scholarly journals Pristine graphene covalent functionalization with aromatic aziridines and their application in the sensing of volatile amines – an ab initio investigation

RSC Advances ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 7070-7077
Author(s):  
Sabrine Baachaoui ◽  
Sarah Aldulaijan ◽  
Fayçal Raouafi ◽  
Rafaa Besbes ◽  
Luca Sementa ◽  
...  
Keyword(s):  
Physical Properties ◽  
Ab Initio ◽  
Pristine Graphene ◽  
Functionalized Graphene ◽  
Total Volatile ◽  
Covalent Functionalization ◽  
Volatile Amines

Simulations show that the total volatile basic amines (TVB) from spoiled fish can be sensed by aziridine-functionalized graphene nanomaterials to induce substantial changes in the physical properties.

scholarly journals The Degree of Oxidation of Graphene Oxide

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 560
Author(s):  
Alexandra Carvalho ◽  
Mariana C. F. Costa ◽  
Valeria S. Marangoni ◽  
Pei Rou Ng ◽  
Thi Le Hang Nguyen ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Ab Initio ◽  
State Of The Art ◽  
High Accuracy ◽  
Precise Determination ◽  
Photoemission Spectroscopy ◽  
Pristine Graphene ◽  
X Ray ◽  
Degree Of Oxidation

We show that the degree of oxidation of graphene oxide (GO) can be obtained by using a combination of state-of-the-art ab initio computational modeling and X-ray photoemission spectroscopy (XPS). We show that the shift of the XPS C1s peak relative to pristine graphene, ΔEC1s, can be described with high accuracy by ΔEC1s=A(cO−cl)2+E0, where c0 is the oxygen concentration, A=52.3 eV, cl=0.122, and E0=1.22 eV. Our results demonstrate a precise determination of the oxygen content of GO samples.

Layer by layer assembled functionalized graphene oxide-based polymer brushes for superlubricity on steel-steel tribocontact

Soft Matter ◽  
2021 ◽  
Author(s):  
Suprakash Samanta ◽  
Rashmi Ranjan Sahoo
Keyword(s):  
Graphene Oxide ◽  
Nucleophilic Addition ◽  
Polymer Brushes ◽  
Addition Reaction ◽  
Layer By Layer ◽  
Functionalized Graphene ◽  
Covalent Functionalization ◽  
Functionalized Graphene Oxide ◽  
Nucleophilic Addition Reaction ◽  
Branched Polyethylenimine

Present study demonstrates a simple and multistep approach for the preparation of covalent functionalization of chemically prepared graphene oxide (GO) by branched polyethylenimine (PEI) through nucleophilic addition reaction to prepare...

scholarly journals Highly Water Dispersible Functionalized Graphene by Thermal Thiol-Ene Click Chemistry

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2830
Author(s):  
Farzaneh Farivar ◽  
Pei Lay Yap ◽  
Tran Thanh Tung ◽  
Dusan Losic
Keyword(s):  
Click Reaction ◽  
High Water ◽  
Pristine Graphene ◽  
Functionalized Graphene ◽  
Specific Chemical ◽  
Simple Modification ◽  
Water Dispersible ◽  
Chemical Hazards ◽  
Water Dispersibility ◽  
C And N

Functionalization of pristine graphene to achieve high water dispersibility remains as a key obstacle owing to the high hydrophobicity and absence of reactive functional groups on the graphene surface. Herein, a green and simple modification approach to prepare highly dispersible functionalized graphene via thermal thiol-ene click reaction was successfully demonstrated on pristine graphene. Specific chemical functionalities (–COO, –NH2 and –S) on the thiol precursor (L-cysteine ethyl ester) were clicked directly on the sp2 carbon of graphene framework with grafting density of 1 unit L-cysteine per 113 carbon atoms on graphene. This functionalized graphene was confirmed with high atomic content of S (4.79 at % S) as well as the presence of C–S–C and N–H species on the L-cysteine functionalized graphene (FG-CYS). Raman spectroscopy evidently corroborated the modification of graphene to FG-CYS with an increased intensity ratio of D and G band, ID/IG ratio (0.3 to 0.7), full-width at half-maximum of G band, FWHM [G] (20.3 to 35.5) and FWHM [2D] (64.8 to 90.1). The use of ethanol as the reaction solvent instead of common organic solvents minimizes the chemical hazards exposure to humans and the environment. This direct attachment of multifunctional groups on the surface of pristine graphene is highly demanded for graphene ink formulations, coatings, adsorbents, sensors and supercapacitor applications.

