Recent progress in gelatin hydrogel nanocomposites for water purification and beyond

Innovative characteristics of hydrogels such as swellability, modifiability and hydrophilicity make them materials of choice for water treatment and other applications. Hydrogels have shown excellent adsorptive performance for different types of water pollutants comprising toxic dyes, nutrients and heavy metals. Among different types of hydrogel based materials, hydrogel-nanomaterials combination represent a highly viable method to further improve the properties of hydrogel for numerous applications. The combination of hydrogel and nanomaterials leads to the development of hybrid hydrogel with multifunctional network. This novel combination gives synergistic effect to the newly formed novel hydrogel materials. In this article, we briefly review the recent progress in gelatin based hydrogel nanocomposites with particular emphasis on wastewater treatment along with biomedical applications

Recent progress in gelatin hydrogel nanocomposites for water purification and beyond

Innovative characteristics of hydrogels such as swellability, modifiability and hydrophilicity make them materials of choice for water treatment and other applications. Hydrogels have shown excellent adsorptive performance for different types of water pollutants comprising toxic dyes, nutrients and heavy metals. Among different types of hydrogel based materials, hydrogel-nanomaterials combination represent a highly viable method to further improve the properties of hydrogel for numerous applications. The combination of hydrogel and nanomaterials leads to the development of hybrid hydrogel with multifunctional network. This novel combination gives synergistic effect to the newly formed novel hydrogel materials. In this article, we briefly review the recent progress in gelatin based hydrogel nanocomposites with particular emphasis on wastewater treatment along with biomedical applications

Sustainability of bioplastics: opportunities and challenges

Recycling is groundwork of the worldwide efforts to diminish the amount of plastics in waste. Mostly around 7.8–8.2 million tons of poorly-used plastics enter the oceans every year. Non-biodegradable plastics settlements in landfills are uncertain, which hinders the production of land resources. Non-biodegradable plastic solid wastes, carbon dioxide, greenhouse gases, various air pollutants, cancerous polycyclic aromatic hydrocarbons and dioxins, released to the environment cause severe damage and harmfulness to the inhabitants. Due to the bio-degradability and renewability of biopolymers, petroleum-based plastics can be replaced with bio-based polymers in order to minimize the environmental risks. In this review article, bio-degradability of polymers has been discussed. The mechanisms of bio-recycling have been particularly emphasized in the present article

Recent progress in sodium alginate based sustainable hydrogels for environmental applications

Recently, there is a growing research interest in the applications and development of novel sustainable hydrogel materials in waste water treatment because of radically distinctive chemical and physical characteristics of hydrogels such as hydrophilicity, swell ability and modifiability to name a few. Hydrogels have exposed the hypernym functioning in the removal of a wide range of aqueous pollutants containing toxic dyes and heavy metal ions. A large amount of water gets incorporated in the three dimensional networks of hydrophilic structures of hydrogels. The prime objective of this review article is to render a presentation on the recent advances in the modifications of sodium alginate based hydrogels for the adsorptive removal of toxic pollutants. In addition, article also briefly gives the classification and properties of hydrogels and alginate

Recent approaches in guar gum hydrogel synthesis for water purification

Guar gum based hydrogels have evoked great attention in research as well as in industry for exploring miscellaneous applications in the field of water purification, medicine, agriculture, explosives, cosmetics, textile, paper, and food to name a few. In this article, latest modifications for developing guar gum based hydrogels and composite materials for water purification application are extensively reviewed. Regenerative nature of Guar gum hydrogels makes it a better choice for treating wastewater as well as other value-added applications. Moreover, nonionic nature makes guar gum an acceptable material for further modifications. In this article, we also present a brief discussion on structure and properties of guar gum

Recent developments in recycling of polystyrene based plastics

Due to their superior properties, plastics derived from petroleum have been extensively used almost in everyday life since last few decades. Because of lack in the manageability of plastic solid waste, their volume is increasing steadily in the natural world. Unfortunately, the disposal of plastics wastes in the oceans and land filling has led to a global issue. To effectively and efficiently deal with plastic solid waste is becoming a great challenge for the society as plastic solid waste creates big threat to our environment. Recycling of plastics solid waste should be performed to produce products having same quality to original plastics. This review article gives an overview of plastics solid waste with particular emphasis on the recent progress in polystyrene based plastics

Progress in lignin hydrogels and nanocomposites for water purification: Future perspectives

Lignin is one of the most abundant natural polymers after cellulose and has attracted great attention in academia as well as in industry for miscellaneous applications. Lignin also exhibits very high potential as a renewable sustainable resource for a galaxy of high value biochemicals. Due to the typical structure of lignin, it can be converted into different types of useful products. From a ligno-cellulose bio-refinery prospective point of view, it can be regarded as an economic bio product and can also be used as filler in several polymers to form blends or composites. Recently lignin-based hydrogels have shown excellent performance for removal of various pollutants from water. The adsorption properties of lignin based hydrogels can further be improved by using a combination of nanomaterials and lignin that results in promising hydrogel nanocomposites. In nature, the most abundant structures are formed by the combination of lignin, cellulose and hemicelluloses. In this article, we have attempted to comprehensively review the research work carried out in the direction of usage of lignin-based hydrogel for removal of toxic pollutants including metal ions and dyes

