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Structure-function relationship in glycolipids for the application of wet foamsThursday (08.10.2020) 15:00 - 15:20 Room 3 Part of:
Growing concern about climate change and increasing environmental awareness are leading to a quest for green chemistry with more sustainable circular processes. Therefore, innovative and sustainable products and production processes are needed. Polymer foams are important products that find a wide variety of uses in industry. A new and innovative possibility for their production offers the use of moist glycolipid foams as a template. Glycolipids are a class of biosurfactants, which have a huge advantage over conventional surfactants as they are not petrochemical-based, can be produced sustainably from renewables, are biodegradable and less harmful to the environment than petrochemical surfactants. They can be produced by microbial synthesis or enzymatically. The latter method offers the advantage of a selective production of a wide variety of different molecule structures and “tailor-made” glycolipids. This provides the possibility to control foam properties as bubble size distribution, foam stability and foam rheology.
In this study, the structure-function-relationship of enzymatically produced glycolipids was investigated regarding different functional groups in the molecules. The influence of polar head groups as glucose, sorbitol, sorbose and glucuronic acid on foaming properties was evaluated. Saturated, unsaturated and branched fatty acids were used as hydrophobic tail-groups. Surface tension and surface elasticity of glycolipid solutions above the critical micelle concentration were measured and foam stability, bubble size distribution, gas volume content and foam rheology were analyzed to characterize the wet foams made of the same solution. Glycolipids with saturated fatty acids showed higher foam stability and a narrower bubble size distribution than those with unsaturated tail groups. Saturated fatty acid esters showed similar or even higher foam stability, independent of the polar head groups applied, than foams stabilized with the commercially available surfactants Tween 60 and Span 20.
This study is part of the research center ZAFH InSeL funded by the European Regional Development Fund and the Ministry of Science, Research and the Arts of the State of Baden-Württemberg.