Herein, we demonstrate a simple and versatile way for preparing stable Ti3C2T x MXene dispersions in nonpolar organic solvents through a simultaneous interfacial chemical grafting reaction and phase transfer method. Alkylphosphonic acid ligands were chemically grafted on the hydroxyl terminal groups of Ti3C2T x flakes at the liquid–liquid interface between water and water-immiscible organic medium to form a covalent Ti–O–P bond via interfacial nucleophilic addition and sequential condensation reaction at room temperature; the surface-functionalized Ti3C2T x flakes concurrently migrated from the aqueous phase to the organic phase. Unlike conventional surface chemical modification methods that require many complex and tedious steps, this is a simple and easy process for fabricating a Ti3C2T x organic dispersion in various organic solvents, from highly polar to nonpolar. The nonpolar Ti3C2T x dispersion in chloroform also exhibits strong oxidation resistance and stable long-term storage. This approach provides an opportunity for preparing MXene nanocomposites with nonpolar polymeric matrices that are soluble in organic media for future applications such as stretchable electrode.

No abstract

Electrospinning of polyvinyl alcohol (PVA), gelatin (GE), and a PVA/GE blend was conducted with the aim of fabricating biodegradable scaffolds for tissue engineering. The process parameters including the concentration of GE in PVA/GE blends, electrical field, and tip-to-collector distance (TCD) were investigated. Electrospinning processes were conducted at three different GE concentrations (PVA/GE = 2/8, 6/4, and 8/2), and the voltage and TCD were varied from 18 to 24 kV and 7 to 20 cm, respectively. The average diameter of the electrospun PVA, GE, and PVA/GE blend fibers ranged from 50 to 150 nm. The TCD had significant effects on the average diameter of the PVA/GE nanofiber, while changes in the voltage did not significantly affect the diameter of the PVA/GE nanofiber. The miscibility of the PVA/GE blend fibers was examined by differential scanning calorimetry, and X-ray diffraction was used to determine the crystallinity of the membrane. Tensile strength was measured to evaluate the physical properties of the membrane. Based on the combined results of this study, the PVA/GE membrane holds great promise for use in tissue engineering applications, especially in bone or drug delivery systems.

In this study, an electro-spun co-polymer PLGA/PCL blend was fabricated using various percentages of PLGA in the blend PLGA/PCL solutions. The PLGA/PCL ratios used to fabricate the electrospun fibrous mats were reflected in the FT-IR (Fourier Transform Infrared Spectroscopy) data. Experimental results from the MTT assay showed that the biocompatibility of the electro-spun co-polymer increased at increasing percentages of PLGA. In vitro cells adhesion and proliferation of fibroblast cells on electro-spun mats were characterized by SEM morphology. In addition, we found that increasing PLGA concentrations affected the mechanical properties of electro-spun membranes and increased the biocompatibility of PLGA/PCL electro-spun fibrous mats.

In this study, we developed a fast, simple and novel process to fabricate cross-linked electro-spun gelatin with limited amounts of glutaraldehyde (GA) using trifluoroacetic acid (TFA) as the solvent. Using SEM, the uncross-linked gelatin fibers were determined to have diameters between 50-300 nm, while the cross-linked gelatin electro-spun fibers had diameters between 100-500 nm. FT-IR revealed that the un-cross-linked and cross-linked electro-spun gelatin was fabricated successfully by electro-spinning using TFA as a solvent, which has not been reported until now. Stress-strain curves showed that the addition of small amounts of GA increased the strength of the gelatin by two fold and allowed for the creation of a water insoluble gelatin electro-spun membrane