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Chemistry, Chimie, Energy, Énergie, Chemical industry parachemical industry, Industrie chimique et parachimique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Physics, Physique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Matériaux particuliers, Specific materials, Fullerènes et matériaux apparentés; diamants, graphite, Fullerenes and related materials; diamonds, graphite, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés électriques, magnétiques et optiques, Electrical, magnetic and optical properties, Addition bore, Boron additions, Aniline polymère, Polyanilines, Bore, Boron, Graphène, Graphene, Matériau dopé, Doped materials, Structure sandwich, Sandwich structures, Supercondensateur, Supercapacitors, Synthèse, Synthesis, 8105T, 8105U, and 8235C

The physicochemical property of chemically prepared graphene can be significantly changed due to the incorporating of heteroatoms into graphene. In this article, boron-doped graphene sheets are used as carbon substrates instead of graphene for loading polyaniline by in situ polymerization. Compared with the individual component and polyaniline/non-doped graphene, the sandwich-like polyaniline/boron-doped graphene exhibits remarkably enhanced electrochemical specific capacitance in both acid and alkaline electrolytes. In a three-electrode configuration, the hybrid has a specific capacitance about 406 F g―1 in 1 M H2SO4 and 318 F g―1 in 6 M KOH at 1 mV s―1. In the two-electrode system of a symmetric supercapacitor, this hybrid achieves a specific capacitance about 241 and 189 F g―1 at 0.5 A g―1 with a specific energy density around 19.9 and 30.1 Wh kg―1, in the acid and alkaline electrolytes, respectively. The as-obtained polyaniline/boron-doped graphene hybrid shows good rate performance. Notably, the obtained electrode materials exhibit long cycle stability in both acid and alkaline electrolytes (~100% and 83% after 5000 cycles, respectively). The improved electrochemical performance of the hybrid is mainly attributed to the introduction of additional p-type carriers in carbon systems by boron-doping and the well combination of pseudocapacitive conducting polyaniline.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Pharmacologie. Traitements medicamenteux, Pharmacology. Drug treatments, Pharmacologie générale, General pharmacology, Technologie pharmaceutique. Industrie pharmaceutique, Pharmaceutical technology. Pharmaceutical industry, Amine polymère, Amine polymer, Amina polímero, Amine tertiaire, Tertiary amine, Amina terciaria, Cinétique, Kinetics, Cinética, Colorant organique, Organic dye, Colorante orgánico, Effet structure, Structure effect, Efecto estructura, Effet température, Temperature effect, Efecto temperatura, Etude expérimentale, Experimental study, Estudio experimental, Gel colloïdal, Colloidal gel, Gel coloidal, Gonflement, Swelling, Inflamiento, Libération, Release, Liberación, Méthacrylate polymère, Methacrylate polymer, Metacrilato polímero, Polymère vecteur, Control release polymer, Polímero vector, Polymérisation radicalaire, Free radical polymerization, Polimerización radicalar, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Préparation, Preparation, Preparación, Rhodamine, Rodamina, Triazole dérivé polymère, Triazole derivative polymer, Triazol derivado polímero, Vecteur médicament, Drug carrier, Vector medicamento, pH, Effet densité réticulation, Interaction pi pi, Polymère sensible stimuli, DMAEMA, anticancer, hydrogels, sustained release, and triazole

The purpose of this study is to develop novel triazole-containing hydrogels (TGs) as drug carrier and to investigate the sustained drug release accomplished by their time-dependent swelling behavior. The synthetic pathway of TGs includes: (1) DCC-coupling on hydroxyethyl methacrylate (HEMA) to prepare HEMA-alkyne (HA), (2) click-coupling to prepare a triazole-ring-containing monomer (TM), and (3) the synthesis of a series of TGs. The aggregation between triazole rings is found to be responsible for drug release controllability. Rhodamine 6G is studied as a model anticancer drug for release experiments. The effects of pH and temperature on the properties of sustained drug release are also studied.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Adhérence, Adhesion, Adherencia, Biocompatibilité, Biocompatibility, Biocompatibilidad, Biomatériau, Biomaterial, Caprolactone polymère, Polycaprolactone, Caprolactona polímero, Cristallisation, Crystallization, Cristalización, Cycle thermique, Thermal cycle, Ciclo térmico, Effet mémoire forme, Shape memory effect, Efecto memoria forma, Liaison covalente, Covalent bond, Enlace covalente, Polymère réticulé, Crosslinked polymer, Polímero reticulado, Polymère semicristallin, Semicrystalline polymer, Polímero semicristalino, Procédé sol gel, Sol gel process, Procedimiento sol gel, Traitement thermique, Heat treatment, Tratamiento térmico, advanced characterization testing, biomaterial, creep and stress rupture, and mechanical

