Search results for "Sponges"
showing 10 items of 56 documents
Polystyrene as Graphene Film and 3D Graphene Sponge Precursor
2019
[EN] Polystyrene as a thin film on arbitrary substrates or pellets form defective graphene/graphitic films or powders that can be dispersed in water and organic solvents. The materials were characterized by visible absorption, Raman and X-ray photoelectron spectroscopy, electron and atomic force microscopy, and electrochemistry. Raman spectra of these materials showed the presence of the expected 2D, G, and D peaks at 2750, 1590, and 1350 cm(-1), respectively. The relative intensity of the G versus the D peak was taken as a quantitative indicator of the density of defects in the G layer.
New Generation of Zeolite Materials for Environmental Applications.
2016
International audience; The influence of the morphology (microcrystals, nanocrystals, nanosponges and nanosheets) of MFI and *BEA-type zeolites on their adsorption capacities and adsorption rate of n-hexane at 25 ˚C has been investigated. The capacity of n-hexane adsorption sensitive to micro- and mesopore volume is enhanced by the use of zeolite nanocrystals or hierar-chical nanoporous materials (nanosheets and nanosponges). In the case of hierarchical zeolites MFI and *BEA nano-sponges, the n-hexane adsorption capacities reached values of about 790 and 693 mg/g, respectively, that are much higher than those in the corresponding microcrystals (130 and 103 mg/g, respectively). On the opposi…
Organo-Clay Nanomaterials Based on Halloysite and Cyclodextrin as Carriers for Polyphenolic Compounds
2018
Hybrid material based on halloysite covalently linked to a hyper-reticulated cyclodextrin network was investigated as a potential carrier for polyphenolic compounds. The absorption ability of the hybrid system was studied in different pH conditions as well as the kinetic release of curcumin, chosen as a drug model. A preliminary study was performed to assess the antioxidant capacity of the obtained carrier. The obtained results highlighted that the curcumin molecule can have sustained release from the carrier over the time, retaining its antioxidant properties due to the combination of two different host systems that give rise to an hyper-reticulated structure, allowing an increase in the d…
Trans-visceral migration of retained surgical gauze as a cause of intestinal obstruction: a case report
2008
AbstractIntroductionA retained surgical sponge in the abdomen is uncommon although it is likely that this finding is underreported in the medical literature. The intravisceral migration of retained surgical gauze is even rarer, as demonstrated by the very few cases reported.Case presentationThree years after undergoing anterior resection of the rectum, a 75-year-old man presented with symptoms of small bowel obstruction. Plain abdominal radiography and CT showed a radio-opaque marker; a foreign body was suspected, probably a piece of retained surgical gauze. An ileotomy of about 5 cm. was performed to confirm this diagnosis and remove the gauze.ConclusionAlthough rare, retained gauze in the…
Expression of one sponge Iroquois homeobox gene in primmorphs from Suberites domuncula during canal formation
2003
SUMMARY Sponges (Porifera) represent the evolutionary oldest multicellular animals. They are provided with the basic molecules involved in cell–cell and cell–matrix interactions. We report here the isolation and characterization of a complementary DNA from the sponge Suberites domuncula coding for the sponge homeobox gene, SUBDOIRX-a. The deduced polypeptide with a predicted Mr of 44,375 possesses the highly conserved Iroquois-homeodomain. We applied in situ hybridization to localize Iroquois in the sponge. The expression of this gene is highest in cells adjacent to the canals of the sponge in the medulla region. To study the expression of Iroquois during development, the in vitro primmorph…
Synergistic Activity of Silver Nanoparticles and Polyaminocyclodextrins in Nanosponge Architectures
2019
Four new composite materials, formed by silver nanoparticles embedded in polyamino-cyclodextrin nanosponge architectures, were designed exploiting the affinity of polyamino-cyclodextrins towards Ag+ ions. These materials were characterized by means of different techniques (thermogravimetry, FT-IR, solid state NMR, SEM, HR-TEM), and tested as catalysts for the reduction of nitroarenes and the oxidative coupling of anilines. The results obtained showed synergistic activity between the supramolecular binding abilities of the nanosponge matrix and the catalytic properties of the metal nanoparticle, and open the way towards the design of new composite smart nanomaterials with improved catalytic …
Antimicrobial effect of cyclodextrin-based nanodevices capable of antibiotic release
2018
FFC-NMR Relaxometric Characterization of Nanosponges for Rationalizing their Adsorption and Release abilities
Synthesis and Characterization of Halloysite-Cyclodextrin Nanosponges for Enhanced Dyes Adsorption
2017
Inorganic-organic nanosponge hybrids based on halloysite clay and organic cyclodextrin derivatives (HNT-CDs) were developed by means of microwave irradiations in solvent-free conditions. The HNT-CDs nanomaterials characterized by FT-IR, TGA, BET, TEM, SEM, DLS, and zeta-potential have showed a hyper-reticulated network which possesses both HNT and cyclodextrin peculiarities. The new HNT-CDs nanosponge hybrids were employed as nanoadsorbents, first choosing Rhodamine B as the dye model, and furthermore for the removal of some cationic and anionic dyes, under different pH values (1.0, 4.54, and 7.4). The collected results showed that the pH solution as well as the electrostatic interactions a…
Nanosponge-C3N4 composites as photocatalysts for selective partial alcohol oxidation in aqueous suspension
2023
A set of four composite materials was prepared, consisting of a nanosponge matrix based on beta-cyclodextrin in which carbon nitride was dispersed. The materials were characterized by the presence of diverse cross-linker units joining the cyclodextrin moieties, in order to vary the absorption/release abilities of the matrix. The composites were characterized and used as photocatalysts in aqueous medium under UV, visible and natural solar irradiation for the photodegradation of 4-nitrophenol, and for the selective partial oxidation of 5-hydroxymethylfurfural and veratryl alcohol to the corresponding aldehydes. The nanosponge-C3N4 composites showed higher activity than the pristine semiconduc…