Morphology Control And Optical Properties Research Of The Barium Carbonate-silica Biomimetic Material

Ba CO₃-SiO₂ biomorphs are a kind of inorganic biomimetic materials with the simple preparation approach and the easy-to-control morphology,which could be formed by the self-organization of Ba CO₃ nanocrystals in SiO₂ matrix.At present,compared with natural biomaterials,the morphological diversity and complexity of biomorphs are far from rich,and the application of biomorphs is few.Therefore,this work was focused on the preparation of the biomorphs with new morphologies and the research of optical properties for further application.Different from the traditional preparation strategies based on the single-factor control method,the reaction temperature and the content of Mg²⁺were synergistically regulated to simulate the growth of natural biomaterials,resulting in the complex hierarchical biomorph“triangles”.The analysis results of scanning electron microscope showed a spontaneous four-stage morphological evolution in the formation of the“triangles”,including stem growth,vertical growth,dissolve to branch,and triangularization.The crystal structure,elemental composition,and surface structure of the typical samples at various stages were characterized by transmission electron microscope,X-ray energy dispersive spectroscopy and atomic force microscope.The results showed that the growth of polycrystalline Ba CO₃ and single crystal Ba CO₃ were controlled by CO₂ and Mg CO₃ respectively,which led to the stem growth and vertical growth stages.And the Ostwald ripening and the diffusion-limited growth of single crystal Ba CO₃ led to the dissolve to branch and triangularization stages.The formation mechanism of the biomorph with the specific morphology was used to guide the preparation of novel biomorphs.As a result,the growth pathways of the polycrystal and single crystal were regulated to prepare several derivative hierarchical biomorphs by changing the reaction temperature and the content of Mg²⁺.In addition,biomorphs were developed as optical anti-counterfeiting labels and optical waveguide device with the help of inherently microstructures.It was found that the Ba CO₃-SiO₂ system had good compatibility with organic fluorescent dyes.With the addition of organic fluorescent dyes into the reaction solution,the fluorescence coding of helicoid and worm-shaped biomorphs was achieved at different levels and sequences by the seed-growth method.As a result,the encoded biomorphs possessed spatially separated fluorescence regions,and the fluorescence behaviors of biomorphs exhibited significant differences among different coding sequences or levels,which could be used as optical anti-counterfeiting labels.Moreover,by changing the growth sequence and time in different reaction solutions,the funnel-shaped biomorph was loaded with chromophores of different types and amounts.Benefiting from the transmission ability to visible light,the biomorph used limited chromophores to realize multicolor luminescence and even white-light emission.The above results not only enhance the morphological diversity and complexity of biomorphs,but also expand the application of biomorphs in the optical field,which can guide the further research and application of biomorphs as biomimetic functional material.