This paper investigates the shape memory capabilities of semicrystalline networks, focusing the attention on poly(e-caprolactone) (PCL) systems, a class of materials that allows to satisfy important requirements for their applications as biomedical devices, such as the good biocompatibility, the fast recovery of large temporary shape configurations, and the easy tailoring of the transformation temperatures. The materials were prepared with various crosslink densities and crosslinking methodologies; in particular, beside a thermal crosslinking based on reactive methacrylic end groups, a novel type of covalently crosslinked semicrystalline systems was prepared by a sol-gel approach from alkoxysilane-terminated PCL precursors, so as to avoid potentially toxic additives typically used for free-radical thermal curing. The materials were subjected to biological tests, to study their ability in sustaining cell adhesion and proliferation, and to thermal characterizations, to evaluate the possibility to tailor their melting and crystallization temperatures. The one-way shape memory (i.e., the possibility to set the material in a given configuration and to recover its pristine shape) and the two-way shape memory response (i.e., the triggered change between two distinguished shapes on the application of an on-off stimulus) were studied by applying optimized thermo-mechanical cyclic histories. The ability to fix the applied shape and to recover the original one on the application of heating (i.e., the one-way effect) was evaluated on tensile bars; further, to investigate a potential application as self-expandable stents, isothermal shape memory experiments were carried out also on tubular specimens, previously folded in a temporary compact configuration. The two-way response was studied through the application of a constant load and of a heating/cooling cycle from above melting to below the crystallization temperature, leading to a reversible elongation/contraction effect, involving maximum strain changes up to about 80%, whose extent may be controlled through the crosslink density.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Protéines, Proteins, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Chirurgie (generalites). Transplantations, greffes d'organes et de tissus. Pathologie des greffons, Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases, Technologie. Biomatériaux. Equipements, Technology. Biomaterials. Equipments, Acide nucléique, Nucleic acid, Acido nucleico, Acrylique acide polymère, Acrylic acid polymer, Acrílico ácido polímero, Article synthèse, Review, Artículo síntesis, Biomatériau, Biomaterial, Cryogel, DNA, Elastomère, Elastomer, Elastómero, Fibre animale, Animal fiber, Fibra animal, Fibre naturelle, Natural fiber, Fibra natural, Fibroïne, Fibroin, Fibroína, Gel colloïdal, Colloidal gel, Gel coloidal, Gélification, Gelation, Gelificación, Génie tissulaire, Tissue engineering, Ingeniería de tejidos, Matériau poreux, Porous material, Material poroso, Pollution eau, Water pollution, Contaminación agua, Polymère linéaire, Linear polymer, Polímero lineal, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Propriété mécanique, Mechanical properties, Propiedad mecánica, Protéine animale, Animal protein, Proteína animal, Préparation, Preparation, Preparación, Pétrole brut, Crude oil, Petróleo bruto, Pétrole, Petroleum, Petróleo, Relation structure propriété, Property structure relationship, Relación estructura propiedad, Soie, Silk, Seda, Sorbant, Sorbent, Sorbente, Echafaudage tissulaire, Cryogels, Elasticity, Porosity formation, and Swelling

Polymeric gels belong to the most important class of functional polymers in modem biotechnology. They are useful materials for drug delivery systems, artificial organs, separation operations in biotechnology, processing of agricultural products, on-off switches, sensors, and actuators. Despite this fact and considerable research in this field, the design and control of gel-based devices still present some problems due to the their poor mechanical performance and slow rate of response to external stimuli. Cryogelation techniques discovered more than 30 years ago overcome these limitations by producing macroporous gels with high toughness and superfast responsivity. This chapter discusses how and why the properties of gels significantly alter upon transition from homogeneous gelation to a cryogelation regime. The formation and structure-property relationships of cryogels starting from monovinyl-divinyl monomers, as well as from linear polymer chains, are reviewed using examples from the recent literature. Some novel cryogels with a wide range of tunable properties and their applications are also presented in detail. These include DNA cryogels for the removal of carcinogens from aqueous environments, silk fibroin cryogels as mechanically strong scaffolds for bone tissue engineering applications, poly(acrylic acid) cryogels as self-oscillation systems, and rubber cryogels as reusable oil sorbent for the removal of oil spill from seawater.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Divers, Miscellaneous, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés de surface, Surface properties, Acide nucléique, Nucleic acid, Acido nucleico, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Article synthèse, Review, Artículo síntesis, Chaîne flexible, Flexible chain, Cadena flexible, Conformation, Conformación, DNA, Distribution densité, Density distribution, Distribución densidad, Effet surface, Surface effect, Efecto superficie, Fonction Green, Green function, Función Green, Interaction électrostatique, Electrostatic interaction, Interacción electrostática, Modélisation, Modeling, Modelización, Particule sphérique, Spherical particle, Partícula esférica, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Propriété surface, Surface properties, Propiedad superficie, Surface plane, Plane surface, and Superficie plana

