Michel Grisel

• Professor
• Professor (Full) at Université Le Havre Normandie

This study presents an innovative method for encapsulating α-tocopherol (TOCO) by complex coacervation, employing diisopropyl adipate as the carrier oil, and combining fungal chitosan (FC) with gum Arabic (GA) as biopolymers. This research specifically integrates tannic acid (TA), a naturally occurring and multifunctional polyphenol, as a cross-lin...

Encapsulation revolutionizes industries through enhanced stability, controlled release, and targeted performance of active ingredients. The novel aspect of this study explores the impact of the wall material-to-active (WM:A) ratio on the stability of ascorbic acid (AA) encapsulated in a maltodextrin (MD) and gum arabic (GA) blend (2:1 w/w). Micropa...

Characterizing molecular interactions at the microscopic level remains difficult and, therefore, represents a key target to better understand macromolecule and biomacromolecule behaviors in solution, alone, or in mixtures with others. Therefore, accurate characterization in liquid media, especially in aqueous solutions, without causing any perturba...

Lignins, heterogeneous assemblies of polyphenolic oligomers present in lignocellulosic plant biomass, are valorized mainly by combustion because of their low solubility in commonly used solvents. However, in addition to antioxidant, anti‐UV and antimicrobial properties, and marked interfacial properties are part of lignins physicochemical propertie...

The research reported in this paper concerns the examination of the ability to dye cotton textiles with plant-derived colorants in the presence of various natural additives. For this purpose, cotton textile samples were dyed with commercially available plant-derived dyes, which are usually used for food application, using a cold dyeing process in a...

The research aimed to dye silk satin textiles with a plant-derived colorant in the presence of additives of natural origins, such as chitosan and shellac, to investigate whether they can dye silk textiles with satisfactory results. In this study, a series of mechanical properties (Young modulus, elongation at break, and tensile strength), and color...

The cosmetics industry is searching for efficient and sustainable substances capable of stabilizing emulsions or colloidal dispersions that are thermodynamically unstable because of their high surface energy. Therefore, surfactants are commonly used to stabilize the water/oil interface. However, the presence of a surfactant is not always sufficient...

In the automotive sector, the use of nonwoven preforms consisting of natural and thermoplastic fibers processed by compression molding is well known to manufacture vehicle interior parts. Although these natural fiber composites (NFCs) have undeniable advantages (lightweight, good life cycle assessment, recyclability, etc.), the latter release volat...

Application of plant-derived colorants in products, i.e., cosmetics or food, apart from imparting the desired color without harming the environment, may provide other benefits. Valuable ingredients in cosmetic formulations include antioxidants showing an advantageous effect on the skin by neutralizing free radicals that accelerate the aging process...

Objective: Fatty esters are known for their versatility, but in addition to their performance as emollients, emulsifiers, solubilizers, or dispersing agents, they have to meet more and more criteria to be used in cosmetic products. Thus, their olfactory characteristics are expected to be as neutral as possible. However, despite a step of deodoriza...

Nowadays, there is a growing demand for effective cosmetic skincare products that can address the specific skin problems of consumers. Delivery systems play an important role in the effective action of cosmetic skincare formulations. Delivery systems are attractive and smart technologies used as carriers for cosmetic ingredients, which are sensitiv...

This research aimed to dye leather fabric samples with the application of plant-derived colorants and natural additives. Two grades of chitosan were used as additives, in addition to caffeine, nettle extract, and shellac solution. The ability of colorants to dye leather fabric and the impact of additives on leather fabric properties such as structu...

Xanthan gum (XG) was modified through esterification using various alkenyl succinic anhydrides in green media. FTIR and NMR spectroscopy confirmed that the alkenyl succinic hydrophobic groups were successfully grafted on octenyl-grafted (XG-C8), dodecenyl-grafted (XG-C12), and hexadecenyl-grafted (XG-C16) xanthan backbone. Grafted chains were evalu...

This review provides a report on properties and recent research advances in the application of plant-derived colorants in food, cosmetics and textile materials. The following colorants are reviewed: Polyphenols (anthocyanins, flavonol-quercetin and curcumin), isoprenoids (iridoids, carotenoids and quinones), N-heterocyclic compounds (betalains and...

