Nanofibers or nanofibrous membranes prepared by electrospinning possess many attractive properties, including excellent mechanical properties, high specific surface area and high porosity, making them attractive for sensor application, especially for the electrochemical sensors. Many nanomaterials are used as additives to improve the conductivity, sensitivity and selectivity of sensors. Based on the different modifiers of electrode materials, electrochemical sensors can be divided into enzyme sensors and non-enzyme sensors. In this review, we summarize the recent progress of the electrochemical sensors fabricated by electrospinning, including hydrogen peroxide (H₂O₂) sensors, glucose sensors and other sensors. In addition, the sensing mechanisms of various electrochemical sensors are introduced in detail. Finally, future research directions of electrochemical sensors based on electrospinning and the challenges faced by large-scale applications of electrospun electrochemical sensors are presented.

Ultra-high molecular weight polyethylene (UHMWPE) and high-density polyethylene (HDPE) blend fibers with the highest tensile strength of 1.13 GPa were prepared by a melt spinning process. The mechanical behavior and crystal structure of the as-spun filaments and fibers were studied by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray diffraction (XRD), sound velocity orientation testing, and tensile testing. The orientation degree, crystallinity, tensile strength, and initial modulus of the fibers increased with the increasing of the draw ratios. The grain size was shortened in the radial direction and elongated in the axial direction. The results suggested that the improvement of the tensile strength and initial modulus was a result of the compact crystal structure formed by slender grains composed of highly oriented molecular chains. Blending with HDPE could improve the formation of a slender and compact crystal structure, and the tensile strength and initial modulus of the blend fibers were higher.

In this paper, glass fiber-reinforced polyamide-6 (PA-6) composites with up to 70 wt% fiber contents were successfully manufactured using a pultrusion process, utilizing the anionic polymerization of caprolactam (a monomer of PA-6). A novel thermoplastic reaction injection pultrusion test line was developed with a specifically designed injection chamber to achieve complete impregnation of fiber bundles and high speed pultrusion. Process parameters like temperature of injection chamber, temperature of pultrusion die, and pultrusion speed were studied and optimized. The effects of die temperature on the crystallinity, melting point, and mechanical properties of the pultruded composites were also evaluated. The pultruded composites exhibited the highest flexural strength and flexural modulus, reaching 1061 MPa and 38,384 MPa, respectively. Then, effects of fiber contents on the density, heat distortion temperature, and mechanical properties of the composites were analyzed. The scanning electron microscope analysis showed the great interfacial adhesion between fibers and matrix at 180 °C, which greatly improved the mechanical properties of the composites. The thermoplastic reaction injection pultrusion in this paper provided an alternative for the preparation of thermoplastic composites with high fiber content.

The influence of spinning temperature on ultrahigh-molecular-weight polyethylene/high-density polyethylene as-spun blend filaments and the influence of drawing temperature on ultrahigh-molecular-weight polyethylene/high-density polyethylene-blend fibers were investigated. The results showed that the optimum spinning and hot-drawing temperatures were 310℃ and 85℃, respectively, and blending with high-density polyethylene improved the orienting ability of the molecular chains and the crystallization ability. The blend filaments spun at 310℃ had the best molecular chain orientation, crystallinity and crystal orientation of the filaments examined; both lower and higher spinning temperatures were detrimental to the crystal structure growth of the as-spun blend filaments. The optimum drawing temperature of the blend fibers was 85℃, which resulted in blend fibers with the best molecular chain orientation, crystallization, and crystal orientation as well as the thinnest grains of the fibers examined. The highest tensile strength and initial modulus were 1204 MPa and 20.4 GPa, respectively; these high values can be attributed to the fibrillar structure, which consisted of extended molecular chains and thin grains. The results in this paper can help disclose the effect mechanism of formation temperature on the melt spinning method used to produce high-strength ultrahigh-molecular-weight polyethylene fibers.