Search results for "Graphe"

Functional biopolymer-based nanocomposites incorporating graphene nanoplatelets

2016

The effectiveness of the antimicrobial activity over time is mainly determined by the release rate of the antimicrobial compounds. The rate of release depends on different factors such as preparation method, environmental conditions, interactions between antimicrobial and matrix. In this regard, nanoparticles can potentially be used to control the release of antimicrobial agents. Moreover, it is well known that the incorporation of nano-sized fillers into a biopolymeric matrix is an effective way to improve its properties. Aim of this work was to prepare and characterize biopolymer-based nanocomposites with antimicrobial properties. In particular, graphene nanoplatelets (GnPs) as fillers an…

PREPARATION AND CHARACTERIZATION OF BIOPOLYMERIC POROUS STRUCTURES FOR ADVANCED APPLICATIONS

Porous biopolymers received an increasing academic and industrial interest finding application in several fields such as tissue engineering, bioprocess intensification and waste removal. Tissue engineering combines the knowledge of materials science and bioengineering in order to develop structures able to substitute and restore the normal function of injured or diseased tissues. In this context, polymeric 3D or 2D scaffolds are widely investigated as temporary cell guidance during the tissue restore. Porous biomaterials can offer a versatile and cost effective way for immobilization of filamentous microorganisms in submerged fermentation processes for the production of biologically active …

Potential models for the simulation of methane adsorption on graphene: development and CCSD(T) benchmarks

2018

Different force fields for the graphene–CH4 system are proposed including pseudo-atom and full atomistic models. Furthermore, different charge schemes are tested to evaluate the electrostatic interaction for the CH4 dimer. The interaction parameters are optimized by fitting to interaction energies at the DFT level, which were themselves benchmarked against CCSD(T) calculations. The potentials obtained with both the pseudo-atom and full atomistic approaches describe accurately enough the average interaction in the methane dimer as well as in the graphene–methane system. Moreover, the atom–atom potentials also correctly provide the energies associated with different orientations of the molecu…

Photocatalytic CO 2 Valorization by Using Ti O2 , ZrO2 and Graphitic Based Semiconductors

2018

In this century, a broad scientific interest has been devoted to fulfill sustainable industrial processes and climatic change remediation. In this prospective, various green technologies have been studied to valorize CO 2• The aim of this research is the CO 2 reduction in presence of water by using the photocatalytic technology with nanomaterials as the photocatalysts. The present work overviews the main outcomes obtained by using graphitic and oxide based photocatalysts both in gas/solid and liquid/solid batch reactors under simulated solar light. In all gas/solid regime tests the major products detected were methane, carbon monoxide, and acetaldehyde.

CONTROLLING THE FUNCTIONALIZATION OF CARBON NANOTUBES AND GRAPHENE NANOPLATELETS

2013

The functionalization of carbon nanostructures by diazonium chemistry is a versatile strategy to obtain soluble nanomaterials with degrees of functionalization among the highest ever reported.[1,2] Starting from these premises we have studied the functionalization of single, double and multi-walled carbon nanotubes and graphene nanoplatelets by addition of aryl diazonium salts generated in situ by treatment of 4-substituted anilines with isopentylnitrite. Taking advantage of highly controlled flow synthesis [3-5] and following a thorough purification and characterization protocol (UV-vis, TGA, ATR-IR, AFM and other surface tools), we have investigated the key parameters to obtain both funct…

Functionalization of Metal and Carbon Nanoparticles with Potential in Cancer Theranostics

2021

Cancer theranostics is a new concept of medical approach that attempts to combine in a unique nanoplatform diagnosis, monitoring and therapy so as to provide eradication of a solid tumor in a non-invasive fashion. There are many available solutions to tackle cancer using theranostic agents such as photothermal therapy (PTT) and photodynamic therapy (PDT) under the guidance of imaging techniques (e.g., magnetic resonance—MRI, photoacoustic—PA or computed tomography—CT imaging). Additionally, there are several potential theranostic nanoplatforms able to combine diagnosis and therapy at once, such as gold nanoparticles (GNPs), graphene oxide (GO), superparamagnetic iron oxide nanoparticles (SP…

The automated assesment of artery hemodynamic parameters from ultrasound video

2012

The custom designed video processing software for analysis of B-mode and Doppler-mode ultrasound video has been proposed in this work. The software allows adjusting user-defined thresholds and tolerance levels to enhance contour detection in noisy and artifacted ultrasound images. The developed software is able to evaluate 16 hemodynamic parameters (artery diameter, pulse rate and flow velocity related parameters) in each cardiac cycle. The measurements were performed intermittently recording artery diameter (B-mode) and flow velocity (Doppler-mode). Software has validated in femoral artery measurements. The hemodynamic parameters computed by software were consistent with those obtained by …

Association between radiography-based subchondral bone structure and MRI-based cartilage composition in postmenopausal women with mild osteoarthritis

2016

Summary Objective Our aim was to investigate the relation between radiograph-based subchondral bone structure and cartilage composition assessed with delayed gadolinium enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T 2 relaxation time. Design Ninety-three postmenopausal women (Kellgren–Lawrence grade 0: n  = 13, 1: n  = 26, 2: n  = 54) were included. Radiograph-based bone structure was assessed using entropy of the Laplacian-based image ( E Lap ) and local binary patterns ( E LBP ), homogeneity indices of the local angles (HI Angles,mean , HI Angles,Perp , HI Angles,Paral ), and horizontal (FD Hor ) and vertical fractal dimensions (FD Ver ). Mean dGEMRIC index and T 2 relax…

Simulations of a Graphene Nanoflake as a Nanovector To Improve ZnPc Phototherapy Toxicity: From Vacuum to Cell Membrane

2017

International audience; We propose a new approach to improving photodynamic therapy (PDT) by transporting zinc phthalocyanine (ZnPc) in biological systems via a graphene nanoflake, to increase its targeting. Indeed, by means of time-dependent density functional theory simulations, we show that the ZnPc molecule in interaction with a graphene nanoflake preserves its optical properties not only in a vacuum but also in water. Moreover, molecular dynamic simulations demonstrate that the graphene nanoflake/ZnPc association, as a carrier, permits one to stabilize the ZnPc/graphene nanoflake system on the cellular membrane, which was not possible when using ZnPc alone. We finally conclude that the…

Nanoscale ear drum: graphene based nanoscale sensors.

2012

The difficulty in determining the mass of a sample increases as its size diminishes. At the nanoscale, there are no direct methods for resolving the mass of single molecules or nanoparticles and so more sophisticated approaches based on electromechanical phenomena are required. More importantly, one demands that such nanoelectromechanical techniques could provide not only information about the mass of the target molecules but also about their geometrical properties. In this sense, we report a theoretical study that illustrates in detail how graphene membranes can operate as nanoelectromechanical mass-sensor devices. Wide graphene sheets were exposed to different types and amounts of molecul…