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Fayna Mammeri

Bio: Fayna Mammeri is an academic researcher from University of Paris. The author has contributed to research in topics: Nanoparticle & Hybrid material. The author has an hindex of 16, co-authored 46 publications receiving 1325 citations. Previous affiliations of Fayna Mammeri include University of Poitiers & Saint-Gobain.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the properties of hybrid O-I materials are dependent on their micro-and nanostructures and on the nature and extent of the interfaces between the OI interfaces.
Abstract: Homogeneously dispersed organic–inorganic hybrid nanocomposites can be obtained by increasing the interfacial interactions between both components via the formation of hydrogen bonds or covalent bonds, by mixing various polymers or via the adequate choice of the inorganic precursors The mechanical response of these advanced functional materials is an issue of paramount importance when industrial applications are targeted Large progress in the understanding of the mechanical properties of O–I hybrids has been gained by testing these materials under different conditions (static and dynamic, low and large deformations up to fracture) and using specific techniques developed for the mechanical characterization of conventional materials such as polymers, glasses or ceramics However, the mechanical properties of hybrid O–I materials are dependent on their micro- and nanostructures and on the nature and extent of the O–I interfaces Consequently, predictable mechanical properties for hybrids still represent a major challenge for hybrid materials science Industrial attraction for hybrid materials has been emphasized by the development of new functional coatings An important issue is the interface between the film and the substrate since strong adhesion can be tailored and ensures that delamination of the film will be limited

442 citations

Journal ArticleDOI
TL;DR: The scope of the polyol process has been extended to the preparation of more electropositive metals, such as post-transition metals and semi-metals, and the potential of this method is also clearly displayed for the prepared of alloys, intermetallics and core-shell nanostructures with a very large diversity of compositions and architectures.
Abstract: After about three decades of development, the polyol process is now widely recognized and practised as a unique soft chemical method for the preparation of a large variety of nanoparticles which can be used in important technological fields. It offers many advantages: low cost, ease of use and, very importantly, already proven scalability for industrial applications. Among the different classes of inorganic nanoparticles which can be prepared in liquid polyols, metals were the first reported. This review aims to give a comprehensive account of the strategies used to prepare monometallic nanoparticles and multimetallic materials with tailored size and shape. As regards monometallic materials, while the preparation of noble as well as ferromagnetic metals is now clearly established, the scope of the polyol process has been extended to the preparation of more electropositive metals, such as post-transition metals and semi-metals. The potential of this method is also clearly displayed for the preparation of alloys, intermetallics and core–shell nanostructures with a very large diversity of compositions and architectures.

327 citations

Journal ArticleDOI
21 Sep 2010-Langmuir
TL;DR: The as-designed hairy CNTs served as efficient platforms for the in-situ synthesis and massive loading of 3 nm sized palladium nanoparticles (NPs) and exhibited an efficient catalytic effect in the C-C Suzuki coupling reaction.
Abstract: Poly(glycidyl methacrylate), PGMA, was prepared via ATRP in bulk solution, and its epoxy groups were further acid-hydrolyzed in order to obtain a polymer with glycerol moieties (noted POH). The POH chain end C−Br bonds were subjected to a nucleophilic attack by NaN3, resulting in azide-terminated POH (POH−N3). The CNTs were modified by in-situ-generated alkynylated diazonium cations from the para-alkynylated aniline of the formulas H2N−C6H4−C≡C−H, yielding CNT−C6H4−C≡C−H nanotubes. The azide-functionalized polymer POH−N3 was clicked to the alkynyl-modified CNTs giving CNT@POH hybrids, which were further subjected to an oxidation resulting in carboxylated polymer-modified CNTs (noted CNT@PCOOH). The as-designed hairy CNTs served as efficient platforms for the in-situ synthesis and massive loading of 3 nm sized palladium nanoparticles (NPs). The CNT@PCOOH@Pd heterostructures prepared so far exhibited an efficient catalytic effect in the C−C Suzuki coupling reaction and were regenerated up to four times with...

