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11.
Bacterial cellulose films: Evaluation of the water interaction
Patricia Cazón, Gonzalo Velazquez, Manuel Vazquez, 2020, original scientific article

Abstract: 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.
Keywords: GAB model, Moisture adsorption isotherms, Bacterial cellulose, Mechanical properties, UV-barrier properties
Published in RUNG: 09.12.2020; Views: 2435; Downloads: 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 properties
Patricia Cazón, Gonzalo Velazquez, Manuel Vazquez, 2020, original scientific article

Abstract: 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.
Keywords: GAB model, Moisture adsorption isotherms, Plasticization, Bacterial cellulose, Mechanical properties, UV-barrier properties
Published in RUNG: 09.12.2020; Views: 2378; Downloads: 90
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14.
Introduction of a Redox-Responsive Switch into calix[4]arene-based Covalent Organic Nanosheets for Environmental Applications
Tina Skorjanc, 2018, published scientific conference contribution abstract

Keywords: redox chemistry, viologen, covalent organic polymers, calixarene, dye adsorption, iodine adsorption
Published in RUNG: 11.09.2020; Views: 2405; Downloads: 0
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15.
Redox-Tunable Polycationic Polymers for Environmental Applications
Tina Skorjanc, Goinda Das, Selbi Nuryyeva, Thirumurugan Prakasam, Ali Trabolsi, 2017, published scientific conference contribution abstract

Keywords: covalent polymers, viologen, redox chemistry, pollutant removal, dye adsorption, iodine capture
Published in RUNG: 10.09.2020; Views: 2420; Downloads: 0
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17.
Highly efficient carcinogenic bromate removal from water by a cationic covalent organic framework
Tina Skorjanc, Dinesh Shetty, Felipe Gandara, Liaqat Ali, Ali Trabolsi, 2019, published scientific conference contribution abstract

Keywords: bromate, covalent organic frameworks, Zincke reaction, adsorption, water purification
Published in RUNG: 03.09.2020; Views: 2669; Downloads: 0
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Calix[4]arene-based porous organic nanosheets
Dinesh Shetty, Tina Škorjanc, original scientific article

Keywords: calixarene, nanosheets, covalent polymer, iodine adsorption
Published in RUNG: 02.09.2020; Views: 2894; Downloads: 0
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20.
Thioether-crown-rich calix[4]arene porous polymer for highly efficient removal of mercury from water
Dinesh Shetty, Tina Škorjanc, original scientific article

Keywords: Mercury, Sulfur, Metals, Adsorption, Polymers
Published in RUNG: 02.09.2020; Views: 2604; Downloads: 0
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