Predicting the Surface Tension of Liquids: Comparison of Four Modeling Approaches and Application to Cosmetic Oils

The efficiency of four modeling approaches, namely group contributions, corresponding-states principle, σ-moment-based neural networks, and graph machines, are compared for the estimation of the surface tension (ST) of 269 pure liquid compounds at 25 °C from their molecular structure. This study focuses on liquids containing only carbon, oxygen, hydrogen or silicon atoms since our purpose is to predict the surface tension of cosmetic oils. Neural network estimations are performed from σ-moment descriptors as defined in the COSMO-RS model, while methods based on group contributions, corresponding-states principle and graph machines use 2D molecular information (SMILES codes). The graph machine approach provides the best results, estimating the surface tensions of 23 cosmetic oils, such as hemisqualane, isopropyl myristate or decamethylcyclopentasiloxane (D5), with accuracy better than 1 mN.m–1. A demonstration of the graph machine model using the recent Docker technology is available for download in the Supplementary Information

Glycerol Acetals and Ketals as Bio-based Solvents: Positioning in Hansen and COSMO-RS spaces, Volatility and Stability towards Hydrolysis and Autoxidation

Four recently launched cyclic glycerol acetals or ketals are evaluated as bio-based solvents. Three of them are industrially available and result from the condensation of glycerol with formaldehyde, acetone and isobutyl methyl ketone. The fourth is under development and is prepared by the reaction of glycerol with benzaldehyde under heterogeneous acidic catalysis. Their solvent properties are evaluated through Hansen and COSMO-RS (COnductor-like Screening MOdel for Real Solvents) approaches, in comparison to traditional petrochemical solvents. Dioxolane- and dioxane-type isomers have close solubility parameters; however the nature of the starting aldehyde/ketone significantly impacts the solvency properties. Stability to hydrolysis depends heavily on both the aldehyde/ketone part and on the size of the ring. In acidic medium, acetals are found to be more stable than ketals and glycerol-based ketals are more stable than ethylene glycol-based ketals. In the case of benzaldehyde glycerol acetal, it is shown that the 6-member ring isomer (dioxane-type) is approximately 8 times more stable than the 5-member ring counterpart (dioxolane-type) at low pH. Stability towards autoxidation by O2 is high for formaldehyde and acetone-derived acetals and drops for the other two compounds. Glycerol acetals and ketals are promising potential alternatives to some harmful solvents such as glycol ethers and aniline

Light-driven Pickering interfacial catalysis for the oxidation of alkenes at near-room temperature †

In this study, we have developed an emulsion system combining plasmonic Au-loaded amphiphilic silica nanoparticles (Au/SiO2–C3) and tri(dodecyltrimethylammonium) phosphotungstate ([C12]3[PW12O40]) nanoparticles acting as an on-site photoassisted heater/activator and a catalyst, respectively, at the water/oil interface. The system exhibits a 5-fold increase of activity compared to the thermal reaction for the near-room temperature oxidation of alkenes with H2O2. The nanoparticles show excellent recyclability and structural stability. This study opens an avenue to design multiphase photoreactors for oxidation reactions at mild temperature, with a potential energy saving of 74% compared to that of thermally heated reactors at isoconversion

Acidic Pretreatment of Wheat Straw in Decanol for the Production of Surfactant, Lignin and Glucose

Wheat straw is an abundant residue of agriculture which is increasingly being considered as feedstock for the production of fuels, energy and chemicals. The acidic decanol-based pre-treatment of wheat straw has been investigated in this work. Wheat straw hemicellulose has been efficiently converted during a single step operation into decyl pentoside surfactants and the remaining material has been preserved keeping all its promises as potential feedstock for fuels or value added platform chemicals such as hydroxymethylfurfural (HMF). The enzymatic digestibility of the cellulose contained in the straw residue has been evaluated and the lignin prepared from the material characterized. Wheat-based surfactants thus obtained have exhibited superior surface properties compared to fossil-based polyethoxylates decyl alcohol or alkyl oligoglucosides, some of which are largely used surfactants. In view of the growing importance of renewable resource-based molecules in the chemical industry, this approach may open a new avenue for the conversion of wheat straw into various chemicals

