This technology has applications in industries that require high temperature-resistant fibers for fabrication of refractory textiles or reinforcement of structural materials where it can improve the strength of basalt fibers.
Glass fiber is widely used as a reinforcement material to improve the strength and stiffness of structures. However, glass fiber’s utility is limited in applications where resistance to high temperatures and high loads is required. Basalt fibers with carbon nanotubes (CNTs) deposited on their surface is a promising alternative to glass fiber in high-temperature, high-strength applications. Existing methods of depositing CNTs are poorly compatible with basalt fibers due to substrate degradation during the deposition process or the need for an additional catalyst deposition step before CNTs can be grown. This invention addresses these problems with a method of growing CNTs on basalt fibers in which the use of growth catalyst is optional.
The CNT growth process described by the Inventors is compatible with basalt fibers in the form of filament, thread, or fabric. After undergoing a cleaning process to remove potential surface contaminants, the basalt fiber substrate is optionally treated with a catalyst. Subsequently, it is inserted into a chemical vapor deposition (CVD) furnace where it is heated to temperatures in excess of 300 ℃ under a reducing atmosphere. At this point, a hydrocarbon is introduced into the furnace, where it supplies carbon atoms for CNT growth on the fiber surfaces. This process results in a mixture of CNTs, carbon nanofibers (CNFs), and vertically aligned CNTs (VACNTs) on the surface of the fibers. The relative proportions of these nanostructures can be tuned by manipulating the growth conditions.
Optional use of catalyst reduces cost and process complexity
- CNT growth process does not degrade mechanical properties of substrate fiber, leading to a net overall improvement in mechanical performance of the augmented fiber