The laboratory was founded in 2019 thanks to funding from CAMART2 project. It will consist of 2 rooms for high temperature synthesis, 1 room for technological synthesis (spray coating etc.), 1 room for powder technologies, 2 rooms for basic synthesis and 1 room for material characterisation.
|Guntars||Vaivars||Head of Laboratoryfirstname.lastname@example.org|
1.Ion conducting polymer materials and membranes - synthesis and characterization.
Chlorosulphonated polyetheretherketone membranes with different sulphonation degrees, including the sulphonation degrees influence on membrane physical properties and composite formation, as well as process kinetics. Specifically, the composites with zirconium oxide nanoparticles, ionic liquids and carbon dispersions. Membrane testing in solid state ionics devices for alternative energy and other applications (fuel cells, batteries, chemical reactors). Ion transport measuring methods (impedance etc.). Proton conductivity.
Colloidal chemistry methods- particle surface studies, polymer membrane preparation from nanodispersions. Zeta potential measurements. Rheology of polymer materials – glass transition temperature.
2. Resolution of problems extensively investigated in the field of luminescent up-converting nanomaterials, as: stabilization, modification and (bio)functionalization.
The design and preparation of multifunctional up-converting nanomaterials and core-shell hybrid structures with improved performances – the development of synthetic methods, structural, morphological and optical characterization. Exclusively, doped phosphates, vanadates and fluorides hosts. These structures might be employed as light-emitting diodes, as well as for imaging agents, cancer detection, drug delivery and temperature sensors.
The modification of oxide coatings on metal surfaces based on the aluminate (SrAlO4) in order to enhance their optical (and other) properties with Plasma Electrolytic Oxidation (PEO) method which can lead to production of coatings with novel properties.
For increased particle stability in solutions, improvement of wettability, prevention of particle core dissolution, improvement of physical and chemical functions, increased efficiency, cost and material savings, protective function, biocompatibility and functionality, synthesized luminescent up-converting nanomaterials were and will be coated with polymers or inorganic layers (e.g. SiO2).
Future plans: Synthesize of up-converting materials via chemical co-precipitation and microwave hydrothermal techniques to obtaine samples usable in production of temperature sensing and solar cell devices.
3. Membranes for solid state devices.
Synthesis of SPEEK and SPEEK composites (with carbon, inorganic oxides and other nanoparticles) for electrochemical reactor membranes for CO2 electrosynthesis from ethylene. Membranes are modified to provide a proton conductivity and separate teh anode from cathode. SPEEK polymers as a binders for catalytic electrodes.
4. Thin film coatings (metal, oxides, salts etc.) on different substrates (glass etc.) produced by chemical methods (wet chemistry).
Currently the main achievement is the lab eqipping with the new purchased equipment.
- LitesizerTM 500 (Anton Paar) is suitable for measuring particle size distribution and measuring zeta potential. For nanocomposite forming from polymer solutions the colloidal dispersions are used. Zeta potential is used as a measure for colloid stability. Final product preferably is formed as a thin film by different methods, e.g. electrophoresis. The process efficiency is determined by the surface potential and charge. Particle sizes in dispersions are in range from 0,3nm to 10 micrometers, but zeta potential is measured also for larger particles –up to 100 micrometers. Method is based on laser dispersion at different angles- 15, 90 and 175 degrees. Additionlly, the viscosity and refraction index is measured. Both parameters are used to calculate the zeta potential. SurPassTM is used to measure the surface zeta potential for films and membranes as a function of pH using automatic titration. So far the measurements are performed in a water solutions.
- Rigaku MiniFlex 600 X-ray diffractometer allow to characterize in-situ fresh synthesized materials and phases. High work safety make it suitable also for students not only professionals.
- Thermal analysis is important part of material characterization- composition, heat effects and temperature stability. SETARAM LABSYS evo STA device is suitable for measurements up to 1600oC with precision 0,02 µg (up to 100mg). For larger samples the precision 0,2 µg.
