DEBNÁRIKOVÁ, M. Příprava chitinových filmů [online]. Brno: Vysoké učení technické v Brně. Fakulta chemická. 2019.

Posudky

Posudek vedoucího

Abdellatif, Abdelmohsan

The bachelor work is well written in clear and concise manner (total of 67 pages). In addition to the literature search (14 pages), an experimental part is elaborated in detail, where the student demonstrated complete independence not only in the laboratory but also in the design of both experiments and different characterization methods. During her bachelor work, she gots a lot of experience in purification of chitin, preparation pure fibrils chitin , dissolvation of chitin in green solvent and fabrication of biofilms from PVA/chitin solutions.The results obtained are a very good basis for the future thesis. Also the student showed the ability to work in a team and independently evaluate complex experimental data. I believe this diploma thesis is very well done and I did not find any reason for not approving this work. I recommend this thesis with grade A.

Dílčí hodnocení
Kritérium Známka Body Slovní hodnocení
Kvalita zpracování výsledků A
Interpretace výsledků, jejich diskuse A
Závěry práce a jejich formulace B
Využívání konzultací při řešení práce B
Celkový přístup k řešení úkolů A
Splnění požadavků zadání A
Studium literatury a její zpracování B
Využití poznatků z literatury A
Navrhovaná známka
A

Posudek oponenta

Abdelrahman, Rasha

The diploma thesis was written by Bc. Micheala Debnáriková was focused on extraction and characterization of pure chitin from shrimp shell using green treatment of the shrimp surface. this thesis is divided into three parts. Firstly, Micheala extracted pure chitin by acid/base surface treatments and obtained pure chitin with a very low concentration of proteins. The pure chitin was characterized by different techniques like FTIR, TGA, SEM, protein percentage. The degree of deacetylation of pure chitin was confirmed by different tools solid NMR and acid-base titration and both methods didn't show any significant difference in the value of the degree of deacetylation of chitin. Secondly, she used a green solvent [ mixture of urea/sodium hydroxide at low temperature] to dissolve the chitin product. Different concentrations of chitin (0.5-5 %) were prepared and the viscosity of the all solutions was measured and evaluated. In the third part of her work, she prepared films from a blend solution of polyvinyl alcohol PVA/chitin using different ratios between PVA to chitin solution. The prepared films were characterized by different tools like SEM, FTIR, TGA and the mechanical properties of the prepared film were measured and evaluated. The thesis is written in relatively good English. There are only minor typing errors. The results and discussion were explained as well and at the end, she achieved the goal of her thesis. in my opinion the thesis fulfills relevant requirements and is ready to be defined. Comments and Questions 1. Did you measured the residual of metal contents in the pure chitin? 2. Can you reduce the time of dissolution the chitin to be one or two days maximum? 3. The mechanical properties of the film very low compared with net PVA. Who you can improve the mechanical and the optical transmittance properties of chitin film?

Dílčí hodnocení
Kritérium Známka Body Slovní hodnocení
Splnění požadavků zadání A
Logické členění práce A
Kvalita zpracování výsledků A
Interpretace výsledků, jejich diskuse B
Využití literatury a její citace A
Úroveň jazykového zpracování A
Formální úroveň práce – celkový dojem B
Závěry práce a jejich formulace A
Navrhovaná známka
A

eVSKP id 115983