Combining Cellulose and Cyclodextrins: Fascinating Designs for Materials and Pharmaceutics

Cellulose and cyclodextrins possess unique properties that can be tailored, combined, and used in a considerable number of applications, including textiles, coatings, sensors, and drug delivery systems. Successfully structuring and applying cellulose and cyclodextrins conjugates requires a deep understanding of the relation between structural, and soft matter behavior, materials, energy, and function. This review focuses on the key advances in developing materials based on these conjugates. Relevant aspects regarding structural variations, methods of synthesis, processing and functionalization, and corresponding supramolecular properties are presented. The use of cellulose/cyclodextrin conjugates as intelligent platforms for applications in materials science and pharmaceutical technology is also outlined, focusing on drug delivery, textiles, and sensors

A New Synergistic Strategy for Virus and Bacteria Eradication: Towards Universal Disinfectants

In response to the COVID-19 and monkeypox outbreaks, we present the development of a universal disinfectant to avoid the spread of infectious viral diseases through contact with contaminated surfaces. The sanitizer, based on didecyldimethylammonium chloride (DDAC), N,N-bis(3-aminopropyl)dodecylamine (APDA) and γ-cyclodextrin (γ-CD), shows synergistic effects against non-enveloped viruses (poliovirus type 1 and murine norovirus) according to the EN 14476 standard (≥99.99% reduction of virus titer). When a disinfectant product is effective against them, it can be considered that it will be effective against all types of viruses, including enveloped viruses. Consequently, “general virucidal activity” can be claimed. Moreover, we have extended this synergistic action to bacteria (P. aeruginosa, EN 13727). Based on physicochemical investigations, we have proposed two independent mechanisms of action against bacteria and non-enveloped viruses, operating at sub- and super-micellar concentrations, respectively. This synergistic mixture could then be highly helpful as a universal disinfectant to avoid the spread of infectious viral or bacterial diseases in community settings, including COVID-19 and monkeypox (caused by enveloped viruses)

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

Host–guest chemistry is useful for the construction of nanosized objects. Some of the widely used hosts are probably the cyclodextrins (CDs). CDs can form water-soluble complexes with numerous hydrophobic compounds. They have been widespread used in medicine, drug delivery and are of interest for the biocides encapsulation. Indeed, this enables the development of more or less complex systems that release antimicrobial agents with time. In this paper, the general features of CDs and their applications in the field of biocides have been reviewed. As the key point is the formation of biocide–CD inclusion complexes, this review deals with this in depth and the advantages of biocide encapsulation are highlighted throughout several examples from the literature. Finally, some future directions of investigation have been proposed. We hope that scientists studying biocide applications receive inspiration from this review to exploit the opportunities offered by CDs in their respective research areas

Applications des systèmes d’émulsions de Pickering éco-compatibles à base de cyclodextrines

International audienc

16 Pickering emulsions and biomass

International audienceIn this chapter, the main key parameters governing the physicochemistry of the Pickering emulsions are described, with a focus on the utilization of biomass as stabilizing particles of Pickering emulsions and on the use of catalytic Pickering emulsions to convert biomass. The interest of these versatile systems is illustrated in pharmaceutical, cosmetics and food applications notably as drug delivery systems as well as in catalysis for the conversion of glycerol and the production of biodiesel.Dans ce chapitre, les principaux paramètres clés régissant la physicochimie des émulsions de Pickering sont décrits, en mettant l'accent sur l'utilisation de la biomasse comme particules stabilisantes des émulsions de Pickering et sur l'utilisation d'émulsions catalytiques de Pickering pour convertir la biomasse. L'intérêt de ces systèmes polyvalents s'illustre dans les applications pharmaceutiques, cosmétiques et alimentaires notamment comme systèmes d'administration de médicaments ainsi qu'en catalyse pour la conversion du glycérol et la production de biodiesel