Department of Solid State Chemistry

Granting Departments:	Department of Solid State Chemistry
Study Programme/Specialization:	Drugs and Biomaterials ( in English language )
Supervisor:	Ing. Jan Čejka, Ph.D.

Annotation

API's multiple-component crystals are a valuable option in modfying pharmacokinetic profile, stability of API etc. The application properties of any particular active compound are often rendered by means of the component is built in the structure. This work aims to prepare single crystals of salts, solvates, co-crystals and polymorphs of selected compounds, study potentional temperature dependent phase transitions, their complex characterization using a bundle of analytical methods accenting X-ray structure analysis and consequent correlation of parameters and solvent occupied voids.

Granting Departments:	Department of Solid State Chemistry
Study Programme/Specialization:	Chemistry and Technology of Materials ( in English language )
Supervisor:	doc. Ing. Barbora Doušová, CSc.

Annotation

Aluminosilicates, together with e.g. powdered building waste, biochar, lignin are able to adsorb and keep a large amount of water compare to soils and sediments. The mixing of these materials with selected soils in controlled dosages can support water retention in soils, which is significant due to more and more often "dry periods" and generally lower precipitation. A controlled dosage of the material with high water retention to soil ecosystems can improve markedly a water regime and hydrological cycle.

Granting Departments:	Department of Solid State Chemistry
Study Programme/Specialization:	Drugs and Biomaterials ( in English language )
Supervisor:	Ing. Jan Čejka, Ph.D.

Annotation

Topic of this work will be focused on preparation and crystal growth of volatile and subliming organic compounds with accent on active pharmaceutical ingredients (polymorhps, solvates, salts or cocrystals) from gaseous phase and solution in order to prepare large-volume crystals thereof. The work will be focused on sublimation apparatus design and optimization of the crystal growth procedure of organic compounds from gaseous state using horizontal two section resistive furnace with separate temperature regulation. This method is based on transferring (subliming) the starting material into gaseous state in the storage part of the growth system and its subsequent crystallization (desublimation) in the dedicated coolest place of the system. Setting of suitable temperature regime in both furnace sections defines and controls the growth rate of growing crystal. An integral part of the work comprises: (i) a new crystallization container divided into storage and crystallization stages will be designed, (ii) growth conditions (temperature gradient in the furnace, temperature regimes) will be optimized, and (iii) the physical, structural and optical properties of the prepared crystals will be characterized. Second part of this work will be focused on preparation of crystals of model organic compounds grown from solution. The solvents influence on the crystallization process and final crystal quality will be evaluated. Results of characterizations performed on crystals obtained from diverse procedures as well as of used procedures will be compared.

Granting Departments:	Department of Solid State Chemistry
Study Programme/Specialization:	Chemistry and Technology of Materials ( in English language )
Supervisor:	doc. Ing. Barbora Doušová, CSc.

Annotation

In soil profiles several toxic elements (arsenic, antimony, selenium) occur as oxyanions primarily bound to HFO phases, forming stable surface complexes. This process runs as the balanced adsorption of oxyanions from a soil solution to active adsorption sites of soil particles, in the presence of another anions and dissolved organic matter. During this process the binary and/or ternary soil complexes of HFO, organic matter and oxyanion have been formed. The adsorption and complexation proceed in a colloid environment, which is susceptible to the ionic strength of soil solution (stabilization or aggregation of particles). According to recent results the stability of formed ternary complexes is critical for the long-term stability of binding oxyanions. The aim of this work will be to qualify the formation of organic matter – ferric oxide – anionic particle ternary komplexes, to describe their structure and binding properties, and to estimate the environmental impact to the stability of complex components, particularly the toxic oxyanionic forms.