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Study on transport of liquid lignohumates through plant leaves and plant cuticles
Rampáčková, Eliška ; Weidlich, Tomáš (referee) ; Smilek, Jiří (advisor)
This thesis deals with the study of transport commercial solution of pottasium lignohumate through the plant cuticles, as the main barriers in transport of active ingredience to plant tissues. The problematics has been studied to obtain the informations about ability of transport liquid active ingredience during foliar fertilization, which became popular in theme of efective utilization fertilizers and reduction their negative impact to enviroment. The aim of this thesis was to optimize technics of diffusion for demanded purposes in the Stokes diffusion cells. As the transport barriers have been used the plant cuticles, that have been isolated by various methods. The ultraviolet and visible spectrometry (UV-VIS) was the analytical method for determination of transported volume of lignohumate and to the mentioned experiments the cuticles of Prunus laurocerasus and cuticles of tomato fruit have been used. The isolated cuticles have been analyzed by optical microscopy, scanning electron microscopy and profilometry. The characterisation of the used solution of lignohumate was also important part of this thesis. It has been used the basic physico-chemical methods and also the advanced methods as tensiometry, size exclusion chromatography with UV detector and differential refractive index detector (SEC-UV-dRI) and thermogravimetry (TGA).
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Effect of chemical modification of humic acids on their interactions with organic ions
Fryšová, Eva ; Weidlich, Tomáš (referee) ; Sedláček, Petr (advisor)
This master thesis deals with the interaction of humic acids with organic ions and effect of chemical modification of humic acids on this interaction. Rhodamine 6G was used as a model organic ion. The interaction were studied by fluorescence quenching, dialysis in diffusion cells and differential UV-VIS spectroscopy. Results showed that the bond between the reactants was not primarily dependent on carboxylic functional groups of humic acids. Fluorescence experiments indicated static quenching mechanism and differential UV-VIS spectroscopy demonstrated the existence of - interactions.
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Material characterization of novel hydrogels containing humic substances intended for pharmaceutical and cosmetic applications
Pavlicová, Renata ; Weidlich, Tomáš (referee) ; Sedláček, Petr (advisor)
This thesis is focused on the development and characterization of hydrogels containing humic substances with possible use in cosmetic and pharmaceutical industries. This work follows on the bachelor thesis, theoretical and experimental part is based on already acquired knowledge. The aim of this work was to develop a literature review focusing on the potential use humic gels in practice and also to enhance the consistency of other active ingredients. Based on this literature review, the main aim was to prepare model humic hydrogels with selected active ingredients and their characterization by basic methods of material analysis. These basic methods were especially rheology and visual assessment of consistency during the preparation, then the samples were subjected process of drying and swelling. Experimental results showed considerable influences during the preparation and composition of each sample, which then reflected in their structure and consistency. Furthermore, it was found that the suitable composition and combination of ingredients form hydrogels acceptable characteristics for further use in cosmetic or pharmaceutical applications.
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