107 citations

Journal ArticleDOI
TL;DR: This review introduces the previous work on magneto-plasmonic hetero-nanostructures and focuses on the most important progress made with regard to their use in nanomedicine, keeping in mind the correlation between their morphology—namely spherical and non-spherical, core-satellite and core-shell, and the desired applications.
Abstract: Iron oxide and gold-based magneto-plasmonic nanostructures exhibit remarkable optical and superparamagnetic properties originating from their two different components. As a consequence, they have improved and broadened the application potential of nanomaterials in medicine. They can be used as multifunctional nanoprobes for magneto-plasmonic heating as well as for magnetic and optical imaging. They can also be used for magnetically assisted optical biosensing, to detect extreme traces of targeted bioanalytes. This review introduces the previous work on magneto-plasmonic hetero-nanostructures including: (i) their synthesis from simple "one-step" to complex "multi-step" routes, including seed-mediated and non-seed-mediated methods; and (ii) the characterization of their multifunctional features, with a special emphasis on the relationships between their synthesis conditions, their structures and their properties. It also focuses on the most important progress made with regard to their use in nanomedicine, keeping in mind the same aim, the correlation between their morphology-namely spherical and non-spherical, core-satellite and core-shell, and the desired applications.

64 citations

Journal ArticleDOI
TL;DR: In this article, the performance of PMMA-SiO 2 based thin films was investigated using nanoindentation, and the structure and the mechanical behaviour were reported for thin films as a function of the fraction of silica.
Abstract: The sol–gel process allows to design hybrid organic–inorganic materials constituted by organic molecules or macromolecules and inorganic metal oxo-polymers interpenetrated at the nanometer scale. These hybrids were deposited as functional coatings with tunable thickness on float glass substrates. Good adhesion and mechanical behaviour of the coatings are required to keep their functionality in time hence; the performance of the PMMA-SiO 2 based thin films was investigated using nanoindentation. This study validates nanoindentation measurements as an appropriate technique to characterize hybrid organic–inorganic thin films, despite visco-elastic behaviours. Specific analysis procedures and the use of appropriate models allowed us to determine the indentation modulus and hardness of the hybrid layers reproductively. The structure and the mechanical behaviour are reported for thin films as a function of the fraction of silica.

57 citations


Cited by
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Journal ArticleDOI
TL;DR: Characterization and Properties 3928 8.2.1.
Abstract: 5. In Situ Polymerization 3907 5.1. General Polymerization 3907 5.2. Photopolymerization 3910 5.3. Surface-Initiated Polymerization 3912 5.4. Other Methods 3913 6. Colloidal Nanocomposites 3913 6.1. Sol-Gel Process 3914 6.2. In Situ Polymerization 3916 6.2.1. Emulsion Polymerization 3917 6.2.2. Emulsifier-Free Emulsion Polymerization 3919 6.2.3. Miniemulsion Polymerization 3920 6.2.4. Dispersion Polymerization 3921 6.2.5. Other Polymerization Methods 3923 6.2.6. Conducting Nanocomposites 3924 6.3. Self Assembly 3926 7. Other Preparative Methods 3926 8. Characterization and Properties 3928 8.1. Chemical Structure 3928 8.2. Microstructure and Morphology 3929 8.3. Mechanical Properties 3933 8.3.1. Tensile, Impact, and Flexural Properties 3933 8.3.2. Hardness 3936 8.3.3. Fracture Toughness 3937 8.3.4. Friction and Wear Properties 3937 8.4. Thermal Properties 3938 8.5. Flame-Retardant Properties 3941 8.6. Optical Properties 3942 8.7. Gas Transport Properties 3943 8.8. Rheological Properties 3945 8.9. Electrical Properties 3945 8.10. Other Characterization Techniques 3946 9. Applications 3947 9.1. Coatings 3947 9.2. Proton Exchange Membranes 3948 9.3. Pervaporation Membranes 3948 9.4. Encapsulation of Organic Light-Emitting Devices 3948