Polyelectrolytes are macromolecules composed of charged monomers and exhibit unique properties due to the interplay of their flexibility and electrostatic interactions. In solution, they are attracted to oppositely charged surfaces and interfaces and exhibit a transition to an adsorbed state when certain conditions are met concerning the charge densities of the polymer and surface and the properties of the solution. In this review, we discuss two limiting cases for adsorption of flexible polyelectrolytes on curved surfaces: weak and strong adsorption. In the first case, adsorption is strongly influenced by the entropic degrees of freedom of a flexible polyelectrolyte. By contrast, in the strong adsorption limit, electrostatic interactions dominate, which leads to particular adsorption patterns, specifically on spherical surfaces. We discuss the corresponding theoretical approaches, applying a mean-field description for the polymer and the polymer-surface interaction. For weak adsorption, we discuss the critical adsorption behavior by exactly solvable models for planar and spherical geometries and a generic approximation scheme, which is additionally applied to cylindrical surfaces. For strong adsorption, we investigate various polyelectrolyte patterns on cylinders and spheres and evaluate their stability. The results are discussed in the light of experimental results, mostly of DNA adsorption experiments.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Divers, Miscellaneous, Autodiffusion, Self diffusion, Autodifusión, Etude théorique, Theoretical study, Estudio teórico, Modélisation, Modeling, Modelización, Mélange polymère, Polymer blends, Polymère cyclique, Cyclic polymer, Polímero cíclico, Polymère linéaire, Linear polymer, Polímero lineal, Relation composition propriété, Property composition relationship, Relación composición propiedad, Modèle liaison fluctuante, Bond-fluctuation model, Cyclic polymers, Mean-squared displacement, and Ring-linear blends

We use the bond-fluctuation model to measure self-diffusivity of asymmetric blends of cyclic and linear polymers, where the number of monomers in the cyclic and linear polymer are different. We consider two series of asymmetric blends and vary the relative composition. In particular, Nc = 300 and NL = 150, and Nc = 150 and NL = 300, where Nc and NL are the number of monomers in the cyclic and linear polymers, respectively. Compared to cyclic polymers, the self-diffusivity of linear polymers is relatively insensitive to the blend composition, and is approximately within a factor of two of the pure linear self-diffusivity. In sharp contrast, the self-diffusivity of cyclic polymers exhibits a strong order of magnitude variation with the blend microenvironment. The latter data appear to be consistent with trends expected from previous simulations of symmetric cyclic-linear blends, as a function of the fraction of linear polymer.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Divers, Miscellaneous, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Article synthèse, Review, Artículo síntesis, Cinétique, Kinetics, Cinética, Densité charge, Charge density, Densidad carga, Diffusion lumière, Light scattering, Difusión luz, Effet pH, pH effect, Efecto pH, Effet température, Temperature effect, Efecto temperatura, Force ionique, Ionic strength, Fuerza iónica, Force surface, Surface forces, Interpolymère, Interpolymer, Interpolímero, Microscopie force atomique, Atomic force microscopy, Microscopía fuerza atómica, Mécanisme formation, Formation mechanism, Mecanismo formacion, Méthode étude, Investigation method, Método estudio, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Protéine, Protein, Proteína, Solution chimique, Chemical solution, Solución química, AFM, DLS, PEC, PEM, Relaxation time, and Rheology

Polyelectrolyte complex formation is a well-studied subject in colloid science. Several types of complex formation have been studied, including PEMs, macroscopic polyelectrolyte complexes, soluble complexes and polyelectrolyte complex micelles. The chemical nature of the complex-forming polyelectrolytes and the environmental conditions (e.g., pH, ionic strength and temperature) influence the final structural properties of these complexes. This chapter deals with the kinetics of polyelectrolyte complex formation and discusses how ionic strength, charge density and pH influence the dynamics of the complexes, which can range from glass-like (solid) precipitates to liquid-like phases. The switching between the glass-like and liquid-like phase as a function of the ionic strength has a strong analogy to the phase behaviour of polymer melts as function of temperature. By performing calorimetry during complex formation it has been found that the enthalpy of complex formation of systems that form glass-like phases has an opposite sign to the enthalpy of systems that form liquid-like phases, i.e., the formation of glass-like phases is exothermic and the formation of liquid-like phases is endothermic. The free energy (ΔfG), enthalpy (ΔfH) and entropy (ΔfS) of polyelectrolyte complex formation and how they vary as a function of the ionic strength will be discussed. Results from dynamic light scattering (DLS) titrations, Atomic Force Microscopy (AFM), surface force measurements and rheology will be used to illustrate how differences in kinetics show up in experiments on colloidal micellar systems. In the section on DLS titrations, three-component systems containing two oppositely charged polyelectrolytes and protein molecules will be discussed. This chapter concludes with a section dedicated to the complex formation of oppositely charged protein molecules.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères minéraux et organominéraux, Inorganic and organomineral polymers, Propriétés et caractérisation, Properties and characterization, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Pharmacologie. Traitements medicamenteux, Pharmacology. Drug treatments, Pharmacologie générale, General pharmacology, Technologie pharmaceutique. Industrie pharmaceutique, Pharmaceutical technology. Pharmaceutical industry, Activité biologique, Biological activity, Actividad biológica, Anticancéreux, Antineoplastic agent, Anticanceroso, Article synthèse, Review, Artículo síntesis, Cellule tumorale, Tumor cell, Célula tumoral, Encapsulation, Encapsulación, Phosphazène polymère, Phosphazene polymer, Fosfaceno polímero, Polymère vecteur, Control release polymer, Polímero vector, Préparation, Preparation, Preparación, Vecteur médicament, Drug carrier, Vector medicamento, Anti-cancer drug, Drug delivery system, Poly(organophosphazene), and pH-responsiveness

