The purpose of the experiment B - Nanoscale Thin Films was of obtaining thin films by electro deposition.
We are from “Miron Costin” High School, Pascani, Romania and our team consisted of five students, two students in class 9th – Ionela Axinte and Alexandra Martinas and three students in class 10th – Daiana Coman, Raluca Ivanesei and Andreea Stihi. We were coordinated by teachers of chemistry and physics, Elena Cornea and Ion Cazacu-Davidescu.
The experiment consisted of three parts: 1. Achieving thin films by electrodeposition; 2. Study the optical properties of films made; 3. Study electrochromic property of Prussian Blue films.
The first part began with the preparation of the graphite electrode, size comparable to that of glass.
It then passed, under the guidance of professor of Physics, at preparing electrolytic cell electrodes by fitting lid supports and preparation of materials needed for the electric circuit. In the absence of a galvanostat to sustaine current intensity in the circuit, we connected a high resistance resistor in series.
In compliance with work safety rules for handling chemicals, we prepared solutions to the experiment, under the guidance of professor of Chemistry.
We continued with face detection conductive glass electrode using a multimeter, we marked the front and we defined the area that will be introduced in the solution for film deposition.
After installing electrodes in media type "crocodile", we arranged them to be parallel, we poured solutions into electrolysis vessel, introduced electrodes up to the mark and closed circuit.
First electrode had a deposit for 60 seconds. After the passage of time, we opened the circuit, removed the glass electrode and dried it and the cell solution was prepared fresh for a new deposit.
Glass electrodes were prepared as the first and subsequent deposition times were 120 seconds and 150 seconds.
In the second part we studied the optical properties of thin films of Prussian Blue using the methodology indicated worksheet based on RGB color code.
In the last part, a glass electrode, which was previously deposited thin film was placed in a slightly acidic solution of KCl and studied film electrochromic property of Prussian Blue.
For this we used a 1.5 V battery and following the procedure indicated by the chart paper. We observed transformations that suffered film became transparent and regained turn blue when applying suitable potential.
Finally we interpret the results, identified sources of error and made recommendations for future laboratory work.
Also we plan to develop to the school site (www.lmcpascani.ro) a subdomain dedicated nanotechnology to search thus our knowledge in this area for the future and to share our experience with colleagues.