The Hydrophobicity of Lignocellulosic Fiber Network Can Be Enhanced with Suberin Fatty Acids

Suberin fatty acids were extracted from outer bark of Silver birch (Betula pendula Roth.) using an isopropanolic sodium hydroxide solution. Laboratory sheets composed of lignocellulosic fiber networks were prepared from unbleached and unrefined softwood kraft pulp and further impregnated with suberin fatty acid monomers and cured with maleic anhydride in ethanol solution. The treatment resulted in hydrophobic surfaces, in which the contact angles remained over 120 degrees during the entire measurement. The fiber network also retained its water vapor permeability and enhanced fiber–fiber bonding resulted in improved tensile strength of the sheets. Scanning electron microscopy (SEM) images revealed that the curing agent, together with suberin fatty acids, was evenly distributed on the fiber surfaces and smoothing occurred over the wrinkled microfibrillar structure. High concentrations of the curing agent resulted in globular structures containing betulinol derivates as revealed with time-of-flight secondary ion mass spectrometry (ToF-SIMS). Also, the larger amount of suberin fatty acid monomers slightly impaired the optical properties of sheets

The Hydrophobicity of Lignocellulosic Fiber Network Can Be Enhanced with Suberin Fatty Acids

Suberin fatty acids were extracted from outer bark of Silver birch (Betula pendula Roth.) using an isopropanolic sodium hydroxide solution. Laboratory sheets composed of lignocellulosic fiber networks were prepared from unbleached and unrefined softwood kraft pulp and further impregnated with suberin fatty acid monomers and cured with maleic anhydride in ethanol solution. The treatment resulted in hydrophobic surfaces, in which the contact angles remained over 120 degrees during the entire measurement. The fiber network also retained its water vapor permeability and enhanced fiber–fiber bonding resulted in improved tensile strength of the sheets. Scanning electron microscopy (SEM) images revealed that the curing agent, together with suberin fatty acids, was evenly distributed on the fiber surfaces and smoothing occurred over the wrinkled microfibrillar structure. High concentrations of the curing agent resulted in globular structures containing betulinol derivates as revealed with time-of-flight secondary ion mass spectrometry (ToF-SIMS). Also, the larger amount of suberin fatty acid monomers slightly impaired the optical properties of sheets

Kvalitetsarbete vid kontinuerligt enstycksflöde hos Ferruform

Validerat; 20101217 (root

Byproduct Formation Mechanisms and Effect of Mass Transfer in Plant Sterol Hydrogenation

Plant sterols, a mixture of several des-4-methyl sterols, were hydrogenated over a Pd/C catalyst by varying catalyst amount and stirring rate. Reactions were carried out under kinetic regime and under the influence of external mass transfer limitations. All reaction were done in the absence of internal diffusion limitations. Under external mass transfer limitations of hydrogen more byproducts due to hydrogenolysis and double bond migration were formed. Under mass transfer limited reactions higher catalyst amounts led to a more extensive byproduct formation. Because of double bond migration two very similar byproducts from sitosterol were formed having <i>trans-</i> and <i>cis-</i>fused rings. Interestingly hydrogenolysis also resulted in two similar stereoisomers of sitostane, in the same way as sitostanone, indicating that the hydrogenolysis occurred during the double bond migration when the double bond is in the Δ3 position. An intermediate product of stigmasterol was observed, in which the ring structure is hydrogenated but the alkyl chain double bond is intact, proving that the ring double bond is hydrogenated prior to alkyl chain double bond hydrogenation. The results show that under mass transfer limitation an optimal amount of catalyst should be used to minimize unwanted byproduct formation

Antimicrobial treatments with chitosan microencapsulated angelica (Angelica archangelica) and marsh Labrador tea (Rhododendron tomentosum) supercritical CO2 extracts in linen-cotton jacquard woven textiles

In this study antimicrobial linen-cotton jacquard textiles were manufactured using green chemistry methods. The functionalization of the fabrics was executed by impregnating chitosan microencapsulated bio-based oils from angelica (Angelica archangelica L.) (AAC) and marsh Labrador tea (Rhododendron tomentosum Harmaja) (MLTC) obtained with pilot scale supercritical carbon dioxide extraction. The chemical compositions of the extracts of angelica and marsh Labrador tea were analyzed by a combination of gas chromatography and mass spectrometry. The antimicrobial activities of the extracts, AAC and MLTC microcapsules, and the microencapsulated textiles (AAC and MLTC textiles) were analyzed against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria, dimorphic yeast Candida albicans and filamentous mold Aspergillus brasiliensis. The AAC textile proved 40% inhibition against S. aureus, whereas the MLTC textile demonstrated 43.8% and 51.7% inhibition against both S. aureus and E. coli, respectively. Although the chitosan shell material itself indicated mild activity against both bacterial strains, the extracts increased the antibacterial activities in microencapsulated textiles. In addition, the antifungal impact of the MLTC textile was demonstrated against A. brasiliensis. According to the Fourier transform infrared spectroscopy with attenuated total reflection and field emission scanning electron microscopy analyses, covalent bonding between the microcapsules and textile fibers was established with citric acid as a cross-linker. The antimicrobial activity was also shown to persist in the MLTC textiles after six domestic washing cycles.In this study antimicrobial linen-cotton jacquard textiles were manufactured using green chemistry methods. The functionalization of the fabrics was executed by impregnating chitosan microencapsulated bio-based oils from angelica (Angelica archangelica L.) (AAC) and marsh Labrador tea (Rhododendron tomentosum Harmaja) (MLTC) obtained with pilot scale supercritical carbon dioxide extraction. The chemical compositions of the extracts of angelica and marsh Labrador tea were analyzed by a combination of gas chromatography and mass spectrometry. The antimicrobial activities of the extracts, AAC and MLTC microcapsules, and the microencapsulated textiles (AAC and MLTC textiles) were analyzed against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria, dimorphic yeast Candida albicans and filamentous mold Aspergillus brasiliensis. The AAC textile proved 40% inhibition against S. aureus, whereas the MLTC textile demonstrated 43.8% and 51.7% inhibition against both S. aureus and E. coli, respectively. Although the chitosan shell material itself indicated mild activity against both bacterial strains, the extracts increased the antibacterial activities in microencapsulated textiles. In addition, the antifungal impact of the MLTC textile was demonstrated against A. brasiliensis. According to the Fourier transform infrared spectroscopy with attenuated total reflection and field emission scanning electron microscopy analyses, covalent bonding between the microcapsules and textile fibers was established with citric acid as a cross-linker. The antimicrobial activity was also shown to persist in the MLTC textiles after six domestic washing cycles

COST strategic workshop : health and the natural outdoors - final report

There is a convincing evidence base that confirms the benefits to human health and well-being of close contact with nature, animals and plants. A COST Strategic Workshop was held in April 2007 in Larnaca, Cyprus. Its purpose was to identify the extent of knowledge in this field and the implications for policy and for future research. The Workshop found that nature-based approaches can contribute significantly to health objectives in Europe by ensuring that people have contact with nature in their everyday lives and that nature would be an integral feature of health care environments and approaches. More effective coordination and communication of existing knowledge and understanding, combined with increased investment in new research, is necessary to capitalise on the benefits of nature-based approaches.peer-reviewe