Application of Graphene Aqueous Dispersion in Water-based Coatings

Overview: The unique properties of graphene enhance the performance of water-based coatings, driving development and bringing new expectations to the coatings industry. Initially used in solvent-based coatings, graphene aqueous dispersion has also shown significant progress in modifying water-based coatings. Modification methods include blending, in-situ polymerization, and sol-gel techniques, and can be further refined using coupling agents for different functional modifications.

Graphene’s Impact on Coatings: Graphene’s incorporation improves the performance of water-based coatings. The introduction of graphene requires careful experimentation to determine its feasibility and application in different formulations. Key aspects of paint production, such as dispersion, storage, application, and film performance, are directly impacted by the choice of dispersants and other chemical additives. The dispersion quality is influenced by both the dispersant used and the formulation and raw material selection.

Types of Graphene Coatings:

1. Pure Graphene Coatings:
   • These coatings leverage graphene’s properties to provide anti-corrosion and conductivity on metal surfaces.
2. Graphene Composite Coatings:
   • These involve combining graphene with polymer resins to create functional coatings that significantly enhance the properties of the polymer.

Benefits of Graphene in Coatings:

1. Enhanced Anti-corrosion Performance:
   • Adding graphene to existing epoxy anti-corrosion coatings improves impact resistance, adhesion, water resistance, and hardness. This is particularly useful in marine engineering, transportation, industrial equipment, and municipal infrastructure.
2. Green Coatings:
   • Water-based coatings, known for their low VOC content, are a key focus in developing environmentally friendly coatings. Graphene aqueous dispersion improves the anti-corrosion performance of water-based coatings, a crucial factor for large-scale application.

Studies on Graphene in Water-based Epoxy Anti-corrosion Primers:

1. Corrosion Resistance:
   • Graphene addition significantly reduces the amount of zinc powder needed while greatly enhancing the anti-corrosion performance of the coating. Graphene’s structure provides a dense physical barrier, and its high conductivity and chemical stability further improve the anti-corrosion performance.
2. Salt Spray Resistance:
   • Even with just 1% graphene content, the salt spray resistance can be improved by 200 hours compared to non-graphene coatings.

Graphene in Topcoats:

1. Improved Film Properties:
   • The high surface area and strong adsorption capacity of graphene create a network structure during film curing, enhancing adhesion, stability, and strength. Graphene-enhanced paints show significant improvements in impact resistance, cupping performance, hardness, and weather resistance.
2. Challenges and Solutions:
   • Despite its benefits, graphene’s high surface area can hinder its performance. This can be mitigated by using dispersants like polyvinyl alcohol (PVA), which helps in uniformly dispersing graphene in the solution, thus enhancing the performance of the composite material.

Conclusion: Graphene aqueous dispersion has proven to significantly improve the performance of water-based coatings, particularly in terms of anti-corrosion and mechanical properties. Ongoing research and development focus on optimizing the formulation and dispersion methods to maximize these benefits, ensuring a broader application and cost-effective production of graphene-enhanced coatings.