Crystal Perfection in Zinc Oxide with Occluded Carboxyl-Functionalized Latex Particles

Carboxyl-functionalized latex particles can be incorporated into zinc oxide crystals growing from an aqueous medium, giving zinc oxide−latex hybrid materials. The intracrystalline polymer particles do not disturb the long-range order of the zinc oxide host. This has been investigated by X-ray diffraction (XRD) and vibrational spectroscopies. The results from Rietveld refinement of XRD data show a slight but distinct compression of the zinc oxide lattice in the presence of latex, which is relaxed by thermal reequilibration of the lattice strains when the polymer is burned off. We suggest that the latex has an indirect effect related to the introduction and stabilization of defects at the interface with the polymer in the course of the crystallization from aqueous media, rather than a direct effect due to mechanical interaction between latex and zinc oxide. The changes in the lattice parameters are independent of the latex content in the material. The crystallization of zinc oxide in the presence of surface-modified latex particles might serve as a model for analogous biological phenomena concerning mineralization of inorganics in the presence of biomacromolecules.