The objective was to investigate the influence of synergism between xanthan gum (X) and galactomannans (guar gum (G) and locust bean gum (L)) on the stickiness of the film formed after the application of polysaccharides on a surface. The adhesion of the film was evaluated using a texture analyzer. X, G, and L were examined in concentrated solutions...

Background: This is a study about the skin aging exposome, focusing on the effect of cigarette smoke. Human living skin explants (HSE) were exposed to cigarette smoke (CS) of two cigarettes for 2 hours using a custom-made exposure chamber, the Pollubox®. Effects on the surface physico-chemistry and molecular properties of the skin were analyzed an...

The high thickening properties of pristine xanthan (PX) were combined with the interfacial stabilizing properties of hydrophobically modified xanthan (HMX) in order to obtain stable oil-in-water (O/W) emulsions. It was demonstrated that such a combination led to stable emulsions in which properties were higher than the sum of those of PX and HMX ta...

This study focuses on the fate of excipients contained in topical emulsions once applied on the skin. The aim was thus to develop a methodology to characterize the residue left on the skin shortly after emulsion application. To this end, both the role and the impact of the different excipients on the formation and properties of the residue left on...

An original non-biological skin model has been developed to mimic skin surface properties. This skin model presents several improvements when compared to existing ones: it has a topography identical to in vivo skin and a lipid composition close to skin face. This imparts to the model surface a physico-chemistry similar to in vivo skin. Concept and...

In many applications such as cosmetics, emulsions are largely developed thanks to organic surfactants which lower the interfacial oil/water tension thus enhancing dispersions stability. However, molecular organic surfactants may be toxic to the skin as well as cause environmental contamination issues. The objective of the present work is to develop...

The impact of xanthan chemical modification under both ordered and disordered conformations on oil-in-water (O/W) emulsion stabilization was investigated. While both hydrophobically modified xanthan (HMX) are able to stabilize the O/W interface, a dramatic difference was observed macroscopically. When HMX ord (ordered conformation) could produce st...

Background The work is aimed at the development of a methodology to characterize the tactile properties of topical products during application. Specific attention was paid to the study of the residual properties left at the surface of the skin. This approach was interestingly used to better understand the formulation factors governing the skinfeel...

The effect of urban pollutants on skin properties has been revealed through several epidemiological studies. However, comprehension of involved mechanisms remains undetermined. In addition, the impact of such stressors on skin surface properties, especially skin physico-chemistry has not been investigated. Consequently, the present study aims to de...

Physico-chemical properties such as surface free energy, polarity or hydrophobicity of solid surfaces have been largely studied in literature because they are involved in many physical phenomena: adhesion, friction, wetting … Nowadays, the study of biointerfaces is of great interest for the medical, the pharmaceutical or the cosmetic field but also...

Prediction of sensory texture attributes using instrumental measurements is a very important challenge for cosmetic industry because in vivo sensory studies are expensive, time consuming and limited by the safety issue of applied products. The aim of this work is to investigate how residual sensory properties of cosmetic products can be predicted w...

Objective The sensory perception of cosmetic emulsions is complex as it is governed by an important number of parameters like the choice of raw materials, their interactions, the structural organisation of the system, etc. The aim of the present work was to go further in the interpretation of the emollient‐surfactant interactions, towards the emuls...

Oil-in-water (O/W) emulsions were prepared using exclusively a hydrophobically modified xanthan (HMX) under ordered conformation without any surfactant. A series of HMX differing in grafting density were utilized at different concentrations. It was demonstrated that HMX stabilizes O/W emulsions where pristine xanthan do not. Indeed, in some cases,...

The present research focuses on the alkyl polyglucoside, a non-ionic surfactant, in combination with a fatty alcohol of the same chain length used as a co-surfactant. A series of solutions were prepared, with varying both APG/FA ratio and its concentration in water. Different structures were then obtained, depending on these two parameters: aqueous...