Symmetry-general ab initio computation of physical properties using quantum software integrated with crystal structure databases: results and perspectives

2002 ◽  
Vol 58 (3) ◽  
pp. 349-357 ◽  
Author(s):  
Yvon Le Page ◽  
Paul W. Saxe ◽  
John R. Rodgers
Keyword(s):  
Crystal Structure ◽  
Physical Properties ◽  
Ab Initio ◽  
Materials Science ◽  
Science Research ◽  
Elastic Tensor ◽  
Pure Phase ◽  
Simulation And Experiment ◽  
Structure Databases ◽  
Using Data

The timely integration of crystal structure databases, such as CRYSTMET, ICSD etc., with quantum software, like VASP, OresteS, ElectrA etc., allows ab initio cell and structure optimization on existing pure-phase compounds to be performed seamlessly with just a few mouse clicks. Application to the optimization of rough structure models, and possibly new atomic arrangements, is detailed. The ability to reproduce observed cell data can lead to an assessment of the intrinsic plausibility of a structure model, even without a competing model. The accuracy of optimized atom positions is analogous to that from routine powder studies. Recently, the ab initio symmetry-general least-squares extraction of the coefficients of the elastic tensor for pure-phase materials using data from corresponding entries in crystal structure databases was automated. A selection of highly encouraging results is presented, stressing the complementarity of simulation and experiment. Additional physical properties also appear to be computable using existing quantum software under the guidance of an automation scheme designed following the above automation for the elastic tensor. This possibility creates the exciting perspective of mining crystal structure databases for new materials with combinations of physical properties that were never measured before. Crystal structure databases can accordingly be expected to become the cornerstone of materials science research within a very few years, adding immense practical value to the archived structure data.

COMPUTATIONAL MODELING OF EPOXY-BASED HYBRID COMPOSITES REINFORCED WITH CARBON FIBERS AND FUNCTIONALIZED GRAPHENE NANOPLATELETS

2021 ◽  
Author(s):  
HASHIM AL MAHMUD ◽  
, MATTHEW RADUE ◽  
WILLIAM PISANI ◽  
GREGORY ODEGARD
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Hybrid Composites ◽  
Graphene Nanoplatelets ◽  
Pristine Graphene ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide ◽  
Aspect Ratios ◽  
The Impact ◽  
Nanoscale Level

The impact on the mechanical properties of unidirectional carbon fiber (CF)/epoxy composites reinforced with pristine graphene nanoplatelets (GNP), highly concentrated graphene oxide (GO), and Functionalized Graphene Oxide (FGO) are investigated in this study. The localized reinforcing effect of each of the graphene nanoplatelet types on the epoxy matrix is predicted at the nanoscale-level by molecular dynamics. The bulk-level mechanical properties of unidirectional CF/epoxy hybrid composites are predicted using micromechanics techniques considering the reinforcing function, content, and aspect ratios for each of the graphene nanoplatelets. In addition, the effect of nanoplatelets dispersion level is also investigated for the pristine graphene nanoplatelets considering a lower dispersion level with four layers of graphene nanoplatelets (4GNP). The results indicate that the shear and transverse properties are significantly affected by the nanoplatelet type, loading and aspect ratio. The results of this study can be used in the design of hybrid composites to tailor specific laminate properties by adjusting nanoplatelet parameters.

Ab initio study on physical properties of wurtzite, zincblende, and rocksalt structures of zinc oxide using revised functionals

2015 ◽  
Vol 31 ◽  
pp. 700-708 ◽  
Author(s):  
Fang-Guang Kuang ◽  
Xiao-Yu Kuang ◽  
Shu-Ying Kang ◽  
Ming-Min Zhong ◽  
Xiao-Wei Sun
Keyword(s):  
Zinc Oxide ◽  
Physical Properties ◽  
Ab Initio ◽  
Ab Initio Study

Ab initio Investigation to Model Stilbene Photo-Physical Properties by Combining CC2 Topological Investigation and CASPT2 Energy Corrections

2007 ◽  
Author(s):  
Gaia Tomasello ◽  
Piero Altoè ◽  
Marco Garavelli ◽  
Giorgio Orlandi ◽  
Theodore E. Simos ◽  
...  
Keyword(s):  
Physical Properties ◽  
Ab Initio
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