Synthesis of biopolymer intercalated inorganic-layered materials: Intercalation of collagen peptide and soybean peptide into Zn–Al layered double hydroxide and layered zinc hydroxide Original Research Article

In order to develop a new type biocompatible organic/inorganic nanohybrid material, we have been investigated an intercalation of collagen peptides (CP) and soybean peptide (SP) into Zn–Al layered double hydroxide (LDH) and layered zinc hydroxide (LZH) by coprecipitation reaction. The solid products have been characterized by element chemical analysis, powder X-ray diffraction (XRD), Raman spectroscopy, thermal analysis and transmission electron microscopy. According to the XRD patterns and Raman spectra, the solid products were found to show broad diffraction peaks with layered structures and to incorporate peptide. The CP/LDH and SP/LDH has the expanding LDH structure, d003=2–3 nm, confirming that both peptides were intercalated into the LDH interlayer space with a disordered arrangement. The CP/LZH has an ordered layered structure in comparison with the peptide/LDH. The d-values are 3.0 nm for the CP1000/LZH and 4.4 nm for the CP2000/LZH, supporting that CP was orderly intercalated into the LZH interlayer space. These results confirmed that the orientation of the intercalated peptide depends on amino acid composition of peptide.