The impact of the chain stiffness on physicochemical properties has been studied by chemical modification of xanthan under both ordered and disordered conformations. Corresponding rheological properties were studied and results showed that amphiphilic xanthan exhibited completely different behaviors depending on its conformation during modification...

Using the Spectrum Descriptive Analysis method, the present work defines a methodology developed in order to discriminate and characterize cosmetic oil-in-water emulsions as well as their respective aqueous phases containing xanthan gum. The objective was to describe and understand how composition parameters govern texture perception, through the s...

In the present study the effect of cosmetic emollients (oils and esters) varying from their chemical structure on the lamellar liquid crystals organization has been investigated. The cetearyl alcohol/cetearyl glucoside emulsifier, known for its ability to form lamellar phases was used at a level of 10% in emulsions. At this high concentration a str...

The impact of two differently coated TiO2-nanoparticles (NPs) was evaluated on two representative bacteria from the cutaneous microbiota (Staphylococcus aureus and Pseudomonas fluorescens) in conditions of use. Particles were coated in order to exhibit either hydrophilic or hydrophobic behavior. A first exposure scenario within some fresh/aged mode...

The study focuses on the impact of structural and physicochemical properties of emollients on their spreadability. Fifty-three emollients, among which esters, silicones, vegetable and mineral oils, have been characterized. Their viscosity, surface tension, density and spreadability have been measured. Vitro-skin®, an artificial skin substitute, was...

In this chapter, we look at the current trends and challenges in natural polymers in industry and give some perspectives for the future. We look at the technologies in development with regards to natural polymers’ applications in industry today, identify some limitations in applications and processing, and propose some approaches to address such. T...

Cosmetic and personal care products are complex mixtures intended to be applied to the external parts of the human body. In the long list of ingredients are included polymers which are either natural or synthetic. This chapter presents the main natural polymers used in cosmetics which are mainly polysaccharides and proteins obtained from vegetable,...

Titanium dioxide (TiO2) nanoparticles (NP) are commonly used in cosmetics as UV filters. For cosmetic grades, coatings (silica or alumina) are applied to prevent TiO2 from forming radicals. These coatings procure to the NP their surface properties (polarity ,charge) and impose their behavior in emulsion. HAL Id: hal-02468129 https://hal-normandie-u...

In this study, we investigate the shear viscoelasticity of xanthan and hydrophobically modified xanthans at silicone oil/water interface. Xanthan is well known to adopt two distinct conformations in water solution, a rigid conformation at low temperature and a flexible one at high temperature. Hence, we first studied the un-modified xanthan as a fu...

Model emulsions were developed with or without commercial titanium dioxide nanoparticles (NP) carrying various surface treatments in order to get close physicochemical properties whatever the NP surface polarity (hydrophilic and hydrophobic). Rheology and texturometry highlighted that the macroscopic properties of the three formulated emulsions wer...

The behavior of flax fibers was investigated at temperatures of 80 °C, 200 °C, 215 °C, and 230 °C for a period of 60 min. First, thermogravimetric and colorimetric analyzes were carried out to characterize the impact of the temperature on the weight loss and the color of the fibers. Then, the release of volatile and odorous compounds from flax fibe...

After carrying out an ethnomedical survey which has showed an intensive use of Commiphora africana as traditional healing medicinal plant in Mauritania [1], we chose to investigate the oleoresin as the mostly used by Mauritanian healers. Oleoresin from identified plant has been collected in from 4 Mauritanian localities and extracted with the aid S...

An easy ethnomedicinal method, applicable to classify plant parts and healed symptoms have been developed. It may allow a rational choice of the most promising parts and efficiently adequate biotests. Since Commiphora africana is insufficiently investigated and Mauritanian ethnotherapy uses it to heal several symptoms, we applied this method to cla...

Filament stretchability of xanthan gum (XG) and hydroxypropyl guar (HPG) was investigated in aqueous solutions (0.125, 0.25, 0.5, 1, 1.2 and 1.5% w/w) and in O/W emulsions using a texture analyzer. Additionally, rheological characterizations were carried out on the systems and shear and oscillation parameters were used to interpret stretching prope...

