Sustainable Reactive Dyeing of Cotton Fabric in Green Non-Aqueous Medium: A Density Function Theory (DFT) Modeling Study

2015 ◽  
Vol 671 ◽  
pp. 139-148 ◽  
Author(s):  
Lu Yi Chen ◽  
Jian Gang Chen ◽  
Xin Hui Ruan ◽  
Su Xin Xu ◽  
Yi Qi Yang ◽  
...  

Sustainable reactive dyeing of cotton in green non-nucleophilic solvents was investigated. Dye fixation in the new medium was modeled using DFT calculations with the aim of understanding the role of organic bases. The novel procedure uses non-nucleophilic green solvents instead of water to eliminate the dye hydrolysis. All residuals in the spent dye bath could be conveniently recycled and reused. The three major stages in cotton reactive dyeing, cellulose swelling, dye adsorption and dye fixation were optimized respectively. Two organic bases and potassium carbonate were studied for dye fixation. The mechanisms of the amine-promoted dye fixation were modeled using density function theory (DFT) calculations. The formation of the amine-dye intermediate was elucidated and analyzed using high performance liquid chromatography (HPLC) analysis. The quaternary ammonium catalysis effect on intermediates forming was observed. A 10-cycle repeated dyeing sequence was demonstrated using Reactive orange 5 to give consistently high shade buildup, excellent colorfastness and dramatic reduction in resource consumption. The results have implications for better understanding the new hydrolysis-free and recyclable solvent dyeing process.

2002 ◽  
Vol 2002 (11) ◽  
pp. 544-546
Author(s):  
Davood Nori-Shargh ◽  
Bita Soltani ◽  
Saeed Jameh-Bozorghi ◽  
Mohammad-Reza Talei Bavil Olyai

Ab initio molecular orbital and density function theory (DFT) calculations as used to calculate the structure optimisation and configurational features of cycloundeca-1,2,4,5,7,8,10-heptaene (2) showed that the combination of two allenic units of the same chirality and a unit of opposite chirality yields an enantiomeric Z-isomer pair ( RSR and SRS) of C2 symmetry, which is the most stable configuration.


2011 ◽  
Vol 197-198 ◽  
pp. 701-704 ◽  
Author(s):  
Sheng Qian Ma

Hydrogen is a clean, abundant, no-toxic, renewable fuel and packs more energy per unit mass than others. It is important to find a efficient way to store it. Hydrogen molecules adsorbed on the Al doped BN sheets are investigated by using density function theory (DFT) calculations. The results indicate that the H2molecule is very easy to be absorbed on the doped BN sheet of B substituted by an Al atom (AlB-BN), which is most stable structure in all the Al doped configurations. Therefore, AlB-BN is a promising material in storage H2.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Madhumita Hazra ◽  
Tanushree Dolai ◽  
Akhil Pandey ◽  
Subrata Kumar Dey ◽  
Animesh Patra

The photo physical properties of two mononuclear pentacoordinated copper(II) complexes formulated as [Cu(L)(Cl)(H2O)] (1) and [Cu(L)(Br)(H2O)] (2)HL = (1-[(3-methyl-pyridine-2-ylimino)-methyl]-naphthalen-2-ol) were synthesized and characterized by elemental, physicochemical, and spectroscopic methods. The density function theory calculations are used to investigate the electronic structures and the electronic properties of ligand and complex. The interactions of copper(II) complexes towards calf thymus DNA were examined with the help of absorption, viscosity, and fluorescence spectroscopic techniques at pH 7.40. All spectroscopy's result indicates that complexes show good binding activity to calf thymus DNA through groove binding. The optical absorption and fluorescence emission properties of microwires were characterized by fluorescence microscope. From a spectroscopic viewpoint, all compounds strongly emit green light in the solid state. The microscopy investigation suggested that microwires exhibited optical waveguide behaviour which are applicable as fluorescent nanomaterials and can be used as building blocks for miniaturized photonic devices. Antibacterial study reveals that complexes are better antimicrobial agents than free Schiff base due to bacterial cell penetration by chelation. Moreover, the antioxidant study of the ligand and complexes is evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical assays, which demonstrate that the complexes are of higher antioxidant activity than free ligand.


2011 ◽  
Vol 221 ◽  
pp. 180-183 ◽  
Author(s):  
Jian Li ◽  
Xun Zhang Yu ◽  
Kai Zhang

The ring-opening reaction between bisphenol A and epichlorohydrin was calculated by Gaussian03. The Density Function Theory (DFT) method were employed to study the geometry structures of bisphenol A and epichlorohydrin and the product was obtained on the base of B3LYP/6-31G+ model in this paper. The transitional states (Ts1, Ts2) during the ring-opening process were found by TS method and the energy changing of the system was proved by IRC calculation. Results showed that the energy reduced by 64.37726kJ/mol during the ring-opening process. The product was confirmed to be thermodynamically stable.


2021 ◽  
Vol 91 (5) ◽  
pp. 828-834
Author(s):  
K. V. Zaitsev ◽  
A. Yu. Oprunenko ◽  
I. P. Gloriozov ◽  
M. S. Nechaev ◽  
Yu. F. Oprunenko ◽  
...  

2011 ◽  
Vol 36 (4) ◽  
pp. 323-328
Author(s):  
Yiling Bei ◽  
Qingyang Liu

The reaction of silylene with acetylene was observed by the density function theory (DFT) method at the 6 - 311 g (d,p) level. A new reaction pathway has been identified involving the tetra-conjugated: SiH2CH==CHH2Si:. Thermodynamic and kinetic analysis confirms the reaction to be spontaneous at room temperature. The new intermediate proposed in this work offers a resolution of the conundrum of the silylene/acetylene reaction.


Author(s):  
Cui Zhou ◽  
Ding Haonan ◽  
Yu Feng

A new subfamily of Heusler alloys, i.e. double half-Heusler alloys Mn2CoCrZ2 (Z=P, As), are investigated by employing the density function theory combined with the nonequilibrium Green’s function. The calculations on...


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