Bacterial cellulose as a raw material for food and food packaging applications.

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Bacterial Cellulose-Hydroxyapatite Nanocomposites for Bone Regeneration

The aim of this study was to develop and to evaluate the biological properties of bacterial cellulose-hydroxyapatite (BC-HA) nanocomposite membranes for bone regeneration. Nanocomposites were prepared from bacterial cellulose membranes sequentially incubated in solutions of CaCl2 followed by Na2HPO4. BC-HA membranes were evaluated in noncritical bone defects in rat tibiae at 1, 4, and 16 weeks. Thermogravimetric analyses showed that the amount of the mineral phase was 40%–50% of the total weight. Spectroscopy, electronic microscopy/energy dispersive X-ray analyses, and X-ray diffraction showed formation of HA crystals on BC nanofibres. Low crystallinity HA crystals presented Ca/P a molar ratio of 1.5 (calcium-deficient HA), similar to physiological bone. Fourier transformed infrared spectroscopy analysis showed bands assigned to phosphate and carbonate ions. In vivo tests showed no inflammatory reaction after 1 week. After 4 weeks, defects were observed to be completely filled in by new bone tissue. The BC-HA membranes were effective for bone regeneration

A Silsesquioxane Organically Modified with 4-Amino-5-(4-pyridyl)-4 H

The octakis(3-chloropropyl)silsesquioxane (SS) was organofunctionalized with 4-amino-5-4(pyridyl)-4H-1,2,4-triazole-3-thiol. The product formed (SA) was undergo another reactions in two steps, first with copper and so hexacyanoferrate (III) to form CuHSA. The organofunctionalized silsesquioxane was characterized by the following techniques: scanning electron microscopy (SEM), Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) in solid state, and thermogravimetric analysis in air and nitrogen atmosphere. The composite CuHSA was incorporated into a graphite paste electrode and the electrochemical behavior studies were conducted with cyclic voltammetry. The cyclic voltammogram of the modified graphite paste electrode with CuHSA showed one redox couple with formal potential Eθ′=0.75 V versus Ag/AgCl(sat) (KCl 1.0 mol L−1; v = 20 mV s−1) attributed to the redox process Fe(II)(CN)6/Fe(III)(CN)6 of the binuclear complex formed. The redox couple presents an electrocatalytic response of sulfhydryl compounds such as n-acetylcysteine and l-cysteine. For determination of n-acetylcysteine and l-cysteine the modified graphite paste electrode showed a linear region in the concentration range of 2 to 20 mmol L−1. The modified electrode was chemically and electrochemically stable and showed good reproducibility

A Silsesquioxane Organically Modified with 4-Amino-5-(4-pyridyl)-4H-1,2,4-triazole-3-thiol: Thermal Behavior and Its Electrochemical Detection of Sulfhydryl Compounds

The octakis(3-chloropropyl)silsesquioxane (SS) was organofunctionalized with 4-amino-5-4(pyridyl)-4H-1,2,4-triazole-3-thiol. The product formed (SA) was undergo another reactions in two steps, first with copper and so hexacyanoferrate (III) to form CuHSA. The organofunctionalized silsesquioxane was characterized by the following techniques: scanning electron microscopy (SEM), Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) in solid state, and thermogravimetric analysis in air and nitrogen atmosphere. The composite CuHSA was incorporated into a graphite paste electrode and the electrochemical behavior studies were conducted with cyclic voltammetry. The cyclic voltammogram of the modified graphite paste electrode with CuHSA showed one redox couple with formal potential = 0.75 V versus Ag/AgCl (sat) (KCl 1.0 mol L −1 ; v = 20 mV s −1 ) attributed to the redox process Fe (II) (CN) 6 /Fe (III) (CN) 6 of the binuclear complex formed. The redox couple presents an electrocatalytic response of sulfhydryl compounds such as n-acetylcysteine and l-cysteine. For determination of n-acetylcysteine and l-cysteine the modified graphite paste electrode showed a linear region in the concentration range of 2 to 20 mmol L −1 . The modified electrode was chemically and electrochemically stable and showed good reproducibility

Bacterial cellulose as a raw material for food and food packaging applications.

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Einsatz von RFID unternehmensindividuell bewerten - RFID - Business Case Calculation : Erfahrungsbericht der Planung und Bewertung des RFID-Einsatzes

Organic-inorganic composite membranes were prepared from membranes of the bio-polymer bacterial cellulose (BC) and organic-inorganic sal composed of nanoparticulate boehmite and epoxi modified siloxane. Bacterial cellulose membranes are obtained in a highly hydrated state (1% cellulose and 99% cellulose) from cultures of Gluconacetobacter xylinus and could be used in the never-dried or in the dried state. Depending on the use of dried or never-dried BC membranes two main kinds of composites were obtained. In the first one dried BC membranes coated with the hybrid sol have lead to transparent membranes displaying a hi-phase structure where the two components could be easily distinguished, with individual structures preserved. A decrease was observed for tensile strength (50.5 MPa) and Young's Modulus (2.8 GPa) when compared to pure BC membrane (112.5 MPa and 12.7 GPa). Elongation at break was observed to increase (2.5% against 1.5% observed for BC). When never-dried BC membranes were used transparent membranes were also obtained, however an improvement was observed for mechanical properties (tensile strength - 116 MPa and Young's Modulus - 13.7 GPa). A lower value was obtained for the elongation at break (1.3%). In the last case the interaction between the two-phases lead to changes in the cellulose crystallinity as shown by X rays diffraction results. Multifunctional transparent membranes displaying the cellulose structure in one side and the boehmite-siloxane structure at the opposite face could find special applications in opto-electronics or biomedical areas taking advantage of the different chemical nature of the two components. (C) 2012 Elsevier Ltd. All rights reserved.CAPESCAPESCNPqCNPqFAPESPFAPESPCAPESCOFECUB (Brazil and France)CAPES-COFECUB (Brazil and France

Bacterial cellulose–SiO2@TiO2 organic–inorganic hybrid membranes with self-cleaning properties

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