Laboratory for Functional Organic and Hybrid Polymer Systems

Scientific results:

1. Within the project, we have synthesized and researched conjugated donor-acceptor D-A polymers that have wide intervals of variation of number-average molecular weight (Mn). 
2. Our research demonstrates that 2,3-diphenylquinoxaline links in combination with IDT donor groups form wide-band-gap polymers. In this work we found that PIDTTQ with high molecular weight (PIDTTQ-HMW) ensure a higher photo-electric current, fill factor and efficiency thanks to improved light absorption and charge carrier transport properties and lower losses on non-radiative recombination.
3. We have created a new approach to producing nanocomposite materials with the use of sequential anionic polymerization and post-synthetic etherification reactions with chemically modified graphene sheets (CMG). Anionically synthesized precursors of diblock copolymers of the PS-b-PI-OH type were grafted to chemically modified groups –COOH CMG, which resulted in the production of output composite materials, namely polystyrene-b-poly(isoprene)-g-CMG, which manifested improved physical and chemical properties. 
4. The successful synthesis was confirmed using several methods of molecular characterization together with thermogravimetric analysis to check the increased thermal stability, while the structure-properties relation was researched using transmission electron microscopy (TEM). 
5. We have studied the locations of CMG in the structure for the cases of formation of lamellar and cylindrical morphologies.
6. Magnetic nanoparticles with a diameter of 10 nm have been synthesized by coprecipitation. A mixture of 8,6 g of FeCl₃·6H₂O and 3,1 g of FeCl₂·4H₂O was dispersed in 25 ml of water Mili Q-grade and treated with ultrasound for 1 hour. Iron oxide maghemite nanoparticles (γ-Fe₂O₃) with a diameter of 10-11 nm were modified with the use of chlorosilane chemistry. The morphological characterization was conducted using TEM and atomic force microscopy (AFM). We demonstrated the regular distribution of nanoparticles in the polymer matrix.
7. It has been demonstrated that planar conformation of conjugated polymer chains is necessary to achieve high mobility of charge carriers along the direction of molecular π-π stacking, but is often accompanied by poor charge transfer in other directions. This is especially true for molecules functionalized with alkyl chains that provide good technological effectiveness (solubility), but create isolating regions in the structure. In our work we demonstrated that soluble flat dumbbell-like molecule consisting of two triazatruxene (ТАТ) links that are covalently bound with the central segment of thiophene-tienopyrroldiol-thiophene (TPD), self-assemble into the initial structure that ensures efficient three-dimensional charge transport. Wide-angle scattering of X-rays in a sliding beam geometry, as well as micro-focus X-ray experiments on monocrystals demonstrate that derivatives of ТАТ form a columnar nematic mesophase in which columns of stocked ТАТ units, separated by liquid-like alkyl chains, are connected with TPD bridges. During annealing, a crystalline phase is formed that emerges from the initial hexagonal mesophase with a direction of molecular packaging that lies in the plane of the substrate. Changes of transport in the crystalline phase caused unusually mobility of holes outside of the plane amounting to 0,17 cm²/V×s and a lower bound of in-plane mobility of 0,05 cm²/V×s. The results indicate that TPD segments that connect neighboring stacks of TAT columns are responsible for efficient hole transport in 3D.

Implemented results of research:

Thee patents have been obtained and more than 17 articles have been published.

Education and career development:

Four internships have been organized for postgraduates and employees: 3 trips of Russian postgraduates abroad and one trip of a foreign postdoc researcher to Russia.

Organizational and infrastructural transformations:

The Laboratory has established close connections with faculties and universities, we are providing training to undergraduate and postgraduate students in the domain of the project.

Collaborations:

The Laboratory works closely with the Department of Materials Science Engineering, University of Ioannina (Greece). Within this collaboration we conduct joint research as well as experience exchange between employees and postgraduates.

Russian organizations: Sirius University of Science and Technology, National University of Science and Technology MISIS, Institute of Problems of Chemical Physics of the Russian Academy of Sciences.