Hydrophobic octyl moieties have been grafted in various densities onto the carboxylic acid functions of xanthan under its ordered conformation. The outcoming amphiphilic and associative properties were studied by fluorescence spectroscopy and rheology. Results showed that the conformation of xanthan is not affected by the chemical modification, and...

Formulations incorporating different cosmetic grade TiO2 nanoparticles were developed according to a self-produced protocol on the basis of typical sunscreen cream oil-in-water emulsions. Role of nanoparticles and, more specifically, the impact of two different lipophilic surface treatments on microstructure and stability of the formulations were a...

The filament stretching properties of various polysaccharides (including xanthan, carob, hydroxypropyl guar, hydroxypropylmethyl and hydroxyethyl celluloses) were investigated and compared to synthetic polymers generally used as texturing agents in cosmetic emulsions. The stretchability was examined by sensory evaluation as "the amount of sample th...

The objectives of the study were to investigate the effect of various polymers on both the rheological and mechanical properties of cosmetic O/W emulsions on one hand, and to investigate the relationships between rheological and textural parameters of the emulsions on the other hand. For this purpose, eight hydrophilic polymers, either natural (e.g...

A methodology, particularly well adapted to the evaluation of cosmetic creams containing various texturing agents, is defined here using the S pectrum D escriptive A nalysis method. The objectives were to describe and to understand the contributions of the texturing agents to the texture attributes of oil‐in‐water emulsions. The study focused on ei...

This study deals with the impact of emollients on the spreading properties of cosmetic products using a combined sensory-instrumental approach. To that purpose, three esters and one silicone were selected and incorporated separately into an oil phase. Different cosmetic o/w emulsions were then prepared with these different oil phases. Both of them...

Xanthan gum (GX) and acacia gum (GA) are widely employed in food industry, indeed xanthan gum is used for its thickening properties of aqueous solutions and acacia gum for its emulsifying ability. The present work aims to study the effect of GX–GA mixtures on the stability of oil-in-water (o/w) emulsions; attention is particularly focused on the im...

Dealing with the latest information on polysaccharide gum research, particularly focused on gum Arabic, as discussed at the World Conference on "New developments in Acacia Gums Research and Products", this book covers the production, identification, classification and application of these important carbohydrate polymers. Written by the world's lead...

Five samples of Acacia senegal gum were selected because of their different emulsifying properties. Acacia gum samples were first characterized by various analytical methods including intrinsic viscosity and arabino-galactan protein amount as determined by gel permeation chromatography. In a second step, stability of emulsions containing orange ess...

This work aims to point out the influence of the polymer surface layer on the adhesion of polymer matrix composites. To this end, correlations between surface parameters (chemistry, roughness, wettability, morphology, etc.) resulting from several surface treatments or preparations and single lap shear tests are performed. The results presented here...

The aim of this paper was to link physico-chemical characteristics of both xanthan and guar gums with the behaviour of aroma compounds in model systems. The chemical compositions of guar gums and xanthan gums were determined from several commercial samples. The guar samples differed mainly in their mannose/galactose (M/G) ratio, which varied from 1...

The present work describes the validation of an easy, fast and efficient precolumn derivatization method for the quantification of oligosides, mannose and galactose obtained by degradation of galactomannans. This work combines an acid hydrolysis and an enzymatic degradation of natural galactomannans with the quantification of released residues by r...

The viscoelastic properties of schizophyllan, a neutral fungal polysaccharide, were studied in presence of small amounts of borate ions. We observed the ability to get physical gels as the result of the complexation between the diol sites of the biopolymer and the borate ions, leading to the establishment of a tridimensional network. Kinetic of gel...

The choice of a manufacturing process is of primary importance to control composite materials properties and optimize their performance. Moreover, various parameters of a given implementation may also modify these properties in a significant way. Hence, this paper aims to underline the role of tool preparations in an autoclave process of composite...

In spite of numerous studies and abundant literature, xanthan(X)/galactomannan(GM) interactions still remain controversial while such mixtures have been intensively employed for a long time. The present work aims to bring new highlights on the nature of the interactions involved between both polysaccharides through an original approach: the behavio...