Currently, most of administered anti-cancer drugs are low molecular weight compounds (as compare to polymers) and hydrophobic in nature. Such small molecular anti-cancer drugs possess fast clearance rate from the blood circulating system and have toxic side effects. Poly(organophosphazenes) have wide range of biomedical applications owing good biocompatibility, sustainability and degradability into non-toxic by-products. So, in this review, we have carefully selected such poly(organophosphazenes), which proved to be good anti-cancer drug carriers because of overcoming crucial issues related to the administration of anti-cancer drugs i.e. poor hydrophilicity, lack of cancer cells specificity, and fast clearance rate from blood circulating system. Thence, the main focus of this review is to highlight the advancement that have been achieved in the synthesis of poly( organophosphazenes) and their application in anti-cancer drug delivery system (DDS).

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Bois. Papiers. Non tissés, Wood. Paper. Non wovens, Papiers, cartons, non tissés, Paper, paperboard, non wovens, Fabrication des papiers et cartons, Paper and paperboard manufacturing, Adhésivité, Adhesivity, Adhesividad, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Dérivé de la lignine, Lignin derivatives, Lignina derivada, Etat actuel, State of the art, Estado actual, Fibre bois, Wood fiber, Fibra madera, Fibre naturelle, Natural fiber, Fibra natural, Fibre végétale, Plant fiber, Fibra vegetal, Hémicellulose, Hemicellulose, Hemicelulosa, Interpolymère, Interpolymer, Interpolímero, Lignosulfonate, Lignosulfonato, Mécanisme formation, Formation mechanism, Mecanismo formacion, Papier, Paper, Papel, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété surface, Surface properties, Propiedad superficie, Propriété traction, Tensile property, Propiedad tracción, Pâte papier, Paper pulp, Pasta papel, Renforcement mécanique, Strengthening, and Refuerzo mecánico

The use of polyelectrolyte complexes (PECs) provides new opportunities for surface engineering of solid particles in aqueous environments to functionalize the solids either for use in interactive products or to tailor their adhesive interactions in the dry and/or wet state. This chapter describes the use of PECs in paper-making applications where the PECs are used for tailoring the surfaces of wood-based fibres. Initially a detailed description of the adsorption process is given, in more general terms, and in this respect both in situ formed and pre-formed complexes are considered. When using in situ formed complexes, which were intentionally formed by the addition of oppositely charged polymers, it was established that the order of addition of the two polyelectrolytes was important, and by adding the polycation first a more extensive fibre flocculation was found. PECs can also form in situ by the interaction between polyelectrolytes added and polyelectrolytes already present in the fibre suspension originating from the wood material, e.g. lignosulphonates or hemicelluloses. In this respect the complexation can be detrimental for process efficiency and/or product quality depending on the charge balance between the components, and when using the PECs for fibre engineering it is not recommended to rely on in situ PEC formation. Instead the PECs should be pre-formed before addition to the fibres. The use of pre-formed PECs in the paper-making process is described as three sub-processes: PEC formation, adsorption onto surfaces, and the effect on the adhesion between surfaces. The addition of PECs, and adsorption to the fibres, prior to formation of the paper network structure has shown to result in a significant increase in joint strength between the fibres and to an increased strength of the paper made from the fibres. The increased joint strength between the fibres is due to both an increased molecular contact area between the fibres and an increased molecular adhesion. The increased paper strength is also a result of an increased number of fibre/fibre contacts/unit volume of the paper network.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Domaines d'application, Application fields, Application, Aplicación, Dimension particule, Particle size, Dimensión partícula, Etat actuel, State of the art, Estado actual, Floculant, Flocculation reagent, Floculante, Floculation, Flocculation, Floculación, Force ionique, Ionic strength, Fuerza iónica, Interpolymère, Interpolymer, Interpolímero, Mécanisme formation, Formation mechanism, Mecanismo formacion, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Pâte papier, Paper pulp, Pasta papel, Traitement eau, Water treatment, Tratamiento agua, Dual system, Polyanion, Polycation, Polyelectrolyte complex, and Pre-mixed complexes

