“Formation and modification of nanostructured composite materials with electron and photon beams” Doctoral Thesis

Author, institution: Rita Plaipaitė-Nalivaiko, Kaunas University of Technology

Science area, field: Physical Sciences, Physics – 02P

The Doctoral Dissertation is available at the library of Kaunas University of Technology (K. Donelaičio St. 20, Kaunas).

Scientific Supervisor: Prof. dr. Diana ADLIENĖ (Kaunas University of Technology, Physical Sciences, Physics – 02P)

Dissertation defence board of Physics Science Field:

Prof. Dr. Habil. Arvaidas GALDIKAS, (Kauno technologijos universitetas, fiziniai mokslai, fizika – 02P) – pirmininkas;
Dr. Darius GERMANAS, (Institute of Physics at Center for Physical Sciences and Technology, Physical Sciences, Physics – 02P)
Prof. Dr. Liutauras MARCINAUSKAS, (Kauno technologijos universitetas, fiziniai mokslai, fizika – 02P);
Dr. Šarūnas MEŠKINIS, (Kauno technologijos universitetas, fiziniai mokslai, fizika – 02P);
Assoc. Prof. Dr. Saulius MICKEVIČIUS, (Vytautas Magnus University, Physical Sciences, Physics 02P).

Annotation:

Embedding nanoparticles into the polymer matrix or forming nanoderivatives in polymer it is possible to create new nanostructured materials – nanocomposites characterized by unique chemical, physical, mechanical, optical, electrical properties. Various technologies are available for the modification of nanocomposites properties; high energy X-ray and electron irradiation technologies are among them.

Investigation of electron and photon beam induced formation and modification mechanisms of different nanostructured nanocomposites and assessment of radiation impact on mechanical and optical properties of fabricated composites was performed in this work. It was found that high energy electrons and photons initiated the restructuration of the amorphous hydrogenated carbon coatings followed by the hydrogen desorption from the coatings as well as the formation of new polymeric structures with embedded graphite clusters. The optical transparency of modified carbon coatings was decreasing while the hardness was slightly increasing. It was found, that applying the two-step irradiation mechanism it is possible to synthesize stable silver/polymer nanocomposites from the mixture of aqueous solutions of silver salt and polymer. It was shown that dissolving the silver salt directly in polymer solution and irradiating it, it was possible to form silver/polymer nanocomposites, however the high agglomeration tendency of silver nanoparticles was observed. A new sonoelectrochemical method for the synthesis of metal alloy nanoparticles was proposed and explored. It was shown that this technique allows production of W-Co nanoparticles. Embedding the nanoparticles in to polymer matrix, led to formation of nanocomposites characterized by good X-rays absorption properties.