Air pollution is one of the biggest health and environmental problems in the world and a huge threat to human health on a global scale. Due to the great impact of respiratory viral infections, chronic obstructive pulmonary disease, lung cancer, asthma, bronchitis, emphysema, lung disease, and heart disease, respiratory allergies are increasing significantly every year. Because of the special properties of electrospun nanofiber mats, e.g., large surface-to-volume ratio and low basis weight, uniform size, and nanoporous structure, nanofiber mats are the preferred choice for use in large-scale air filtration applications. In this review, we summarize the significant studies on electrospun nanofiber mats for filtration applications, present the electrospinning technology, show the structure and mechanism of air filtration. In addition, an overview of current air filtration materials derived from bio- and synthetic polymers and blends is provided. Apart from this, the use of biopolymers in filtration applications is still relatively new and this field is still under-researched. The application areas of air filtration materials are discussed here and future prospects are summarized in conclusion. In order to develop new effective filtration materials, it is necessary to understand the interaction between technology, materials, and filtration mechanisms, and this study was intended to contribute to this effort.

Electrospun nanofiber mats are nowadays often used for biotechnological and biomedical applications, such as wound healing or tissue engineering. While most studies concentrate on their chemical and biochemical properties, the physical properties are often measured without long explanations regarding the chosen methods. Here, we give an overview of typical measurements of topological features such as porosity, pore size, fiber diameter and orientation, hydrophobic/hydrophilic properties and water uptake, mechanical and electrical properties as well as water vapor and air permeability. Besides describing typically used methods with potential modifications, we suggest some low-cost methods as alternatives in cases where special equipment is not available.

Chitosan is a natural biopolymer that can be suitable for a wide range of applications due to its biocompatibility, rigid structure, and biodegradability. Moreover, it has been proven to have an antibacterial effect against several bacteria strains by incorporating the advantages of the electrospinning technique, with which tailored nanofibrous scaffolds can be produced. A literature search is conducted in this review regarding the antibacterial effectiveness of chitosan-based nanofibers in the filtration, biomedicine, and food protection industries. The results are promising in terms of research into sustainable materials. This review focuses on the electrospinning of chitosan for antibacterial applications and shows current trends in this field. In addition, various aspects such as the parameters affecting the antibacterial properties of chitosan are presented, and the application areas of electrospun chitosan nanofibers in the fields of air and water filtration, food storage, wound treatment, and tissue engineering are discussed in more detail.

In this study, new adsorbents were prepared by modifying a montmorillonite clay (Mt) with cethyltrimethyl ammonium bromide (CTAB) to form CTAB-Mt, followed by a second modification process with polyaniline (PAni) to form PAni@CTAB-Mt by in situ polymerization of aniline. X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), cyclic voltammetry (CV) and the Brunauer–Emmett–Teller (BET) technique were used to characterize the samples. These adsorbents were used in a batch process to remove methylene blue (MB) from aqueous solution. Factors investigated included initial pH of the solution, contact time and temperature. The adsorption data fit the Freundlich isotherm better than the Langmuir and Temkin isotherms. The maximum adsorption capacities (q_eq) obtained were 108.82 mg·g⁻¹, 71.20 mg·g⁻¹ and 57.36 mg·g⁻¹ for PAni@CTAB-Mt, CTAB-Mt and Mt, respectively. The enhanced adsorption capability of the hybrid material is due to increase in surface area and pore volume of the PAni@CTAB-Mt adsorbent. The adsorption results were found to fit well with the pseudo-second-order kinetics model, with highest correlation coefficient (R²) values of 0.954, 0.942 and 0.958 for Mt, CTAB-Mt and PAni@CTAB-Mt adsorbents, respectively. The pH and temperature had a significant effect on the adsorption process, and the negative values of ΔG suggest that the adsorption process was spontaneous and feasible. The desorption and reusability experiment indicated that PAni@CTAB-Mt has the potential to be a reusable adsorbent for MB removal.

In recent years, ecological issues have led to the search for new green materials from biomass as precursors for producing carbon materials (CNFs). Such green materials are more attractive than traditional petroleum-based materials, which are environmentally harmful and non-biodegradable. Biomass could be ideal precursors for nanofibers since they stem from renewable sources and are low-cost. Recently, many authors have focused intensively on nanofibers’ production from biomass using microwave-assisted pyrolysis, hydrothermal treatment, ultrasonication method, but only a few on electrospinning methods. Moreover, still few studies deal with the production of electrospun carbon nanofibers from biomass. This review focuses on the new developments and trends of electrospun carbon nanofibers from biomass and aims to fill this research gap. The review is focusing on recollecting the most recent investigations about the preparation of carbon nanofiber from biomass and biopolymers as precursors using electrospinning as the manufacturing method, and the most important applications, such as energy storage that include fuel cells, electrochemical batteries and supercapacitors, as well as wastewater treatment, CO₂ capture, and medicine.