Highly porous layered double hydroxide (LDH) and its calcined mixed metal oxide (MMO) were obtained by utilizing egg white (EW) as a biogenic porous template. The LDH was prepared through coprecipitation under the existence of a beaten EW meringue, and the corresponding MMO was obtained by calcining LDH at 500 °C. According to X-ray diffraction, the crystal structure of LDH and MMO was well-developed with or without EW. In contrast, the crystallinity analyses and microscopic investigations clearly showed differences in the particle orientation in the presence of EW; the protein arrangement in the EW foam induced the ordered orientation of LDH platelets along proteins, resulting in well-developed inter-particle pores. As a result, the distinctive particle arrangement in EW-templated samples compared with non-templated ones showed dramatically enhanced specific surface area and porosity. The nitrogen adsorption–desorption isotherm exhibited that the high specific surface area was attributed to the homogeneous nanopores in EW-templated LDH and MMO, which originated from the sacrificial role of the EW.

Cinnamic acid (CA) was successfully incorporated into Zn-Al layered double hydroxide (LDH) through coprecipitation. The CA moiety was stabilized in the interlayer space through not only electrostatic interaction but also intermolecular π-π interaction. It was noteworthy that the CA arrangement was fairly independent of the charge density of LDH, showing the important role of the layer–CA and CA-CA interactions in molecular stabilization. Computer simulations using the Monte Carlo method as well as analytical approaches including infrared, UV-vis spectroscopy, and differential scanning calorimetry showed the existence of intermolecular interaction. In order to reinforce molecular stabilization, a neutral derivative of CA, cinnamaldehyde (CAD), was additionally incorporated into LDH. It was clearly shown that CAD played a role as a π-π interaction mediator to enhance the stabilization of CA. The time-dependent release of CA from LDH was first governed by the layer charge density of LDH; however, the existence of CAD provided additional stabilization to the CA arrangement to slow down the release kinetics.