Addition of Al(OH)3 versus AlO(OH) nanoparticles on the optical,thermo-mechanical and heat/oxygen transmission properties of microfibrillated cellulose films

Cellulose - Differently structured aluminum (tri/mono) hydroxide (Al(OH)3 /AlO(OH)) nanoparticles were prepared and used as thermal-management additives to microfibrillated cellulose (MFC),...     

Antimicrobial properties of viscose yarns ring-spun with integrated amino-functionalized nanocellulose

Cellulose - Bio-based, renewable and biodegradable products with multifunctional properties are also becoming basic trends in the textile sector. In this frame, cellulose nanofibrils (CNFs) have...     

Enzymatic phosphorylation of cellulose nanofibers to new highly-ions adsorbing,flame-retardant and hydroxyapatite-growth induced natural nanoparticles

This study confirms the enzyme-mediated phosphorylation of cellulose nanofibers (CNF) by using hexokinase and adenosine-5′-triphosphate in the presence of Mg-ions, resulting in a phosphate group’s creation predominantly at C-6-O positioned hydroxyl groups of cellulose monomer rings. A proof-of-concept is provided using ¹²C CPMAS, ³¹P MAS nuclear magnetic resonance, attenuated total reflectance-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy (XPS) analyzing methods. The degree of substitution (DS) is determined by elemental analysis and compared to DS estimated by XPS analysis. From the thermal degradation measurements using thermo-gravimetric analysis, the C-6-O phosphorylation was found to noticeably prevent the CNF derivatives from weight loss in the pyrolysis process, thus, providing them flame-resistance functionality. Furthermore, phosphorylation significantly enhanced adsorption capacity of Fe³⁺ ions making them interesting for fabrication of biobased filters and membranes. Finally, the biomimetic growth of Ca–P crystals (hydroxyapatite) in simulated body fluid was characterized by scanning electron microscopy and energy dispersive X-ray, showing potential application as biomedical materials.     

Shock-wave velocity of a femtosecond-laser-produced plasma

Fluorescence measurements have been used to characterize the velocity of atoms in a femtosecond-laser-produced plasma. Nanogram amounts of a copper sample were ablated by the focused radiation (λ=775 nm) of an all-solid-state laser. The laser was operated at a pulse rate of 10 Hz with an energy of 200μJ per pulse. The microplasma expanded into a defined argon atmosphere of pressures between 0.02 and 850 mbar. Atomic fluorescence was excited in the laser plume by a dye-laser pulse with the wavelength set to the line Cu I 282.4 nm. The narrowed beam of the dye-laser was directed into the plasma at different heights above the sample surface. The fluorescence radiation was measured with an échelle-spectrometer, equipped with an intensified-charge-coupled device as the detector. The velocity depends strongly on the pressure of the ambient atmosphere and the distance from the sample surface. The highest velocity found at an argon pressure of 0.02 mbar was 1.0×10⁶ cm s⁻¹.     

CE detection of N‐(3‐dimethylaminopropyl)‐N‐carbodiimide/N‐hydroxysuccinimide‐coupled proteins after homo‐ and hetero‐crosslinking reactions

Protein–protein conjugates formed by carbodiimide crosslinking reactions have been analyzed for the first time using CE. Lysozyme and BSA were chosen as model proteins to study the efficacy of N‐(3‐dimethylaminopropyl)‐N‐ethylcarbodiimide and N‐hydroxysuccinimide as crosslinkers. Detection of the molecular mass increase was checked by SDS‐PAGE. Commercially available, PVA‐coated capillaries showed appropriate selection, while phospho‐deactivated and dynamic PVA‐coated capillaries did not give suitable resolution. CE was found to be an efficient tool to characterize homo‐ (lysozyme–lysozyme) and hetero‐ (lysozyme–BSA) protein coupling by suitable variations of electrophoretic mobilities.     

Femtosecond laser analytical mass spectrometry applied to plant samples

The unique ability of ultra-short laser pulses to couple energy into material faster than the energy diffuses, enables laser ablation of bio-samples without heat transfer to the surrounding material. In particular, individual plant cells can be investigated without collateral damage. Femtosecond laser-based mass spectrometry technique suitable for investigation of ion contents in plant cells is reported. The technique is applied to the measurement of iron in dried maize leaves. PACS 42.62 Be; 52.38 Mf     

An Operations Research Approach to the Problem of the Sugarcane Selection

Selection for superior clones is the most important aspect of sugar cane improvement programs, and is a long and expensive process. While studies have investigated different components of selection independently, there has not been a whole system approach to improve the process. This study observes the problem as an integrated system, where if one parameter changes the state of the whole system changes. A computer based stochastic simulation model that accurately represents the selection was developed. This paper describes the simulation model, showing its accuracy as well as how a combination of dynamic programming and branch and bound can be applied to the model to optimise the selection system, giving a new application of these techniques. The model can be directly applied to any region targeted by sugarcane breeding programs or to other clonally propagated crops.     

Morphological patterns of poly(N-isopropylacrylamide) derivatives synthesized with EGDMA, DEGDMA, and TEGDMA crosslinkers for application as thermosensitive drug carriers

A number of poly(N-isopropylacrylamide) (polyNIPAM) microgels were prepared with dimethacrylate cross-linking agents of various lengths, ether and ester groups in the backbone, and pendant vinylidine functionality. These materials were characterized by examining their morphological patterns using optical and scanning electron microscopy. When ethylene glycol dimethacrylate (EGDMA) was used as a cross-linking agent, microspheres of approximately 1 μm in diameter were obtained. Diethylene glycol dimethacrylate (DEGDMA) cross-linking resulted in relatively large spherical structures (1–5 μm) as well as spherical nanostructures (200 nm). Using triethylene glycol dimethacrylate (TEGDMA) resulted in spheres with diameters between 1 μm and 3 μm. The hydrodynamic particle diameter decreased with the increasing chain length of the dimethacrylate cross-linking agents. The turbidity increased with the temperature of transition points occurring at approximately 31–32°C confirming the thermosensitivity of the obtained polymeric structures.