Brief annotation and scientific rationale:

The aim of the project is to accumulate a database for a better understanding of the fundamental laws of high-intensity ionization in model and structural materials. Knowledge of fundamental mechanisms is of considerable importance for nuclear power engineering, nanotechnology applications and for testing target materials for nuclear physics experiments. As an innovative approach, it is proposed to study the effects of dense ionization on a previously created defect structure, which was formed by exposure to "conventional" radiation (hundreds of keV and units of MeV, ion irradiation), which is the most reliable way to simulate damage produced by fission products. The main approach to achieving the goals of the project will be the use of modern structural analysis techniques – high-resolution transmission electron microscopy in combination with molecular dynamics methods for modeling track formation processes. Structural changes will be also investigated using scanning electron microscopy, X-ray diffraction, confocal Raman and luminescence microscopy, and real-time optical spectroscopy under ion irradiation. The radiation resistance of promising reactor materials and target materials for nuclear physics experiments will be investigated by micro- and nanomechanical testing methods.

Expected results upon completion of the project:

1. Advanced understanding of the fundamentals physical laws of high-density ionization in solids, based on the studied dependencies of the kinetics of swift structural changes in the tracks of fast heavy ions in the near-surface areas of nanostructured dielectrics - nanoparticles, interfacial layers, layered structures;

2. Results of modeling by molecular dynamics methods of lattice relaxation processes and the formation of regions with a modified structure in the near-surface and interphase regions of composite materials exposed to energetic ions – nanoclusters in matrices, layered materials;
3. Data on the combined effect of dense ionization density and helium on the transport properties of fission fragments in protective layers and inert matrices;
4. Accumulation of a database on the parameters of ion tracks in conventional and nanostructured ceramics promising for nuclear physics applications;
5. Data on the long-term stability of target materials during prolonged irradiation with intense  heavy ions beams.

Expected results of the project current year: 

1. Investigation of the microstructure of the interface layers AlN/Al2O3, CeO2/ZrO2:Y, Si/Al2O3 irradiated with high-energy heavy ions by high-resolution transmission electron microscopy.
2. Measurement by TEM methods of the parameters of helium porosity in nickel- and titanium-based alloys uniformly ion-doped with helium and annealed.
3. Micromechanical tests by nanoindentation of ferrite ODS alloys irradiated with high-energy xenon ions.

Brief annotation and scientific rationale:

The project’s goal is to develop nanocomposite and functional track-etched membranes (TMs) for applications in nanotechnology, biomedicine, sensor technologies, and novel membrane separation processes.

TMs are an example of the industrial application of ion-track technology. They have a number of significant advantages over conventional membranes due to their precisely determined structure. Their pore size, shape, and density can be varied in a controllable manner so that a membrane with the required transport and retention characteristics can be produced. The modern trends in biology, medicine, environmental research, green energy harvesting, and other areas formulate the demands for membranes with specific novel functionalities. These functionalities can be provided by tuning (setting) the geometry, morphology, and chemical properties of TMs. The present project will focus on the development of various functional track-etched membranes using the following approaches:

1. tuning the pore architecture;
2. composite structures;
3. hybrid structures;
4. targeted chemical and biochemical modification;
5. selection of bulk material.

Special attention will be focused on biomedical applications of track-etched membranes. The main result of the project will be the creation of scientific and technical foundations for the development of new membranes with specific functions. The applicability of the developed membranes in practically important membrane separation processes, biomedical procedures and analytical tasks will be investigated.

Expected results upon completion of the project:

1. Functionalized TMs obtained from ion-irradiated polymer films using soft photolysis and liquid extraction of degradation products from tracks for electrodialysis and the electro-baromembrane process:
   - determination of ion-selective properties of the membranes;
   - investigation of the possibility of mono- and multivalent-ion separation on nanoporous TMs using the electrodialysis and electro-baromembrane process.
   
   
2. Experimental verification of the possibility of manufacturing nanocomposite, functionalized, and hybrid TMs:
   - TMs with asymmetric and modified nanopores for the separation of racemic mixtures;
   - microfiltration TMs with immobilized proteins for the detection of free RNA and DNA and their use in biosensors;
   - functionalized nanoporous membranes made of polyvinylidene fluoride (PVDF) for selective preconcentration of toxic metals and their quantitative determination;
   - TMs functionalized with silver nanoparticles and bioactive substances for the creation of bactericidal and viricidal filtration materials;
   - modified TMs with improved cell adhesion for cell culture systems;
   - affinity ultra- and microfiltration TMs for exosome separation;
   - nanocomposite TMs with immobilized silver and gold nanoconjugates and aptamers for the diagnosis of viral diseases using SERS and fluorescence spectroscopy;
   - hybrid TMs with surface polymer nanofiber structures and modified selective complex compounds, ligands and metal-organic frameworks for  selective removal of toxic metals from water.
   
   
3. Data on ion-selective, electrokinetic, and osmotic properties of modified nanopores, including asymmetric nanopores, depending on their geometry and functional groups on the surface.

Expected results of the project current year: 

1. Investigation of the patterns of track formation in polyvinylidene fluoride under heavy-ion irradiation and production of nanoporous PVDF TMs. Development of methods for modification of nanoporous PVDF TMs by functional monomers using postradiation graft polymerization
2. Production of track membranes functionalized by a layer of nanoparticles with a core/shell structure consisting of silver and gold for further use in the analysis of viruses employing aptamers
3. Study of the membrane distillation process using TMs with nanoscale hydrophobic coatings obtained by electron-beam dispersion of polymers.
4. Study of the selective properties of the metal-organic frame structure on the surface of TMs in electrolyte solutions.
5. Development of a method for modifying track membranes with biocompatible conjugates of curcumin and quercetin, as well as the evaluation of their biological effectiveness against RNA and DNA-containing viruses.
6. Development of a technique for baromembrane separation of the culture medium of human mesenchymal stem cells using TMs.