1,915 citations

Journal ArticleDOI
TL;DR: Polyoxometalates (POMs) are discrete anionic metaloxygen clusters which can be regarded as soluble oxide fragments which play a great role in various areas ranging from catalysis, medicine, electrochemistry, photochromism,5 to magnetism.
Abstract: Polyoxometalates (POMs) are discrete anionic metaloxygen clusters which can be regarded as soluble oxide fragments. They exhibit a great diversity of sizes, nuclearities, and shapes. They are built from the connection of {MOx} polyhedra, M being a d-block element in high oxidation state, usually VIV,V, MoVI, or WVI.1 While these species have been known for almost two centuries, they still attract much interest partly based on their large domains of applications. They play a great role in various areas ranging from catalysis,2 medicine,3 electrochemistry,4 photochromism,5 to magnetism.6 This palette of applications is intrinsically due to the combination of their added value properties (redox properties, large sizes, high negative charges, nucleophilicity...). Parallel to this domain, the organic-inorganic hybrids area has followed a similar expansion during the last 10 years. The concept of organic-inorganic hybrid materials * To whom correspondence should be addressed. E-mail: dolbecq@ chimie.uvsq.fr. Chem. Rev. 2010, 110, 6009–6048 6009

1,475 citations

Journal ArticleDOI
TL;DR: The description and discussion of the major applications of hybrid inorganic-organic (or biologic) materials are the major topic of this critical review.
Abstract: Today cross-cutting approaches, where molecular engineering and clever processing are synergistically coupled, allow the chemist to tailor complex hybrid systems of various shapes with perfect mastery at different size scales, composition, functionality, and morphology. Hybrid materials with organic–inorganic or bio–inorganic character represent not only a new field of basic research but also, via their remarkable new properties and multifunctional nature, hybrids offer prospects for many new applications in extremely diverse fields. The description and discussion of the major applications of hybrid inorganic–organic (or biologic) materials are the major topic of this critical review. Indeed, today the very large set of accessible hybrid materials span a wide spectrum of properties which yield the emergence of innovative industrial applications in various domains such as optics, micro-electronics, transportation, health, energy, housing, and the environment among others (526 references).

1,159 citations

Journal ArticleDOI
TL;DR: The present review summarizes the current state of the art in the use of MOFs as solid catalysts according to the type of site, making special emphasis on the more recent strategies to increase the population of these active sites and tuning their activity, either by adapting the synthesis conditions or by post-synthetic modification.
Abstract: Metal organic frameworks (MOFs) are a class of porous crystalline materials that feature a series of unique properties, such as large surface area and porosity, high content of transition metals, and possibility to be designed and modified after synthesis, that make these solids especially suitable as heterogeneous catalysts. The active sites can be coordinatively unsaturated metal ions, substituents at the organic linkers or guest species located inside the pores. The defects on the structure also create these open sites. The present review summarizes the current state of the art in the use of MOFs as solid catalysts according to the type of site, making special emphasis on the more recent strategies to increase the population of these active sites and tuning their activity, either by adapting the synthesis conditions or by post-synthetic modification. This review highlights those reports illustrating the synergy derived from the presence of more than one of these types of sites, leading to activation of a substrate by more than one site or to the simultaneous activation of different substrates by complementary sites. This synergy is frequently the main reason for the higher catalytic activity of MOFs compared to homogeneous catalysts or other alternative solid materials. Besides dark reactions, this review also summarizes the use of MOFs as photocatalysts emphasizing the uniqueness of these materials regarding adaptation of the linkers as light absorbers and metal exchange at the nodes to enhance photoinduced electron transfer, in comparison with conventional inorganic photocatalysts. This versatility and flexibility that is offered by MOFs to optimize their visible light photocatalytic activity explains the current interest in exploiting these materials for novel photocatalytic reactions, including hydrogen evolution and photocatalytic CO2 reduction.

978 citations

Journal ArticleDOI
TL;DR: This critical review describes the methods that are used for electrografting, their mechanism, the formation and growth of the layers as well as their applications.
Abstract: Electrografting refers to the electrochemical reaction that permits organic layers to be attached to solid conducting substrates. This definition can be extended to reactions involving an electron transfer between the substrate to be modified and the reagent, but also to examples where a reducing or oxidizing reagent is added to produce the reactive species. These methods are interesting as they provide a real bond between the surface and the organic layer. Electrografting applies to a variety of substrates including carbon, metals and their oxides, but also dielectrics such as polymers. Since the 1980s several methods have been developed, either by reduction or oxidation, and some of them have reached an industrial stage. This critical review describes the methods that are used for electrografting, their mechanism, the formation and growth of the layers as well as their applications (742 references).

834 citations