Porous polytetrafluoroethylene (PTFE) membranes are widely used in high-efficiency filtration, protective ventilation, and medical applications, but their traditional stretching-based preparation methods suffer from significant problems such as pollution, high energy consumption, and lengthy processes. Here, we prepared PTFE nanofiber membranes based on in-situ fiber forming technology. Exploiting the excellent melt processability of polycaprolactone (PCL) over a wide temperature window (90–180 °C), a microstructure-controllable fabrication strategy for PTFE nanofiber membranes was developed. By systematically regulating processing temperature, screw speed, and circulation time, the shear force imposed on PTFE crystals was precisely tuned, enabling fine control over fiber diameter, pore size, and membrane thickness. The resulting PTFE nanofiber membranes exhibit tunable fiber diameters (70–185 nm), pore sizes (0.23–1.4 µm), and thicknesses (8–24 µm), while maintaining a high porosity (> 76%). The membranes demonstrate excellent tensile strength of up to 25.3 MPa and outstanding chemical stability. In oil–water separation, the membranes show high oil permeance and separation efficiency. Moreover, in high-precision solid–liquid filtration, the membranes achieve a rejection rate approaching 99.9% for submicron particles such as carbon nanotubes (CNTs), significantly outperforming commercial stretched PTFE membranes in filtration precision. This research provides a versatile strategy with high structural customizability to address the challenges in controlled fabrication of PTFE nanofiber membranes and their application in high-precision filtration fields.

In the era of advanced wearable electronic devices, the triboelectric nanogenerators (TENGs) as energy harvesting and self-powered sensing units hold great promise. Selecting appropriate triboelectric material is the crucial factor to optimize the performance of TENG, while polytetrafluoroethylene (PTFE) stands out as a highly versatile option among the various materials. In this study, we present an ultrafine nanofibrous PTFE (NF-PTFE) films prepared by novel in-situ fibrillation strategy as the triboelectric material in TENG devices. The innovative processing methodology facilely addresses the dilemma between high porosity and fine pore size of traditional porous PTFE films, meanwhile achieves exceptional mechanical strength, hydrophobicity, air permeability, and chemical resistance of the films. With the integration of nanofibrous PTFE films into contact-separation mode TENG and droplet-based TENG, these devices realize the peak electrical output of 131 V/10.8 μA and 54 V/14 μA with great durability, which surpass the performance of TENGs using traditional expanded PTFE films. Furthermore, a smart glove capable of recognizing hand gestures is proposed, which demonstrates the versatility, flexibility, and practicality of this material for potential use in smart devices. This reported NF-PTFE film provides insights for the design of high-performance TENG device for advanced wearable electrical applications.