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In this study, interaction and compatibility between sugar-beet pulp (SBP) and polyvinyl alcohol (PVA) in blend films was assessed. Film-forming dispersions of different ratios of SBP to PVA (100/0, 75/25, 50/50, and 25/75) were cast at room temperature. The effects of adding PVA to SBP on the resulting film's physical, mechanical and barrier properties and thermal stability were investigated. X-ray diffraction and environmental scanning electron microscopy (ESEM) were used to characterize the structure and morphology of the composites. When PVA was also added to the composite films, the films became softer, less rigid and more stretchable than pure SBP films. The addition of PVA gave significantly greater elongation at break (12.45%) and lower water vapor permeability (1.55 3 10 210 g s 21 m 21 Pa 21 ), but tensile strength did not markedly change, remaining around 59.68 MPa. Thermogravimetric analysis also showed that SBP/PVA film had better thermal stability than SBP film. The ESEM results showed that the compatibility of SBP50/PVA50 was better than those of other composite films. These results suggest that when taking all the studied variables into account, composite films formulated with 50% PVA are most suitable for various packaging applications.

Several studies have been reported on the use of cellulose, lignocellulose, chitin and other biological macromolecules for food packaging. One of the major drawbacks limiting their wide uses is their limited antimicrobial and water vapor barrier properties. In this study, cedarwood (Thuja occidentalis) essential oil (CWO), known to contain terpenes, polyphenols and tung oil, known to contain fatty acids, were used as additives to improve water vapor barrier, antimicrobial, and physical properties of laboratory cast lignocellulose films. Physicochemical and mechanical properties were tested to evaluate the impact of the addition of oils in the films formulations. The addition of 15 % CWO and tung oils improved water vapor permeability by more than 25 % as also evidenced by the increase of contact angle between water and film by 134 % from 38.98°to 89.36°with 15 % tung oil. FTIR was used to monitor the presence of hydrophobic groups at 1463 and 1741 cm -1 from the oil on the film spectra confirming the improvement of film hydrophobicity from oils interactions. However, the addition of 15 % hydrophobic oils promoted a significant decrease in tensile properties of films (p B 0.05) by 40 % for CWO and 32 % for tung oil, respectively, due to a partial incompatibility between hydrophilic lignocellulose and hydrophobic oils. The use of a tailored coupling agent to reduce the incompatibility and to improve the load charge transfer between hydrophobic and hydrophilic group might reduce the decrease of the tensile properties with the addition of hydrophobic compounds. No significant difference (p [ 0.05) was observed on the thermal stability of films using TGA. The antimicrobial effects of lignocellulose films against bacteria namely Listeria innocua, Escherichia coli, and Salmonella enterica was tested by disk inhibition zone method and showed an improvement with the addition of 5 % CWO in the film. The Microbe Growth Index of the lignocellulose cellulosic films containing 20 % w/w of CWO decreases by 80 %. CWO and tung oil are good candidates to control microbial growth and water vapor permeability in flexible films. Future work will focus on the olfactory and tensile properties for applications in food packaging.

ZrO2-SiO2 gels were prepared by prehydrolysis method with sol-gel process. Then,the wet gels were aged at different temperatures (60,110,170 °C) in ethanol or alkaline solution (pH=8). Finally, the monolithic ZrO2-SiO2 aerogels were obtained by supercritical fluid drying. N2 adsorption-desorption, scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the microstructure of aerogels. The aim of this research is to study the effect of aging temperature and pH value of aging solution on the microstructure of ZrO2-SiO2 aerogels. The results show that the specific surface area and pore volume of ZrO2-SiO2 aerogels aging in alkaline solution (pH=8) is lower than that of aging in the ethanol. And there is a shift of the pore size distribution towards larger values. This is because the cross-linking reaction in alkaline solution enlarges the particle size. As the aging temperature increases, the specific surface area and pore volume decrease and the particle size distribution of ZrO2-SiO2 aerogels is more uniform.