Antibacterial Inorganic Coating of Calcium Silicate Hydrate Substrates by Copper Incorporation

Area of Science:

• Materials Science
• Surface Chemistry
• Microbiology

Background:

• Biofilms cause structural degradation on surfaces, necessitating new protective strategies following the EU ban on high-copper-content paints.
• Developing inherently biofilm-repellent surfaces through material modification is a key alternative strategy.

Purpose of the Study:

• To investigate the incorporation of copper into calcium silicate hydrate (CSH) substrates via ion exchange to create biofilm-repellent surfaces.
• To assess the structural integrity and chemical composition of copper-modified CSH films.
• To quantify the effect of copper incorporation on biofilm development by *Pseudomonas aeruginosa*.

Main Methods:

• Ultrathin CSH films were synthesized on silicon wafers.
• Copper was incorporated into CSH films using ion exchange.
• Biofilm development was analyzed using a multi-resistant *Pseudomonas aeruginosa* strain.
• Structural and chemical analyses were performed using ESEM, FT-IR, XPS, and ToF-SIMS.

Main Results:

• Copper incorporation resulted in a homogeneous 3D distribution within the CSH structure without causing structural deformation.
• Copper-free CSH surfaces exhibited random bacterial distribution.
• Copper-modified CSH surfaces showed significantly reduced bacterial colonization and enhanced cluster formation.

Conclusions:

• Copper-modified CSH films are structurally stable and exhibit inherent biofilm-repellent properties.
• This approach offers a viable alternative for surface protection against biofilm formation in environments where traditional methods are restricted.