Membrane fouling is one of the main drawbacks encountered during the practical application of membrane separation processes. Cleaning of a membrane is important to reduce fouling and improve membrane performance. Accordingly, an effective cleaning method is currently of crucial importance for membrane separation processes in water treatment. To clean the fouling and improve the overall efficiency of membranes, deep research on the cleaning procedures is needed. So far, physical, chemical, or combination techniques have been used for membrane cleaning. In the current work, we critically reviewed the fouling mechanisms affecting factors of fouling such as the size of particle or solute; membrane microstructure; the interactions between membrane, solute, and solvent; and porosity of the membrane and also examined cleaning methods of microfiltration (MF) membranes such as physical cleaning and chemical cleaning. Herein, we mainly focused on the chemical cleaning process. Factors affecting the chemical cleaning performance, including cleaning time, the concentration of chemical cleaning, and temperature of the cleaning process, were discussed in detail. This review is carried out to enable a better understanding of the membrane cleaning process for an effective membrane separation process.

Chronic wounds are caused by bacterial infections and create major healthcare discomforts; to overcome this issue, wound dressings with antibacterial properties are to be utilized. The requirements of antibacterial wound dressings cannot be fulfilled by traditional wound dressing materials. Hence, to improve and accelerate the process of wound healing, an antibacterial wound dressing is to be designed. Electrospun nanofibers offer a promising solution to the management of wound healing, and numerous options are available to load antibacterial compounds onto the nanofiber webs. This review gives us an overview of some recent advances of electrospun antibacterial nanomaterials used in wound dressings. First, we provide a brief overview of the electrospinning process of nanofibers in wound healing and later discuss electrospun fibers that have incorporated various antimicrobial agents to be used in wound dressings. In addition, we highlight the latest research and patents related to electrospun nanofibers in wound dressing. This review also aims to concentrate on the importance of nanofibers for wound dressing applications and discuss functionalized antibacterial nanofibers in wound dressing.

Membrane fouling is one of the most significant issues to overcome in membrane-based technologies as it causes a decrease in the membrane flux and increases operational costs. This study investigates the effect of common chemical cleaning agents on polymeric nanofibrous membranes (PNM) prepared by polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), and polyamide 6 (PA6) nanofibers. Common alkaline and acid membrane cleaners were selected as the chemical cleaning agents. Membrane surface morphology was investigated. The PAN PNM were selected and fouled by engine oil and then cleaned by the different chemical cleaning agents at various ratios. The SEM results indicated that the use of chemical agents had some effects on the surface of the nanofibrous membranes. Moreover, alkaline cleaning of the fouled membrane using the Triton X 100 surfactant showed a two to five times higher flux recovery than without using a surfactant. Among the tested chemical agents, the highest flux recovery rate was obtained by a binary solution of 5% sodium hydroxide + Triton for alkaline cleaning, and an individual solution of 1% citric acid for acidic cleaning. The results presented here provide one of the first investigations into the chemical cleaning of nanofiber membranes.

In the present study, PCL (polycaprolactone) nanofibres were produced by the electrospinning method. The use of PCL electrospun biopolymer in biomedical applications has attracted considerable interest due to its chemical resistance, biodegradability, biocompatibility, and non-toxic characteristics. However, the hydrophobic nature of PCL polymer restricts the useage of PCL nanofibres for the cell adhesion and absorption. A hydrophilic and biocompatible PCL electrospun mat with a low water contact angle is an attractive strategy for development in tissue engineering and wound dressing. In this study, we demonstrate a feasible and simple method to produce hydrophilic PCL nanofibres for possible application in wound dressing. Chloroform/ethanol (EtOH) and chloroform/dimethylformamide (DMF) mixtures were used as two different solvent systems. The impact of the polymeric solution concentration, applied voltage, and solvent mixtures on the fibre surface morphology and water contact angle was investigated. Consequently, bead structures were observed at low concentrations but disappeared with increases in the concentration. It was observed that the size of beads decreased and the diameter of fibres increased with increasing voltage. The wettability of the webs changed from hydrophobic to hydrophilic with changes of the polymer concentration. The contact angle of the nanofibre mats decreased in both solvent systems as the concentration increased. The results showed that the lowest contact angle was obtained in 24% wt. PCL+chloroform/EtOH solution and was 68°. The highest contact angle was obtained in 4% wt. PCL+chloroform/EtOH solution and was 112°. Using this method, the surface hydrophilicity of the PCL nanofibres improved easily without any surface treatment.