Enhancing the flame retardancy, thermal stability, and superhydrophobicity of paper through Na₂O·nSiO₂ and polydimethylsiloxane modification

The water absorption and flammability of paper pose significant challenges to its long-term effectiveness. Hence, this study introduced a paper modification strategy that synergistically incorporated both superhydrophobicity and flame retardancy. This method involved the formation of a micro or nano-level rough structure on the paper surface through sodium silicate modification. Further modification of the paper surface with polydimethylsiloxane yielded a functional paper with excellent superhydrophobic properties. The modified paper exhibited a water contact angle (WCA) and sliding angle (SA) of 153.5° and 9°, respectively, indicating excellent self-cleaning, abrasion resistance, and chemical resistance. The limiting oxygen index, thermogravimetry-derivative thermogravimetry analysis, and cone calorimeter test results indicated that the superhydrophobic paper exhibited excellent thermal stability and flame-retardant properties. These properties enhanced product safety during paper use. The comprehensive improvement in paper properties, including enhanced superhydrophobicity, flame retardancy, and thermal stability, significantly expands its application range and enhances overall utility.