Surface tension model for surfactant solutions at the critical micelle concentration

Das

et al. 2018

J Surfact & Detergents

Production of a rhamnolipid biosurfactant (RBS) using discarded mixed bakery waste (BW) employing bacterial strain Pseudomonas aeruginosa strain PG1 (identified by 16 s rDNA sequencing) was investigated for bioconversion of the food waste. Dry and powder form BW was supplemented with mineral salt media (MSM) as a sole carbon source for production of RBS. RBS production was measured based on the drop collapse assay and surface tension (ST) reduction of the culture media. Production of RBS in the culture media was enhanced by optimizing the carbon source (BW) concentration and the proper nitrogen source along with the pH of the MSM. Under optimized culture conditions, 11.56 g L −1 day −1 crude biosurfactant (BS) was achieved. The RBS had the ability to reduce the ST of the optimized MSM from 72.0 to 25.8 mN m −1 during culture, where the critical micelle concentration (CMC) of the biosurfactant was found to be 100 mg L −1 . Liquid Chromatography Mass Spectroscopy (LC-MS), Fourier Transform Infrared spectroscopy (FTIR), and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDS) analyses of the purified BS confirmed that it is of rhamnolipid in nature and it is made up of both monorhamnolipid and dirhamnolipid congeners. Furthermore, the RBS did not express any cytotoxic effect on the cell line of mouse L292 fibroblastic cell indicating the biosafety nature of the high-value biomolecule.

Section: Resultsmentioning

confidence: 99%

Recycling of Bakery Waste as an Alternative Carbon Source for Rhamnolipid Biosurfactant Production

Das

et al. 2018

J Surfact & Detergents

J of Physical Organic Chem

“…Figure represents the surface tension data of compounds 2 to 4 in aqueous solution. The concentration dependence of the surface tension for all compounds has the shape similar to that of ordinary surfactants . All the compounds have different but relatively high CMC values in the range from tens to hundreds of millimolar (Table ).…”

Section: Resultsmentioning

confidence: 99%

Novel type of isoprenoid membrane anchors: an investigation of binding properties with dipalmitoylphosphatidylcholine vesicles

Faizullin

Dzyurkevich

Valiullina

et al. 2016

In this work, we present a new type of amphiphilic membrane‐anchoring agents that can be easily obtained by the Diels‐Alder reaction between terpene myrcene and N‐substituted maleimides. The interaction between the compounds and small unilamellar dipalmitoylphosphatidylcholine vesicles was investigated using infrared spectroscopy, microgravimetry, and turbidimetry. The ability of the compounds to embed in the phospholipid membrane was shown to be strongly dependent on the charge of their polar group. The insertion of the compounds studied into the lipid bilayer did not lead to disruption of the dipalmitoylphosphatidylcholine vesicles up to the highest tested drug to lipid molar ratio of 0.5 to 0.6. Low lipid solubilization ability of the compounds as well as their rigid nonplanar structure makes them an interesting alternative to the common membrane‐anchoring structural motifs.

“…At very low concentrations, the surfactant molecules become adsorbed to the steel surface to form a boundary lubricant layer. At the CMC, the individual molecules begin to aggregate to form micelles in solution, driven by hydrophobic force, so that the contact between the hydrophobic tails of the surfactant and water is limited [51,52]. The CMC decreases with the increasing chain length of the alkyl group, from 250 mM for C6 to 25 mM of C8 and 2.2 mM for C10.…”

Section: Discussionmentioning

confidence: 99%

Macroscopic Friction Studies of Alkylglucopyranosides as Additives for Water-Based Lubricants

et al. 2020

Water-based lubricants might become an interesting alternative to conventional oil-based lubricants and help to reduce wear as well as improve the energy efficiency of transport processes. Since pure water is generally a rather poor lubricant due to its low viscosity and corrosiveness, it must be tribologically optimized with suitable additives. Here, we study the friction behavior of alkyl glucopyranosides (AGPs) with varying lengths of the alkyl chain. Sliding experiments show that a significant reduction in the coefficient of friction compared to that of pure water is observed. The extent of friction reduction depends strongly on the concentration and on the shearing conditions. It is assumed that the low coefficients of friction are due to the ability of AGPs to form liquid crystalline phases with an ordered structure in the friction gap. Furthermore, the interaction of the AGPs with the surface forms a wear protection layer (boundary lubrication). The friction properties of the water-based system are compared to those of a conventional, mineral oil-based lubricant.