Ion-exchange reactions and photothermal patterning of monolayer assembled polyacrylate-layered double hydroxide nanocomposites on solid substrates

Hydrotalcite-like, layered double hydroxide [Mg4Al2(OH)(12)]CO3 center dot nH(2)O (LDH) nanocrystals immobilized on solid substrates were incorporated with anionic polymers as host matrixes in the intercalation of polyacrylates to produce polymer-inorganic hybrid nanocomposites films on the substrates. The novel functional hybrid films were prepared through a direct ion-exchange reaction of poly(acrylic acid) (PAA) macromolecules into the immobilized LDH in binary solvent systems at 120 degrees C. SEM images reveal that designed solvent mixing such as alcohol and toluene prevents dissolution of LDH compounds, preserving the high crystallinity of PAA-LDH materials after anion-exchange reaction. X-ray diffraction spectra for polymer/LDH nanohybrids materials gave interlayer spacing of 22 angstrom regardless to the starting materials with different molecular weights, suggesting a molecular modeling of polymer species in gallery space of LDH. The UV-light decomposition of PAA-LDH composite nanocrystals on Si changes their thickness, restoring their pristine basal spacings. This study describes tailoring of PAA-LDH composite systems on the solid substrates and their applications in light-induced patterning.