1. Synthesis of artificial opals Yu Letian Hwa Chong Institution

2. Table of Contents Introduction Background Research Question Hypotheses Methods Experimental Design Statistical Analyses Results Analysis & Interpretation Conclusions

3. Introduction Background Wide application of photonic crystals Research Question Is the “smart control” really helpful in producing ideal silica nanoparticles? K. Nozawa, H. Gailhanou, L. Raison, P. Panizza, H. Ushiki, E. Sellier, J. P. Delville, and M. H. Delville “Smart Control of Monodisperse Stober Silica Particles: Effect of Reactant Addition Rate on Growth Process”

4. Introduction Hypotheses Tested 1.“Smart control” has no influence over the uniformity of the final product. 2.“Smart control” has no influence over the size of the final product.

5. Methods Data Set: Size of the silica nanoparticles collected from SEM One-sample t-test to compare size against standard H 0 : Size of the particle on average () is < 0.2158 micrometer H a : Size of the particle on average () is ≥ 0.2158 micrometer t-test at 95% confidence level ( = 0.05) and 49 degrees of freedom ()

6. Methods Data Set: Size distribution of the silica nanoparticles collected from SEM One-sample t-test to compare size distribution against standard H 0 : Size distribution of the particle on average () is ≥ 0.02914 H a : Size diistribution of the particle on average () is < 0.02914 t-test at 95% confidence level ( = 0.05) and 49 degrees of freedom ()

7. Results 0.42ml/s 4.2ml/s 42ml/s

8. Analysis & Interpretation The sample of 50 silica nanoparticles obtained via an injection rate of 0.42ml/s does not vary significantly from the standard sample. Given the results obtained, the null hypothesis cannot be rejected.

9. Conclusions Based on the sample of silica nanoparticles analyzed in this experiment, we cannot conclude that “smart control” is significantly effective.

10. Improvements Alternative method to improve the uniformity of the final products Centrifugation is performed, which shows significant improvements on the uniformity

11. Spectrometry on the improved sampled obtained Analysis

12. Thank you!