Determination of CMCs – Results from CESIO/TEGEWA Working Groups / Joachim Venzmer in SOFW JOURNAL, Vol. 146, N° 3 (03/2020)  

[article]  inSOFW JOURNAL > Vol. 146, N° 3 (03/2020) . - p. 60-65 Titre : Determination of CMCs – Results from CESIO/TEGEWA Working Groups Type de document : texte imprimé Auteurs : Joachim Venzmer, Auteur Année de publication : 2020 Article en page(s) : p. 60-65 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Concentration micellaire critique Surfactants Tension superficielle Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : Because of the trend towards “micellar” formulations, surfactant manufacturers often get requests to prove the existence of micelles and/or provide values for Critical Micelle Concentrations (CMC). Therefore, the CESIO Working Group “Test Methods of Surfactants” and the TEGEWA Working Group "Surface Active Substances" have conducted round robin tests using “technical” surfactants, i.e. surfactants having alkyl chain length distributions : A) fatty alcohol ethoxylates with 9EO and different alkyl chain lengths (C12-C18) and B) two alkylamidopropyl betaines (coco vs. C12). The methods employed were the standard procedures established in industry, e.g. Wilhelmy Plate, du Noüy Ring or Pendant Drop. Two aspects have been the focus of this work : A) the effect of alkyl chain length variations on the CMC values, and B) the influence of the experimental procedures on the results of the surface tension measurements. There is indeed a significant influence of the experimental procedure on the surface tension values – especially for surfactants with broad alkyl chain distribution. Since these differences are mostly below CMC, the values of the CMCs itself are somewhat consistent. However, giving more “precise” values than one significant digit does not make much sense. But this should be sufficient, since in practical applications one is always well above CMC. Note de contenu : - Fig. 1 : Surface tension of C12/14E9 as a function of concentra-tion; filled symbols in blue: Automated CMC by stepwise addition of surfactant stock solution to water; filled symbols in brown: Pendant Drop method of individually prepared surfactant solutions; open symbols: Automated „reverse“ CMC. (Different shapes are a code for the different participants, e.g. data D, E and L have been determinded in the same laboratory) - Fig. 2 : Surface tension of C12-18E9 as a function of concentra-tion; filled symbols in blue: Automated CMC by stepwise addition of surfactant stock solution to water; filled symbols in brown: Pendant Drop method of individually prepared surfactant solutions; open symbols: Automated „reverse“ CMC. (Different shapes are a code for the different participants, e.g. data D, E and L have been determinded in the same laboratory) - Fig. 3 : Surface tension of C10E9 as a function of concentration; filled symbols in blue: Automated CMC by stepwise addition of surfactant stock solution to water; filled symbols in brown: Pendant Drop method of individually prepared surfactant solutions; open symbols: Automated „re-verse“ CMC. (Different shapes are a code for the different participants, e.g. data D, E and L have been determinded in the same laboratory) - Fig. 4 : Surface tension of C18E9 as a function of concentration; filled symbols in blue: Automated CMC by stepwise addition of surfactant stock solution to water; filled symbols in brown: Pendant Drop method of individually prepared surfactant solutions; open symbols: Automated „re-verse“ CMC. (Different shapes are a code for the different participants, e.g. data D, E and L have been determinded in the same laboratory) - Fig. 5 : Surface tension of LAPB (brown) and CAPB (blue) as a func-tion of concentration using the Pendant Drop Method; (Different shapes are a code for the different participating laboratories) - Fig. 6 : Surface tension of LAPB as a function of concentration; filled symbols in blue: Automated CMC by stepwise addition of surfactant stock solution to water; filled symbols in brown: Pendant Drop method of individually prepared surfactant solutions; open symbols: Automated „reverse“ CMC. (Different shapes are a code for the different participants, e.g. data E, L and N have been determinded in the same laboratory) - Fig. 7 : Surface tension of CAPB as a function of concentration; filled symbols in blue: Automated CMC by stepwise addition of surfactant stock solution to water; filled symbols in brown: Pendant Drop method of individually prepared surfactant solutions; open symbols: Automated „reverse“ CMC. (Different shapes are a code for the different participants, e.g. data E, L and N have been determinded in the same laboratory) En ligne : https://drive.google.com/file/d/1VV58Fyw_nkcAQQ29o1Z4x2ObA6dNwzTv/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33829 [article]

