A review of surface modification studies of basalt fibers

As a high-performance inorganic fiber material, basalt fiber's excellent mechanical properties, Chemical resistance, and high-temperature stability have led to various applications in civil engineering, composite materials, and environmental protection. However, basalt fibers have smooth surfaces and lack active functional groups, resulting in poor interfacial bonding properties with matrix materials. Therefore, surface modification of basalt fibers can significantly improve their interfacial bonding properties and enhance their application in composites and environmental protection fields. The following is the research progress of several major modification methods.

1. Silane coupling agent surface modification

Silane coupling agent is a commonly used surface treatment agent that improves the interfacial bonding properties between fibers and matrix materials through chemical bonding.

KH-550 Modification

The study shows that treating basalt fibers with a silane coupling agent KH-550 solution forms stable chemical bonds on the fiber surface and improves the interfacial bonding between the fiber and asphalt. The reasonable concentration of KH-550 is 1.0%, and the treatment time is 30 minutes. After modification, the adhesion between basalt fiber and asphalt was improved by 1 grade. The oil absorption rate increased by 65.5%, which significantly enhanced the adhesion with asphalt.

KH-570 Modification

KH-570 modifies basalt fibers to roughen their surface and increase the active points on the fiber surface. In the composite material, with the increase of the modified fiber length and the amount of addition, the mechanical properties of the composite material are significantly improved.

2. Surfactant modification

CTAC modification

Physical coating of basalt fibers with the cationic surfactant cetyltrimethylammonium chloride (CTAC) improves the hydrophilicity and dispersibility of the fibers in water. This modification method has a significant effect on microbial film adhesion: the microbial adhesion strength is significantly increased. Increasing the amount of microbial attachment facilitates the application in wastewater treatment.

3. Organic iron liquid phase deposition modification

The modification of basalt fibers by organic iron liquid phase deposition can improve the bio-adhesion ability of the fiber surface and further enhance its application in the field of wastewater treatment. This modification method can form a stable iron oxide coating on the surface of the fiber to improve its adsorption and degradation of pollutants.

4. Coating modification by nano-silica

Nanosilica particles are uniformly dispersed in the infiltrant or dispersion, and can be basalt fiber coating modification: between basalt fiber and epoxy resin, nanosilica particles play a bridge role, significantly improving the interfacial compatibility between the two. After modification, the surface roughness of basalt fiber increases, the specific surface area increases, and the oxygen-containing functional groups increase. The study showed that with the use of a nanosilica-modified basalt fiber carrier: the actual amount of microbial film per gram of fiber mounted increased by 21.39%. The pollutant removal efficiency was significantly improved.

Conclusion and Outlook

The surface activity, interfacial bonding properties and functionality of basalt fibers were significantly improved by different surface modification methods. Among them:

1. silane coupling agent modification is more suitable for improving the adhesion of basalt fibers with matrix materials (e.g. cement, asphalt, epoxy resin, etc.).
2. Surfactant modification and organic iron deposition modification are more suitable for the environmental protection field, especially for microbial carrier application in sewage treatment.
3. Nano-silica coating modification, with the advantages of improving mechanical and functional properties, has a wide range of prospects in the field of Composite Materials and environmental protection.

Future research can further optimize the modification process parameters and explore the synergistic effect of different modification methods to meet the needs of different applications.