Natural Stones with a Self-Cleaning Surface via Self-Assembled Monolayers

Heritage buildings and monuments are mostly made from natural stone, which undergoes irreversible decay under outdoor conditions. The main reason for the contamination, degradation, and cracking of natural stones is water and oil permeation. Hence, modifications on stones rendering their surface self-cleaning are effective for stone protection. Reported in this paper is the development of a bionic approach to enabling self-cleaning stone surface via growing self-assembled polydopamine (PDA) as the adhesive layer on the stone surface, followed by depositing Al2O3 nanoparticles derivatized by self-assembled monolayers of a fluorophosphonic acid (FPA). This approach ensured a robust surface modification that realized superhydrophobicity, as demonstrated on natural marbles, Hedishi, and Qingshi. The surface modification was thermally stable up to 400 degrees C.

Automated summary

This paper reports the development of a bionic approach for enabling self-cleaning stone surface by growing self-assembled polydopamine as the adhesive layer and depositing Al2O3 nanoparticles on its surface. This method can protect the stone from water and oil contamination and degradation, and maintain stability at high temperatures.