The challenge in Interface Science is to address various and complex questions within diverse systems
At TECLIS, we like sharing our knowledge of interface science. Our aim is helping you to better understand your scientific problem and to provide you with the best experimental support. Beyond providing reliable and accurate measuring instruments, our desire is above all to bring added value to your research; to guide you; to share and increase our scientific knowledge together.
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No matter your question is about:
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Aqueous Foams, Non aqueous Foams, Oil/water Emulsions, Water/oil Emulsions, Powders...
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Dispersed particles, Transfer of molecules, Membranes, Electrostatics, Sterics, Osmotic pressure, Coalescance....
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Behaviors at interfaces Gas/Liquid, Liquid/Liquid, Solid/Liquid, Adsorption/desorption Kinetics, Equilibrium, Polymerisation, Oxydation, Hydrolysis, Encapsulation...
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Non ionics, Cationics, Anionics Surfactants, Insolubles Surfactants (Phospholipides, Polymers, Fatty acids…), Soluble but with irreversible adsorption (Proteines, Peptides, Particules…)
You have a Research project you would like to discuss? You have a specific question you don't know how to address?
Download our recent application notes
Characterizing foams produced by an external device
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Hands disinfection particularly arose over the covid19 sanitary crisis. Because they are convenient in use and cost-effective, foam dispensers are commonly used to deliver hands- disinfectant in the form of foam. For hands- disinfectant manufacturers, it is of the utmost importance to control the volume of foam delivered by the dispenser and the properties of the foam, such as stability or texture, when it is mashed in the hands.
FOAMSCAN™ foam analyzer enables to characterize the foam properties of foams, generated by dispensers, by measuring 2 key parameters: liquid fraction and foam structure (size and distribution of the bubbles)...
The influence of experiment settings on foaming capacity
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The aptitude of a liquid to form a foam is closely linked to the method used to produce the foam. TECLIS foam analyzers can be used to generate the foam either by bubbling a gas into a liquid through a glass frit, or by mechanical agitation of a liquid.
Each time, the choice of the experiment settings, such as the volume of liquid, the stirring speed rate, the glass frits' porosity, the gas flow rate, the temperature... can influence the results of the measurement...
Standard error, five reasons you should check the drop profile
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The measurement of surface tension/Interfacial using the pendant (or rising) drop method is based on the analysis of the profile of a Laplacian drop. It means that the contour of the drop follows a shape described by the Laplace equation. When the drop is not Laplacian, the calculation of the surface/Interfacial tension by drop shape analysis is made with an error. Therefore, it is the most importance to ensure this standard error is not significant before making the measurement. To assess the value of the standard error, the TRACKER™ Software function “one measurement” analyzes the residuals between the theoretical model and the real profile of the drop...
Interfacial rheology a tool to probe interfaces
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Surface tension is not enough to characterize interfaces…
Interfacial tension is a major parameter in the characterization of the interfacial activity of a molecule. Monitoring Interfacial tension allows, among other parameters:
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to determine if the molecule is surface-active
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to characterize the adsorption kinetics to the interface of the molecule
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in some cases, to determine the interfacial concentration of this molecule
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Impact of frequency, amplitude and concentration on interfacial viscoelastic modulus
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Interfacial dilatational rheology defines a relationship between stress, deformation, and strain rate thanks to elastic and viscous coefficients.
In practice, the interfacial viscoelastic modulus can be written as : E = E′ + E′′ with E' the elastic modulus and E’’ the viscous modulus.
Interfacial rheology measurement is driven by 3 experimental parameters: the frequency and the amplitude of the stress applied and the concentration of the solution...
Interfacial rheology: micro and macro illustrations
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Besides decreasing the value of interfacial tension, the presence of surface-active molecules at a fluid/fluid interface confers rheological properties radically different from the ones exhibited by the equivalent bare interface. The interfacial viscoelastic modulus is hence a powerful parameter for the characterization of fluid/fluid interfaces . At the macro-scale, the properties of foams, emulsions and bubbly liquids such as the stability, the transport and the mechanical behavior strongly depend on their composition and the properties (interfacial tension and viscoelastic modulus) of the fluid/fluid interfaces composing them ...
Dispersity: an indicator to classify the foam dissipation
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Foams describe a large class of material made of gas and liquid. Depending on whether it is desired or not, it is crucial to know the characteristics of the foam in order to orient the formulation towards the desired behavior. In some applications, foam longevity is looked for, whereas a foam that dissipates quickly is wanted . The way the foam dissipates gives precious information and help to rank the different formulations. While aging, foam dissipates by three main mechanisms that are drainage, coalescence and coarsening. Drainage operates due to gravity, coalescence (bubble burst) occurs when the foam film becomes thin enough and coarsening is driven by the difference of pressure between neighboring bubbles...
The deposition of a monolayer of phospholipids at the oilwater interface
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In many areas, monolayers are at the crossroad of interfaces between immiscible phases forming emulsions. There are different types of monolayers which can be surfactants molecules, like lipids, polymers, proteins, asphaltenes, solid particles… Generally one of the 2 immiscible phases is water and the other can be natural oil, alkane of variable chains or volatile solvent like chloroform, toluene… Lipid droplets [1] are organelles consisted of a core of neutral lipids (triglycerides, sterol esters, liposoluble vitamins and a monolayer of phospholipids in which proteins are embedded (involved in regulation, structure, synthesis and lipid mobilization)...
How to control the surface pressure of an interface
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The presence of surface- active molecules at an interface changes its physico-chemical properties. The amplitude of these changes, that can be characterized by surface pressure, depends strongly on the surface concentration.
The surface pressure (Π) is defined as the difference of interfacial tension between a pure interface and an interface in the presence of surface-active molecules...
How to determine the maximum surface pressure of a molecule
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The drop tensiometer TRACKER™ can measure the ability of a molecule to bind an interface, to remain adsorbed and/or to be ejected there. A parameter noted ΠMAX , highlighted by D. Small's research group, allows to determine the maximum pressure that peptide, once established at the interface, can withstand before being ejected back into the aqueous phase...
How to determine the surface exclusion pressure of a molecule
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Lipid-molecule interactions are of crucial importance in many physiological and industrial processes. To better understand these mechanisms and quantify the affinity between a molecule and a lipid monolayer, its exclusion pressure is often determined [1-4].
Πe corresponds to the surface pressure above which a molecule can no longer insert itself at an interface...