text: Yo, check it out, listen to this rap,
  'bout aerogels and xerogels, a scientific trap.
  Colloidal assembly, nanoparticles in the mix,
  Highly porous materials, lightweight as a flick.
  
  BaTiO3 xerogels, green bodies in the game,
  A versatile route, ceramic materials to claim.
  Minimizing additives, reducing calcination heat,
  Compared to powder sintering, it's a whole new feat.
  
  Watch the structural changes, as the xerogels go dry,
  Microstructure analyzed, no need to ask why.
  Supercritical drying, preserving the intermediate,
  Insight into the process, never seen this rate.
  
  First, the macropores shrink, capillary forces at play,
  Then the mesopores collapse, in a dense xerogel array.
  97% volume shrinkage, surface area takes a hit,
  From 300 to 220, that's a significant split.
  
  Sintering comes next, more shrinkage in sight,
  Up to 8% it goes, but the pores still ignite.
  Crystal sizes increase, average pore size too,
  But at 700 degrees, a phase transition comes through.
  
  BaTi2O5, an unexpected sight to behold,
  At higher temperatures, it's a story yet untold.
  So there you have it, the tale of gels and more,
  In the world of science, there's always new lore.