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Determination of surface tension of surfactant solutions from a regulatory perspective / Joachim Venzmer in SOFW JOURNAL, Vol. 149, N° 10 (10/2023)  

[article]  inSOFW JOURNAL > Vol. 149, N° 10 (10/2023) . - p. 32-39 Titre : Determination of surface tension of surfactant solutions from a regulatory perspective Type de document : texte imprimé Auteurs : Joachim Venzmer, Auteur Année de publication : 2023 Article en page(s) : p. 32-39 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Concentration micellaire critique Epaississants Solubilité Surfactants Tension superficielle Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : Determining the surface tension of surfactant solutions sounds simple, and the state of the art for decades has been Pendant Drop Tensiometry (Drop Shape Analysis). According to DIN/EN/ISO standards and OECD guidelines, the only legally existing methods in the field of surfactants are the ring/plate methods, basically from the pre-computer era. For many technical surfactants and especially for surface-active polymers, these vintage methods have serious technical shortcomings caused by an inherently uncontrolled surface age. This will be demonstrated by discussing the surface tension results of two associative thickeners. Normalization activities have been initiated to „legalize“ the current state of the art, Pendant Drop Tensiometry, also in the field of surfactants. Note de contenu : - History - Wilhemly and du Noüy - State of the art : Drop shape analysis - Solubility in water as prerequisite - Determination of Critical Micelle Concentration (CMC) - Interpretation of the surface tension results - Examples : Associative thickeners - Normalization activities En ligne : https://drive.google.com/file/d/1h_k7klQOAVpEOzIhF4cN8QywiXBxRVzi/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40099 [article]

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Elaborer des formules lavantes fortement chargées en huile / Uta Kortemeier in EXPRESSION COSMETIQUE, N° Hors série (12/2015)  

[article]  inEXPRESSION COSMETIQUE > N° Hors série (12/2015) . - p. 329-333 Titre : Elaborer des formules lavantes fortement chargées en huile Type de document : texte imprimé Auteurs : Uta Kortemeier, Auteur ; Peter Schwab, Auteur ; Jochen Kleinen, Auteur ; Christian Hartung, Auteur ; Joachim Venzmer, Auteur Année de publication : 2015 Article en page(s) : p. 329-333 Langues : Multilingue (mul) Catégories : Cheveux -- Soins et hygiène Conditionneurs (cosmétique) Formulation (Génie chimique) Huiles et graisses Hydrophobie Hygiène Peau -- Soins et hygiène Produits nettoyants shampooings Surfactants Index. décimale : 668.5 Parfums et cosmétiques Résumé : Evonik a récemment développé un système innovant de tensioactifs structurés qui utilise des quantités relativement faibles de tensio-actifs hydrophobes, tels que les dialkyl-sulfosuccinates, permettant l'incorporation de niveaux exceptionnellement élevés d'huile (jusqu'à 50%), tout en combinant de bonnes propriétés moussantes pour des textures douces et esthétiques. Flexible, ce système permet de travailler avec un large choix d'huiles cosmétiques - à des concentrations variables - et de tensioactifs. Résultats : concevoir des produits d'hygiène 2 en 1 réellement innovants où la dimension soin est forte, et ce malgré l'absence de sulfate d'éther alkyle. Note de contenu : - Des systèmes de tensioactifs structurés - Nettoyants pour le corps - Soins capillaires - shampoings conditionneurs relipidants/conditionneurs lavants En ligne : https://drive.google.com/file/d/1T_m7YGrX2xLOP4oWwX28jciYDYPkzsYs/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=25175 [article]

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Fact and fancy about lamellar emulsions - A closer look inside / Sebastian Johannes Beckers in SOFW JOURNAL, Vol. 148, N° 3 (03/2022)  

