Green synthesis of ultra-long K₂Ti₄O₉ whiskers via cornstarch foamed calcination for large scale application

A green synthesis approach of ultra-long K₂Ti₄O₉ whiskers suitable for large-scale application via cornstarch foamed calcination was investigated. The addition of cornstarch forms well-defined ∼ 10 μm pores and a CO₂-rich atmosphere to inhibit K₂CO₃ decomposition. The delayed decomposition generates high amounts of K₂O melt which fosters the interface growth of whiskers with lengths up to 1 mm and high aspect ratios exceeding 5000. The resulting whiskers exhibit high crystallinity, meeting strict size requirements for various applications.