This review concentrates on the interactions between oppositely charged polyelectrolytes and on the formation of complexes, which can be used for different applications such as paper retention or water treatment. Three different possibilities for the appearance of polyelectrolyte complexes (PECs) in flocculation applications are described. Starting with the classical dual system (step-by-step addition of polycation and polyanion to a negatively charged suspension of fibers or particles), the interaction between a soluble polyanion (such as anionic trash) with polycation is described as well as the formation of well-defined pre-mixed PECs and their application as flocculants. The influence of several parameters related to the characteristics of the solid materials (e.g., charge, particle size), the polyelectrolyte (e.g., type of charge, charge density, molar mass, hydrophobicity) and the flocculation regime (e.g., order of addition, pH, ionic strength) are discussed. Research in this area shows great potential. Over the past 30 years, dual systems have been applied mainly in the paper industry. The application of PECs, described as particle-forming flocculants, provides new possibilities in solid-liquid separation processes. For an effective system, the application parameters have to be optimized (e.g. polymer type, concentration, charge, molecular weight). Therefore, direct and efficient methods for the characterization of the flocculation behavior (sedimentation velocity, packing density of the sludge, particle size distribution) are necessary and will be described. Finally, the most advanced applications for PECs are discussed.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Chirurgie (generalites). Transplantations, greffes d'organes et de tissus. Pathologie des greffons, Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases, Technologie. Biomatériaux. Equipements, Technology. Biomaterials. Equipments, Article synthèse, Review, Artículo síntesis, Biocompatibilité, Biocompatibility, Biocompatibilidad, Biomatériau, Biomaterial, Cellulose, Celulosa, Chitosane, Chitosan, Quitosano, Cryogel, Dispositif médical, Medical device, Dispositivo médico, Gel dégel, Freeze thaw cycle, Hielo deshielo, Gel physique, Physical gel, Gel físico, Hydrogel, Hidrogel, Matériau composite, Composite material, Material compuesto, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Nanocomposite, Nanocompuesto, Nanofibre, Nanofiber, Nanofibra, Oside polymère, Oside polymer, Osido polímero, Polymère vecteur, Control release polymer, Polímero vector, Propriété biologique, Biological properties, Propiedad biológica, Propriété mécanique, Mechanical properties, Propiedad mecánica, Résistance choc, Impact strength, Resistencia choque, Vinylique alcool polymère, Polyvinylalcohol, Vinílico alcohol polímero, Controlled release, Physical crosslinking, and Poly(vinyl alcohol)

Poly(vinyl alcohol) (PVA) is a hydrophilic and biocompatible polymer that can be crosslinked to form a hydrogel. When physically crosslinked using a freeze-thaw cycling process, the product hydrogel or cryogel (PVA-C) possesses unique mechanical properties that can be tuned to closely match those of soft tissues, thus making it an attractive candidate for biomedical and especially medical device applications. We review the freeze-thaw cycling process and processing parameters that impact on the properties of PVA-C and its nanocomposite products. Both the mechanical properties and diffusion properties relevant to biomedical application are discussed. Applications to orthopedic and cardiovascular devices are summarized and discussed. The concept of biomaterial-tissue hybrids that can impart the necessary hemocompatibility to PVA-C for cardiovascular device is introduced and demonstrated.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines classiques de la physique (y compris les applications), Fundamental areas of phenomenology (including applications), Optique, Optics, Matériaux optiques, Optical materials, Autres matériaux pour optique non linéaire; matériaux photoréfractifs et semiconducteurs, Other nonlinear optical materials; photorefractive and semiconductor materials, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés électriques, magnétiques et optiques, Electrical, magnetic and optical properties, Propriété optique, Optical properties, Propiedad óptica, Effet photoréfractif, Photorefractive effect, Efecto fotorefractivo, Etat actuel, State of the art, Estado actual, Holographie, Holography, Holografía, Matériau photoréfractif, Photorefractive material, Material fotorefractivo, Mélange 4 ondes, Four wave mixing, Mezcla 4 ondas, Photoconductivité, Photoconductivity, Fotoconductividad, Polymère, Polymer, Polímero, Propriété électrooptique, Electrooptical properties, Propiedad electroóptica, Xérographie, Xerography, Xerografía, diffraction, holography, host-guest systems, imaging, photorefractive effects, photorefractive gain, and photorefractive polymer

This review describes the current state-of-the-art of photorefractive polymers for holography. The analysis of this rich field begins with a brief historical perspective followed by descriptions of prevailing physical models relating basic parameters of the polymer constituents to the bulk response of the final device. Methods for probing these responses and the underlying phenomena are discussed followed by an overview of the recent holographic applications of photorefractive polymers.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Cristallisation, Crystallization, Lactone polymère, Lactone polymer, Lactona polímero, Caprolactone polymère, Polycaprolactone, Caprolactona polímero, Cinétique, Kinetics, Cinética, Cristallisation isotherme, Isothermal crystallization, Cristalización isotérmica, Cristallisation état fondu, Melt crystallization, Cristalización estado fundido, Effet température, Temperature effect, Efecto temperatura, Etude comparative, Comparative study, Estudio comparativo, Etude expérimentale, Experimental study, Estudio experimental, Nucléation, Nucleation, Nucleación, Polymère linéaire, Linear polymer, Polímero lineal, Polymère monodispersé, Monodispersed polymer, Polímero monodispersado, Relation masse moléculaire propriété, Molecular weight property relation, Relación masa molecular propiedad, Température transformation, Transformation temperature, Temperatura transformación, Autonucléation, (SSA), Crystallization, Cyclic poly(ε-caprolactone), Self-nucleation, and Successive Self-nucleation and Annealing