For heat effects 2 sensors are used – first up to +800 °C (sensitivity 0,5 µW) and second for higher temperatures (10 µW). Itis important for limited material amount (nanomaterials, thin films). DSC equipment is used to measure glass transition temperature of polymers, which is crucial for hot-pressing and 3D printing technologies.
- University of Latvia, Faculty of Chemistry;
- Riga Technical University;
- University of Stellenbosch;
- University of Cape Town.
- University of Gothenburg, Department of Physics;
- Uppsala University.
- G. Vaivars, J. Kleperis and A. Lusis. Antimonic Acid Hydrate Xerogels as Proton Electrolytes// Solid State Ionics 61 (1993) 317-32
- A. Azens, L. Kullman, D.D. Ragan, C.G. Granqvist, B. Hjorvarsson, G. Vaivars. Optical and Electrochemical Properties of DC Magnetron Sputtered Ti-Ce Oxide Films// Appl. Phys. Lett. 68, 26 (1996) 3701-3703.
- G. Vaivars, J. Kleperis, A. Azens, C.G. Granqvist and A. Lusis. Proton Conducting Composite Electrolytes Based on Antimonic Acid// Solid State Ionics 97, 1-4 (1997) 365-368.
- C.G. Granqvist, A. Azens, A. Hjelm, L. Kullman, G.A. Niklasson, D. Rönnow, M. Stromme Mattsson, M. Veszelei and G. Vaivars. Recent Advances in Electrochromics for Smart Windows Applications// Solar Energy 63, 4 (1998) 199-216.
- A. Azens, L. Kullman, G. Vaivars, H. Nordborg and C.G. Granqvist. Sputter-Deposited Nickel Oxide for Electrochromic Applications// Solid State Ionics 113-115 (1998) 449-456.
- G. Vaivars, A. Azens and C.G. Granqvist. Proton Conducting Polymer Composites for Electrochromic Devices// Solid State Ionics 119, 1-4 (1999) 269-273.
- A.Azens, G.Vaivars, M.Veszelei, L.Kullman and C.G.Granqvist. Electrochromic devices embodying W oxide/Ni oxide tandem films// Appl Phys Lett 89, 12 (2001) 7885-788
- Ji Shan, H. Lou, R. Mohamed, G. Vaivars and V. Linkov. Sulfonated polyether ether ketone (PEEK-WC)/phosphotungstic acid composite: Preparation and characterization of SPEEK-WC/HPW composite membranes// Pure and Applied Chemistry 78, 9 (2006) 1779–1789.
- H. Luo, G. Vaivars, M. Mathe. Cross-linked PEEK-WC proton exchange membrane for fuel cell// International Journal of Hydrogen Energy 34 (2009) 8616-8621.
- H.Luo, G.Vaivars, B.Agboola, S.Mu, M.Mathe. Anion exchange membrane based on alkali doped poly(2,5-benzimidazole) for fuel cell// Solid State Ionics, 208 (2012) 52-55.
Patent 1. A.Azens, G. Vaivars, M. Veszelei, L. Kullman. and C.G. Granqvist. Electrochromic Device Comprising Tandem Layers of Cathodic/Anodic Material. Patent (Sweden), 1998.09.22, No. 9803210-5. F: Patent_98_Sweden; US patent US 6211995, Issued/Filed Dates: April 3, 2001 / Dec. 17, 1998, Priority Number Sept. 22, 1998 SE1998000003210; Patent number WO0017701, publication date: 2000-03-30, Priority number(s): SE19980003210 19980922. Priority data: 1998. 09.22. 1.
Patent 2. A. Azens, G. Vaivars, M. Veszelei, L. Kullman. and C.G. Granqvist. 6-layer Electrochromic Device. Patent (USA), 2000.05.10, No.51018-54243-JL/KCL.
Patent 3. Luo, H., Vaivars, G., and Kleperis, J., A novel double cross-linked proton conducting membrane and the methods. Latvian Patent Application P-07-145, 2007.
MSc students (chemistry) are visiting as a part of study courses Surface and Colloidal chemistry (Ķīmi5052) and Solid State Ionics (Ķīmi6005).
Top-scoring participants of National Chemistry Olympiad are visiting the Institute.