The conservation of historic stones is a crucial and arduous task. Now, stone conservation is primarily achieved through surface treatments by the use of organic materials, but the protective effects do not satisfy the protectors. So it has been focused on to develop new materials or methods. In this paper, we have prepared a new protective material by a bioinspired method, in which chondroitin sulfate was selected as a controlling template and the supersaturated solution of calcium oxalate as a stock solution, and the processing parameters was optimized through orthogonal experiments. The structure and microtopography of protective materials have been analyzed by X-ray diffraction (XRD) and atomic force microscopy (AFM), which indicate that the stone substrate is coated by a film of calcium oxalate about 100 nm thick. Moreover, its protective performances have also been evaluated by its abilities to resist water, soil and acid. The analyses reveal that the protective effects of the film are favorable. The method for stone conservation by biomimetic approach should develop a category of new protective methods or ideas.

Key words: biomineralized film, bioinspired preparation, calcium oxalate, conservation of historic stone