A series of low polydispersity cyclic PCL samples (C-PCLs), as well as their linear analogs (L-PCLs), were synthesized by click chemistry in a number average molecular weight (Mn) range of 2-22 kg/mol. They were investigated by Polarized Light Optical Microscopy (PLOM) and Differential Scanning Calorimetry (DSC). The nucleation and overall crystallization kinetics were studied, as well as their self-nucleation behavior and SSA (Successive Self-nucleation and Annealing) thermal fractionation. Cyclic PCLs were found to nucleate and crystallize faster than linear PCLs due to: (a) faster diffusion of C-PCL chains and (b) larger supercoolings of C-PCLs at any given crystallization temperature, as compared to L-PCLs. A bell shape curve was obtained when the overall crystallization rate was examined as a function of Mn, this effect is probably due to a competition between nucleation and diffusion. It was found for the first time, that since cyclic molecules have lower entanglement densities, they can quickly recover their pseudo-equilibrium compact coil conformations upon melting and therefore exhibit much smaller crystalline memory effects than their linear counterparts of identical chain lengths. SSA revealed that C-PCLs are more sensitive to annealing than L-PCLs because their ring topology and limited lamellar chain folding facilitates crystal thickening.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Structure, morphologie et analyse, Structure, morphology and analysis, Butadiène polymère, Butadiene polymer, Butadieno polímero, Chromatographie phase liquide, Liquid chromatography, Cromatografía fase líquida, Etude expérimentale, Experimental study, Estudio experimental, Méthode étude, Investigation method, Método estudio, Peptide polymère, Aminoacid polymer, Péptido polímero, Polymère cyclique, Cyclic polymer, Polímero cíclico, Procédé tandem, Tandem process, Procedimiento tándem, Spectrométrie 2 dimensions, Two dimension spectrometry, Espectrometría bidimensional, Spectrométrie masse, Mass spectrometry, Espectrometría masa, Structure moléculaire, Molecular structure, Estructura molecular, Styrène polymère, Styrene polymer, Estireno polímero, Séparation physique, Physical separation, Separación física, Peptoïde polymère, Ion mobility separation, LC-MS, Polymer architecture, Supramolecular polymer, and Tandem mass spectrometry

Several synthetic methods have been developed for the tailored preparation of cyclic macromolecules due to their unique physical and chemical properties. Unequivocal characterization of the macrocyclic architectures has remained challenging, however, because isomeric linear structures often exist, or the spectral features of linear vs. cyclic chains are similar. To address this problem, multidimensional mass spectrometry (MS) techniques have been evaluated for the separation and identification of polymeric macrocycles. Tandem mass spectrometry (MS2) is found to be ideally suitable for the differentiation of linear and cyclic architectures whose molecular ions exhibit distinct fragmentation characteristics. Conversely, differences in macromolecular sizes and shapes can be exploited to identify the correct architecture by ion mobility mass spectrometry (IM-MS). A third option, chromatographic separation (LC) before MS analysis, is available for the detection of cyclics in complex mixtures. The capabilities of these techniques and combinations thereof are demonstrated with specific covalent or supramolecular (co)polymers. .

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Amidon et polyosides divers, Starch and polysaccharides, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés spéciales (catalyseur, réactif ou support), Special properties (catalyst, reagent or carrier), Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Pharmacologie. Traitements medicamenteux, Pharmacology. Drug treatments, Pharmacologie générale, General pharmacology, Technologie pharmaceutique. Industrie pharmaceutique, Pharmaceutical technology. Pharmaceutical industry, Adhérence, Adhesion, Adherencia, Article synthèse, Review, Artículo síntesis, Cinétique, Kinetics, Cinética, Libération, Release, Liberación, Muqueuse, Mucosa, Mécanisme, Mechanism, Mecanismo, Polymère vecteur, Control release polymer, Polímero vector, Vecteur médicament, Drug carrier, Vector medicamento, Mucoadhérence, Mucoadhésif, Mucoadhesive drug delivery systems, Mucoadhesive natural, synthetic and semi-synthetic polymers, and Pharmaceutical materials science pharmaceutical research and development