Etude des techniques de dépôt et des propriétés mécaniques de films polymères et polymères revêtus

The Ph.D. work objective was the measurements of the mechanical properties of polymer foils and metal coated polymers, in connection with their microstructures. Two similar micro-tensile deformation devices were developed, which differ by their original non-contact deformation measurement techniques that are electronic speckle pattern interferometry and optical mark-tracking, at the Universities of Kaunas and Poitiers, respectively. The elongation range of both equipments allows for the investigation of elastic and plastic properties of polymer foils, coated polymer foils with thin metallic films. The substrates were either Kapton® HN or PET foils that were coated by electron beam evaporation with Al, Ag, Cr and Ni 0.5 thick thin films on both sides. The Young s moduli of the metallic thin films (Ef) were deduced from the stress-strain curves of the substrates and of the metallic/substrate composites. For Al and Ag, the deduced Ef values are in good agreement with those of bulk materials (Eb), while the Ef values for Ni and Cr are found drastically smaller than those of Eb. It was however observed that the Al and Ag metallic layers were uniform, whereas Ni and Cr films were far less regular and exhibit cracks. The microstructures and metal/polymer interfaces were essentially studied on the Ag/PET system. The influence of metal coverage on interface composition, structure, morphology and particle size has been studied by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and X-ray diffraction (XRD). In addition, the role of deposition temperature over the temperature range 20C-140C, i.e. below and above Tg (Tg = 80C is the PET glass transition temperature), was also examined to understand how microstructure, residual stress, chemical composition and morphology of the Ag/PET layer structure is affected. It was observed that Ag 1 m thick films evaporated at different temperatures show a compressive stress state with either a (111) texture component below Tg or a random grain orientation above Tg. The texture is formed at the very early stage of growth, at a thickness of nearly 20 nm where the Ag film is still discontinuous. Within the investigated temperature range, the Ag grain size does not depend on the deposition temperature and the deposited films are mostly composed of pure Ag with partially oxidized surface.Le but de ce travail de thèse était de caractériser, en relation avec leurs microstructures, les propriétés mécaniques de films polymères seuls ou revêtus de films minces de matériaux métalliques. Pour cela, deux micromachines de déformation très similaires ont été développées à l'Université de Kaunas et de Poitiers, qui se différencient par leur technique de mesure de déformation sans contact avec l'échantillon, à savoir respectivement la technique par interférométrie de granularité laser et celle de suivi de marqueurs par corrélation d'images. Les élongations permises par les deux équipements autorisent l'étude de la déformation à la fois élastique et plastique des films polymères et polymères revêtus de films minces métalliques. Les substrats ont été des films de Kapton® HN ou de PET revêtus par évaporation par canon à électrons sur chaque face de films minces de Al, Ag, Cr et Ni de 0.5 m d'épaisseur. Les modules d'Young (Ef) des couches métalliques ont été déduits des courbes contrainte-déformation des films polymères seuls et revêtus. Pour les films d'Al et Ag, les valeurs de Ef calculées sont en bon accord avec celles couramment rapportées dans la littérature pour les matériaux massifs (Eb), tandis que pour Ni et Cr les valeurs de Ef sont nettement plus faibles que celles de Eb. Il a été corrélativement observé que les couches d'Al et d'Ag étaient uniformes, tandis que celles de Ni et Cr étaient nettement plus irrégulières et présentaient des fissures. Les microstructures et les interfaces métal/polymère ont été principalement étudiées pour le système Ag/PET. L'influence de la couverture métallique sur la composition de l'interface, sa structure, sa morphologie et la taille des particules a été étudiée par XPS, AFM et XRD. De plus, le rôle de la température de dépôt a été étudié sur une plage allant de 20C à 140C, c'est-à-dire en dessous et au-dessus de la température de transition vitreuse, Tg = 80C pour le PET, afin de comprendre mieux comment la microstructure, les contraintes internes, la composition chimique et la morphologie du système Ag/PET peuvent être influencées. Les films d'Ag de 1 m d'épaisseur évaporés à différentes températures sont en compression, texturés (111) au dessous de Tg et non texturés au dessus. La texturation existe dès le début de la croissance du film, à une épaisseur de 20 nm lorsque le film est encore discontinu. Sur la plage de température étudiée, la taille des grains d'Ag ne dépend pas de la température de déposition et les films déposés sont majoritairement composés d'Ag pur avec une oxydation partielle de surface.POITIERS-BU Sciences (861942102) / SudocSudocFranceLithuaniaFRL