[article]  inSOFW JOURNAL > Vol. 148, N° 3 (03/2022) . - p. 40-44 Titre : Fact and fancy about lamellar emulsions - A closer look inside Type de document : texte imprimé Auteurs : Sebastian Johannes Beckers, Auteur ; Achim Friedrich, Auteur ; Joachim Venzmer, Auteur Année de publication : 2022 Article en page(s) : p. 40-44 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Emulsifiants Emulsions -- Emploi en cosmétologie Ester de polyglycérol Formulation (Génie chimique) Ingrédients cosmétiques Stabilisants (chimie) Index. décimale : 668.5 Parfums et cosmétiques Résumé : Motivated by the hype about lamellar emulsions, we wanted to take a closer look at the microstructure of modern cosmetic emulsions stabilized by polyglycerol ester emulsifiers. Previously, we have developed a structure model of an emulsion stabilized by a polyglycerol ester emulsifier and consistency enhancers by using a number of highly specialized (e.g. scattering) methods. According to these results, the oil droplets are surrounded by several, irregularly spaced bilayers consisting of emulsifier and consistency enhancer. We now have extended this work to four alternative polyglycerol ester emulsifiers by using Cryo-TEM to study the microstructure of model emulsions. In none of the cases there was evidence for areas of stacked bilayers, i.e. a lamellar phase or multilamellar vesicles, which could be recognized by birefringence (e.g. Maltese crosses) in polarization microcopy if they were present. Such lamellar phases or multilamellar vesicles can be generated by overdosing the emulsifier, or could be a consequence of incomplete mixing. Therefore, polarization microcopy results can hardly be an indication for superior application performance and should not be confused with claim substantiation. Note de contenu : - What are "lamellar emulsions" ? - Molecular architecture determines the types of surfactant aggregate - What are "lamellar emulsions" ? - A deep dive into the structure of o/w-emulsions - How general are these findings ? - Table 1 : Composition of the model formulations used En ligne : https://drive.google.com/file/d/1JL2FPEpk72Y5haOaLVqKS2Bg25aOCO7z/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37195 [article]

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HLB – Alternative concepts / Arjan Gelissen in SOFW JOURNAL, Vol. 146, N° 12 (12/2020)  

[article]  inSOFW JOURNAL > Vol. 146, N° 12 (12/2020) . - p. 24-28 Titre : HLB – Alternative concepts Type de document : texte imprimé Auteurs : Arjan Gelissen, Auteur ; Renke Rommerskirchen, Auteur ; Joachim Venzmer, Auteur Année de publication : 2020 Article en page(s) : p. 24-28 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Emulsions Equilibre hydrophile-lipophile Inversion de phase (chimie) Microémulsions Surfactants Index. décimale : 660.2 Génie chimique Résumé : Alternative classification concepts of emulsifiers have to cope with HLB’s main flaw, which is assigning a single, “universal”, calculated number to an emulsifier, as discussed in our previous paper. For emulsions, the influence of the oil phase needs to be considered as well as temperature, pH or salinity. Both alternatives to HLB discussed here make use of a thermodynamic equilibrium state as a reference – in case of oil/water/surfactant this means a microemulsion. The Hydrophilic-Lipophilic Deviation (HLD) describes the deviation of an entire formulation of water, oil, and a surfactant from the optimum, balanced reference state. From this the characteristic curvature (Cc) of surfactants can be determined, which is a number that describes their hydrophilicity or hydrophobicity. In contrast, the PIT-slope method characterizes the hydrophilicity/hydrophobicity of a surfactant in relation to C10E4 in an octane/water system; therefore, it is also able to capture all effects of molecular structure of the surfactant. Note de contenu : - Basics – Emulsions and microemulsions - HLD - PIT-slope - Table 1 : General differences between (macro-)emulsions andmicroemulsions - Fig. 1 : Idealized fish diagram of oil/water/surfactant to explain the formation of microemulsions - Fig. 2 : Optimum salinity of di-hexyl sulfosuccinate sodium salt with varying EACN at 25°C En ligne : https://drive.google.com/file/d/1aqygJ7v---6UJbl2KRfLgg3Fbk3GJFAu/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35005 [article]

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HLB - Sense or nonsense ? / Joachim Venzmer in SOFW JOURNAL, Vol. 146, N° 10 (10/2020)  

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Micellar formulation - Old wine in new skins ? / Kathrin Brandt in SOFW JOURNAL, Vol. 146, N° 3 (03/2020)  

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Thickening and foaming performance of surfactant formulations / Jochen Kleinen in SOFW JOURNAL, Vol. 150, N° 4 (04/2024)  

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Thickening of surfactant formulations using worm-like micelles / Jochen Kleinen in SOFW JOURNAL, Vol. 147, N° 3 (03/2021)  

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Water soluble or not ? A simple question difficult to answer / Joachim Venzmer in SOFW JOURNAL, Vol. 149, N° 10 (10/2023)  

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