Preparation of PI/PTFE–PAI Composite Nanofiber Aerogels with Hierarchical Structure and High-Filtration Efficiency

Abstract

Electrospun nanofiber, showing large specific area and high porosity, has attracted much attention across various fields, especially in the field of air filtration. The small diameter contributes to the construction of filters with high-filtration efficiency for fine particulate matter (PM), however, along with an increase in air resistance. Herein, composited nanofiber aerogels (NAs), a truly three-dimensional (3D) derivative of the densely compacted electrospun mat, were constructed with the blocks of polytetrafluoroethylene–polyamideimide (PTFE–PAI) composite nanofiber and polyimide (PI) nanofiber. PI/PTFE–PAI NAs with hierarchically porous architecture and excellent mechanical properties have been obtained by thermally induced crosslink bonding. Results indicated that sintering at 400 °C for 30 min could complete the decomposition of polyethylene (PEO) and imidization of polyamic acid (PAA) into PI, as well as generate sufficient mechanical bonding between adjacent nanofibers in the NAs without extra additive. The well-prepared PI/PTFE–PAI NAs could withstand high temperature up to 500 °C. In addition, the filtration tests illustrated that the composite NAs had an excellent performance in PM filtration. More importantly, the filtration behavior could be adjusted to meet the requirements of various applications. The excellent thermal stability and high-filtration efficiency indicated its great potential in the field of high-temperature air filtration.

Electrospun Nanofiber Membranes for Air Filtration: A Review

“…The fiber films prepared by the electrospinning of multiple polymers make up for the defect of the singular function of a single polymer to a certain extent, as shown in Table 2 . For example, the fiber membrane of lead zirconate titanate/polyvinylidene fluoride (PZT/PVDF) not only has an excellent filtering ability, but also realizes the sensing function of volatile organic compounds (VOCs) [ 164 ], and the composite prepared by electrospinning polytetrafluoroethylene–polyamideimide/polyimide (PTEF–PAI/PI) can withstand high temperatures of up to 500 °C and the filtration performance can be adjusted to meet various demands [ 176 ]. However, the filter materials prepared by a variety of polymers still cannot meet the growing needs, and the materials still need to be modified, such as by adding antibacterial silver nanoparticles and adsorptive activated carbon.…”

Optimization of Technological Parameters of the Process of Forming Therapeutic Biopolymer Nanofilled Films

“…Polymer nanomaterials, films, and coatings are widely used in various industries, including pharmaceuticals and medicine. Polymer tapes and films are used in equipment construction as working elements [ 1 , 2 ], to ensure the tightness of threaded joints during the life cycle of the product [ 3 , 4 ], for elastic fixation of broken bones during surgery on human limbs [ 5 , 6 ], for filtering liquids and gases [ 7 , 8 ], for aqueous nanostructures containing antimicrobials of natural origin have been developed to inactivate SARS-CoV-2 surrogates on surfaces [ 9 ], for wound healing [ 10 , 11 , 12 ] and dentistry [ 13 , 14 , 15 ].…”

Fabrication and evaluation of aramid fiber/polytetrafluoroethylene emulsion/tourmaline particle composite filter media: Filtration performance, thermal behavior, and mechanical property

“…[23][24][25] Poly(tetrafluoroethylene) (PTFE) has advantages in harsh environments due to its superior thermal stability and chemical resistance, and is widely used in the impregnation process as a coating material. 26,27 In this study, AF/PTFE/TM composite filter media was fabricated first, which was made of AF filter media as the framework, PTFE emulsion as the connector or matrix, and TM particles as the electret or enhancer. The optimum concentration of PTFE emulsion and the optimum content of TM powder were obtained from the test results.…”