Nowadays the interest of surface preparation in order to manufacture lighter bonded assemblies is well recognized. However only few study dealing with ageing of bonded composite assembly is described in the literature. The present paper mainly aims to compare the influence of the polymer surface thickness of carbon/epoxy composites on the adhesion...

It is well establishment that polysaccharides are commonly used in many fields of formulation such as food and cosmetic industries as viscosity modifiers or gelling agents. Among the different impacts on the mixture properties, these materials are also known to affect the aroma release or retention thus its sensory perception; the effect depends wh...

Wettability of glass/epoxy and carbon/epoxy composites materials has been determined via sessile drop technique. Good–Van Oss approach has been used to evaluate surface free energy parameters of smooth and rough surfaces. Results obtained point out the influence of fibre reinforcement on surface free energy of composite materials. In addition, the...

The gas/liquid partition coefficient (K) of aroma compounds was measured in pure polysaccharide solutions and in polysaccharide mixtures, using the Phase Ratio Variation method. With this method, the retention in 0.1% and 0.02% polysaccharide concentrations was determined. The results showed that in semi-dilute regime (0.1%) all solutions and mixtu...

The use of an excimer laser treatment, as a way to control the adhesion performances of glass/epoxy and carbon/epoxy composites has been investigated. Such a specific surface treatment can provide a selective removal of the organic matrix without any degradation of fibre reinforcements.Then, the influence of such treatments has been studied through...

Introduction Why Treat a Composite Surface?Available Treatments for Composite SurfacesMaterials and Methods Composite MaterialsSurface AnalysesSingle Lap Shear TestsResults and Discussion Why Excimer Laser Treatment?Excimer Laser Surface Treatment Surface CharacterizationMechanical TestsConclusion References Why Treat a Composite Surface?Available...

This study aimed to elucidate the mechanisms governing the release of limonene from model matrices in aqueous xanthan solutions. The aroma compound release behaviour from the matrices has been linked with both the rheological and the surface tension properties of the solutions. Considering the limonene release as a function of the polymer concentra...

Glass/epoxy and carbon/epoxy composites were manufactured using a series of polyester and polyamide based peel ply treatments. The influence of peel ply removing upon surface characteristics was assessed with performing contact angle measurements, laser profilometry, SEM and ToF-SIMS analysis.The surface properties of the composite material prior t...

The mechanisms governing adhesion are often complicated as adhesion properties depend on several physical and chemical parameters. Owing to the growing importance of adhesion in several fields of research, there are an increasing number of studies in the hope to bring a better understanding of these phenomena. The aim of the present paper is to sho...

AbstractThis study deals with the effect resulting from the association of pentaerythritol with flax fibres in an intumescent PP/Fibre/ammonium polyphosphate/pentaerythritol/melamine system. This consists only in a preliminary to prove the efficiency of intumescent additives systems in polyolefin/flax composites considering the fire behaviour and t...

A detailed study of limonene release behaviour from water-based low-concentration polysaccharide solutions and weak gels is reported. On the one hand, rheological measurements made it possible to characterize xanthan (X) and galactomannan [guar gum (G) and carob gum (C)], alone or mixed together. On the other hand, release behaviour of limonene fro...

Instabilities appearing in the circular Couette flow with a dilute or semidilute solution of high molecular weight polyethyleneoxide in water have been investigated when the outer cylinder is kept at rest. The shear-thinning behavior of solutions was determined through low shear viscosity measurements. We have found that, depending on concentration...

We report the behavior of polyethyleneoxide/water solutions in the Couette-Taylor system when the outer cylinder is fixed. For low concentrations, Taylor Vortex Flow (TVF) followed by Wavy Vortex Flow (WVF) are observed, as for Newtonian fluids. For more concentrated solutions the flow undergoes a transition from the base azimuthal Couette Flow to...

The water soluble fraction of peeled prickly pear nopals called native sample (NS) has been characterised mainly by SEC/MALLS analysis. Two main components have been identified: one with high average molar mass (Mw of 13×106gmol−1) called the high weight sample (HWS), the other being a low Mw fraction (LWS). After extensive ultra filtration of NS,...