Search results for "GELS"

Radiation engineering of functional biomaterials: from smart hydrogels to theragnostic nanodevices

2009

Inorganic/organic hybrid nanoparticles synthesized in a two-step radiation-driven process

2022

In this work, we have synthesized inorganic-organic hybrid nanoparticles via radiation synthesis of inorganic nanoparticles (Ag and CeO2) in aqueous dispersions containing radiation-synthesized poly(N-vinyl pyrrolidone) (PVP) nanogels (NG). The experiments show that there are strong interactions between the inorganic precursors (Ag+ and Ce3+) and the nanogel prior to irradiation. The two hybrid systems (Ag/NG and CeO2/NG) were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD confirms the formation of crystalline Ag and CeO2. TEM reveals that the inorganic nanoparticles are evenly distributed in/on the nanogel. Both XRD and TEM show that size of the…

The Urban Map of the Grammichele City (Ct): Novel Gels Used for the Restoration of a Painted Stone Work Of Art

2009

Etude par spectroscopies de RMN 23Na, 31P et 1H : effets de la teneur en sel (NaCl) dans des matrices alimentaires

2008

The reduction of salt (NaCl) content in food has become a matter of public health. However, the multiple functions of salt in food make the reduction of its content difficult. The aim of this work was to demonstrate the applicability of NMR innovative techniques in order to characterise the mobility of sodium ions (distinction between ‘free’ and ‘bound’ sodium), to bring a better understanding of the role of salt in the organisation of the food matrix (in particular phosphorous molecules in dairy systems) and to study impact of salt on the mobility of aroma compounds. In a first step, the 23Na NMR study of iota-carrageenan gels validated the quantification of total sodium (Single-Quantum, S…

Infinite coordination polymer networks metallogelation of aminopyridine conjugates and in situ silver nanoparticle formation

2018

Herein we report silver(i) directed infinite coordination polymer network (ICPN) induced self-assembly of low molecular weight organic ligands leading to metallogelation. Structurally simple ligands are derived from 3-aminopyridine and 4-aminopyridine conjugates which are composed of either pyridine or 2,2'-bipyridine cores. The cation specific gelation was found to be independent of the counter anion, leading to highly entangled fibrillar networks facilitating the immobilization of solvent molecules. Rheological studies revealed that the elastic storage modulus (G') of a given gelator molecule is counter anion dependent. The metallogels derived from ligands containing a bipyridine core dis…

Subcomponent Self-Assembly A Quick Way to New Metallogels

2013

Subcomponent self-assembly, introduced by the Nitschke group,[1] is a process which allow complex structures to be generated from simple building blocks (generally aldehydes and amines). In this bottom-up approach, the building blocks spontaneously self-assemble around templates (usually metal ions) leading to a simultaneous covalent (C=N) and dative (N– metal) bonds formation. The method has been successfully used to construct well-defined metal-organic macrocycles, helicates, catenanes, rotaxanes, grids,[2] and cages.[3] Our field of interest lies not in building-up of defined structures but in designing gelator molecules for a formation of supramolecular gels as functional nanomaterials.…

Aristocracia alada, adalides del rey del Cielo. Ángeles militares en la pintura barroca americana

2016

El presente trabajo aborda el estudio de las imágenes de los ángeles militares en los virreinatos americanos y su interpretación a partir de la función cultural de las imágenes. Para ello se analizan las distintas tipologías visuales del arcángel san Miguel en el virreinato de Nueva España y su uso regiopolítico, la definición beligerante del resto de ángeles en la tradición teológica y la imagen de los conocidos como arcángeles arcabuceros. Identifica la tradición bélica del lenguaje posterior al concilio de Trento y, en el caso de los arcángeles arcabuceros, defiende su vinculación con la fiesta barroca. The present work focuses on the study of images of military angels in American Coloni…

Inter-individual variability in aroma release during sweet mint consumption

2011

Inter-individual variations of in vivo aroma release kinetics have been observed widely in the literature. However, the corresponding causes are yet to be clearly identified. For this purpose, 68 subjects in whom salivary flow rates (at rest and Parafilm™-stimulated) had been determined were recruited for the study. The release of menthone was measured using atmospheric pressure ionisation–mass spectrometry during the consumption of a sweet mint tablet. The subjects complied with an imposed protocol of oral movements. Inter-individual variability was investigated through a qualitative analysis of the oral movements inducing menthone release, and through quantitative analysis. Swallowing eve…

Remineralization potential of grape seed extract hydrogels on bleached enamel compared to fluoride gel : an in vitro study

2019

Background Remineralizing of bleached enamel is a common procedure that aims to compensate enamel mineral lose. This study aimed to evaluate the remineralization effectiveness of experimentally prepared grape seed extract hydrogels (GSE) compared to fluoride gel on bleached enamel. Material and methods Thirty extracted maxillary incisor were bleached using white smile bleaching agent. Bleached specimens were divided into three groups (10/group) according to the remineralizing agents tested: [GSE 6%, GSE 10%, or fluoride gel]. After bleaching and remineralization procedure, the specimens were stored in artificial saliva at 37°C. Micro-hardness and Energy-Dispersive X-ray and ultra-morphologi…

The use of hydrogels in bone-tissue engineering

2010

Many different types of scaffold materials have been used for tissue engineering applications, and hydrogels form one group of materials that have been used in a wide variety of applications. Hydrogels are hydrophilic polymer networks and they represent an important class of biomaterials in biotechnology and medicine because many hydrogels exhibit excellent biocompatibility with minimal inflammatory responses and tissue damage. Many studies have demonstrated the use of hydrogels in bone-tissue engineering applications. In this report, the summary was conducted on various kinds of polymers and different modification methods of hydrogels to enhance bone formation. The results revealed that hy…