Vislielākais burtu izmērs
Lielāks burtu izmērs
Burtu standarta izmērs

Executive summary of the programme “Multifunctional Materials and composites, photonics and nanotechnology (IMIS2)” for the period 2014. – 2018.

19.09.2018.

The realization of the program develops knowledge base in photonics, nanotechnology, innovative and advanced materials as well as enhance human resources and improve the competitiveness of the state economy, develops the nano-materials and technology sector, as well as quantum technology and bio-photonics. In the implementation of the programme more than 150 scientists and more than 100 students are involved. The main planned tasks have been completed on time.

The realization of the program develops knowledge base in photonics, nanotechnology, innovative and advanced materials as well as enhance human resources and improve the competitiveness of the state economy according to the European Commission Key Enabling Technologies in the areas where Latvia possesses high scientific potential and demand of the economy.

The program is thematically structured in 4 projects:

  1. Photonics and materials for photonics;
  2. Nanomaterials and nanotechnology;
  3. Nanocomposite materials;
  4. Nanomaterials and nanotechnologies for medical applications.

In the implementation of the projects more than 150 scientists and more than 100 students are involved. Within the frames of the program the students elaborate their scientific and academic qualification works.

The main planned tasks have been completed on time. The gained results are presented in chapter “List of results of the programme”. Detailed scientific results obtained by each project during reporting period are presented in Part 2 “Programme Project Information”.

In photonics field the understanding of the factors, which adversely influence the optical properties of SiO2-based materials was improved. For the first time a full detailed characterization of Cl2 impurity luminescence band in glassy SiO2 was performed, thus ending controversy about attributing this band to peroxy linkages. Data reveal strong cage effect for Cl2 in SiO2 and give first proof of photochemical creation of chlorine oxides in SiO2. The results are important for applications of SiO2 materials in ultraviolet spectral region. Validation of the electro-optic coefficient measurements performed with three commonly applied techniques was carried out. A novel approach based on using Abeles matrix formalism is implemented for the retrieval of electro-optic coefficients from experimental data. A Z-scan method which comprises a computer controllable opto-mechanical setup has been implemented and tested by measuring the two-photon absorption coefficient and optical Kerr coefficient of chloroform and, for the first time, of several NLO indandione derivatives synthesized in Latvia. The key role of photoinduced birefringence in surface relief formation process on amorphous chalcogenide and azobenzene thin films was shown. For the first time erbium doped oxyfluoride glass ceramics containing hexagonal NaYF4 nanocrystals has been obtained. Upconversion luminescence in the material has been studied. The results show that the material could be used as an active media for lasers.

Several nanotechnologies have been developed and optimized. Technology of TiO2 - WO3 composite electrophoretic deposition from suspension on the metal support was developed and functional coatings of TiO2 nanoparticles on glass fibers by electrophoretic deposition from sol were obtained. The possibility of graphene transfer using Ge nanowire mass sensor was shown. It was shown that the extraction-pyrolythic method allows to obtain several new oxide nanocomposite materials and as example new ZnO-CdO thin films have been synthesized and characterized. The developed production technologies of nanocomposites of ZrO2-CeO2-ReO/Cr2O3 by using plasma chemical vapour phase and wet chemical microwave assisted synthesis were described in technological manual and transferred to “Plasma and Ceramics Technologies Ltd.” for producing of nanocomposites. Textured copper nitride (Cu3N) thin films were successfully prepared using DC magnetron sputtering of metal copper target in pure N2 atmosphere. The relationship between thin film preparation conditions and a degree of their crystallinity was determined by x-ray diffraction and x-ray absorption spectroscopy. Study of Cu3N thin films is motivated by its numerous possible applications in the thin film form as a material for optical storage devices, for the fabrication of low-resistance magnetic tunnel junctions, as promising cathodic electrocatalysts in alkaline fuel cells, in optical lithography and as an absorber for photovoltaic and photoelectrochemical solar cells.

Layered graphene/nanostructured Bi2Se3 thin films are synthesized, and their properties are investigated. It is found out that thin films formed by vertically oriented relative to the graphene surface Bi2Se3 nanostructures show better thermoelectric effect and are perspective for application in thermoelectric devices and sensors. Performed investigations of large surface carbon (graphene) nanomaterials for various gas adsorption and resulting material sorption characteristics were improved by material doping. Technology in creation of large surface carbon nanomaterials was aacquired and approbated in Latvian company SIA “Keramserviss”.

Multi-walled carbon nanotubes dispersed in the polymer matrix lead to the linear increase of thermal diffusivities and thermal conductivities of the system; also surface hardness and indentation modulus of the systems increase up to 70%.

Investigations about environmentally friendly/biodegradable multifunctional polymer nanocomposites including polymer hybrid nanocomposites were performed. Biodegradable polymer (thermoplastic starch) nanocomposites with layered silicates (montmorillonite clay MMT) were developed. It has been established that ionic liquids can be successfully used for both, plasticizing of thermoplastic polymer matrix and modification of MMT, leading to the decrement of permeability and coefficient of diffusion (more than 2 fold) and increment of modulus elasticity (more than 2 times) and strength. An original elastomer / carbon nanocomposite sample manufacturing method is elaborated by vulcanization of samples in autoclave at neutral gas atmosphere at various constant temperatures. Piezopermittivity effect in the samples, consisting of elastomer / carbon nanoparticle composites, was detected. A prototype of an active element for mechanical vibration energy harvester made of elastomer composite possessing piezopermittivity effect was elaborated. An original method is proposed for 1D carbon nanoparticles orientation in silicone oil by using electrostatic field and periodic treatment of suspension with ultrasonic homogenizer.

A new step has been made to develop new and improved innovative biomaterials – nanostructured composite materials (such as calcium phosphates, bioglasses, bone cements, titanium oxide biomaterials, biopolymers etc.) for bone and tissue regeneration as well as to investigate incorporation of pharmaceutically active substances in the biomaterials. A simple and clean technology of preparation of calcium phosphate bioceramics with various and replicated chemical (containing up to 10 mol% of Sr) and phase (hydroxyapatite and β-tricalcium phosphate phase ratios in a wide range) composition were developed through modification of the wet chemical precipitation method by realizing addition of precursor of substituting ions. Novel technology for preparation of amorphous or low crystalline calcium phosphates has been developed. Methodology for the preparation and characterization of novel hydroxyapatite/ɛ-polylysine composites as bone tissue engineering matrices were developed.

Several biodegradable polymers are being considered for fabrication of composites such as the synthetic poly a-hydroxy esters. Specific properties such as high initial strength and tailored elastic modulus close to the elastic modulus of bone of composites based on calcium phosphates and biodegradable polymers for bone tissue engineering applications were identified. Methods suitable for nanomaterial samples biocompability testing by evaluating cell based testsystem growth dinamics were identified and work Schedule was developed.

In the field of biomedicine a novel microrheological method has been developed based on newly constructed physical model that describes the motion of a superparamagnetic particle in a specific external magnetic field configuration in a viscoelastic medium.

In the field of astrophysics upgrading of Schmidt Telescope optical channel was performed and novel methods for radar VLBI data processing developed. At University Institute of Astronomy computer program for searching very red star (color indices [J-K]> 1.3 mag) in the 2 micron all sky survey 2MASS is created. The observation list of stars with color indices [J-K]> 1.3 mag. is obtained in sky area 50 deg. < δ < 90 deg.

As the results of the programme 411 SCI reports in scientific journals, 406 presentations at international conferences and 284 interactive activities including popular science publications, seminars, exhibitions are presented.