Growth of strontium hydrogen phosphate/gelatin composites: a biomimetic approach

Recent research has focused on the crystal growth of strontium phosphates via different methods due to the bioactivity and biocompatibility of these materials with bone tissue. Here, we use a biomimetic method to synthesize strontium hydrogen phosphate/gelatin composites via single diffusion in gelatin. We compare the composite crystals with analytical-grade strontium hydrogen phosphate using infrared spectroscopy (IR), scanning electron microscopy (SEM), thermal gravimetric analysis, and X-ray diffraction. The IR spectra reveal that gelatin is incorporated into strontium hydrogen phosphate crystals due to CH2 and amide I vibrations. The SEM data exhibit arrow-like crystals and microspheres of strontium hydrogen phosphate with bundled nano-flakes and flower-like surface arrangements of crystals. Furthermore, we find that the thermal stability of the strontium hydrogen phosphate/gelatin composite crystals is higher than that of the analytical-grade strontium hydrogen phosphate. The ion concentration and the preparation method had only a small influence on the broadening of the X-ray Bragg reflections. Our study confirms that gelatin is a useful hydrogel for studying the crystallization of strontium hydrogen phosphate.