The presence of a mucus layer that covers the surface of a variety of organs has been capitalized to develop mucoadhesive dosage forms that remain in the administration site for prolonged times, increasing the local and/or systemic bioavailability of the administered drug. The emergence of micro and nanotechnologies together with the implementation of non-invasive and painless administration routes has revolutionized the pharmaceutical market and the treatment of disease. Aiming to overcome the main drawbacks of the oral route and to maintain patient compliance high, the engineering of innovative drug delivery systems administrable by mucosal routes has come to light and gained the interest of the scientific community due to the possibility to dramatically change pharmacokinetics. In addition, to achieve the goal of mucosal drug administration, the development of biomaterials has been refined to fit specific applications. The present review initially describes the potential of nano-drug delivery systems conceived for mucosal administration by diverse non-parenteral routes (e.g., oral, inhalatory, etc.). Then, the benefit of the incorporation of mucoadhesive polymers into the structure of these innovative pharmaceutical products to prolong their residence time in the administration site and the release of the drug cargo will be discussed with focus in the developments of the last decade. In addition, the regulatory status of the most extensively used mucoadhesive polymers will be emphasized. Finally, a thorough overview of the different pharmaceutical applications of mucoadhesive polymers will be addressed.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés mécaniques, Mechanical properties, Courbe rationnelle traction, True stress true strain curve, Curva verdadera esfuerzo deformación, Déformation finie, Finite strain, Deformación finita, Effet mémoire forme, Shape memory effect, Efecto memoria forma, Elastoviscoplasticité, Elastoviscoplasticity, Elastoviscoplasticidad, Equation constitutive, Constitutive equation, Ecuación constitutiva, Hyperélasticité, Hyperelasticity, Hiperelasticidad, Rupture, Ruptura, Thermographie IR, Infrared thermography, Termografía IR, Thermoélasticité, Thermoelasticity, Termoelasticidad, Traitement thermomécanique, Thermomechanical treatment, Tratamiento termomecánico, Uréthanne polymère, Polyurethane, Uretano polímero, Vitesse déformation, Strain rate, Velocidad deformación, Analyse mécanique dynamique, Dynamic mechanical analysis, constitutive model, dynamic mechanical analysis, shape memory polyurethane, strain rate, temperature change, and thermomechanical couplings

Multifunctional new material—polyurethane shape memory polymer (PU-SMP)-was subjected to tension carried out at room temperature at various strain rates. The influence of effects of thermomechanical couplings on the SMP mechanical properties was studied, based on the sample temperature changes, measured by a fast and sensitive infrared camera. It was found that the polymer deformation process strongly depends on the strain rate applied. The initial reversible strain is accompanied by a small drop in temperature, called thermoelastic effect. Its maximal value is related to the SMP yield point and increases upon increase of the strain rate. At higher strains, the stress and temperature significantly increase, caused by reorientation of the polymer molecular chains, followed by the stress drop and its subsequent increase accompanying the sample rupture. The higher strain rate, the higher stress, and temperature changes were obtained, since the deformation process was more dynamic and has occurred in almost adiabatic conditions. The constitutive model of SMP valid in finite strain regime was developed. In the proposed approach, SMP is described as a two-phase material composed of hyperelastic rubbery phase and elastic-viscoplastic glassy phase, while the volume content of phases is specified by the current temperature.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Caténane, Catenane, Catenano, Coefficient diffusion, Diffusion coefficient, Coeficiente difusión, Conformation, Conformación, Etude théorique, Theoretical study, Estudio teórico, Modélisation, Modeling, Modelización, Polymère cyclique, Cyclic polymer, Polímero cíclico, Rayon giration, Radius of gyration, Radio giro, Rayon hydrodynamique, Hydrodynamic radius, Radio hidrodinámico, Relation masse moléculaire propriété, Molecular weight property relation, Relación masa molecular propiedad, Solution chimique, Chemical solution, Solución química, Méthode quaternionique, Polymère têtard, and Double-ring

We evaluate numerically the mean-square (MS) radius of gyration and the diffusion coefficient for topological polymers such as ring, tadpole, double-ring, and caged polymers and catenanes. We consider caged polymers with any given number of subchains, and catenanes consisting of two linked ring polymers with a fixed linking number. Through Kirkwood's approximation we evaluate the hydrodynamic radius, which is proportional to the inverse of the diffusion coefficient, for various topological polymers. Here we take the statistical averages over configurations of topological polymers constructed through the quaternionic algorithm, which generates uniform random walks connecting given two points. It gives ideal chains with no excluded volume. We evaluate numerically the ratio of the square root of the MS radius of gyration to the hydrodynamic radius for several topological polymers, and show for them that the ratio decreases as the topology becomes more complex.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Cinétique, Kinetics, Cinética, Congélation, Freezing, Congelación, Diffusion RX centrale, Small angle X ray scattering, Difusión rayo X central, Effet solvant, Solvent effect, Efecto solvente, Enchevêtrement moléculaire, Molecular entanglement, Encabestradura molecular, Etat actuel, State of the art, Estado actual, Gel physique, Physical gel, Gel físico, Gélification, Gelation, Gelificación, Hydrogel, Hidrogel, Liaison hydrogène, Hydrogen bond, Enlace hidrógeno, Macroporosité, Macroporosity, Macroporosidad, Solution aqueuse, Aqueous solution, Solución acuosa, Vinylique alcool polymère, Polyvinylalcohol, Vinílico alcohol polímero, Cristallisation confinée, Confined polymer crystallization, Cryotropic gelation, Ostwald stage-rule, Poly(vinyl alcohol) hydrogels, and Time-resolving small angle neutron scattering

