11. Bacterial cellulose films: Evaluation of the water interactionPatricia Cazón, Gonzalo Velazquez, Manuel Vazquez, 2020, izvirni znanstveni članek Opis: Bacterial cellulose is a biopolymer that is gaining attention due to its 3D structure, higher purity, porosity and surface area. However, this material can interact with water molecules from the surrounding environment, resulting in alterations of its properties. Hence, the purpose of this study was to analyze the modifications on the mechanical, water vapor permeability and optical properties of bacterial cellulose films as a function of the water activity. Results indicated that water acted as a plasticizer, mainly affecting mechanical and water vapor permeability properties. The moisture adsorption isotherms allowed predicting the moisture content of the bacterial cellulose films at several relative humidity conditions. Values for tensile strength and burst strength ranged from 15.50 to 22.28 MPa and from 145.03–338.10 g, respectively. The elongation and the distance to burst ranged from 1.36 to 3.71 % and from 0.39 to 1.86 mm, respectively. These values increased due to the plasticizing effect of the water molecules. Water vapor permeability values ranged from 1.35·10−12 to 3.13·10-11 g/ m s Pa, showing a significant increase up to 0.48 of water activity. Bacterial cellulose films showed excellent UV-barrier properties in the different water activities evaluated.
Ključne besede: GAB model, Moisture adsorption isotherms, Bacterial cellulose, Mechanical properties, UV-barrier properties
Objavljeno v RUNG: 09.12.2020; Ogledov: 2464; Prenosov: 0
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12. UV-protecting films based on bacterial cellulose, glycerol and polyvinyl alcohol: effect of water activity on barrier, mechanical and optical propertiesPatricia Cazón, Gonzalo Velazquez, Manuel Vazquez, 2020, izvirni znanstveni članek Opis: Biodegradable films based on bacterial cellulose, glycerol and polyvinyl alcohol are a new alternative to develop food packaging with the capac- ity to retard or inhibit the effect of UV radiation. However, these compounds are sensitive to moisture. Therefore, the purpose of this study was to evaluate the modifications of the mechanical, water vapor permeability and optical properties of these composite films depending on their water activity. Results showed that water molecules acted as a plasticizer
agent, modifying the mechanical, water vapor perme- ability and optical properties of the developed films. However, an overplastification process took place at higher activity water, resulting in a weakness of film structure and decreasing drastically the elongation. The transmittance in the UV–VIS light region decreased when the activity water increased. No significant variations were observed in color, trans- parency or opacity properties.
Ključne besede: GAB model, Moisture adsorption isotherms, Plasticization, Bacterial cellulose, Mechanical properties, UV-barrier properties
Objavljeno v RUNG: 09.12.2020; Ogledov: 2403; Prenosov: 90
 Celotno besedilo (552,03 KB) |
13. Structural and CO [sub] 2 capture properties of ethylenediamine-modified HKUST-1 metal-organic frameworkNika Vrtovec, Matjaž Mazaj, Gianpiero Buscarino, Angela Terracina, S. Agnello, Iztok Arčon, Janez Kovač, Nataša Zabukovec Logar, 5, izvirni znanstveni članek Ključne besede: functionalization, modification, adsorption, extended X-ray absorption fine structure, materials
Objavljeno v RUNG: 17.10.2020; Ogledov: 2605; Prenosov: 0 |
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15. Redox-Tunable Polycationic Polymers for Environmental ApplicationsTina Skorjanc, Goinda Das, Selbi Nuryyeva, Thirumurugan Prakasam, Ali Trabolsi, 2017, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: covalent polymers, viologen, redox chemistry, pollutant removal, dye adsorption, iodine capture
Objavljeno v RUNG: 10.09.2020; Ogledov: 2447; Prenosov: 0
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16. Immobilization of Redox-Responsive Switches Into Calixarene-Based Covalent Organic Polymers for Environmental ApplicationsTina Skorjanc, Dinesh Shetty, Sudhir Kumar Sharma, Jesus Raya, Dong Suk Han, Ramesh Jagannathan, Ali Trabolsi, 2017, prispevek na konferenci brez natisa Ključne besede: calixarene, redox switches, dye adsorption
Objavljeno v RUNG: 03.09.2020; Ogledov: 2333; Prenosov: 0
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17. Highly efficient carcinogenic bromate removal from water by a cationic covalent organic frameworkTina Skorjanc, Dinesh Shetty, Felipe Gandara, Liaqat Ali, Ali Trabolsi, 2019, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: bromate, covalent organic frameworks, Zincke reaction, adsorption, water purification
Objavljeno v RUNG: 03.09.2020; Ogledov: 2705; Prenosov: 0
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18. Microwave-assisted synthesis of a viologen-based covalent organic polymer with redox-tunable polarity for dye adsorptionGobinda Das, Tina Škorjanc, Thirumurugan Prakasam, Selbi Nuryyeva, John-Carl Olsen, Ali Trabolsi, 2017, izvirni znanstveni članek Ključne besede: viologen, microwave synthesis, phosphazene, dye adsorption, redox chemistry
Objavljeno v RUNG: 02.09.2020; Ogledov: 2405; Prenosov: 0
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