My work at Berkeley lab has been going great so far! I have faced many challenges and learned how to overcome them. I have also gained valuable lab experience, become more independent, and improved my understanding of ionomer thin films and their swelling properties.
After finalizing my calibration curve, I started to focus on my next project: gaining insight on how dispersion state and condition affects the film’s behaviour. To investigate how changes in the dispersion state and condition affect the swelling of thin films, I used heating and cooling setups. It is important to understand the swelling of ionomer thin films since swelling is related to the electrode performance of a fuel cell; the greater the ionomer swelling, the higher the conductivity in the electrodes (given that there is no flooding, excessive swelling). In my project, I have focused on the effect of different processing parameters of dispersions on thin films, as these have not been widely studied. After doing many literature reviews, I discovered that there was no set procedure to carry out an experiment like this. Thus, I decided to design my own procedure. I kept the procedure very similar to the one I used to plot my calibration curve, but I did add a few steps to investigate the processing parameters of the dispersions. I have been making a great variety of films so far, and my swelling data has been very interesting, although there are a few anomalies in the results I need to work on.
I believe these anomalies in my results are related to inconsistencies in my procedure as well as other external factors. My films were sometimes turning out poorly (they were not very uniform and were shattered). After discussing these issues with other scientists in my lab group, I decided to reassess my procedure and take into account every single factor that could be affecting the films. I first thought of the effect that different room temperatures and humidities could have on the films and started monitoring these to keep them as constant as possible. I also started cleaning the substrate more deeply, adjusting the spin program before casting to control the films’ thickness and ensuring the properties of my dispersion are all consistent before casting the films. I am still working on finding the most suitable procedure that will produce the best results, but I feel that I am getting there. These inconsistencies in my films have really taught me the importance of paying attention to every single detail of an experimental procedure.
I have also considerably improved my data analysis skills and learned how to fully understand my results. Right now I am focusing on going deeper into my results analysis to understand why I am getting poor swelling profiles and why I am getting good swelling profiles for different films. I am hoping to figure this out in the next few weeks. Although, as I have realized already, research is very unpredictable and some things are left unanswered.
In the next few weeks, I will hopefully finalize my project, figure out a suitable procedure, and obtain good and consistent results. I am also hoping to carry out a few literature reviews to better comprehend the behaviour of ionomer thin films and maybe even gain some insight on why I am sometimes getting poor films. I will also be improving my MATLAB code used to analyze my results and preparing a presentation for my entire lab group about my research. I still have a few weeks to go, but so far, this has been an unbelievable and very rewarding experience where I have been learning a lot.