Aqueous poly(vinyl alcohol) (PVA) solutions subjected to cryogenic treatment form strong physical gels. The cryogenic treatment basically consists of freezing an initially homogeneous polymer solution at low temperatures, storing in the frozen state for a definite time, and defrosting. These gels are of great interest for biotechnology, medicine, the food industry, and many other applications. The outstanding properties of these systems depend on a complex macroporous architecture, whereby PVA chains and water molecules are organized over different hierarchical length scales. The structure and the principal processes subtending the formation of these systems are discussed in the framework of our current understanding of polymer gels. These processes involve formation of ice crystals, PVA crystallization, liquid-liquid phase separation, hydrogen bonding, and entanglements. Small angle neutron scattering is used to follow the cryotropic gelation of PVA/water solutions and detailed information is extracted concerning the gelation mechanism and kinetic parameters related to the formation of these complex systems.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Action humidité, Humidity effect, Acción humedad, Ammonium(diallyl diméthyl) polymère, Ammonium(diallyl dimethyl) polymer, Amonio(dialil dimetil) polímero, Article synthèse, Review, Artículo síntesis, Conductivité ionique, Ionic conductivity, Conductividad iónica, Effet température, Temperature effect, Efecto temperatura, Interpolymère, Interpolymer, Interpolímero, Modélisation, Modeling, Modelización, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Propriété électrique, Electrical properties, Propiedad eléctrica, Styrènesulfonate polymère, Styrenesulfonate polymer, Estireno sulfonato polímero, Superposition température temps, Temperature time superposition, Superposición temperatura tiempo, Dielectric spectroscopy, Electrolyte, Impedance spectroscopy, Ion conductor, Ion dynamics, and Polyelectrolyte complex

This chapter describes the progress made in understanding the mechanisms of ion conduction in polyelectrolyte complexes (PEC). Understanding of ion dynamics is based on frequency-dependent conductivity data obtained by impedance spectroscopy as a function of temperature, hydration, and composition. In most of the work, strong polyelectrolytes such as poly(alkali 4-styrene sulfonate) (AlkaliPSS) and poly(diallyldimethyl ammoniumchloride) (PDADMAC) are employed, forming complexes of type xAlkaliPSS • (1 - x) PDADMAC. The dc conductivity is always determined by the alkali ions, which exhibit a size-dependent mobility. This holds even in PEC with an excess of PDADMAC. The ion dynamics and transport mechanisms are different in PDADMAC-rich and in NaPSS-rich PEC. We review the treatment of the frequency-dependent shape of conductivity spectra by scaling concepts and by models involving forward-backward hopping motions of small ions as well as localized motions of charges. Thus, many quantitative concepts established in other disordered ion conductors can be transferred to PEC. In addition to the well-known time-temperature superposition principle (TTSP), the novel concept of time-humidity superposition (THSP) was established for PEC and describes the dependence of ion dynamics on water content.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés mécaniques, Mechanical properties, Durée maintien, Holding time, Tiempo funcionamiento, Effet contrainte, Stress effects, Effet mémoire forme, Shape memory effect, Efecto memoria forma, Effet température, Temperature effect, Efecto temperatura, Fluage, Creep, Fluencia, Haute température, High temperature, Alta temperatura, Propriété thermomécanique, Thermomechanical properties, Propriedad termomecánica, Rupture fluage, Creep fracture, Ruptura fluencia, Uréthanne polymère, Polyurethane, Uretano polímero, creep and stress rupture, cyclic behavior, mechanical, nondestructive testing, polyurethane, shape-memory polymers, and stress-holding time

Shape-memory polymers have attracted a lot of interest in recent years. A shape-memory polymer can be deformed and fixed into a temporary shape and subsequently made to recover its original shape when a suitable stimulus is applied. This is accomplished by means of a thermomechanical cycle called programming. Programming can be performed in a stress- or strain-controlled mode. The thermomechanical conditions of the programming affect shape-memory properties differently in each programming mode. One of the parameters which significantly affects shape-memory properties in a stress-controlled procedure is stress-holding time (tH) at high temperature. This paper studies how stress-holding time affects the most significant shape-memory properties under successive thermomechanical cycles. The experiments were conducted using two different programming temperatures in the vicinity of the Tg. The shape-recovery ratio decreased dramatically with cycling even when the holding time was just a few seconds, however, the impact of the stress-holding time depends on the temperature at which it has been applied. Shape-fixity ratio and switching temperature were also studied, but stress-holding time and successive cycles do not seem to affect either of these factors.