Search results for "Layered double hydroxide"
showing 10 items of 47 documents
Layered Double Hydroxides in Bioinspired Nanotechnology
2020
Layered Double Hydroxides (LDHs) are a relevant class of inorganic lamellar nanomaterials that have attracted significant interest in life science-related applications, due to their highly controllable synthesis and high biocompatibility. Under a general point of view, this class of materials might have played an important role for the origin of life on planet Earth, given their ability to adsorb and concentrate life-relevant molecules in sea environments. It has been speculated that the organic–mineral interactions could have permitted to organize the adsorbed molecules, leading to an increase in their local concentration and finally to the emergence of life. Inspired by nature, material s…
Insights into the formation of metal carbon nanocomposites for energy storage using hybrid NiFe layered double hydroxides as precursors
2020
[EN] NiFe-carbon magnetic nanocomposites prepared using hybrid sebacate intercalated layered double hydroxides (LDHs) as precursors are shown to be of interest as supercapacitors. Here, the low-temperature formation mechanism of these materials has been deciphered by means of a combined study using complementaryin situ(temperature-dependent) techniques. Specifically, studies involving X-ray powder diffraction, thermogravimetry coupled to mass spectrometry (TG-MS), statistical Raman spectroscopy (SRS), aberration-corrected scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS) have been carried out. The experimental results confirm the early formation o…
Sepiolite-Hydrogels: Synthesis by Ultrasound Irradiation and Their Use for the Preparation of Functional Clay-Based Nanoarchitectured Materials.
2021
International audience; Sepiolite and palygorskite fibrous clay minerals are 1D silicates featuring unique textural and structural characteristics useful in diverse applications, and in particular as rheological additives. Here we report on the ability of grinded sepiolite to generate highly viscous and stable hydrogels by sonomechanical irradiation (ultrasounds). Adequate drying of such hydrogels leads to low-density xerogels that show extensive fiber disaggregation compared to the starting sepiolite-whose fibers are agglomerated as bundles. Upon re-dispersion in water under high-speed shear, these xerogels show comparable rheological properties to commercially available defibrillated sepi…
ChemInform Abstract: Hybrid Materials Based on Magnetic Layered Double Hydroxides: A Molecular Perspective
2015
ConspectusDesign of functional hybrids lies at the very core of synthetic chemistry as it has enabled the development of an unlimited number of solids displaying unprecedented or even improved properties built upon the association at the molecular level of quite disparate components by chemical design. Multifunctional hybrids are a particularly appealing case among hybrid organic/inorganic materials. Here, chemical knowledge is used to deploy molecular components bearing different functionalities within a single solid so that these properties can coexist or event interact leading to unprecedented phenomena. From a molecular perspective, this can be done either by controlled assembly of orga…
Influence of morphology in the magnetic properties of layered double hydroxides
2018
We report the controlled synthesis of magnetic CoAl and NiFe layered double hydroxides (LDHs) endowed with well-defined morphology (hexagonal and flower-like shapes) by means of modified homogeneous precipitation. These layered magnets display high crystallinity and micrometric size, thus offering a perfect scenario for the elucidation of the role exerted by distortion of the layers in their magnetic behaviour. The magnetic properties have been investigated by means of DC and AC magnetic susceptibility measurements and isothermal magnetization, demonstrating that the distortion of the nanosheets induces a magnetically more disordered behaviour, with marked spin-glass nature, independently o…
Hybrid Magnetic Multilayers by Intercalation of Cu(II) Phthalocyanine in LDH Hosts
2012
The intrinsic flexibility of layered double hydroxides (LDHs) has been here exploited to design hybrid multilayered materials by intercalation of the copper phthalocyaninetetrasulfonate (CuPcTs) complex in the interlamellar space offered by these layered hosts through a simple anion-exchange procedure. Taking advantage of their chemical versatility, two different LDHs, the diamagnetic ZnAl and the ferromagnetic NiAl, have been synthesized and characterized to explore the differences in the magnetic properties of the hybrids introduced by the intercalation of the paramagnetic complex.
Hybrid magnetic materials based on layered double hydroxides: from the chemistry towards the applications
2014
Layered double hydroxides (LDHs) are the leitmotiv of this dissertation. Contradicting the assertion that “any past was better”, LDHs have been continuously revisited from the middle of the twentieth century, and represent an excellent example of the never-ending beauty of Chemistry. New synthetic perspectives are giving a new impetus to LDH chemistry, which among hybrid materials, are finding their heyday. This is resulting in novel materials and also paving the way for new fundamental and practical insights. This dissertation is focused on magnetic LDHs, and for the sake of clarity it is organized in three main parts: we will move from basic synthetic and physical aspects of LDHs, through…
An insight into the interaction between functionalized thermoplastic elastomer and layered double hydroxides through rheological investigations
2018
Abstract Nanocomposites based on maleated poly(styrene-(ethylene-co-butylene)-styrene) copolymer (SEBSgMA) and organo-modified layered double hydroxide (OLDH) have been formulated with the aim to investigate the effects of interfacial interactions between the grafted maleic anhydride groups of the copolymer and the OLDH nanolayers on the rheological properties of nanocomposites. The spectroscopic analysis indicates the establishment of specific polymer/nanofiller interactions, whose extent has been highlighted through morphological and rheological investigations. Specifically, oscillatory melt rheology and shear relaxation tests have been considered in order to deeply investigate the interf…
Illustrating the processability of magnetic layered double hydroxides: layer-by-layer assembly of magnetic ultrathin films.
2013
We report the preparation of single-layer layered double hydroxide (LDH) two-dimensional (2D) nanosheets by exfoliation of highly crystalline NiAl-NO3 LDH. Next, these unilamellar moieties have been incorporated layer-by-layer (LbL) into a poly(sodium 4-styrenesulfonate)/LDH nanosheet multilayer ultrathin film (UTF). Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible light (UV-vis), and X-ray diffraction (XRD) profiles have been used to follow the uniform growth of the UTF. The use of a magnetic LDH as the cationic component of the multilayered architecture enables study of the resulting magnetic properties of the UTFs. Our magnetic data show the appearance of spontaneous …
The synthesis of a hybrid graphene-nickel/manganese mixed oxide and its performance in lithium-ion batteries
2012
[EN] Mixing of aqueous suspensions of delaminated NiMn layered double hydroxide (LDH) and graphene oxide leads to the instantaneous precipitation of a hybrid material that after calcination under inert atmosphere at 450 degrees C leads to Ni6MnO8 nanoparticles deposited on larger reconstituted graphene sheets. This material exhibits electrical conductivity similar to graphite, superparamagnetism and can be used as an anode for Li-ion batteries. A maximum capacity value of 1030 mAh g(-1) was found during the first discharge, and capacity values higher than 400 mAh g(-1) were still achieved after 10 cycles. The methodology used here should allow the preparation of a large variety of hybrid gr…