties and are insoluble in water. To confirm the bactericidal activity of the additives, biological tests were conducted, and the distribution of these additives on the structure of the filtration material was examined using scanning electron microscopy (SEM) equipped with an energy dispersive spectroscopy (EDS) detector.

Air pollution is currently the most significant environmental factor posing a threat to the health and lives of European residents. It is a key cause of poor health, particularly respiratory and cardiovascular diseases. The primary aim of the study was to numerically determine the impact of the air purifier model’s geometry on the distribution of air within a room and to conduct experimental tests on the filtration efficiency and preliminary antibacterial activity of filtration composites. The scope of the work included designing an air purifier model in the form of a pendant lamp and performing computer simulations in Ansys software to identify the optimal shape. The experimental research focused on developing filtration composites consisting of nonwoven fabric with an active hydrosol layer, meltblown nonwovens and a carbon filter. The study results showed that the SMMS composite with 50% thyme and carbon nonwoven exhibited the highest filtration efficiency for both small and large particles.