Particulate matter (PM) pollution from industrial dust and automobile exhaust emissions has caused serious harm to the environment, becoming a global public safety concern. However, conventional filter materials have problems such as high brittleness at high temperatures, so it is of great significance to develop a filter material that can efficiently intercept PM at high temperatures. We prepared mullite fiber sponges with high compressibility, ultraflexibility, and excellent high-temperature filtration performance by electrostatic solution blow spinning using two-component co-spinners PVA and PEO as polymer templates. What’s more, mullite fiber sponge has excellent thermal stability at temperatures ranging from -196 to 1100 °C. In ambient conditions, the filtration efficiency of mullite fiber sponge was 99.67%, with a resistance of 240 Pa, and filtration efficiency of approximately 97% was achieved at 300 °C. The nanofiber sponge demonstrated outstanding filtration performance for automobile exhaust (PM_0.3>97%), indicating significant potential for applications in high-temperature filtration.

Highly purified alginate electrospun nanofibers have not yet been produced; thus, the fabrication of alginate into nanofibers is a great challenge. The OH groups of the repeating units in the polysaccharides act not only as interaction sites with water molecules but also in the formation of hydrogen-bonded complexes between them. The latter contributes to gelation and increases viscosity at low concentrations and must be one of the factors that make fiber difficult to produce. We have attempted a novel approach to obtain nanofibers by suppressing hydrogen bonding between alginate chains and their gelation. An ion complex with anionic alginate and a cationic surfactant could be considered to govern hydrogen-bonded aggregation, yielding nanofibers. This paper consists of two topics: first, the solution properties of the ion complex are discussed from the rheology of the solution and the molecular structure of the soluble ion complex. The other is the study of the structure and properties of nanofibers. It has been reported that ion complexes can be used to prepare alginate nanofibers.