As an efficient reinforcing material in resin matric composites, the application of basalt fibers (BFs) in composites is limited by the poor interfacial adhesion between BFs and the resin matrix. In this study, to obtain the basalt fibers/epoxy resin composites with enhanced mechanical properties, the modification solution containing different concentrations of Lanthanum ions (La³⁺) was synthesized to modify the BFs surfaces to enhance the poor interfacial adhesion between BFs and the matrix. The morphology, the chemical structure and the chemical composition of the modified BFs surface were observed and detected by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, respectively. The results show that, after BFs were soaked in the modification solution, the more active groups (C=O, –OH, C–O, etc.) were introduced to the BFs surfaces and effectively enhanced the bond strength between BFs and the resin matrix. The obtained mechanical performances of prepared basalt fibers/epoxy resin composites showed that the tensile strength, bending strength and interlaminar shear strength (ILSS) were improved with the modified BFs, and reached to 458.7, 556.7 and 16.77 Mpa with the 0.5 wt.% La. Finally, the enhancement mechanism of the modification solution containing La element is analyzed.

The electrospun PVDF fiber membranes with the characteristics of light weight, strong signal and measurability, have been widely applied in the fields of environment, energy sensors and biomedical treatment. Due to the weakness of the piezoelectric and service properties, the conventional PVDF fiber membranes cannot meet the operating requirements. Based on the obtained optimal technological parameter of electrospun pure PVDF fiber membranes (P-PVDF) in the previous experiment (unpublished), three inorganic reinforced substances (AgNO₃, FeCl₃·6H₂O, nanographene) were respectively used to dope and modify PVDF to prepare composite fiber membranes with the better piezoelectric performance. The morphology and crystal structure of the hybrid fiber membranes were observed and detected by scanning electron microscopy and X-ray diffraction, respectively. The results showed that the dopant could effectively promote the formation of β-phase, which can enhance the piezoelectric performance. The mechanical properties test and piezoelectric performance test exhibited that the static flexural strength, the elastic modulus, and the piezoelectric performance were improved with the addition of dopant. In addition, the influence on the addition of dopant and the doping modification mechanism were discussed. Finally, the conclusions showed that the minimum average diameter was obtained with the 0.3 wt% addition of AgNO₃; the piezoelectric performance reached the strongest with the 0.8 wt% addition of FeCl₃·6H₂O; the mechanical properties were best with the 1.0 wt% addition of nanographene.

In this study, the composite nanofiber membranes (AgNPs-PS/PET) composed of hydrophobic polystyrene (PS) embedded with different additions of silver nanoparticles (AgNPs) and hydrophilic hydrolyzed polyethylene terephthalate (PET) were prepared via electrospinning technology to achieve the function of unidirectional water penetration. The addition of AgNO₃ was at 0 wt%, 0.5 wt%, 1.0 wt% and 1.5 wt% as the variables. The surface morphology and structure of AgNPs-PS/PET composite nanofibers were characterized by scanning electron microscopy (SEM), x-ray energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The SEM image showed that the fibers of the composite materials were continuous and uniform as a result of electrospinning. The presence and content of Ag nanoparticles dispersed in the nanofibers were investigated using EDS and TEM. The contact angle (CA) was tested to illustrate the wettability of the composite nanofiber membranes using a static contact angle measuring instrument and the process of unidirectional water penetration was recorded. Meanwhile, the mechanism of unidirectional water penetration was analyzed. Moreover, the electrospinning solution’s viscosity and conductivity were also investigated. Eventually, the optimal addition of AgNO₃ (1.0 wt%) was confirmed and the prepared AgNPs-PS/PET composite nanofiber membranes were able to achieve the function of unidirectional water penetration. These membranes have the potential to be applied in smart textiles, unidirectional water collection and wound dressing.

With increasing attention being paid to environmental issues, the application of natural fibers in fiber-reinforced composites has attracted more and more attention. Composite materials with basalt fibers (BFs) as reinforcement have excellent properties and are widely used in many fields. Hydrothermal aging crucially influences the durability of basalt fiber/epoxy resin composites (BF/ERCs). In this study, BFs were used as reinforcing materials, whose surfaces were modified with a rare earth modification solution (CeCl₃). The density, mechanical performance, and chemical properties of BF/ERCs subjected to hygrothermal aging were analyzed by the weight method, static mechanical performance testing, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR). The effects of the modification solution with different Ce concentrations on the water absorption, tensile, bending and interlaminar shear strength (ILSS) of BF/ERCs were investigated. The test results showed that the water absorption of BF/ERCs treated with a modification solution that contained Ce 0.5 wt % as the minimum value and the retention rate of the mechanical properties of BF/ERCs reached maximum values after hygrothermal aging.