One-step electrospinning membranes with gradual-transition wettability gradient for directional fluid transport

Development of chitosan/polycaprolactone-thymol Janus films with directional transport and antibacterial properties for meat preservation

Reducing contamination from percolate is critical to the preservation of foods with high water content, such as pork. This study aims to develop a novel active packaging material for meat preservation by precisely controlled dual-channel one-step electrospinning. Compared to traditional strategies of preparing Janus films, this method allows for greater flexibility and efficiency. The structure and properties of the Janus film are characterized by scanning electron microscopy (SEM), water contact angle (WCA), directional liquid transport investigation, Thymol release and permeation features, and biocompatibility evaluation. Moreover, the Janus film is applied to the packaging of pork with modified atmosphere packaging to demonstrate its practical application prospects in the food active packaging field. The results revealed that the two sides of the film showed completely different wettability, and the change rate of WCA increased with the increase of the scale of hydrophilic fibers. The permeation features of thymol loaded in the film was consistent with the results of antibacterial properties and biocompatibility assessment. Moreover, the Janus film can effectively prolong the shelf life, improve the quality and safety of the pork.

Multifunctional electrospun membranes with hydrophilic and hydrophobic gradients property for wound dressing

Achieving sustained and stable release of macromolecular antibacterial agents and unidirectional transport of liquids in targeted environment is still a challenge to be addressed in the management of wounds with large amounts of tissue exudates. In this work, a multilayer electrospun membrane (ethylcellulose-ethylcellulose/gelatin-quercetin/Eudragit L-100/polyethylene glycol, EC-EC/Gel-Q/EL/PEG) was designed with hydrophobic-hydrophilic gradients and drug sustained-release properties controlled by self-pumping effect and prepared using sequential electrospinning technology. The capillary force of different layers in the multilayer membrane could be controlled by precisely tuning the polymer concentrations of the inner and middle layers to extract water directly from hydrophobic inner ethylcellulose (EC) layer to hydrophilic middle ethylcellulose/gelatin (EC/Gel) layer. The droplets could not penetrate the hydrophobic side, but the drug molecules in the outer layer quercetin-loaded Eudragit L-100 (Q/EL/PEG) membrane moved after absorbing a large amount of water. The drug release behavior of multilayer wound dressing mainly followed the Korsmeyer-Peppas model. This multifunctional electrospun membrane could rapidly drive the biofluid outflow, effectively block the invasion of external contaminants and continuously release anti-inflammatory drugs, without any obvious cytotoxicity to mouse fibroblast cells. Hence, the above results indicate the excellent therapeutic potential of the proposed biomaterial as a wound dressing for diabetic patients.

One-Step Construction of the Positively/Negatively Charged Ultrathin Janus Nanofiltration Membrane for the Separation of Li+ and Mg2

To coordinate the trade-off between the separation and permeation of the nanofiltration membrane for the separation of Mg²⁺/Li⁺, we regulated poly(ethyleneimine)/piperazine interface polymerization parameters to construct a positively/negatively charged ultrathin Janus nanofiltration membrane at a free aqueous-organic interface. At the optimized interfacial polymerization parameters, 0.03 wt % of piperazine reacted with trimethylbenzene chloride prior to poly(ethyleneimine), forming a primary polyamide layer with fewer defects or limiting large-scale defects of the polyamide layer. The controlled subsequent reaction of poly(ethyleneimine) and trimethylbenzene chloride results in a Janus nanofiltration membrane, with one side enriched with the carboxyl groups, the other side enriched with the amine groups, and a dense polyamide structure in the middle. Under the optimum conditions, the positive potential of the rear surface of the prepared membrane was 14.57 mV, and the water contact angle reached 71.31°, while the negative potential of the front surface was -25.48 mV, and the water contact angle was 12.93°, confirming a Janus membrane with opposite charges and large hydrophilicity differences in the front and rear surfaces. With a high cross-linking degree, a 40 nm thick polyamide layer is 29.09% more thinner than the traditional polyamide membrane. The ultrathin Janus nanofiltration membrane showed an excellent separation factor (S_Li,Mg of 18.26), stability, and water permeability flux (10.6 L·m^-2·h^-1·bar^-1). The rejections to MgCl₂, CaCl₂, MgSO₄, and Na₂SO₄ are measured above 90% at a nearly constant permeability of 10.6 L·m^-2·h^-1·bar^-1, particularly stable rejections to MgCl₂ and Na₂SO₄.

Molecularly Imprinted Membrane Produced by Electrospinning for β-Caryophyllene Extraction

Molecularly imprinted membrane of β-caryophyllene (MIM-βCP) was fabricated incorporating β-caryophyllene molecularly imprinted polymer nanoparticles (βCP-NP) into polycaprolactone (PCL) fibers via electrospinning. The βCP-NP were synthesized by precipitation polymerization using the βCP as a template molecule and acrylic acid as a functional monomer in the proportion of 1:4 mol, respectively. Atomic force microscopy images and X-ray diffraction confirmed the nanoparticles' incorporation into MIM-βCP. MIM-βCP functionalization was evaluated by gas chromatography. The binding capacity was 1.80 ± 0.05 μmol/cm², and the selectivity test was performed with a mixing solution of βCP and caryophyllene oxide, as an analog compound, that extracted 77% of the βCP in 5 min. The electrospun MIM-βCP can be used to detect and extract the βCP, applications in the molecular sieve, and biosensor production and may also contribute as an initial methodology to enhance versatile applications in the future, such as in the treatment of skin diseases, filters for extraction, and detection of βCP to prevent counterfeiting of commercial products, and smart clothing with insect-repellent properties.

Review on the Development and Application of Directional Water Transport Textile Materials

Moisture (sweat) management in textile products is crucial to regulate human thermo-physiological comfort. Traditional hydrophilic textiles, such as cotton, can absorb sweat, but they retain it, leading to undesired wet adhesion sensation and even excessive cooling. To address such issues, the development of functional textiles with directional water transport (DWT) has garnered great deal of interest. DWT textile materials can realize directional water transport and prevent water penetration in the reverse direction, which is a great application for sweat release in daily life. In this review article, the mechanism of directional water transport is analyzed. Then, three key methods to achieve DWT performance are reviewed, including the design of the fabric structure, surface modification and electrospinning. In addition, the applications of DWT textile materials in functional clothing, electronic textiles, and wound dressing are introduced. Finally, the challenges and future development trends of DWT textile materials in the textile field are discussed.