# Variations in CTAC batches from different suppliers highly affect the shape yield in seed-mediated synthesis of gold nanotriangles

## TL;DR

This study shows that the supplier of a surfactant significantly affects the production of gold nanotriangles, impacting shape yield and synthesis reliability.

## Contribution

The novelty lies in demonstrating that CTAC surfactant source critically influences gold nanotriangle synthesis, despite minimal impurity differences.

## Key findings

- Five CTAC batches from different suppliers showed significant variation in gold nanotriangle shape yield.
- Iodine contamination had only a marginal effect, contradicting earlier assumptions about its role.
- The high yield dependency remains unexplained, pointing to unknown reagent characteristics.

## Abstract

The rapidly developing miniaturization in numerous fields require low-demanding but robust methods of nanomaterial production. Colloidal synthesis provides great flexibility in product material, size, and shape. Gold nanoparticle synthesis has been thoroughly studied, however, recent reports on mechanistic insights of crystal formation have been hindered by the numerous procedures and parameter optimization works. With every new study, scientists fill another blank space on the map of understanding anisotropic growth and find out the critical parameters. In the current work, we highlight the choice importance for surfactant supplier in achieving the gold nanotriangle formation. We systematically study the variation in the shape yield when utilizing five batches of cetyltrimethylammonium chloride (CTAC) from varied suppliers. Using analytical techniques, we search for deviations causing such variation, e.g. different impurity content. We found only a marginal effect of iodine contamination on the studied system, excluding this factor as decisive in contrast to what was proposed earlier in the literature, and leaving the high dependency of the yield to originate from yet unknown reagent characteristics. A deeper understanding of these factors would provide highly effective protocols lowering the reagent consumption and increasing the accessibility of nanomaterials manufactured in a sustainable manner.