Väitös (kemia): MSc Sachin Kochrekar

MSc Sachin Kochrekar ”Porphyrin Based Electroactive copolymers: From Electropolymerization to Energy and Environmental Applications” julkisesti tarkastettavaksi Turun yliopistossa torstaina 4.6.2026 klo 12.00 (Turun yliopisto, Quantum, auditorio, Vesilinnantie 5, Turku).

Vastaväittäjänä toimii professori Eunkyoung Kim (Yonsei University, Seoul, Etelä-Korea) ja kustoksena professori Carita Kvarnström (Turun yliopisto). Tilaisuus on englanninkielinen. Väitöksen alana on kemia.

Tiivistelmä väitöstutkimuksesta:

Growing demand for sustainable and energy-efficient technologies has increased interest in smart materials that can perform more than one function at the same time. This research focuses on materials that can both change color and store electrical energy, supporting global efforts to develop greener and more efficient technologies.

This work developed thin polymer films based on porphyrins, molecules that occur widely in nature, for example, in chlorophyll and hemoglobin. The films were produced using electropolymerization. Two different approaches were used. In the first method, porphyrins were combined with a conductive material called EDOT to create hybrid films. In the second method, porphyrins were linked directly using a bridging molecule, avoiding extra preparation steps and providing a simpler way to build these materials. Three versions of the material were prepared by changing the metal at the center of the porphyrin structure: nickel, zinc, and a metal-free form. This helped us understand how small structural changes affect performance.

The results showed that the choice of metal strongly influenced how the materials behaved. The nickel-based film could switch between three different color states, while the zinc-based and metal-free films switched between two. All materials changed color quickly, in less than two seconds, showed clear visual contrast, and maintained their color even after the power was removed.

The films were also tested for energy storage using a water-based electrolyte, which is safer and more environmentally friendly than commonly used alternatives. All three materials showed good energy storage performance. To the best of our knowledge, this is the first report of porphyrin-based polymer films being used as electrochromic supercapacitors in a concentrated water-based electrolyte system.

Overall, this research improves understanding of how material design affects both color-changing and energy-storage performance. The findings show that porphyrin-based materials have strong potential for sustainable technologies that combine multiple functions in one system. In the future, these materials, together with electrochromic supercapacitors, may also find applications in sensing technologies, solar energy systems, flexible electronics, and wearable devices.