What substance initiates the polymerization reaction in nail enhancements?

The polymerization reaction in nail enhancements is initiated by a photoinitiator. Photoinitiators absorb light energy, usually from a UV or LED lamp, and then convert this energy into chemical energy. This energy triggers the polymerization process, where liquid monomers join together to form a solid polymer, creating a durable enhancement on the nail.

While other substances like oligomers, catalysts, and methacrylates play important roles in the formulation and application of nail enhancements, they do not initiate the polymerization reaction in the same way. Oligomers are short polymer chains that can contribute to the final properties of the product but rely on photoinitiators to commence the curing process. Catalysts speed up chemical reactions but do not initiate polymerization in the context of nail enhancements. Methacrylates are the actual monomers that polymerize to form the cured nail product but require a signal to begin this process, which is provided by the photoinitiator. Thus, photoinitiators are crucial for initiating polymerization, making this the correct response.